1. Project introduction:

TC temperature circulation chamber is also known as environmental test chamber, constant humidity heat test chamber, humid heat alternating test chamber or programmable constant temperature and humidity test chamber, which can accurately simulate the complex natural environment of low temperature, high temperature, high temperature and high humidity, low temperature and low humidity, and is used to test the performance of materials in various environments and test the heat, cold, dry and wet resistance of various materials. According to the JED22-A104 standard, temperature cycling (TC) subjects parts to transitions between extreme high and low temperatures. This test is performed by repeatedly exposing the part to these conditions over a predetermined number of cycles (data from the network).

Experimental Objective: To evaluate the contact yield of the interface between metals with different coefficients of thermal expansion in IC products. The method is repeated from high to low temperature by circulating the air flowing.

Test conditions:

Condition B:-55℃ to 125℃ 700/1000cycles

Condition C:-65℃ to 150℃ 500/700cycles

Failure mechanism: fracture of dielectrics, fracture of conductors and insulators, stratification of different interfaces

Reason for failure:

(1) Because the delamination of the chip surface causes ball detachment or ball damage, resulting in open circuit or intermittent open circuit

(2) Because the chip or the passivation layer on the surface of the chip is cracked, resulting in a short circuit

Improvement measures:

(1) Reduce CTE differences between EMC and chips

Reference standard: JESD22-A104