Flexible Circuit Board Testing Standard

Common FPC flexible circuit board test standards are as follows:

1. Appearance of substrate film surface: The appearance of the substrate film surface where the conductor does not exist allows the defect range to be listed in the table. No other irregularities, creases, wrinkles and attached foreign objects that affect the use are allowed.

2. Appearance of cover layer: Defects of the cover film and the appearance of the cover coating: The allowable range is shown in the figure below, and there are no irregularities, creases, wrinkles and delamination that affect the use. 

3, the deviation of the connecting plate and the cover layer: As shown in the figure below, the deviation e of the connection plate and the cover layer is allowed to be ± 0.3mm or less when the outer dimension is less than 100mm, and ± 0.3% or less when the outer dimension is 100mm or more.

4. Infiltration of adhesive and covering coating: As shown in the figure below, the degree of bleeding of the adhesive and cover coating f should be less than 0.2mm. But at the connection disc, plus the deviation of the cover layer and the deviation of the punching, the minimum ring width g≥0.05mm must be met.

5. Color change: The conductor under the cover layer is discolored. After the humidity resistance test of 40 ° C, 90% humidity and 96 hours, it must still meet the requirements of voltage resistance, bending resistance, bending resistance and welding resistance.

6. Missing coating of the coating: As shown in the figure below, the leaky coating of the coating layer is tested according to the solderability requirements. The conductor of the leaky coating portion of the coating layer should not be covered with tin.

7. Poor electroplating combination: The plating layer is not allowed to be delaminated, as shown in the figure below, the width W1, length L of the poor bonding of the plating layer, the length L, and the width W of the conductor after processing, and the poor bonding of the plating layer should not damage the reliability of the contact area.

In the production process of flexible circuit board FPC, the test of flexible circuit board is a crucial link. Without the tested flexible circuit board, the quality cannot be guaranteed and the pass rate is low. If the circuit board is the heart of an electronic product, the flexible circuit board is undoubtedly the flexible heart and blood vessel of the electronic product. If no tested flexible circuit boards flow into the market, it will have an important impact on the function of terminal electronic products.