Publish Time: 2022-02-17 Origin: Site
PCBA is the abbreviation of Printed Circuit Board + Assembly, also called PCB Assembly.
After the PCB goes through the processes of SMT, DIP plug-in, PCBA testing, quality inspection and assembly, a finished product is formed, referred to as PCBA. Almost all electronic products, such as smartphones, computers, TV, LED, etc., require PCBA boards.
PCBA is to process an empty PCB board through a series of processes, and finally process it into an electronic product that can be used by users. In the process of production, one link is linked to the other, and which link has a quality problem, it will have a great impact on the quality of the product.
The basic equipment required for PCBA production includes Stencil Printing Machine, Pick and Place Machine, Reflow Oven, Inspection Equipment, Wave Soldering Machine, SMT Cleaning Machine, ICT, FCT, etc.
PCBA processing plants of different scales will be equipped with different equipment.
The main production equipment of PCBA is as follows:
1. Stencil Printing Machine
The working principle of the solder paste printing machine is: the left and right scrapers print the solder paste on the PCB through the stencil.
2. Pick and Place Machine
Pick and Place Machine, also known as the Surface Mount System, is a device that accurately places components on the PCB pads by moving the placement head in the production line.
3. Reflow Oven
After reflow soldering heats the air or nitrogen to a high enough temperature, blow it to the circuit board with the components attached, so that the solder on both sides of the components is melted and bonded to the motherboard.
4. Inspection Equipment
There are roughly three types of testing equipment on the market, AOI(Automatic Optical Inspection), SPI(Solder Paste Inspection), and AXI(Automatic X-Ray Inspection).
The machine automatically scans the PCB through the camera, detects the defects on the PCB, and marks the defects through the display.
5. Wave Soldering Machine
Wave soldering is to make the soldering surface of the plug-in board directly contact with the high temperature liquid tin to achieve the purpose of soldering.
And a special device makes the liquid tin form a wave-like phenomenon, so it is called "wave soldering machine".
6. SMT Cleaning Machine
The cleaning machine is used to clean the PCBA board, which can remove the residue of the board after soldering.
7. ICT
ICT Test mainly uses the test probes to contact the test points of the PCB layout to detect the open circuit, short circuit, and welding of all parts of the PCBA.
8. FCT
FCT It refers to the test of the target board to measure whether the response of the output terminal meets the requirements.
The PCBA production process can be divided into several major processes, SMT→ DIP → PCBA testing → finished product assembly.
1. SMT
SMT production line can be divided into fully automatic production line and semi-automatic production line according to the degree of automation.
The most common fully automatic SMT production lines include SMT Loader + Stencil Printing Machine + Pick and Place machine + Conveyor + Reflow Oven + AOI + Unloader.
2. DIP
The process of DIP plug-in processing is: plug-in → wave soldering → foot cutting → post-soldering processing → cleaning → quality inspection.
3. PCBA test
PCBA testing is the most critical quality control link in the entire PCBA processing process. It is necessary to strictly follow the PCBA test standards and test the test points of the circuit board according to the customer's test plan (Test Plan).
4. Finished product assembly
Assemble the tested PCBA board to the shell, and then test it.
Printed circuit boards are bridges that carry electronic components and connect circuits, and are irreplaceable in the entire electronic product.
With the advancement of cloud technology, 5G, big data, artificial intelligence, Industry 4.0, Internet of Things and other technologies, the PCB industry, as the fundamental force of the electronics industry chain, has grown steadily in terms of output value.