Product ICI Fail & Pin Low Life Time

Help the customer find out the reason for poor test yield

Although the pin tip was not blunted, but when analyzed through related instruments such as X-ray and FDR, it was discovered that the gold plating layer at the end of the pin had peeled off, which could easily cause ICI Fail.

Problem Description

✔Solve the abnormal user pin problem

A certain test result captured by the user:
ICI Fail occurred a total of eight times;
LINUX fail occurred a total of five times.

Test result

Problem Confirmation

1. The gold plating layer at the end of the pin is suspected of peeling due to external force.
2. Although the pin spring is at a normal value, but it seems to be declining slowly.
3. The head of the pin is suspected of changing color due to high current and high temperature.
4. The machine press did not return; it is suspected of having poor contact.
5. The contact stroke had an over-voltage of 0.38mm after calculation.(measured with actual object)
6. The SLT socket was tested manually and verified with FT and passed.

Pogo Pin Analysis

1. The gold plating layer at the end of the pin is suspected of peeling due to external force.

2. The head of the pin is suspected of changing color due to a high current and high temperature.

3. Although the pin spring is within the normal value, it seems to be declining slowly.

The maximum current value of a single pin must be confirmed in order to analyze the reason why the color change of the pin head and spring are gradually declining.

    
The pin manufacturer measured and replied that there is no reaming between the top plunger & barrel.

Current Condition of the Machine Contact

4. The machine press did not return; it is suspected of having poor contact.

Current Condition One

The gaps between the chuck and IC and base are smaller.

Current Condition Two

The gaps between the chuck and IC and

base are larger, and can easily have the concern of poor contact.

The heights measured at the two site chucks are 4.76 and 4.78

Contact Stroke Confirmation

5. It was found that the contact stroke had an over-voltage of 0.38mm after calculation. (measured with actual object)

IC colloid thickness: 2.32mm + Chuck height: 4.76mm = 7.08mm

Socket depth: 4.2mm + Base thickness:2.50mm = 6.7mm

7.08mm - 6.7mm = 0.38mm

Contact Simulation Diagram

If the IC height is a simulation diagram of the maximum value, the result is over-pressure by 0.48mm.

IC colloid thickness:2.42mm + Chuck height:4.76mm = 7.18mm

Socket depth:4.2mm + Base thickness: 2.50mm = 6.7mm

7.18mm - 6.7mm = 0.48mm

The SLT Socket Was Tested Manually and Verified With FT

6. The SLT socket was tested manually and verified with FT and passed.

The results of the manual testing and verification of the socket are as follows:

The SLT socket that has ICI Fail easily was tested manually with the FT machine and passed.