How To Use Checksheets to Identify Concentration of Defects On a PCB

A checksheet is a form used to identify, gather organize, and evaluate data. A well-designed checksheet can eliminate confusion, enhance accuracy, and reduce time needed to take data.

There are two types of checksheets:

1. Recording check sheet. This is used for recording data on types of defects. The types should be listed in categories, and a mark made each time a defect is found in the sample. It is important not to collect too many types of defects.

It is difficult to properly train production operators to distinguish between very similarly worded types of defects, even if photographs and other methods of graphically presenting them are used. Count the total number of checks for each defect.

2. Location check sheet. This is used to collect the location of the defects, and list how often they occur. This technique is useful to identify concentration of defects on a printed circuit board (PCB).

Other information should be included when available, such as date, part number, lot number, supplier name, supplier date code, area location, etc. Using automatic means of collecting and categorizing data, such as bar code readers and scanners, can speed up the recording of data. The defects data categories could be arranged in bar code format so that an operator with a bar code wand could enter all the data without writing down any information by hand.