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SMT Common Knowledge

SMT Common Knowledge

  • Categories:Company News
  • Author:Becky Su
  • Origin:
  • Time of issue:2022-12-09 15:05
  • Views:

(Summary description)SMT Common Knowledge SMT Common Knowledge Introduction      1 . Generally speaking, the temperature of SMT workshop is 25±3℃.    2. Solder paste printing, the materials and tools needed to prepare the paste, steel plate, scraper, wipe paper, dust-free paper, cleaning agent, stirring knife.      3. generally used alloy composition of the paste is Sn / Pb alloy, and the alloy ratio of 63/37. 4.      4. The main components of the solder paste is divided into two major components of tin powder and flux. 5.      5 flux in the soldering of the main role is to remove the oxide, destroy the surface tension of molten tin, to prevent re-oxidation. 6.      6. The volume ratio of tin powder particles to Flux (flux) in solder paste is about 1:1, and the weight ratio is about 9:1.      7. The principle of taking solder paste is first in first out. 8.      8. when the paste is opened and used, it must go through two important processes: tempering and stirring.      9. The common production methods of steel plate are: etching, laser, electroforming.      10. The full name of SMT is Surfacemount (or mounting) technology, Chinese meaning for surface adhesion (or mounting) technology. 11.      11. the full name of ESD is Electro-static discharge, the Chinese meaning is electrostatic discharge.      12. When making SMT equipment program, the program includes five major parts, this five parts are substrate data; mounting data; loading data; component data; absorbing data, image data.      13. lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 melting point of 217C. 14.      14. The controlled relative temperature and humidity of the parts drying oven is < 10%.      15. commonly used passive components (PassiveDevices) are: resistance, capacitance, point sense (or dipole), etc.; active components (ActiveDevices) are: crystals, IC, etc.      16. The material of the commonly used SMT steel plate is stainless steel.      17. The thickness of the commonly used SMT steel plate is 0.15mm (or 0.12mm).      18. The types of electrostatic charge generated by friction, separation, induction, electrostatic conduction, etc.; electrostatic charge on the electronics industry: ESD failure, electrostatic pollution; electrostatic elimination of the three principles of electrostatic neutralization, grounding, shielding.      19. imperial size LxW 0603=0.06inch*0.03inch, metric size LxW 3216=3.2mm*1.6mm.      20. The 8th code "4" of ERB-05604-J81 indicates 4 circuits with 56 ohms resistance value. Capacitor ECA-0105Y-M31 capacitance C = 106PF = 1NF = 1X10-6F.      21. ECN Chinese full name: engineering change notice; SWR Chinese full name: special requirements work order, must be countersigned by the relevant departments, the documentation center to distribute, in order to be effective.      22. 5S specific content for the organization, tidying, cleaning, cleanliness, literacy.      23. The purpose of PCB vacuum packaging is to prevent dust and moisture.      24. The quality policy is: **Quality control, implementation of the system, to provide the quality of customer needs; full participation, timely processing, to achieve the goal of zero defects.      25. The three no policies of quality are: do not accept ** products, do not manufacture ** products, and do not flow out ** products.      26. QC seven techniques in the fishbone check the cause of 4M1H are (Chinese): people, machines, materials, methods, environment.      27. The composition of the solder paste contains: metal powder, solution, flux, anti-drop agent, active agent; by weight, metal powder accounts for 85-92%, by volume metal powder accounts for 50%; where the main components of metal powder for tin and lead, the ratio of 63/37, the melting point of 183 ℃.      28. Solder paste must be taken out of the refrigerator when using back to temperature, the purpose is: let the refrigerated temperature of the paste back to room temperature, in order to facilitate printing. If not return to temperature in the PCBA into the Reflow easy to produce ** for tin beads.      29. the machine's file supply mode are: ready mode, priority exchange mode, exchange mode and quick connect mode.      30. SMT PCB positioning methods are: vacuum positioning, mechanical hole positioning, bilateral clamping positioning and board edge positioning.         31. The resistor with a silkscreen (symbol) of 272 has a resistance value of 2700Ω, and the resistor with a resistance value of 4.8MΩ has a symbol (silkscreen) of 485.      32. The silkscreen on the BGA body contains information such as manufacturer, manufacturer's part number, specification, and Datecode/(Lot No).      33. The pitch of 208pin QFP is 0.5mm.      34. the seven QC practices, the fishbone diagram emphasizes the search for cause-and-effect relationships;      35. CPK refers to the current process capability under actual conditions;      36. Flux starts to evaporate in the constant temperature zone for chemical cleaning act

SMT Common Knowledge

(Summary description)SMT Common Knowledge

SMT Common Knowledge Introduction 

    1 . Generally speaking, the temperature of SMT workshop is 25±3℃.

   2. Solder paste printing, the materials and tools needed to prepare the paste, steel plate, scraper, wipe paper, dust-free paper, cleaning agent, stirring knife.
 

   3. generally used alloy composition of the paste is Sn / Pb alloy, and the alloy ratio of 63/37. 4.
 

   4. The main components of the solder paste is divided into two major components of tin powder and flux. 5.
 

   5 flux in the soldering of the main role is to remove the oxide, destroy the surface tension of molten tin, to prevent re-oxidation. 6.
 

   6. The volume ratio of tin powder particles to Flux (flux) in solder paste is about 1:1, and the weight ratio is about 9:1.
 

   7. The principle of taking solder paste is first in first out. 8.
 

   8. when the paste is opened and used, it must go through two important processes: tempering and stirring.
 

   9. The common production methods of steel plate are: etching, laser, electroforming.
 

   10. The full name of SMT is Surfacemount (or mounting) technology, Chinese meaning for surface adhesion (or mounting) technology. 11.
 

   11. the full name of ESD is Electro-static discharge, the Chinese meaning is electrostatic discharge.
 

   12. When making SMT equipment program, the program includes five major parts, this five parts are substrate data; mounting data; loading data; component data; absorbing data, image data.
 

   13. lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 melting point of 217C. 14.
 

   14. The controlled relative temperature and humidity of the parts drying oven is < 10%.
 

   15. commonly used passive components (PassiveDevices) are: resistance, capacitance, point sense (or dipole), etc.; active components (ActiveDevices) are: crystals, IC, etc.
 

   16. The material of the commonly used SMT steel plate is stainless steel.
 

   17. The thickness of the commonly used SMT steel plate is 0.15mm (or 0.12mm).
 

   18. The types of electrostatic charge generated by friction, separation, induction, electrostatic conduction, etc.; electrostatic charge on the electronics industry: ESD failure, electrostatic pollution; electrostatic elimination of the three principles of electrostatic neutralization, grounding, shielding.
 

   19. imperial size LxW 0603=0.06inch*0.03inch, metric size LxW 3216=3.2mm*1.6mm.
 

   20. The 8th code "4" of ERB-05604-J81 indicates 4 circuits with 56 ohms resistance value. Capacitor ECA-0105Y-M31 capacitance C = 106PF = 1NF = 1X10-6F.
 

   21. ECN Chinese full name: engineering change notice; SWR Chinese full name: special requirements work order, must be countersigned by the relevant departments, the documentation center to distribute, in order to be effective.
 

   22. 5S specific content for the organization, tidying, cleaning, cleanliness, literacy.
 

   23. The purpose of PCB vacuum packaging is to prevent dust and moisture.
 

   24. The quality policy is: **Quality control, implementation of the system, to provide the quality of customer needs; full participation, timely processing, to achieve the goal of zero defects.
 

   25. The three no policies of quality are: do not accept ** products, do not manufacture ** products, and do not flow out ** products.
 

   26. QC seven techniques in the fishbone check the cause of 4M1H are (Chinese): people, machines, materials, methods, environment.
 

   27. The composition of the solder paste contains: metal powder, solution, flux, anti-drop agent, active agent; by weight, metal powder accounts for 85-92%, by volume metal powder accounts for 50%; where the main components of metal powder for tin and lead, the ratio of 63/37, the melting point of 183 ℃.
 

   28. Solder paste must be taken out of the refrigerator when using back to temperature, the purpose is: let the refrigerated temperature of the paste back to room temperature, in order to facilitate printing. If not return to temperature in the PCBA into the Reflow easy to produce ** for tin beads.
 

   29. the machine's file supply mode are: ready mode, priority exchange mode, exchange mode and quick connect mode.
 

   30. SMT PCB positioning methods are: vacuum positioning, mechanical hole positioning, bilateral clamping positioning and board edge positioning.

        31. The resistor with a silkscreen (symbol) of 272 has a resistance value of 2700Ω, and the resistor with a resistance value of 4.8MΩ has a symbol (silkscreen) of 485.
 

   32. The silkscreen on the BGA body contains information such as manufacturer, manufacturer's part number, specification, and Datecode/(Lot No).
 

   33. The pitch of 208pin QFP is 0.5mm.
 

   34. the seven QC practices, the fishbone diagram emphasizes the search for cause-and-effect relationships;
 

   35. CPK refers to the current process capability under actual conditions;
 

   36. Flux starts to evaporate in the constant temperature zone for chemical cleaning act

  • Categories:Company News
  • Author:Becky Su
  • Origin:
  • Time of issue:2022-12-09 15:05
  • Views:
Information

SMT Common Knowledge

SMT Common Knowledge Introduction 

    1 . Generally speaking, the temperature of SMT workshop is 25±3℃.

   2. Solder paste printing, the materials and tools needed to prepare the paste, steel plate, scraper, wipe paper, dust-free paper, cleaning agent, stirring knife.
 

   3. generally used alloy composition of the paste is Sn / Pb alloy, and the alloy ratio of 63/37. 4.
 

   4. The main components of the solder paste is divided into two major components of tin powder and flux. 5.
 

   5 flux in the soldering of the main role is to remove the oxide, destroy the surface tension of molten tin, to prevent re-oxidation. 6.
 

   6. The volume ratio of tin powder particles to Flux (flux) in solder paste is about 1:1, and the weight ratio is about 9:1.
 

   7. The principle of taking solder paste is first in first out. 8.
 

   8. when the paste is opened and used, it must go through two important processes: tempering and stirring.
 

   9. The common production methods of steel plate are: etching, laser, electroforming.
 

   10. The full name of SMT is Surfacemount (or mounting) technology, Chinese meaning for surface adhesion (or mounting) technology. 11.
 

   11. the full name of ESD is Electro-static discharge, the Chinese meaning is electrostatic discharge.
 

   12. When making SMT equipment program, the program includes five major parts, this five parts are substrate data; mounting data; loading data; component data; absorbing data, image data.
 

   13. lead-free solder Sn/Ag/Cu 96.5/3.0/0.5 melting point of 217C. 14.
 

   14. The controlled relative temperature and humidity of the parts drying oven is < 10%.
 

   15. commonly used passive components (PassiveDevices) are: resistance, capacitance, point sense (or dipole), etc.; active components (ActiveDevices) are: crystals, IC, etc.
 

   16. The material of the commonly used SMT steel plate is stainless steel.
 

   17. The thickness of the commonly used SMT steel plate is 0.15mm (or 0.12mm).
 

   18. The types of electrostatic charge generated by friction, separation, induction, electrostatic conduction, etc.; electrostatic charge on the electronics industry: ESD failure, electrostatic pollution; electrostatic elimination of the three principles of electrostatic neutralization, grounding, shielding.
 

   19. imperial size LxW 0603=0.06inch*0.03inch, metric size LxW 3216=3.2mm*1.6mm.
 

   20. The 8th code "4" of ERB-05604-J81 indicates 4 circuits with 56 ohms resistance value. Capacitor ECA-0105Y-M31 capacitance C = 106PF = 1NF = 1X10-6F.
 

   21. ECN Chinese full name: engineering change notice; SWR Chinese full name: special requirements work order, must be countersigned by the relevant departments, the documentation center to distribute, in order to be effective.
 

   22. 5S specific content for the organization, tidying, cleaning, cleanliness, literacy.
 

   23. The purpose of PCB vacuum packaging is to prevent dust and moisture.
 

   24. The quality policy is: **Quality control, implementation of the system, to provide the quality of customer needs; full participation, timely processing, to achieve the goal of zero defects.
 

   25. The three no policies of quality are: do not accept ** products, do not manufacture ** products, and do not flow out ** products.
 

   26. QC seven techniques in the fishbone check the cause of 4M1H are (Chinese): people, machines, materials, methods, environment.
 

   27. The composition of the solder paste contains: metal powder, solution, flux, anti-drop agent, active agent; by weight, metal powder accounts for 85-92%, by volume metal powder accounts for 50%; where the main components of metal powder for tin and lead, the ratio of 63/37, the melting point of 183 ℃.
 

   28. Solder paste must be taken out of the refrigerator when using back to temperature, the purpose is: let the refrigerated temperature of the paste back to room temperature, in order to facilitate printing. If not return to temperature in the PCBA into the Reflow easy to produce ** for tin beads.
 

   29. the machine's file supply mode are: ready mode, priority exchange mode, exchange mode and quick connect mode.
 

   30. SMT PCB positioning methods are: vacuum positioning, mechanical hole positioning, bilateral clamping positioning and board edge positioning.

        31. The resistor with a silkscreen (symbol) of 272 has a resistance value of 2700Ω, and the resistor with a resistance value of 4.8MΩ has a symbol (silkscreen) of 485.
 

   32. The silkscreen on the BGA body contains information such as manufacturer, manufacturer's part number, specification, and Datecode/(Lot No).
 

   33. The pitch of 208pin QFP is 0.5mm.
 

   34. the seven QC practices, the fishbone diagram emphasizes the search for cause-and-effect relationships;
 

   35. CPK refers to the current process capability under actual conditions;
 

   36. Flux starts to evaporate in the constant temperature zone for chemical cleaning action;
 

   37. the ideal cooling zone curve and reflow zone curve mirror relationship;
 

   38. Sn62Pb36Ag2 solder paste is mainly used for ceramic boards;
 

   39. rosin-based fluxes can be divided into four types: R, RA, RSA, RMA;
 

   40. RSS curve for temperature rise → constant temperature → reflow → cooling curve;
 

   41. we are now using the PCB material is FR-4;
 

   42. the PCB warpage specification does not exceed 0.7% of its diagonal;
 

   43. STENCIL production laser cutting is a method that can be reworked;
 

   44. the BGA ball diameter commonly used on computer motherboards is 0.76mm;
 

   45. ABS system is **coordinate;
 

   46. ceramic chip capacitor ECA-0105Y-K31 error is ±10%;
 

   47. the PCB of the computer currently in use, the material is: glass fiber board;
 

   48. SMT parts packaging its tape tray diameter of 13 inches, 7 inches;
 

   49. SMT general steel plate openings than the PCB PAD 4um smaller to prevent the phenomenon of tin ball **;
 

   50. according to the "PCBA inspection specification" when the two-sided angle > 90 degrees means that the solder paste and wave solder body no adhesion;
 

   51. IC unpacking humidity display card humidity in the case of more than 30% means that the IC moisture and moisture absorption;
 

   52. The correct weight ratio and volume ratio of solder powder to flux in the composition of solder paste is 90%:10%, 50%:50%;
 

   53. early surface mount technology originated in the mid-1960s** and in the avionics field;
 

   54. the current SMT* commonly used solder paste Sn and Pb content is: 63Sn + 37Pb;
 

   55. the common bandwidth of 8 mm paper tape reel feed pitch is 4 mm. 56;
 

   56. In the early 1970s, a new type of SMD emerged in the industry, the "sealed chip carrier", often referred to as HCC;
 

   57. the symbol 272 components should have a resistance value of 2.7K ohms;
 

   58. 100NF components with the same capacitance of 0.10uf;
 

   59. The eutectic point of 63Sn+37Pb is 183°C. 60;
 

   60. The material of electronic parts used in SMT* is ceramic;

        61. soldering furnace temperature curve its curve * high temperature 215C * suitable;
 

   62. tin furnace inspection, the temperature of the tin furnace 245 ℃ is more appropriate;
 

   63. the steel plate opening type square, triangle, round, star, Ben Lei shape;
 

   64. the SMT section has no directional resistance no. 65;
 

   65. the current market sold solder paste, the actual only 8 hours of adhesion time;
 

   66. SMT equipment generally use the rated air pressure of 5KG/cm2;
 

   67. SMT parts maintenance tools are: soldering iron, hot air extractor, suction tin gun, tweezers;
 

   68. QC is divided into: IQC, IPQC, FQC, OQC;
 

   69 high-speed placement machine can be mounted resistors, capacitors, IC, transistors;
 

   70. the characteristics of static electricity: small current, affected by humidity;
 

   71. front PTH, reverse SMT over the tin furnace when using what kind of welding method disturbance double wave soldering;
 

   72. SMT common inspection methods: visual inspection, X-ray inspection, machine vision inspection
 

   73. chromium iron repair parts heat transfer method is conduction + convection;
 

   74. the current BGA material of the main tin ball into Sn90 Pb10;
 

   75. the production method of steel plate laser cutting, electroforming method, chemical etching;
 

   76. the temperature of the furnace according to: using the thermometer to measure the applicable temperature;
 

   77. the SMT semi-finished products are exported in the soldering condition when the parts are fixed on the PCB;
 

   78. the development of modern quality management history TQC-TQA-TQM;
 

   79. ICT test is a needle bed test. 80;
 

   80. the ICT test can test electronic parts using static test. 81;
 

   81. solder characteristics are lower melting point than other metals, physical properties to meet the welding conditions, low temperature fluidity than other metals;
 

   82. the very soldering furnace parts change process conditions to change to re-measure the measurement curve;
 

   83. Siemens 80F / S belongs to the more electronic control drive;
 

   84. solder paste thickness meter is the use of Laser light measurement: solder paste degree, solder paste thickness, solder paste printed out of the width;
 

   85. SMT parts feeding methods are vibration feeder, tray feeder, tape feeder;
 

   86. SMT equipment using which mechanism: cam mechanism, side bar mechanism, screw mechanism, sliding mechanism;
 

   87. if the visual inspection section can not be confirmed, what should be done according to the BOM, manufacturer's confirmation, sample board;
 

   88. If the part packaging method is 12w8P, the counter Pinth size should be adjusted by 8mm each time;
 

   89. types of welding machine: hot air type welding furnace, nitrogen type welding furnace, laser type welding furnace, infrared type welding furnace;
 

   90. SMT parts sample trial can use the method: flow line production, hand printing machine mount, hand printing hand mount;
 

   91. commonly used MARK shape are: round, "ten", square, diamond, triangle, million characters;
 

   92. SMT section due to improper setting of Reflow Profile, may cause parts micro-crack is the preheating area, cooling area;
 

   93. Uneven heating of the two ends of the SMT section is likely to cause: empty solder, offset, and tombstone;
 

   94. The Cycle time of high-speed machine and general-purpose machine should be balanced as much as possible;
 

   95. The true meaning of quality is to do it right the **time;
 

   96. SMT machine should first paste small parts, then paste large parts;
 

   97. BIOS is a basic input/output system, the full English is: Base Input/Output System;
 

   98. SMT parts are divided into LEAD and LEADLESS according to the part foot;
 

   99. There are three basic types of common automatic placement machine, successive placement type, continuous placement type and mass transfer type placement machine;
 

   100. SMT process can be produced without LOADER;

        101. The SMT process is board feeding system - solder paste printing machine - high speed machine - general purpose machine - large flow soldering - board closing machine;
 

   102. When the temperature and humidity sensitive parts are opened, the parts can be used only when the color in the circle of the humidity card is blue;
 

   103. The size of 20mm is not the width of the material belt;
 

   104. process due to printing ** cause short circuit: a. solder paste metal content is not enough, resulting in collapse b. steel plate opening too large, resulting in too much tin c. steel plate quality is not good, under the tin **, change the laser cutting template d. Stencil back residual solder paste, reduce the scraper pressure, using the appropriate VACCUM and SOLVENT
 

   105. General solder back to the main purpose of the project in each zone of the furnace Profile: a. Preheating zone; project purpose: volatilization of flux in the paste. b. Equalization zone; project purpose: flux activation, removal of oxides; evaporation of excess water. c. Soldering zone; project purpose: solder melting. d. Cooling zone; project purpose: the formation of alloy solder joints, parts feet and pads connected as one;
 

   106.SMT process, the main reasons for tin beads: poor design of the PCBPAD, poor design of the steel plate opening, placement depth or placement pressure is too large, Profile curve rising slope is too large, paste collapse, paste viscosity is too low.

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