sales@ipcb.com
What is PCBA testing?
PCBA manufacturing process includes PCB board process, component procurement and inspection, SMT mount assembly, DIP insert, PCBA test and other important processes. Among them, PCBA test is the key quality control link in the whole PCBA processing process, which determines the final performance of the product.
PCBA testing refers to the test of IC burn-in, circuit on/off, current, voltage, pressure, etc. on PCBA board.
PCBA testing
PCBA production process there are many uncontrollable factors, it is difficult to ensure that the PCBA is a good product, PCBA testing is a strict control of the necessary aspects of the quality of the goods. Below to introduce the main process of PCBA testing.
PCBA mainly includes what test
PCBA test will vary according to different products and different customer requirements, generally speaking, PCBA test mainly includes ICT online test, FCT function test and aging test.
PCBA testing process
PCBA testing is generally based on the customer's test plan to develop a specific test process, the basic PCBA test process is as follows:
Programming → ICT test → FCT test → fatigue test → harsh environment → aging test
Some products also need to have: vibration test, high and low temperature test, drop test
1.Programming
After PCBA board front-end soldering process is completed, engineers begin to program the MCU in the PCBA board, so that the MCU to achieve specific functions.
2.ICT Test
ICT test mainly through the test probe contact PCBA test point to test the PCBA circuit open and short circuit and electronic components welding. ICT test mainly contains circuit on and off, voltage and current values and fluctuation curves, amplitude, noise, etc..
3.FCT Test
FCT test needs to be carried out after the IC programmed programming of the entire PCBA function of the analogous test, to find the hardware and software problems, and equipped with the necessary playing pieces of fixtures and playing pieces of test rack. FCT test can test the PCBA environment, current, voltage, pressure and other parameters, the test content is more comprehensive, can ensure that the PCBA board parameters to meet the designer's design requirements.
4.Fatigue test
Fatigue test is mainly for PCBA sampling, and carry out the function of high-frequency, long-term operation, to observe whether the failure occurs, to determine the probability of testing failures, so as to affect the working efficiency of the PCBA in electronic products.
5.Harsh environment test
Harsh environment test is mainly to expose the PCBA to extreme values of temperature, humidity, drop, splash, vibration, to obtain random sample test results, and thus deduce the reliability of the entire batch of PCBA products.
6.Aging Test
Aging test by constantly energising the PCBA, analogous to the user's use of the scene, to detect some of the defects that are not easy to find, test to ensure the stability of the product.
7.Vibration Test
For some of the PCBA with vibration test requirements, the use of professional vibration tester for long-term testing to ensure that the welding components do not have any shedding situation, PCBA sampling test ratio according to customer requirements.
8.High and low temperature test
Customers with high and low temperature testing needs, will be equipped with a professional test room for its products, and targeted to provide -40 ° C to 100 ° C and other common temperature testing services, fully analogous to the product's ambient temperature, to maximise the reliability of the product.
9.Drop Test
Drop test is to place the PCBA at a certain height for free fall to check the solidity of the PCBA soldering.
PCBA testing
PCBA testing mainly has these common methods:
1.Manual test
Manual test is to rely directly on the visual test, through the visual comparison to confirm the PCBA component mounting,this technology is very widely used.But a large number,and small components,making this method less and less applicable. And there are some functional defects are not easy to be found, data collection is not good.In this way,the need for more professional PCBA testing methods.
2.Automatic Optical Inspection (AOI)
Automatic Optical Inspection (AOI), also known as automatic visual test, carried out by a special detector,used before and after reflow,the polarity of the components to check the effect is better.Easy to follow the diagnosis, is a relatively common method, but this method is worse for short circuit identification.
3.Flying needle tester
Due to the progress in mechanical accuracy,speed and reliability, needle test in the past few years has been generally welcomed.In addition,now for the prototype (Prototype) manufacturing,low production volume manufacturing needs to have a rapid conversion,the ability to test the system without fixtures,making flying needle test become the choice.
4.Functional Test
Functional test is a specific PCBA or specific unit test method,by the special equipment to complete.Functional test mainly has the final product test (Final Product Test) and the new physical model (Hot Mock-up) two kinds.
5.Manufacturing Defect Analyser (MDA)
Manufacturing Defect Analyser test method's main advantages are lower up-front costs,high output,easy to follow the diagnosis and fast and complete short circuit and open circuit test.The disadvantages are that PCBA functional testing cannot be performed,there is usually no test coverage training,fixtures must be used,and testing costs are high.
In the PCBA playing pieces of the production process,may be due to equipment or improper operation of a variety of problems,can not guarantee that the production of products are qualified, the need to carry out PCBA testing to ensure that each product does not appear quality problems.PCBA after a series of PCBA test,the test will be qualified PCBA paste qualified labels, and finally packaged for shipment.