How does smt plant control PCBA quality?

The most important process of PCBA patch processing, I wonder if you have similar doubts, why the factory equipment size is similar, but the products are different?

Advanced equipment is the introduction of quality, but good quality is more than equipment parameters competition.

In this issue we will combine several key steps with materials and talk about Youqin's quality control of PCBA.

material

PCB: The quality of PCB board determines the quality of welding. To check PCB board deformation, fly line, scratch, line damage, hole plugging, leakage ink and board surface is smooth. kingford Electronics PCB partner is the industry famous factory, 100% electrical test.

Steel mesh: in the solder paste printing stage, the solder paste is leaked to the corresponding solder pad of PCB through the steel mesh. The quality of the steel mesh directly affects the quality of the solder paste printing. Need to check the opening of the steel mesh, thickness, flatness, etc., intact steel mesh can leak good solder paste, to improve the welding quality of the sequence to lay a good foundation.

Solder paste: The storage and use of solder paste is extremely strict. Tin paste is generally stored between 0℃ and 10℃. Before use, it is necessary to fully stir, so that its viscosity has excellent printability and release property. Use according to the "first in first out" principle, and do a good record, to ensure that the return temperature time is greater than four hours. Make sure reflow welding is completed within 2 hours after printing. High quality solder paste can avoid bad printing. Youqin Electronic adopts first-line brand solder paste, such as Qianzhu and Letai.

Components: As one of the important components of SMT mounting, the quality and performance of components directly affect the quality of reflow welding. Youqin strictly controls the procurement channels of components, only picking up goods from large traders and original factories, avoiding second-hand materials and fake materials from the source. At the same time 100% incoming material inspection, to ensure that components without fault.

Inspection and management

Solder paste detection

AOI AOI detector is commonly placed in the back of the reflow welding process, AOI can detect a lot of bad defects in the previous process, such as more tin, less tin, polarity direction, monument and so on. The defective PCB board can be detected through AOI detection to avoid the process of transferring the defective board to the later sequence, which is a very important link to improve the quality of PCBA patch.

Through the first piece inspection, it can be found that systematic causes such as serious wear of fixture or installation and positioning errors, poor accuracy of measuring instruments, incorrect reading of drawings, feeding or formulation errors exist, so as to take corrective or improvement measures to prevent the occurrence of batch nonconforming products

The last point is the most important and the most overlooked: plant management. Almost all factories claim to follow the ISO9001:2008 quality management system. As we all know, it is not difficult to obtain this certificate. If a factory is not willing to apply for the certificate, it can be concluded that it is a factory that cannot cooperate with the situation

2. What is the difference between aluminum substrate and glass fiber board?

Aluminum substrate and glass fiber plate difference and application

First, glass fiber board (FR4, single-sided, double-sided, multi-layer PCB circuit board, impedance board, blind buried hole board), suitable for computer, mobile phone and other electronic and digital products.

Glass fiber board is called there are many, we first together to understand; FR-4 also known as fiberglass board; Glass fiber board; FR4 reinforcement plate; FR-4 epoxy resin plate; Flame retardant insulation board; Epoxy plate, FR4 light plate; Epoxy glass cloth plate; Circuit board drilling pad, generally used for soft bag base, and then bag cloth, leather, etc., made of beautiful wall, ceiling decoration. It's very widely used. With sound absorption, sound insulation, heat insulation, environmental protection, flame retardant and other characteristics.

Fiberglass board is a composite made of epoxy resin with Filler and fiberglass.

Main technical characteristics and application of FR4 light plate: Stable electrical insulation performance, good flatness, smooth surface, no pit, thickness tolerance exceeds the standard, suitable for high performance electronic insulation requirements of products, such as FPC reinforcement board, tin furnace high temperature resistant board, carbon diaphragm, precision star wheel, PCB test rack, electrical (electrical) equipment insulation partition, insulation plate, transformer insulation parts, motor insulation parts, Deflection coil terminal board, electronic switch insulation board, etc

Glass fiber board is widely used in conventional electrical, electronic and digital products because of its good material characteristics. The price is higher than paper and half glass fiber, the specific price is different because of different product requirements. Glass fiber board is widely used in digital electronic products.

Because of the special advantages of glass fiber board, it is widely used in electronic manufacturers. The glass fiber board has V slot, stamp hole, bridge and other board ways.

Two, aluminum substrate (single-sided aluminum substrate, double-sided aluminum substrate), aluminum substrate mainly has excellent heat dissipation performance, suitable for LED technology, the bottom plate is aluminum.

Aluminum substrate is a kind of metal base copper-covered plate with good heat dissipation function. Generally, a single panel is composed of three layers, which are circuit layer (copper foil), insulation layer and metal base layer. For high-end use are also designed for double panels, the structure of the circuit layer, insulation layer, aluminum base, insulation layer, circuit layer. Very few applications for multilayer board, can be made of ordinary multilayer board and insulation layer, aluminum base fit.

Aluminum base board is a kind of PCB, aluminum base board is metal-based printed board, with high thermal conductivity, generally used in solar energy, LED lights and other products that need heat dissipation, but the circuit board material is aluminum, our general circuit board material is glass fiber, but because of the LED heating is larger, so the circuit board used for LED lamps is generally aluminum base board, which can conduct heat quickly. Other equipment or electrical circuit board or glass fiber board!

LED aluminum substrate is mostly used in led energy-saving lamps, led TV will also be used, mainly used in the need for heat conduction objects, because the larger the led current, the brighter the light, but afraid of high temperature, high temperature in addition to the dead lamp beads, is light decline.

Aluminum substrate,LED aluminum substrate main uses:

1. Audio equipment: input, output amplifier, balance amplifier, audio amplifier, preamplifier, power amplifier, etc.

2. Power supply equipment: switch regulator, DC/AC converter, SW regulator, etc.

3. Communication electronic equipment: high frequency amplifier 'filter electrical' sending circuit

4. Office automation equipment: motor drivers, etc.

5. Automobile: electronic regulator, igniter, power controller, etc.

6. Computer: CPU board, floppy disk drive, power device, etc.

7. Power module: converter, solid relay, rectifier bridge, etc.

8. Lamps and lighting: With the promotion of energy-saving lamps, a variety of energy-saving and gorgeous LED lights are popular in the market, and aluminum substrate applied in LED lights has also begun to be used on a large scale.