PCBA processing technology has three kinds of surface mount process, insert process and mixed installation process, of which the surface mount process is the SMT patch and insert process that we often hear and are most familiar with is DIP plug-in, and the mixed assembly process refers to one side of SMT mount, the other side of DIP insert process, the specific classification is as follows:
First of all, we will introduce the SMT PCB process, which is a technical process that will install components on the surface of the PCB circuit board. The SMT process is usually mounted by machine operation. The overall SMT process is roughly: Open steel mesh, printed solder paste, component mounting, SPI testing, over reflow soldering, AOI testing, washing board, test assembly of these steps, surface mounting process is now a popular PCBA processing process, and very advantageous. For example: high assembly density, small size and high production efficiency.
With the development of SMT processing technology, SMT chip processing has gradually replaced DIP plug-in processing. However, due to the large size of some electronic components in SMT PCBA production, plug-in processing has not been replaced, and still plays an important role in the electronic assembly processing process. DIP plug-in processing after the SMT processing, the general use of pipeline manual plug-in.
The main process of DIP plug-in has six steps: plug-in - wave soldering - cutting foot - post-welding processing - washing board - quality inspection.
1、Plug-in: The plug-in material is processed with pins and inserted on the PCB board
2、Wave soldering: The inserted board is welded over the wave crest, which will spray liquid tin onto the PCB board, and then cool to complete the welding.
3、Cutting foot: For welded board, its pin is too long need to be cut foot.
4、Post-welding process: manual welding of components using electric soldering iron.
5、Washing board: After wave soldering, the board will be dirty, need to use washing water and washing board trough for cleaning, or use a machine for cleaning.
6、Quality inspection: PCBA board inspection, unqualified products need to be repaired, qualified products can enter the next process.
The mixed assembly process, in popular terms, is the process combining SMT mounting and DIP plug-in, which mainly includes single-side mixed assembly and double-side mixed assembly. Single-side mixed assembly means that the patch components and plug-in components are on the same surface of the PCB. Generally, the surface mount process needs to be carried out first, and the DIP plug-in process needs to be carried out after the part that needs to be mounted is completed. The double-sided mixed packaging process refers to one side of the mounting process, the other side of the plug-in or mixed packaging process, is generally after the completion of the plug-in process.
After PCBA completes the plug-in, the next step is the PCBA test, the main test methods include ICT test, FCT test, fatigue test, simulated environment test, aging test, etc. Manufacturers need to choose different test methods according to the different requirements of products and customers
The first is ICT test: ICT test is mainly to detect the welding conditions of components, circuit on and off, voltage and current values and wave curves, amplitudes and noise.
The second is the FCT test: the FCT test requires the firing of IC program, and then the PCBA board is connected to the load, and the function of the assembling circuit boards is tested by simulating user input and output, so as to find the problems in the hardware and software, realize the joint adjustment of hardware and software, and ensure the normal manufacturing and welding of the front-end.
The third is fatigue test: the fatigue test is mainly to sample the prototype printed circuit board assembly, and at the same time simulate the high-frequency and intermittent operation of the function of the user to observe whether there is failure, such as continuously clicking the mouse for 100,000 times or turning off the LED light for 10,000 times to judge the probability of failure in the test, so as to feedback the working performance of the PCBA board in the electronic products.
The fourth is the simulated environmental test: the PCBA board is mainly exposed to the temperature, humidity, drop, splash and vibration of the limit value, and the test results of random samples are obtained, so as to infer the reliability of the entire PCBA batch of products.
The fifth, aging test: aging test is to carry out a long-term power test on the PCBA board, simulate the use of users, maintain its normal work and observe whether there is a failure, after aging test electronic products can be sold in batches.
SeekPCB focuses on high-speed PCB design technical services, research and development of prototypes and small and medium-sized batch research and development and production services. It is committed to building a first-class hardware innovation platform, accelerating the hardware innovation process of electronic products, and improving product quality. Equipped with new imported YAMAHA, automatic solder paste printing machine, 10/12 temperature zone reflux furnace, wave soldering and other high-end equipment, and equipped with AOI, 3D XRAY, 3D SPI, intelligent first piece tester, and other equipment, focus on high-quality research and development of express, small and medium-sized batch SMT , and printed circuit assembly services.