Test Background
The substrate material for flexible printed circuit boards (FPC) is mainly composed of flexible insulating base film and metal foil. The commonly used FPC substrate material uses adhesive to bond the insulating base film and metal foil. A typical flexible substrate material is flexible copper clad laminate (FCCL), which is also called flexible copper clad laminate. The flexible copper-clad foil thermal shock resistance test can evaluate the thermal shock resistance of flexible copper-clad foil materials.
Zhongke Testing Reliability Experiment Center has the reliability performance of various flexible copper-clad foils and provides professional thermal shock resistance testing services for flexible copper-clad foils.
Scope of tests
Classified by dielectric substrate: polyester film flexible copper clad laminate and polyimide film flexible copper clad laminate;
Classified by flame retardant performance: flame retardant and non-flame retardant;
Classified by manufacturing process methods: two-layer method and three-layer method to manufacture flexible copper-clad laminates.
Currently, the flexible copper-clad laminates used in most cases are flame-retardant and non-flame-retardant flexible copper-clad laminates manufactured using polyester and polyimide films as dielectric films using a three-layer method.
Test method
The thermal stress test procedure is as follows:
a) Clean the copper foil surface of the sample, and process the sample in an air circulation oven at 105°C ± 2°C for 60 minutes; for flexible polyimide copper-clad foil boards, treat the sample in an air circulation oven at 135°C ± 10°C for 60 minutes, and then immediately hang it in a room temperature drying oven to cool to room temperature.
b) Nail the sample to the window position of the float soldering fixture shown in Figure 16 with a thumbtack or pin, with the copper foil side facing down.
c) The temperature of the tin bath can be selected from 260 ℃ ± 5 ℃, 288 ℃ ± 5 ℃ or the test temperature specified in the product standard.
d) After the tin bath temperature stabilizes, float the sample on the clean molten solder surface for 10 s. Make sure that the copper foil surface of the sample is flat and in contact with the solder surface.
e) Remove the sample and carefully remove excess solder and clean the surface of the sample. Use normal vision or corrected 1.0/1.0 vision to check whether the sample has blistering, delamination, wrinkles, shrinkage, distortion, or melting.
Test standard:
GB/T 13557-2017 Test method for flexible copper-clad foil materials for printed circuits
GB/T 2036-1994 Printed circuit terminology
GB/T 4722-2017 Test method for rigid copper-clad laminates for printed circuits
GB/T 5169.22 Fire hazard test for electrical and electronic products Part 22: Test flame 50W flame Device and confirmation test method
