First: What is the maximum temperature resistance of the pcb circuit board, and what is the temperature resistance time?

The maximum temperature resistance of the pcb board is 300 degrees, 5-10 seconds. When the lead-free wave soldering is about 260, the lead is 240 degrees.

Second: heat resistance test

Pre-preparation: circuit board production board

1. Sampling 10*10cm substrate (or plywood, finished board) 5pcs; "(with copper substrate without blistering delamination)

Substrate: 10cycle or more

Plywood: LOW CTE 150 10cycle or more

HTg material 10cycle or more

Normal material 5cycle or more

Finished board:

LOW CTE 150 5cycle or more

HTG material 5cycle or more

Normal material 3cycle or more"

2. Set the temperature of the tin furnace to 288 +/- 5 degrees, and use the contact temperature measurement to correct;

3, first use a soft brush to soak the flux, apply to the surface of the board, and then use the tongs to take the test board into the tin furnace, after 10 seconds, take out and cool to room temperature, visually see if there is a bubble burst, this is 1cycle ;

4. If the problem of foaming and blasting is found by visual inspection, stop the immersion tin analysis and start the explosion point f/m immediately. If there is no problem, continue the cycle until the blasting plate, with 20 times as the end point;

5, the bubble needs to be sliced analysis, understand the source of the initiation point, and take pictures.