Solder Joint Life

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
cykec_294231
Level 1
Level 1
First like given First reply posted Welcome!

AN72845 Design Guidelines For Cypress Quad Flat No-Lead (QFN) Packaged Devices makes the following statement on page 16:

Typically, QFN-packaged devices are highly reliable when assembled on rigid PCBs when the bottom thermal pad of the QFN package is soldered to the board. When the thermal pad is soldered onto the PCB, the life of the solder joint is extended by 60 percent. For this reason, soldering the thermal pad onto the board is crucial to the reliability of the solder joints on PCBs.

Is there data available to show the 60% solder joint life improvement?  If so can you share it?  I need to show the reliability of the PSoC5 chip I am using and it would be really helpful.

Thanks,

Cyrus

0 Likes
1 Solution
carys_86
Employee
Employee

Hello Cyrus,

The 60% in the application note came from our assembly subcontractor. However, since then we did our own evaluation which confirmed the assembly subcontract's statements.

Below is a summary of the BLR evaluation we performed in August 2016 using a DFN package.

  

8LD DFN BLR Test Summary
BLR No.BM-1602-TC-005BM-1602-TC-007
Package8LD DFN8LD DFN
Dimensions5.0X6.0X0.8mm5.0X6.0X0.8mm
Lead Frame P/N4107541075
EPAD Soldered to PWBYesNo
Number of Units submitted to Stress3232
First Failure N/A854 Cycles
Number of Units Failed023
Number of cycles completed2,0001,250 (Stopped)

Regards,

Cary Stubbles

Cypress Semiconductor

Sr Staff Packaging Engr

View solution in original post

0 Likes
2 Replies
MiSt_296941
Level 4
Level 4
25 replies posted 10 replies posted 10 questions asked

Cypress?  Are you going to reply?

0 Likes
carys_86
Employee
Employee

Hello Cyrus,

The 60% in the application note came from our assembly subcontractor. However, since then we did our own evaluation which confirmed the assembly subcontract's statements.

Below is a summary of the BLR evaluation we performed in August 2016 using a DFN package.

  

8LD DFN BLR Test Summary
BLR No.BM-1602-TC-005BM-1602-TC-007
Package8LD DFN8LD DFN
Dimensions5.0X6.0X0.8mm5.0X6.0X0.8mm
Lead Frame P/N4107541075
EPAD Soldered to PWBYesNo
Number of Units submitted to Stress3232
First Failure N/A854 Cycles
Number of Units Failed023
Number of cycles completed2,0001,250 (Stopped)

Regards,

Cary Stubbles

Cypress Semiconductor

Sr Staff Packaging Engr

0 Likes