The Basic Standards of FPC Testing And Methods To Improve The Efficiency of FPC Testing

As electronic products such as mobile phones and tablets are gradually becoming thinner and lighter, the demand for FPC has also increased. Due to its ultra-thin, high density, high reliability, and bending resistance, in electronic product, FPC is mainly used in circuit connection, it is one of the important materials for the thin design of electronic products. FPC can save redundant cables, reduce the volume and weight of the product, has high flexibility and can be assembled in a limited space. In the FPC manufacturing process, FPC testing is indispensable. In order to improve the good yield of FPC products and prevent defective products from entering the market, testing can be conducted from the three aspects of FPC appearance, process and performance, which will help to find existing defects of FPC in time, and make improvements based on the defects, thereby increasing the good yield of FPC products and reducing costs.

FPC testing can use shrapnel micro-needle modules as connection modules to achieve the purpose of improving test efficiency. The shrapnel micro-needle module is a one-piece shrapnel design, which is very strong adaptable in the field of small pitches. It can cope with the pitch value between 0.15mm-0.4mm and has stable and reliable performance. It will not jam or break the needle, can maintain long-term connection and current transmission. When transmitting current, the shrapnel micro-needle module can pass a large current of 50A, and the current flows in the same material body, with stable over current, constant voltage, no current attenuation, and good connection function. Its service life can reach an average of more than 20w times. It is a long-life module. It does not need to be replaced frequently during use, and its performance is very stable. In the FPC test, it not only has high adaptability, but also high test efficiency.

The basic standards of FPC testing can be divided into the following points:

1. The appearance of the FPC substrate film: check the appearance of the substrate for creases, wrinkles, bumps and foreign matter, etc., which will affect the performance of the FPC.

2. The appearance of the FPC covering layer: the surface of the appearance should not have defects such as bumps, wrinkles, creases, delamination, etc., any of them belong to the scope of defective products.

3. The deviation of the FPC connecting plate and the covering layer: the standard is that the deviation is ±0.3mm or less when the external dimension is less than 100mm, and the allowable deviation is less than ±0.3% of the external dimension when the external dimension is more than 100mm.

4. Missing coating of FPC coating: It needs to be tested in accordance with the solderability requirements of FPC. For the missing part of the coating, tin should not be stuck on the conductor.

5. Discoloration under the conductor of the FPC covering layer: The FPC is required to have the performance requirements of voltage resistance, welding resistance, and bending resistance after passing the humidity resistance test at a temperature of 40°C, a humidity of 90%, and a 96-hour period.

6. The seepage of FPC adhesive and covering layer: The seepage degree should be less than 0.2mm. At the connecting plate, the deviation of FPC covering layer and punching should reach the standard of minimum ring width g≥0.05mm.

7. FPC electroplating bonding: It is required that the FPC electroplating layer cannot be delamination, and the poor bonding of the plating layer cannot destroy the reliability of the FPC contact area.

Testing is the best way to control the good yield of FPC products. The shrapnel micro-needle module is the best aid for FPC testing. Mastering the basic standards of FPC testing is conducive to the stability of FPC testing, and it can also improve the testing efficiency of FPC, so that FPC give full play to the best performance.