3rd week

This week, I was assigned to do a summary on time mapping of the exposed pad using Microsoft Excel. In the summary, some important points such as date, machines number, team, leadframe supplier were to be highlighted so that it could be noticed easily. The summary should be in a simple and presentable form. The reader will be easy to understand what the summary was.

On the other hand,I was given a task to do a simulation of DA ESEC report in order to find the root cause of the exposed pad. The picture shows a tilted leadframe on the middle.




The leadframe was sent to WB. One of the tilted leadframe can be auto aligned by the WB machine but the other needed manual alignment to go through the WB process. After that, the leadframe was sent for mold process. Unfortunately, there was no exposed pad found. This might not be the root cause of the exposed pad.

A 'why why analysis' is used to find the root cause of the exposed pad. First, list out all the possibilities that might cause exposed pad. Then narrow them down by carried out some simulation. After that, eliminate out all the non possible causes and then do a further investigation o the remaining possibilities.

Besides that, I was to monitored the DA ESEC machines for further confirmation if it was to cause the exposed pad problem. The time mapping summary was also updated accordingly.

There was no tilted leadframe detected in four days, but monitoring still going on. A mold engineer told me that if it was for exposed pad to happened in mold process, all the wires in the unit will be broken. This was another helpful information.

On the fifth day, another exposed pad case was discovered. Still, the DA ESEC machine did not have tilted leadframe cases. This showed that the root cause for DA process is low. A WB simulation was carried today, but in the end, no exposed pad was discovered. Other possibilities were to be looked on to find the root cause.