Global Soul Limited Company News

Overview of AOI AOI, the full name of which is Automatic Optical Inspection, namely automatic optical inspection equipment, is an efficient intelligent device that simulates the human eye and operates machine vision technology to replace humans in the welding process production and detect common missing parts in PCBA. As PCBS become increasingly complex and components become smaller and smaller, traditional ICT and functional testing are becoming more and more laborious and time-consuming. It is difficult to obtain the physical space for the test probes of closely spaced and fine-spaced plates by using bed-of-nails testing. For surface mount circuit boards (PCBA) responsible for high density, manual visual inspection is neither reliable nor economical. However, when it comes to tiny components such as Type 0402 and Type 01005, manual visual inspection has actually lost its significance. To overcome the obstacles mentioned above, AOI emerged as a powerful complement to online testing (ICT) and functional testing (F/T). It can help PCBA manufacturers increase the pass rate of ICT(F/T), reduce the labor cost of visual inspection and the production cost of ICT fixtures, prevent ICT from becoming a capacity bottleneck, shorten the capacity expansion cycle of new products, and effectively control product quality through statistics to improve product quality. AOI technology can be applied to multiple positions of the PCBA production line. ALeader AOI can provide effective and high-quality quality inspection at the following five detection positions: After solder paste printing: After the solder paste is printed on the printing machine, defects during the printing process can be detected. By inspecting the printed solder paste, defects in PCBA production before surface mount can be avoided, reducing the maintenance cost of the PCBA board. 2) Before reflow soldering: This position should be after the surface mount and before reflow soldering. This position can detect the quality of solder paste and surface mount, prevent defects in the PCBA before reflow soldering, and reduce the maintenance cost of the PCBA board. 3) After reflow soldering: This position is the most typical one and indispensable. The greatest advantage of using this position for detection is that the defects existing in the ownership process can be detected at this stage, so no defects will flow to the end customers. 4) Red adhesive inspection after reflow oven: The inspection at this position mainly focuses on the red adhesive board, which can effectively detect whether the red adhesive is okay or not, reduce the defects after passing through wave soldering, and effectively lower the labor visual inspection cost and maintenance cost. 5) After the wave soldering furnace: This position is mainly for wave soldering inspection, which includes the inspection of components and plug-ins. The inspection at this position is an effective supplement to the quality inspection and control throughout the wave soldering process.

When soldering circuit board components, what phenomena indicate that the soldering is defective? 1. False soldering: The solder joint is not smooth and appears honeycomb-like. The solder joints have poor contact with the pins and pads. 2. Missed soldering: Some pins are soldered without solder. 3. Continuous soldering: Solder bridging, bridging, etc. occur between circuits or solder pads. 4. Overheating: The solder overheats, causing deformation and breakage of components. The solder pads or copper-clad laminates are lifted up; A monument has been erected for surface mount components. 5. Tin-permeable: For double-layer plates and above, through-holes should be tin-permeable and soldered to ensure connection. 6. Dirt: If the flux or cleaning agent is not removed thoroughly, it can easily lead to short circuits or corrosion of the circuit board 7. Less tin; There is less than or equal to 50% of the solder pad. 8. Loopholes When soldering, excessive force was applied and the insulating paint on the surface of the surrounding PCB fell off. 9. Bulge; During soldering, due to moisture inside the PCB, a small area of the PCB bulges. 10. Pinhole There are small holes on the surface of the solder joint or voids exceeding 25% of the pad when inspecting X-R (which can be passed in my standard).

AOI-PIN algorithm The AOI automatic optical inspection instrument of Shenzhou Vision has multiple algorithms. Among them, the PIN algorithm is a combined algorithm, which is an image processing algorithm integrating the positioning algorithm and the color extraction algorithm. There are two ROI boxes in the PIN algorithm. One is the positioning frame, and the other is the soldering area frame as follows: Shenzhou Vision AOI-PIN algorithm As shown in the above picture, the red area is the pin positioning box, which is used for positioning. The blue area is the solder analysis box, whose function is to analyze soldering

AOI detector -Match2 algorithm A Detailed Explanation of the Aleader Algorithm - The Match2 Algorithm The Match2 algorithm, an extension of the Match algorithm, is a special algorithm among the over 20 detection algorithms of Shenzhou Vision AOI, mainly used to detect whether the ontology is offset. The Match2 algorithm can be divided into the positioning method based on the substrate and the non-substrate positioning method. Among them, the positioning method based on the substrate is a dual positioning method, as shown in the following figure: AleaderAOI detector -Match2 algorithm In the above figure, the red box is the positioning box based on the substrate, and the white box is the positioning based on the ontology. The positioning method based on the ontology searches for the optimal positioning point within the limited search range on the basis of the positioning based on the substrate. Based on the relative offsets of the two positioning boxes, calculate their relative offset values and take them as the true offset values. The calculation schematic diagram of its offset value is as follows: AleaderAOI detector -Match2 algorithm In the above figure, ① is the standard schematic diagram and ② is the schematic diagram of the offset to be measured. For example, in area ①, the center point coordinates of the substrate positioning box are (X, Y), and the center point coordinates of the body positioning box are (X1, Y1). Then the standard relative offset is (DDx, DDy), and the calculation formula is as follows: DDx = X1 – X DDy = Y1 – Y When the positioning box of the ontology to be tested deviates from the basic positioning box to be tested (DDx, DDy), the actual offset is (0, 0). The center point coordinates of the substrate positioning box in Area B are (XX, YY), and the center point coordinates of the body positioning box are (XX1, YY1). Then the standard relative offset is (DDx1, DDy1), and the calculation formula is as follows: DDx1 = XX1 – XX DDy1 = YY1 – YY Then the actual offset of the component to be tested is (Dx, Dy), and the calculation formula is as follows: Dx = DDx1 – DDx Dy = DDy1 – DDy Determine whether the component has shifted by judging the range of (Dx, Dy). There are two positioning modes based on the ontology box in the Match2 algorithm, which are divided into the single-box positioning mode and the double-box combined positioning mode. As follows: AleaderAOI Detector -Match2 Algorithm AleaderAOI Detector -Match2 algorithm In the above figure, ① represents the single-box positioning mode, which is consistent with the Match algorithm; ② is the dual-box combination positioning mode. The positioning area is composed of the solid line single box and the dashed line single box in area B. The combined area of the two boxes is the effective positioning area. Return to the list

Detailed Explanation of AOI Algorithm - Missing Algorithm Among the over 20 algorithms of the AOI(Automatic Optical Inspection Instrument) of Shenzhou Vision, there is one algorithm called the Missing algorithm, which is a specific image processing algorithm for missing components of capacitors. It determines and detects whether there is a missing component in the electrode by comparing the area difference between the external rectangles of the two electrodes of the standard capacitor and those of the two electrodes of the capacitor to be tested. As shown below: A Detailed Explanation of the Aleader Algorithm - The Missing Algorithm The above figure is a schematic diagram of the components when a Missing component occurs. ① represents the outer rectangles of the two highlighted electrode regions at both ends of the normal component, and ② represents the outer rectangles of the two highlighted regions at both ends when a missing component occurs. Then, the difference values under the missing algorithm are as follows: Result = (S2 - S1)/ S1 – 1 Here, S2 represents the area of the circumscribed rectangle B, and S1 represents the area of the circumscribed rectangle A. Hint: The default determination range of the Missing algorithm is (0, 15).

The main application of the AOI algorithm - errors The application of algorithms is a key part of the application of AOI(Automatic Optical Inspection Instrument) algorithms in the field of inspection. Shenzhou Vision AOI has over 20 algorithms, each of which has its specific application. Therefore, on the basis of being familiar with and understanding various AOI algorithms, applying AOI algorithms to each detection item is the prerequisite for AOI engineers to create detection programs. The error component is mainly used for the inspection of the component itself to check whether there is any material error in the component. This test item is a routine test item for AOI inspection. There are four detection algorithms for errors, which are TOC algorithm, OCV algorithm, Match algorithm and OCR algorithm respectively. The detection algorithm for each error item has a different focus on the detection items. The error detection of TOC algorithms is mainly used for the error detection of non-character components, which are mainly capacitors. This type of detection method detects faulty components by extracting the intrinsic color of the component and determining whether the intrinsic color of the component has changed. Among them, the body color parameters of the components have no default parameters. They are color extraction parameters given based on the actual body color. The error detection of the OCV algorithm type is mainly used for the error detection of clear characters, and the components of this type are mainly resistors. This type of detection method determines whether a component has a fault by obtaining the degree of fit between the contour of the character to be tested and that of the standard character. The default range of the determination parameters for this type of detection is (0, 12). If the standard character is "123", the character to be tested is "351", the fitted return value is 28.3, and the determination range is (0, 12), then this component has a "wrong component". The Match type detection algorithm is mainly used for error detection of fuzzy characters. The components of this type mainly include diodes, transistors, etc. This type of detection algorithm mainly determines whether the component has a "wrong part" by obtaining the similarity degree between the character area to be tested and the standard character area. The determination range of this type of error is defaulted to (0,32). OCR type detection algorithms are mainly used for the detection of components in important parts, such as BGA, QFP, BGA, etc. This type of algorithm mainly detects and judges whether errors occur by identifying the character to be tested and determining whether the character to be tested is consistent with the standard character. If the standard character is "123" and the actual character is "122", then the OCR algorithm determines that this type of component has a "wrong component".

Analysis of six Common Causes of Defects in SMT Solder paste Printing I. Tin Ball:Before printing, the solder paste was not fully thawed and stirred evenly. 2. If the ink is not refluxed for too long after printing, the solvent will evaporate and the paste will turn into dry powder and fall onto the ink. 3. The printing is too thick, and the excess solder paste overflows when the components are pressed down. 4. When REFLOW occurs, the temperature rises too quickly (SLOPE>3), causing a boiling over. 5. The pressure on the surface mount is too high, and the downward pressure causes the solder paste to collapse onto the ink. 6. Environmental impact: Excessive humidity. The normal temperature is 25+/-5 ° C, and the humidity is 40-60%. During rain, it can reach 95%, and dehumidification is required. 7. The shape of the pad opening is not good and no anti-solder bead treatment has been done. 8. The solder paste has poor activity, dries too quickly, or there are too many small tin powder particles. 9. The solder paste was exposed to an oxidizing environment for too long and absorbed moisture from the air. 10. Insufficient preheating and slow, uneven heating. 11. Printing offset caused some solder paste to stick to the PCB. 12. If the scraper speed is too fast, it will cause poor edge collapse and lead to the formation of tin balls after reflux. P.S. : The diameter of the tin balls should be less than 0.13MM, or less than 5 for 600 square millimeters. Ii. Erection of a Monument:Uneven printing or excessive deviation, with thick tin on one side and greater tensile force, and thin tin on the other side with less tensile force, causes one end of the component to be pulled to one side, resulting in an empty solder joint, and the other end to be lifted up, forming a monument. 2. The patch is offset, causing uneven force distribution on both sides. 3. One end of the electrode is oxidized, or the size difference of the electrodes is too large, resulting in poor tinning property and uneven force distribution at both ends. 4. The different widths of the pads at both ends result in different affabilities. 5. If the solder paste is left for too long after printing, the FLUX will evaporate excessively and its activity will decline. 6. Insufficient or uneven preheating of REFLOW leads to higher temperatures in areas with fewer components and lower temperatures in areas with more components. The areas with higher temperatures melt first, and the tensile force formed by the solder is greater than the adhesive force of the solder paste on the components. Uneven force application causes monument erection. Iii. Short Circuit1. The STENCIL is too thick, severely deformed, or the holes of the STENCIL are deviated and do not match the position of the PCB pads. 2. The steel plates were not cleaned in time. 3. Improper setting of the scraper pressure or deformation of the scraper. 4. Excessive printing pressure causes the printed graphics to become blurred. 5. The reflux time at 183 degrees is too long (the standard is 40-90 seconds), or the peak temperature is too high. 6. Poor incoming materials, such as poor coplanarity of IC pins. 7. The solder paste is too thin, including low metal or solid content within the solder paste, low shake solubility, and the solder paste is prone to cracking when pressed. 8. The solder paste particles are too large and the surface tension of the flux is too small. Iv. Offset:1). Offset before REFLOW: 1. The placement accuracy is not precise. 2. The solder paste has insufficient adhesion. 3. The PCB vibrates at the furnace inlet. 2) Offset during the.REFLOW process: 1. Whether the PROFILE temperature rise curve and preheating time are appropriate. 2. Whether there is any vibration of the PCB in the furnace. 3. Excessive preheating time causes the activity to lose its effect. 4. If the solder paste is not active enough, choose solder paste with strong activity. 5. The design of the PCB PAD is unreasonable V. Low tin/Open Circuit:The temperature of the board surface is uneven, with the upper part being higher and the lower part lower. The solder paste at the bottom melts first, causing the solder to spread out. The temperature at the bottom can be appropriately reduced. 2. There are test holes around the PAD, and solder paste flows into the test holes during reflow. 3. Uneven heating causes the component pins to be too hot, resulting in the solder paste being led onto the pins, while the PAD has insufficient solder. 4. There is not enough solder paste. 5. Poor coplanarity of components. 6. The pins are soldered or there are connection holes nearby. 7. Insufficient tin moisture. 8. The solder paste is too thin, causing tin loss. The phenomenon of "Open" actually mainly has four types: 1. low solder is usually called low tin 2. When the terminals of a part do not come into contact with tin, it is usually called empty soldering 3. When the terminal of a part comes into contact with tin but the tin does not climb up, it is usually called false soldering. However, I think it is better to accept the refusal to solder 4. The solder paste has not completely melted. It is usually called cold welding Soldering beads/solder balls 1. Though rarely, solder balling is generally acceptable in no-rinse formulations; But solderbeading doesn't work. Solder beads are usually large enough to be seen with the naked eye. Due to their size, they are more likely to fall off the flux residue, causing a short circuit somewhere in the assembly. 2. Solder beads differ from solder balls in several aspects: Solder beads (usually with a diameter greater than 5-mil) are larger than solder balls. Tin beads are concentrated on the edges of larger chip components very far from the bottom of the board, such as chip capacitors and chip resistors 1, while tin balls are anywhere within the flux residue. A solder bead is a large tin ball that comes out from the edge of a sheet component when the solder paste is pressed under the body of the component and during reflow instead of forming a solder joint. The formation of tin balls mainly results from the oxidation of tin powder before or during reflux, usually just one or two particles. 3. Misaligned or overprinted solder may increase the number of solder beads and solder balls. Vi. Core Suction PhenomenonCore-suction phenomenon: Also known as core-pulling phenomenon, it is one of the common soldering defects, mostly seen in gas phase reflow soldering. It is a severe false soldering phenomenon formed when the solder separates from the pad and ascends along the pins to the area between the pins and the chip body. The reason is that the thermal conductivity of the pins is too high, causing rapid temperature rise and resulting in the solder wetting the pins first. The wetting force between the solder and the pins is much greater than that between the solder and the pads. The upward curling of the pins will further intensify the occurrence of core suction. Carefully inspect and ensure the solderability of the PCB pads. 2. The coplanarity of components cannot be ignored. 3. SMA can be fully preheated before welding.

If you have worked in the SMT of an electronics factory, you must understand these Generally speaking, the specified temperature in the SMT workshop is 25±3℃.2. Materials and tools required for solder paste printing: solder paste, steel plate, scraper, wiping paper, lint-free paper, cleaning agent, and stirring knife;3. The commonly used alloy composition of solder paste is Sn/Pb alloy, and the alloy ratio is 63/37.4. The main components of solder paste are divided into two major parts: solder powder and flux.5. The main function of flux in soldering is to remove oxides, break the surface tension of molten tin, and prevent re-oxidation.6. The volume ratio of tin powder particles to Flux(flux) in the solder paste is approximately 1:1, and the weight ratio is approximately 9:1.7. The principle for taking solder paste is first in, first out.8. When solder paste is opened and used, it must go through two important processes: warming up and stirring.9. The common manufacturing methods of steel plates are: etching, laser, and electroforming.10. The full name of SMT is Surface mount(or mounting) technology, which means surface adhesion (or mounting) technology in Chinese.11. The full name of ESD is Electro-static discharge, which means static electricity discharge in Chinese.12. When making the SMT equipment program, the program includes five major parts, and these five parts are PCB data; Mark data;  Feeder data;  Nozzle data;  Part data;13. The melting point of lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 is 217 ° C.14. The relative temperature and humidity of the parts drying oven is less than 10%.15. Commonly used Passive Devices include resistors, capacitors, point inductors (or diodes), etc. Active Devices include: transistors, ics, etc.16. The commonly used material for SMT steel plates is stainless steel.17. The commonly used thickness of SMT steel plates is 0.15mm(or 0.12mm);18. The types of electrostatic charges generated include friction, separation, induction, electrostatic conduction, etc. The influence of electrostatic charge on the electronics industry is :ESD failure, electrostatic pollution; The three principles of static elimination are static neutralization, grounding and shielding.19. The imperial size is 0603 (length x width) = 0.06inch*0.03inch, and the metric size is 3216 (length x width) =3.2mm*1.6mm.20. The 8th code "4" of the resistor ERB-05604-J81 indicates 4 circuits, with a resistance value of 56 ohms. The capacitance value of the capacitor ECA-0105Y-M31 is C=106 pF =1NF =1 × 10-6F.21. The full Chinese name of ECN is: Engineering Change Notice. The full Chinese name of SWR is "Special Needs Work Order". It must be co-signed by all relevant departments and distributed by the document center to be valid.22. The specific contents of 5S are sorting, straightening, sweeping, cleaning and self-discipline.23. The purpose of vacuum packaging for PCBS is to prevent dust and moisture.24. The quality policy is: comprehensive quality control, implementation of systems, and provision of quality that meets customer demands. Full participation, timely handling, to achieve the goal of zero defects;25. The "Three No" policy for quality is: no acceptance of defective products, no manufacturing of defective products, and no release of defective products.26. Among the seven QC techniques, the 4M1H in the fishbone cause examination refer to (in Chinese) : person, machine, material, method, and environment.27. The components of solder paste include: metal powder, solvent, flux, anti-sagging agent and active agent; By weight, metal powder accounts for 85-92%, and by volume, it accounts for 50%. Among them, the main components of the metal powder are tin and lead, with a ratio of 63/37, and the melting point is 183℃.28. When using solder paste, it must be taken out of the refrigerator to warm up. The purpose is to bring the temperature of the refrigerated solder paste back to room temperature to facilitate printing. If the temperature is not warmed up, the defect that is likely to occur after Reflow in the PCBA is the solder beads.29. The file supply modes of the machine include: preparation mode, priority exchange mode, exchange mode and quick access mode.30. The PCB positioning methods of SMT include: vacuum positioning, mechanical hole positioning, double-sided clamp positioning and board edge positioning.31. The symbol (silk-screened) for a resistor with a value of 272 is 2700Ω, and the symbol (silk-screened) for a resistor with a value of 4.8MΩ is 485.32. The silk-screen printing on the BGA body contains information such as the manufacturer, manufacturer part number, specification and Datecode/(Lot No);33. The pitch of the 208-pin QFP is 0.5mm;Among the seven QC techniques, the fishbone diagram emphasizes the search for causal relationships.37. CPK refers to: the process capability under the current actual situation;38. The flux begins to volatilize in the constant temperature zone to carry out the chemical cleaning action.39. The ideal mirror image relationship between the cooling zone curve and the reflux zone curve;40. The RSS curve is the curve of heating up → constant temperature → reflux → cooling.41. The PCB material we are currently using is FR-4;42. The warpage specification of the PCB shall not exceed 0.7% of its diagonal.43. STENCIL's laser cutting is a method that can be reworked.44. Currently, the commonly used BGA ball diameter on computer motherboards is 0.76mm.45. The ABS system is in absolute coordinates;46. The error of the ceramic chip capacitor ECA-0105Y-K31 is ±10%.47. The voltage of the Panasert fully automatic surface mount machine from Panasonic is 3Ø200±10VAC.48. The diameter of the tape reel for SMT component packaging is 13 inches or 7 inches.49. Generally, the holes in SMT steel plates should be 4 μ m smaller than those in PCB pads to prevent the phenomenon of poor solder balls.50. According to the "PCBA Inspection Specifications", when the dihedral Angle is greater than 90 degrees, it indicates that the solder paste has no adhesion to the wave solder body.If you have worked in the SMT of an electronics factory, you must understand these51. After the IC is unpacked, if the humidity on the humidity display card is greater than 30%, it indicates that the IC is damp and absorbing moisture.52. The correct weight ratio and volume ratio of solder powder to flux in the solder paste composition are 90%:10% and 50%:50%.53. The early surface mount technology originated in the military and avionics fields in the mid-1960s;54. Currently, the contents of Sn and Pb in the most commonly used solder pastes for SMT are respectively: 63Sn+37Pb;55. The common feeding distance for paper tape trays with a width of 8mm is 4mm.56. In the early 1970s, a new type of SMD emerged in the industry, known as "sealed pin less chip carrier", which was often abbreviated as HCC.57. The resistance value of the component with the symbol 272 should be 2.7K ohms.58. The capacitance value of the 100NF component is the same as that of 0.10uf.The eutectic point of 59.63Sn +37Pb is 183℃.60. The most widely used electronic component material in SMT is ceramic.61. The temperature curve of the reflow soldering furnace has a maximum curve temperature of 215 ° C, which is the most suitable.62. When inspecting the tin furnace, a temperature of 245 ° C is more appropriate.63. The diameter of the tape reel for SMT component packaging is 13 inches or 7 inches.64. The opening types of steel plates are square, triangular, circular, star-shaped and Ben Lai-shaped.65. The material of the PCB currently in use on the computer side is: fiberglass board;66. What kind of substrate ceramic plates is Sn62Pb36Ag2 solder paste mainly used for?67. Rosin-based fluxes can be classified into four types: R, RA, RSA, and RMA.68. Is there any directionality in the SMT section resistance?69. Currently, the solder paste available on the market actually only has a adhesion time of 4 hours.70. The rated air pressure generally used for SMT equipment is 5KG/cm ².71. What kind of soldering method should be used for the front PTH and the back SMT when passing through the soldering furnace? What kind of soldering method is the disturbed double-wave soldering?72. Common inspection methods for SMT: visual inspection, X-ray inspection, and machine vision inspection73. The heat conduction mode of chromite repair parts is conduction + convection.74. Currently, the main components of the tin balls in BGA materials are Sn90 Pb10.75. The manufacturing methods of steel plates include laser cutting, electroforming and chemical etching.76. The temperature of the reflow furnace is determined by using a thermometer to measure the applicable temperature.77. When the SMT semi-finished products of the reflow oven are exported, their soldering condition is that the parts are fixed on the PCB.78. The Development Process of Modern Quality Management: TQC-TQA-TQM;79. ICT testing is needle-bed testing;80. The testing of ICT can measure electronic components through static testing.81. The characteristics of solder are that its melting point is lower than that of other metals, its physical properties meet the welding conditions, and its fluidity at low temperatures is better than that of other metals.82. When the parts of the reflow furnace are replaced and the process conditions change, the measurement curve needs to be remeasured.83. Siemens 80F/S belongs to more electronic control drive;84. The solder paste thickness gauge uses Laser light to measure: solder paste degree, solder paste thickness, and the width of the solder paste print.85. The feeding methods for SMT parts include vibrating feeders, disc feeders and tape feeders.86. Which mechanisms are used in SMT equipment: CAM mechanism, side rod mechanism, screw mechanism, and sliding mechanism;87. If the visual inspection section cannot be confirmed, which operation BOM, manufacturer confirmation, and sample board should be followed?88. If the packaging method of the part is 12w8P, the Pinth size of the counter needs to be adjusted by 8mm each time.89. Types of re-welding machines: hot air re-welding furnace, nitrogen re-welding furnace, laser re-welding furnace, infrared re-welding furnace;90. Methods that can be adopted for the trial production of SMT component samples: streamlined production, hand-printed machine mounting, and hand-printed hand mounting;91. Commonly used MARK shapes include: circle, cross, square, rhombus, triangle, and swastiform.92. In the SMT section, due to improper setting of the Reflow Profile, it is the preheating zone and the cooling zone that may cause micro-cracks in the parts.93. Uneven heating at both ends of the components in the SMT section can easily lead to: empty soldering, misalignment, and tombstones.94. The tools for SMT component repair include: soldering iron, hot air extractor, solder suction gun, and tweezers.95. QC is divided into :IQC, IPQC,.FQC and OQC;96. High-speed surface mount machines can mount resistors, capacitors, ics, and transistors.97. Characteristics of static electricity: small current, greatly affected by humidity;98. The Cycle time of high-speed machines and general-purpose machines should be balanced as much as possible.99. The true meaning of quality is to do it well the first time.100. The surface mount technology (SMT) machine should place small parts first and then large ones.101. BIOS is a basic Input/Output System. Its full English name is: Base Input/Output System;102. SMT components are classified into two types based on the presence or absence of component pins: LEAD and LEADLESS.103. There are three basic types of common automatic placement machines: successive placement type, continuous placement type and mass transfer placement machine.104. Production can be carried out in the SMT process without a LOADER.105. The SMT process is as follows: board feeding system - solder paste printing machine - high-speed machine - general-purpose machine - reflow soldering machine - board receiving machine;106. When opening temperature and humidity sensitive parts, the color displayed inside the circle of the humidity card should be blue before the parts can be used.107. The size specification of 20mm is not the width of the tape.108. Reasons for short circuits caused by poor printing during the manufacturing process :a. Insufficient metal content in solder paste, resulting in collapse b. 1. The holes in the steel plate are too large, resulting in excessive tin content. n2. The quality of the steel plate is poor, and the tin discharge is not good. Replace the laser cutting template. n3. There is residual solder paste on the back of the pencil. Reduce the pressure of the scraper and use appropriate VACCUM and SOLVENT109. The main engineering purposes of each zone in the general reflow furnace Profile :a. Preheating zone; Project objective: Evaporation of the solvent in the solder paste. b. Uniform temperature zone Engineering objective: Activation of flux and removal of oxides; Evaporate the excess water. c. Re-welding area Project objective: Solder melting. d. Cooling zone Engineering objective: To form alloy solder joints and integrate the part feet with the solder pads as one.110. In the SMT process, the main reasons for the generation of solder beads are: poor design of PCB pads, poor design of openings on steel plates, excessive placement depth or placement pressure, excessive rising slope of the Profile curve, solder paste collapse, and too low viscosity of solder paste.

The causes and solutions of SMT material loss The factors causing SMT material loss can first be analyzed in detail through the human-machine-material-method-environment approach as follows:I. Human factorsWhen installing materials, the tearing tape was too long and too much material was pressed, resulting in material loss and loss.Solution: Train the operator to leave two or three empty Spaces when loading materials. Press the materials until they are in good condition at the material window. This way, the position of the FEEDER gear and the tension of the winding belt can be checked.2. After the FEEDER was installed, there were debris on the TABLE, causing it to be out of place and shake, making it impossible to get the materials.Solution: Train the operator to check whether there are any foreign objects on the machine TABLE and the FEEDER base when installing the FEEDER, and clean the machine TABLE when turning and pulling.3. The material tray was not installed on the FEEDER, causing the chuck and FEEDER TAPE to float and throw materials.Solution: Strictly require the operator to load the material tray onto the FEEDER when changing materials.4. Failure to remove the roll TAPE in time leads to changes in tension, failure to roll the tape, poor feeding, and floating and throwing materials on the FEEDER TAPE.Solution: Strictly require the operator to thoroughly clean the reel when changing materials5. Losses caused by placing the board in the wrong direction, jumping the wrong board, or wiping the board, etc.Solution: Strictly require the operator to operate in accordance with the operation manual, and mark the position of panel assembly, the direction of panel entry and precautions in the manual.The causes and solutions of SMT material lossFactors and Solutions for SMT material loss6. Misreading the material station position or P/N leads to incorrect materials.Solution: Train the operators to verify the P/N of the materials and the machine alarm display, as well as the position of the discharge meter.7. Incorrect quantity of materials, excessive PCBA, and loss of the material tray due to incorrect feeding.Solution: It is required that the material handler must count and record the quantity of all materials and PCBA when entering or leaving the production line, and verify the production quantity and inventory quantity during the shift.8. The packaging parameters in the edited program were set incorrectly, and the number of feedings used did not match the packaging PITCH, resulting in material ejection.Solution: Modify the PACKED DATA according to the material packaging.9. The incorrect setting of the mounting position and station position in the edited program led to incorrect materials.Solution: When programming, check the BOM and drawings. After pasting the first inspection board, reconfirm and check the BOM and drawings.10. During the production process, due to FEEDER, NOZZLE, and material issues, the technician failed to follow up on the material discharge in a timely manner, resulting in a large amount of material discharge.Solution: It is required that the line technicians must monitor the operation status of the machine in real time. When the machine alarms, they must handle and observe on site. The hourly material discharge report must be signed and confirmed by the technician along with improvement measures. If the material is not handled within two hours after being signed and confirmed, the reasons must be analyzed and reported to the assistant engineer for handling.11. The Feeder cover was not fastened properly and the Feeder was not inspected before loading materialsSolution: Require the operator to operate in accordance with WI requirements and check the FEEDER both before and after installation. Technicians and management check and confirm.12. Random stacking of feeders causes deformation, and random disassembly and placement of FEEDER stoppers.Solution: It is required that the operator place all feeders on the FEEDER vehicle and strictly prohibit stacking or randomly placing them. When following the wires, it is strictly forbidden to disassemble FEEDER accessories at will.13. Poor feeders were not sent for repair in time and were reused, resulting in material discharge.Solution: All faulty feeders must be clearly marked by the operator and sent to the FEEDER repair station for maintenance and calibration. Ii. Machine factorsThe suction nozzle is deformed, clogged, damaged, the vacuum pressure is insufficient, and there is air leakage, resulting in the material not being sucked up properly, the material being taken out incorrectly, and the material being thrown out due to failure to pass the identification.Solution: It is required that technicians must inspect the equipment every day, test the NOZZLE center, clean the nozzle, and maintain the equipment regularly as planned.2. Insufficient spring tension, uncoordinated suction nozzle and HOLD, and uneven up and down movement result in poor material retrieval.Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.3. Poor feeding caused by deformation of HOLD/SHAFT or PISTON, bending of suction nozzle, wear and shortening of suction nozzle;Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.4. The material is not taken at the center of the material, and the height of the material taken is incorrect (generally, it is determined by pressing down 0.05MM after touching the part), resulting in misalignment. The material taken is incorrect and has a deviation. When identified, it does not match the corresponding data parameters and is discarded by the recognition system as invalid material.Solution: Regularly maintain the equipment as planned, inspect and replace vulnerable parts, and calibrate the machine's origin.5. The vacuum valve and vacuum filter element are dirty, or there are foreign objects blocking the vacuum air pipe channel, making it unsmooth. During suction, the instantaneous vacuum is insufficient to meet the operating speed of the equipment, resulting in poor material retrieval.Solution: Technicians are required to clean the suction nozzles every day and maintain the equipment regularly as planned.6. The machine is not positioned horizontally and vibrates greatly. The machine resonates with the FEEDER, resulting in poor material picking.Solution: Regularly maintain the equipment as planned and check the horizontal fixing support nuts of the equipment.7. Wear and loosening of the lead screw and bearings cause vibration during operation, changes in stroke and poor material taking.Solution: It is strictly prohibited to blow the interior of the machine with an air gun to prevent dust, debris and components from adhering to the lead screw. Regularly maintain the equipment as planned, and inspect and replace the vulnerable parts.8. Wear of motor bearings, aging of code readers and amplifiers cause changes in the machine's origin, and inaccurate operation data leads to poor material picking.Solution: Regularly maintain the equipment as planned, inspect and replace vulnerable parts, and correct the machine's origin.9. The visual, laser lens and the reflective paper of the nozzle are not clean, and there are impurities interfering with the camera's recognition, resulting in poor handling.Solution: It is required that technicians must inspect the equipment every day, test the NOZZLE center, clean the nozzle, and maintain the equipment regularly as planned.10. Poor processing is caused by improper selection of the light source, aging of the lamp tube, insufficient luminous intensity and gray scale.Solution: Regularly maintain the equipment as planned, test the luminance of the camera and the brightness of the lamp tubes, and inspect and replace the vulnerable parts.11. Poor treatment of the reflective prism due to aging, carbon deposits, wear and scratches.Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.12. Insufficient air pressure and vacuum leakage cause insufficient air pressure, resulting in the material being unable to be picked up or falling off during the process of pasting after being picked up.Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.13. The deformation of the feeder cover and the insufficient spring tension caused the material tape not to get stuck on the ratchet wheel of the feeder, resulting in the tape not being rolled up and the material being thrown out.Solution: All faulty feeders must be clearly marked by the operator and sent to the FEEDER repair station for maintenance, calibration, inspection and replacement of vulnerable parts.14. Loose or aged cameras cause poor recognition and material discharge.Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.15. Wear of the spines, drive claws, and positioning claws of the feeder, electrical failure, and malfunction of the feeding motor can cause poor feeding of the feeder, failure to collect materials or poor material discharge.Solution: All faulty feeders must be clearly marked by the operator and sent to the FEEDER repair station for maintenance, calibration, inspection and replacement of vulnerable parts16. The wear of the machine's feeding platform causes the FEEDER to loosen after installation, resulting in poor material retrieval.Solution: Regularly maintain the equipment as planned, and inspect and replace vulnerable parts.The causes and solutions of SMT material loss SMT patch processing productsIii. Material reasons1. Substandard products such as dirty, damaged components, irregular incoming materials, and oxidized pins lead to poor identification.Solution: Feedback to IQC and communicate with the supplier to replace the materials.2. The components are magnetized, the packaging of the components is too tight, and the friction force between the material frame and the components is too large, causing the components to fail to be lifted.Solution: Feedback to IQC and communicate with the supplier to replace the materials.3. Inconsistent component sizes or package sizes, spacings, and orientations can lead to poor material picking and identification.Solution: Feedback to IQC and communicate with the supplier to replace the materials. When incoming materials are sent, the packaging and body shape of the same P/N material must be inspected.4. The components are magnetized and the tape is too sticky, causing the material to adhere to the tape during winding.Solution: Feedback to IQC and communicate with the supplier to replace the materials.5. The component's suction surface is too small, resulting in poor material retrieval.Solution: Report to IQC and communicate with the supplier to replace the materials and reduce the operating speed of the machine.6. The hole diameter of the material used to hold the components is too large, and the size of the components does not match the packaging size, resulting in the components being placed sideways, flipped over, or in an incorrect position during feeding, leading to poor material retrieval.Solution: Feedback to IQC and communicate with the supplier to replace the materials.7. The feeding hole of the material belt has a large error from the material hole, and the suction position changes after material changeSolution: Feedback to IQC and communicate with the supplier to replace the materials.8. The tension of the rolled material tape is not uniform. If it is too soft, it is prone to elongation and will not roll. It is too brittle to break easily and the material cannot be retrieved.Solution: Feedback to IQC and communicate with the supplier to replace the materials.9. The packaging of incoming materials is not standardized, and bulk materials cannot be pasted by machines.Solution: Feedback to IQC and communicate with the supplier to replace the materials. Iv. Work Methods1. Using the wrong packaging model of FEEDER, using grooves for the paper tape and flat grooves for the tape, resulting in the inability to retrieve the materials.Solution: Train operators to identify material packaging and the selection of feeders.2. Using the wrong specification of FEEDER For material 0603, use 0802FEEDRE; for material 0402, use 0804FEEDER; for material 0603, use Ø1.3MM feed caps; for material 0402, use Ø1.0MM feed caps; for material 0805, use Ø1.0MM feed caps. Adjusting the feeder pitch incorrectly results in no material being retrieved.Solution: Train operators to identify the size and shape of the material body and the selection of FEEDER covers.3. Personnel do not operate in accordance with the standards of the operation instruction manual.Solution: Strictly require operation in accordance with the standards of the operation manual, regularly assess operational skills, and manage, supervise and evaluate.4. Poor material receiving, bending of the material tape, overly tight tension of the rolled material tape, and the holes of the material tape not matching the gears cause poor material picking.Solution: Strictly require operation in accordance with the standards of the operation manual, train and assess operational skills, and manage, supervise and evaluate.5. The tension of the roll tape is insufficient, and the roll tape is not installed in accordance with the standard, resulting in no roll tape.Solution: Strictly require operation in accordance with the standards of the operation manual, train and assess operational skills, and manage, supervise and evaluate.6. There is an empty space after the materials are installed, resulting in the inability to retrieve the materials.Solution: Strictly require operation in accordance with the standards of the operation manual, train and assess operational skills, and manage, supervise and evaluate.V. Production EnvironmentThe high temperature and insufficient humidity in the workshop cause the materials to dry, generating dust and static electricity.Solution: Monitor the temperature and humidity in the workshop in real time, and add air conditioners and humidifiers.2. The high humidity in the workshop and warehouse causes the materials to absorb water from the air, resulting in poor material handlingSolution: Monitor the temperature and humidity in the workshop and warehouse in real time, and add air conditioning and ventilation equipment.3. The workshop has poor sealing and inadequate dust-proof facilities. Excessive dust causes the machines to get dirty easily and the vacuum to be blocked.Solution: It is strictly prohibited to use air guns to blow on machinery, electrical facilities and materials. Add carpets for dust removal at the workshop entrance.4. Insufficient loading platforms and FEEDER vehicles result in non-standard loading and damage or deformation of the FEEDER.Solution: Add loading platforms and FEEDER vehicles, and operate strictly in accordance with WI requirements.

The main application of the AOI algorithm is empty soldering The application of algorithms is a key part of the application of AOI(Automatic Optical Inspection Instrument) algorithms in the field of inspection. Shenzhou Vision AOI has over 20 algorithms, and each algorithm has its specific purpose. Therefore, on the basis of being familiar with and understanding various AOI algorithms, applying AOI algorithms to each detection item is the prerequisite for AOI engineers to create detection programs. Empty soldering is mainly used for the inspection of soldering after the furnace. The ROI area of empty soldering is the solder climbing area of the solder joint, which detects whether the solder joint has an empty soldering phenomenon. The phenomenon of empty soldering refers to the situation where there is no solder at the solder joint; it is merely copper foil. The color characteristics of the empty welding phenomenon are high brightness and reddish chromaticity. The algorithm adopted for the detection of empty welds is the "TOC algorithm", and its default parameters are as follows: Parameter Parameter range The red range interval is (65, 180), where the lower limit is 65 and the upper limit is 180. The green range interval is (0, 70), where the lower limit is 0 and the upper limit is 70. The blue range interval is (0, 60), where the lower limit is 0 and the upper limit is 60. The brightness range interval is (80, 255), with the lower limit being 80 and the upper limit being 255. The determination range interval is (20, 100), where the lower limit is 20 and the upper limit is 100. The above parameters are expressed in the chromaticity triangle as follows:The main application of Shenzhou Vision's AOI algorithm is empty welding ① is the parameter area of color extraction, and ② is the image area represented by the parameters.

The application scope of the aoi algorithm - polarity reversal The application of algorithms is a key part of the application of AOI(Automatic Optical Inspection Instrument) algorithms in the field of inspection. Shenzhou Vision AOI has over 20 algorithms, and each algorithm has its specific purpose. Therefore, on the basis of being familiar with and understanding various AOI algorithms, applying AOI algorithms to each detection item is the prerequisite for AOI engineers to create detection programs. Reverse polarity is a necessary test item for detecting the direction of polar components. The selectable algorithms for detecting missing parts include TOC, Match, OCV, OCR and Histogram algorithms. Among them, the detection algorithms of TOC, Match, OCV and OCR are consistent with those of the erroneous items. The Histogram class detection algorithm uses the maximum value (minimum value) to detect whether the polarity inversion phenomenon occurs in the component. In polar components, there exists a polarity mark. The brightness of this polarity mark is significantly greater (less than) the brightness of the component itself. The maximum (minimum) value can be used to detect and determine whether the component has reversed polarity. If there is a high-brightness area in the polar element and the brightness of this brightness area is greater than 200, the determination range (200, 255) can be set, and the maximum value algorithm can be used for detection, as follows: In the above figure, if the ratio is set to 5, the detection mode is set to Max, and the return value is 243, then the direction of this component is correct.

Are there always misjudgments in AOI inspections? Five Common problems and practical solutions In today's industrial production, the precise inspection process is of vital importance, and AOI (Automatic Optical Inspection), as an advanced inspection technology, plays an indispensable role. However, many enterprises encounter the problem of total misjudgment in AOI inspection in practical applications, which undoubtedly affects production efficiency and product quality. To this end, we have conducted an in-depth analysis of the five common problems in AOI inspection and provided practical and practical solutions to help enterprises enhance the accuracy and reliability of inspection. Are there always misjudgments in AOI inspections? Five Common problems and practical solutions Question 1: Frequent false alarms in character detection Performance description: The system determines components with qualified character printing/engraving and normal function as defective products, triggering false alarms. Cause analysis: The fundamental reason for the high misjudgment rate of AOI character detection lies in the instability of component character images and the singularity of detection standards The character image is unstableSupplier differences: Different suppliers use different character printing/engraving techniques, ink/laser parameters, etc., which result in inconsistent color depth, thickness, contrast, etc. of the characters. Process fluctuation: Under different batches and production conditions from the same supplier, the quality of character printing/engraving may also fluctuate. Environmental interference: Environmental factors such as dust, stains, and reflections on the surface of components can also affect the clarity and recognition difficulty of character images. The testing standard is single. Traditional AOI systems: They usually adopt rule-based traditional image processing algorithms, relying on pre-set character templates and fixed thresholds for comparison, and are difficult to adapt to the diversity and complexity of character images. Lack of adaptive ability: Unable to dynamically adjust recognition parameters based on different character features and image quality, resulting in a persistently high rate of misjudgment. Solution: In response to the above problems, OCR character recognition technology based on deep learning and adaptive light source technology can be adopted to enhance the recognition ability and adaptability of the AOI system for character images Optimization algorithm - Deep Learning OCR algorithm By adopting OCR character recognition algorithms based on deep learning, such as the advanced algorithms equipped in Shenzhou Vision AOI, it can learn from massive character image data, automatically extract character features, and recognize characters of different fonts, sizes, colors, and backgrounds, effectively improving the recognition accuracy. Adaptive light source According to the character printing/engraving processes of different components, it automatically adjusts parameters such as the light source Angle, brightness, and color to optimize the clarity and contrast of character images, providing high-quality image input for OCR recognition. Are there always misjudgments in AOI inspections? Five Common problems and practical solutions Question 2: Misjudgment caused by interference from light sources and the environment Uneven lighting, frequent changes in ambient light, and unreasonable Settings of the device's sensitivity level can all lead to a decline in the quality of the collected images, thereby affecting the detection results of the AOI system and causing misjudgment. Cause analysis: Light source and environmental factors directly affect image quality. Unreasonable lighting conditions and equipment sensitivity Settings will cause the detection images to fail to truly reflect the status of components. Solution: Dynamically adjust the light source parameters: Fully consider the reflective characteristics of the material, set up multi-angle light sources, and through testing and optimization, find the most suitable combination of light angles to achieve the best image contrast and clarity. Meanwhile, calibrate the brightness of the light source regularly to ensure stable illumination. Enclosed detection environment: Install a light shield in the detection area to block external light interference, creating an independent and stable environment for detection and ensuring the stability of image quality. Are there always misjudgments in AOI inspections? Five Common problems and practical solutions Question 3: The algorithm parameters are set too strictly or too loosely Problem description: During the AOI (Automatic Optical Inspection) process, if the threshold Settings in the algorithm model do not match the actual process standards, the following problems will occur Missed inspection: The threshold setting is too loose, resulting in some serious defects not being detected, posing quality risks. False alarm: The threshold is set too strictly, misjudging some minor defects or normal fluctuations as defective products, increasing the workload of manual re-evaluation and reducing production efficiency. For example, take the detection of solder joint offset as an example. If the offset percentage threshold is set too strictly, some solder joints with slight offset but normal function may be judged as defective. Conversely, if the threshold is set too loosely, it may lead to the missed detection of some severely offset solder joints, affecting the reliability of the product. Cause analysis: The fundamental cause of the above problems lies in the rationality of the algorithm parameter Settings and the limitations of the algorithm itself The parameter setting is unreasonable The threshold parameter setting in the algorithm model lacks scientific basis and has not been adjusted in combination with the actual process standards, resulting in the disconnection between the detection results and the actual production situation. Limitations of the algorithm A single algorithm is difficult to meet the detection requirements of various components and various defect types, and it is also difficult to balance detection accuracy and efficiency. Solution: In response to the above problems, the strategy of phased debugging algorithm and the integration of multiple algorithms can be adopted to improve the detection accuracy and adaptability of the AOI system Debug the algorithm in stages Initial stage: Appropriately lower the threshold, increase the defect detection rate, and avoid missed detections. Optimization stage: Gradually tighten the threshold, verify and optimize through a large amount of sample data, reduce false positives, and find the best balance point. Adopt multiple algorithms Algorithm library: For instance, Shenzhou Vision AOI has adopted over 40 deep learning algorithms to build a rich algorithm library. Precise matching: For different types of components and different detection parts, the most suitable algorithm is selected for detection to improve the detection accuracy of complex defects. Question 4: Misjudgment caused by differences in pad design and materials Performance description: When the pad size is not standard or there are differences in material packaging, the positioning components of the AOI system may be incorrect, leading to misjudgment and affecting the production progress and product quality. Cause analysis: The pad design does not meet the standards, and the material packaging is inconsistent, which causes deviations in the preset parameter positioning of the AOI system and makes it impossible to accurately identify the position and status of the components. Solution: Standardize pad design: During the soldering process design stage, ensure that the pad dimensions precisely match those of the component pins, avoid symmetrical arrangement of pads, reduce reflection interference, and enhance positioning accuracy. Establish a material database: Record the character, color and other characteristic information of materials from different batches. During the detection process, the detection parameters are dynamically updated based on the material information to enable the system to adapt to the changes in the materials. Question 5: Insufficient equipment maintenance and calibration deviations Performance description: After long-term use of the equipment, if the hardware ages (such as loose lenses, light source attenuation, etc.) and is not maintained in time, or if the origin sensor is not calibrated regularly during debugging, it will lead to a decrease in detection accuracy and cause misjudgment. Cause analysis: Equipment maintenance is the key to the normal operation of the AOI system. Hardware aging or failure to calibrate in a timely manner will affect equipment performance and detection accuracy, and may lead to misjudgment. Solution: Develop a maintenance plan: Conduct a comprehensive monthly inspection and maintenance of the equipment, including cleaning the lenses, checking the tension of the belts, calibrating the equipment coordinate system, etc., to ensure that all components are in the best condition. Real-time monitoring of equipment status: With the help of professional software systems, key parameters such as light source brightness and camera resolution can be monitored in real time. Once the parameters are abnormal, a timely warning will be issued to facilitate technicians' timely maintenance and adjustment. Are there always misjudgments in AOI inspections? Five Common problems and practical solutions In conclusion, solving the problem of misjudgment in AOI detection requires approaches from multiple aspects. By comprehensively controlling image quality, detection programs, external interference, algorithm optimization, as well as equipment maintenance and calibration, enterprises can effectively reduce the misjudgment rate, enhance the accuracy and reliability of AOI detection, and provide more powerful quality assurance for industrial production. It is hoped that the above five common problems and practical solutions can help everyone further improve the accuracy and reliability of AOI inspection and safeguard industrial production.