Mini Rework Stencils, designed and manufactured by Tecan, guarantee accurate and repeatable printed results for components such as, QFP’s, PLCC’s, BGA’s, uBGA’s and SM connectors when replaced during PCB rework operations.

Rework Stencils mimic the footprints and aperture sizes corresponding to both the device and the major stencil used in the original production. In combination with a rework station, alignment is simple, resulting in a controlled ‘right first time process’.
Designed to ensure optimum reliability and consistent printed results, their strength and rigidity ensure positive gasketting with the PCB surface. Their minimum footprints can be used in all situations, especially where the density of components offers the smallest access area.

In operation the stencil is accurately aligned over the ‘cleaned’ pads and the paste is deposited using the tailored mini squeegee blade provided. The stencil design is optimised to deliver the required volume of paste, with the folded edges providing effective paste containment, the replacement part is then placed and locally reflowed.

The stencils are supplied as complete assemblies with all necessary interfaces to suit existing rework stations and systems. Accurately folded edges and run-on/run-off areas ensure effective paste roll without causing interference with other components on the populated PCB.

Other rework options from the company include dip-transfer plates for BGA fluxing, ‘nest’ plates for direct printing onto BGA terminations and thicker stencils for re-balling BGA’s. Reflow reflector shields are also available to protect susceptible neighbouring components from thermal shock. The stainless steel stencils are precision etched to ensure the accuracy necessary for the finest apertures sizes on today’s devices.

A comprehensive explanatory CD, covering all rework requirements and solutions is available on request to qualifying engineers.

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