PCBA process as the name suggests is the assembly of some special processes and links. Now LHD-TECH will introduce the PCBA process for you.
After preparing the PCB boards and the components required in the BOMLIST, all the information is organized and the quality of the PCBs and the quality and quantity of the components are verified.
Check all relevant details according to the Gerber File, BOM List, Pick and Place, Schematic, and Drill file. After confirming that there is no error, the PCB and components can be assembled.
First, the SMT chip processing link
SMT chip processing process is: solder paste mixing → solder paste printing → SPI → mounting → reflow soldering → AOI → rework
- Solder paste mixing The solder paste from the refrigerator after thawing, using hand or machine for mixing, to be suitable for printing and welding.
- Solder paste printing Place the solder paste on the stencil, through the squeegee and leak the solder paste printed on the PCB pads.
- SPI SPI that is, solder paste thickness detector, can detect the solder paste printing, and play a role in controlling the effect of solder paste printing.
- Mounting
- Reflow soldering will be mounted on the PCB board over the reflow soldering, after the role of high temperature inside, so that the paste heats into liquid, and finally cooled and solidified to complete the welding.
- AOI AOI that is, automatic optical inspection, through the scanning of the PCB board welding effect can be detected, can detect the board is bad.
- Rework AOI or manually detect bad for rework.
Second, DIP plug-in processing links
DIP plug-in processing processes are plug-in → wave soldering → cut foot → post-weld processing → wash board → quality control
- Plug-in materials for the processing of pins, inserted in the PCB plate
- Wave soldering will be inserted into a good board over the wave soldering, this process will have liquid tin spray to the PCB board and finally cooled to complete the welding.
- Cut the foot of the soldered board pins that are too long need to cut the foot.
- After the soldering process use a soldering iron on the components for manual soldering.
- Wash the board After wave soldering, the board will be relatively dirty, need to use the washboard water and washboard tank for cleaning, or the use of machines for cleaning.
- Quality inspection PCB board for inspection, unqualified products need to be reworked, and qualified products to enter the next process.
Third, the PCBA test
PCBA tests can be divided into ICT tests, FCT tests, aging tests, vibration tests, etc.
The process of PCBA testing requires strict operability and control, as well as high technology, requiring the use of precision equipment to test all processes, welding, functionality, and connectivity. In some cases, testing needs to be carried out according to the testing method requested by the customer, while the FCT test is the input and output parameters of the PCBA board to test to see whether it meets the requirements.
Fourth, PCBA three anti-coating
PCBA’s three anti-coating process steps are: painting A surface → surface drying → painting B surface → room temperature curing 5. spray thickness: spray thickness of: 0.1mm-0.3mm 6. All coating operations should be no less than 16 ℃ and relative humidity below 75% of the conditions. PCBA three anti-coating is still a lot of use, especially in some temperatures and humidity is a more harsh environment, PCBA coated with three anti-varnish. PCBA coated with three-proof paint has superior insulation, moisture, leakage, shock, dust, corrosion, aging, mildew, anti-part loosening and insulation corona resistance, and other properties, which can extend the storage time of the PCBA, isolate the external erosion, pollution and so on. One of the spraying methods is the industry’s most commonly used coating method.
Fifth, finished product assembly
Will be coated after the test OK PCBA board for the assembly of the shell, and then test, and finally can be shipped. PCBA production is a ring with a ring, The PCBA production process in any part of the problem will have a very big impact on the overall quality, and the need for strict control of each process. Strict management and professional staff can bring unparalleled protection for PCBA assembly, to ensure the rationality, functionality, and practicality of the product.
LHD-Tech, as an extremely professional supplier, can help you avoid these problems.
We welcome you to visit us.
