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SMT's 110 must know the problem

1. In general, SMT workshop provided a temperature of 25 3 ;
2. Solder paste printing, the required materials and tools ready to paste, steel scraper p p wipe paper, air-laid paper p p cleaning agent mixing knife;
3. Commonly used in solder paste alloy composition of Sn / Pb alloy, and alloy ratio of 63/37;
4. Solder paste is divided into two main ingredients in most of the tin powder and flux.
5. Flux in welding the main role is to remove the damaged melt tin oxide p p to prevent re-oxidation of the surface tension.
6. Solder paste in the tin powder particles and Flux (flux) volume ratio of about 1:1, the weight ratio of about 9:1;
7. Solder paste to access principle is FIFO;
8. Solder paste in Kaifeng use, subject to two important process back to temperature p stirring;
9. Steel production of the common methods are: laser-etching p p electroforming;
10. SMT stands for Surface mount (or mounting) technology, the Chinese meaning of surface mount (or mounting) technology;
11. ESD stands for Electro-static discharge, the Chinese meaning of electrostatic discharge;
12. Produce SMT equipment, procedures, programs, including the majority of five, this five-part for the PCB data; Mark data; Feeder data; Nozzle data; Part data;
13. Lead-free solder Sn / Ag / Cu 96.5/3.0/0.5 the melting point of 217C;
14. Parts oven control of relative humidity and temperature of "10%;
15. Commonly used passive components (Passive Devices) are: resistors, capacitors, points flu (or diode), etc.; active components (Active Devices) are: transistor, IC, etc.;
16. Commonly used SMT steel plate made of stainless steel;
17. Commonly used SMT steel plate thickness of 0.15mm (or 0.12mm);
18. There are several varieties produced by electrostatic charge separation of the friction p p p electrostatic induction conductivity, etc.; electrostatic charge to the Electronic Engineering
Industry affect: ESD failure p electrostatic contamination; static elimination of the three principles for the static and in p p grounding shield.
19. Inch Dimensions length x width 0603 = 0.06inch * 0.03inch, metric dimensions length x width 3216 = 3.2mm * 1.6mm;
20. Exclusion ERB-05604-J81 No. 8 code "4" is expressed as four circuits, resistance of 56 ohms. Capacitor
ECA-0105Y-M31 capacity value of C = 106PF = 1NF = 1X10-6F;
21. ECN English full name: Engineering Change Notice; SWR Chinese full name: the special needs of work orders,
Must be countersigned by the relevant departments, documentation centers, distribution, valid;
22. 5S specific content of the order to rectify p p p clean sweep p accomplishment;
23. PCB purpose of vacuum-packed dust and moisture;
24. Quality Policy as follows: Total Quality Management p p implement systems to provide the quality of customer demand; full participation in a timely manner p
Processing p in order to achieve the goal of zero defects;
25. The quality of three non-policy is: do not accept bad bad product does not manufacture goods p p not out of bad materials;
26. QC practices in the seven major causes of fish bone search 4M1H are means (in Chinese): Human Machine p p p materials
Methods p environment;
27. Paste ingredients include: metal powder flux p p p solvent resistance p vertical flow of agents active agent; by weight points,
Metal powder accounted for 85-92%, by volume integral metal powder accounted for 50%; in which the main ingredient for the tin metal powder and lead, the ratio of 63/37, the melting point of 183 ;
28. Solder paste used to be removed from the refrigerator back to temperature, the purpose is: the temperature returns to normal temperature refrigeration of the solder paste,
In order to facilitate the printing. If you do not back into the Reflow temperature in the PCBA is easy to produce, after the bad for the solder ball;
29. Machine supply model documents are: ready to model the priority exchange mode p p exchange mode and speed access mode;
30. SMT in PCB positioning methods are: vacuum positioning hole location p p mechanical bilateral folder location and Edge positioning;
31. Silk screen (symbol) for 272 of the resistance, resistance to 2700, resistance of the symbol of resistance for the 4.8M
Number (screen printing) to 485;
32. BGA body on a screen printing with manufacturers Part Number p p manufacturers specifications and Datecode / (Lot No) and other information;
33. 208pinQFP the pitch of 0.5mm;
34. QC seven practices, the fish-bone diagram to find cause and effect relationship between stress;
37. CPK means: the actual situation under the current process capability;
38. Flux in the temperature had started volatile chemical cleaning action;
39. The ideal curve and the cooling zone reflow area curve mirroring relationship;
40. RSS curve of constant temperature heating back cooling curve;
41. We are using PCB material is FR-4;
42. PCB warpage specifications does not exceed 0.7% of its diagonal;
43. STENCIL produced can be re-Heavy Industries laser cutting methods;
44. At present the computer motherboard, is often used BGA ball diameter of 0.76mm;
45. ABS system for the absolute coordinates;
46. Ceramic Chip Capacitors ECA-0105Y-K31 error of 10%;
47. Panasert Matsushita automatic placement machine with voltage 3Ø200 10VAC;
48. SMT Tape and Reel part wrap up its 13-inch disc diameter, 7 inches;
49. SMT steel plate openings generally smaller than the PCB PAD can prevent solder ball 4um bad the phenomenon;
50. In accordance with "PCBA inspection rules" Fan When dihedral angle "90 degrees, said solder paste and wave solder body no adhesion;
51. IC, after unpacking the card humidity Humidity displayed more than 30% of the cases, said IC damp and moisture;
52. Paste ingredients in the weight of tin powder and the flux ratio and volume ratio of the right is 90%: 10%, 50%: 50%;
53. Early the surface adhesive mounting technology derived from the mid-20th century, 60 of the military and aerospace electronics;
54. Currently the most commonly used SMT solder paste Sn, and Pb contents of each for: 63Sn +37 Pb;
55. The common bandwidth 8mm tape feed tray of the feeding distance of 4mm;
56. In the early 1970s, the industry in the new doors of a SMD, as "enclosed, foot chip carrier", often on behalf of the HCC Jane;
57. Symbol of resistance for the 272's components should be 2.7K ohms;
58. 100NF components of the capacity value 0.10uf the same;
59. 63Sn +37 Pb eutectic point of 183 ;
60. SMT largest electronic components used material is ceramic;
61. Reflow furnace temperature curve for the curve of the maximum temperature 215C of the most appropriate;
62. Tin furnace inspection, tin furnace temperature of 245C more appropriate;
63. SMT Tape and Reel part wrap up its 13-inch disc diameter, 7 inches;
64. Plate hole pattern square triangle p p circles, stars, the lei-shaped;
65. Currently using the computer side of the PCB, the materials are: glass plate;
66. Sn62Pb36Ag2 the main trial to which the solder paste, ceramic substrate board;
67. With the rosin-based flux can be divided into four kinds: R p RA p RSA p RMA;
68. SMT whether the exclusion in paragraph directional None;
69. Sale of the solder paste is currently available in the market, actually only 4 hours of viscous time;
70. SMT devices typically used for the rated pressure 5KG/cm2;
71. Positive PTH, had negative SMT soldering tin stove which means the use of double-wave soldering spoiler;
72. SMT common testing methods: visual inspection p p X-ray inspection machine vision inspection
73. Ferrochrome repair parts for the conduction heat conduction + convection;
74. At present BGA solder ball material of their principal into Sn90 Pb10;
75. Steel plate production method of laser cutting electroforming method p p chemical etching;
76. Jiong welding furnace temperature according to: the use of temperature measuring device Measure the applicable temperature;
77. Jiong of SMT solder furnace semi-finished products in the export part of its welding position is fixed on the PCB on the;
78. Modern quality management development course TQC-TQA-TQM;
79. ICT test is needle-bed test;
80. ICT testing of electronic components can be measured using the static test;
81. Solder feature is a low melting point than other metals welding conditions to meet the physical properties of p p low temperature fluidity better than the other metals;
82. Jiong welding furnace parts replacement process conditions change to re-measurement measure curve;
83. Siemens 80F / S belong to the more electronic control transmission;
84. Solder paste thickness is the use of Laser Optical Measurement: Solder paste thickness p p degree of the width of the printed solder paste;
85. SMT parts feeding methods are vibrating Feeder Feeder p p discoid Tape Feeder;
86. SMT equipment, the use of which agency: Side-bar linkage cam p p p screw bodies sliding body;
87. Visual inspection in accordance with paragraph if it can not confirm what items Zexu companies operating BOM p p samples confirmed that board;
88. If the parts packed way 12w8P, then the counter Pinth necessary to adjust the size of each into the 8mm;
89. Jiong Welder Type: Hot-air welding furnace p nitrogen Jiong Jiong welding furnace stove p p laser welding infrared Jiong Jiong welding furnace;
90. SMT components can be used to make the sample test methods: flow-line type production p p handprint handprints hands-mount placement machine;
91. Common MARK shape: round, "10" shaped p square, diamond, triangle, 10000-shaped;
92. SMT segment due to Reflow Profile are set incorrectly, may result in part micro-crack is the preheat zone p cooling zone;
93.SMT parts at both ends of paragraphs can easily result in uneven heating: the empty tomb welding p p deviation;
94. SMT parts maintenance tools: soldering iron hot air extractor device p p Desoldering gun, tweezers;
95. QC is divided into: IQC p IPQC p. FQC p OQC;
96. High-speed placement machine can mount resistor capacitor p p IC p. Transistor;
97. Electrostatic characteristics: small current p influenced by humidity;
98. High-speed machine and the Pan-use machine Cycle time should be balanced;
99. Quality real intention is to do a good job the first time;
100. Mounter should subsidize the small parts, after the paste large parts;
101. BIOS is a basic input output system, all English as: Base Input / Output System;
102. SMT parts based on part feet has no divided into two kinds of LEAD and LEADLESS;
103. Common automatic placement machine has three basic patterns, follow-style place-based, continuous placement type and a large number of transfer-type placement machine;
104. SMT manufacturing process can not LOADER production;
105. SMT process is sent to board system - solder paste printing - high-speed machine - the Pan-use machines - Jiong Reflow - close board machine;
106. Temperature and humidity-sensitive components of Kaifeng, the humidity card circle shows the color blue, spare parts before use;
107. Sizes are not expected with a width of 20mm;
108. Manufacturing process caused by short circuit due to the printing bad reasons:
a. solder paste metal content is not enough, resulting in collapse
b. plate hole is too large, resulting in excessive tin
c. poor quality steel plate, the next tin poor templates for laser cutting
d. Stencil on the back of a solder paste residues, reducing scraper pressure, the use of appropriate VACCUM and SOLVENT
109. General Reflow Oven Profile of major projects in various districts Purpose:
a. preheating zone; Project Objective: To paste in the capacity of volatile agent.
b. average temperature zone; Project Objective: flux activation, removal of oxide; evaporate excess moisture.
c. Back to the welding area; Project Objective: To solder melting.
d. cooling zone; Project Objective: alloy solder joint formation, part of one foot and pad access;
110. SMT process, the tin beads resulted primarily from: PCB PAD poor design, poor design of plate openings, and placing pieces of depth or excessive pressure on home items, Profile rising slope of the curve is too large, solder paste, collapsed over solder paste viscosity low.

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