IMAGE ANALYSIS OF STENCILS
With lead-free materials, lack of spread during the reflow process requires a tighter process window, making the aperture position on the stencil and the placement of the solder on the pad more critical. Tighter control of registration from Gerber data to stencil to board is mandatory to maximize pad coverage.
Experience has shown that the only way to find even the slightest deviation from position and size is with an automated optical inspection system.
Using LPKF ScanCheck technology, MicroScreen does 100% AOI verification of all laser cut stencils. We firmly believe that today’s technology for the manufacture of stencils requires an AOI system such as the ScanCheck.
Image analysis of stencils is critical given the growing trend towards boards heavily populated with small and tightly spaced components. However, with the switch to lead free stencils, it is even more important that stencils be verified using sophisticated inspection systems.
Our equipment automatically does a comparative inspection against original Gerber data. We use the system at 12,000 dpi to 100% inspect every stencil for aperture presence/absence and blockage.
Every aperture is then checked for size and positional accuracy. ScanCheck’s linear scanning technology captures the entire board area up to 18.5” x 26” in one pass.