Lump detection of solder paste used in printed circuit board manufacture

Lump detection of solder paste used in printed circuit board manufacture

Solder paste is a colloid that is applied to hybrid circuit boards, used to attach and link surface mounted components on the board. The quality of the joints is dictated by the surface characteristics of the dried paste. Poor performance results can be traced back to irregularities in the surface of the paste that are caused by large or irregular lumps in the matrix.

As a result of this effect quality assurance of the composition and topography of the paste, pre and post application, is a very important parameter. The measurement task is to identify particle size and distribution. However, the question arises how to differentiate one lump from another on what is effectively already a lumpy surface.

The specification for the paste is that it must not have a certain number of lumps with a defined height or diameter within a square centimeter.
The optical 3D measurement device InfiniteFocus meets all necessary requirements that are necessary for a robust and accurate surface inspection and numerical quantification of lumps. As the only measurement device which simultaneously captures the entire surface topographic information in combination with its true color information, InfiniteFocus enables the easy identification of a lump.
All out of range features are fully automatically identified and measured as the system automatically scans the selected region also over large field of views.

From these results the user can also perform accurate surface measurement of profile, roughness, area and volume enabling detailed and numerical verification of the lumps and their relation to the sub surface matrix.