Introduction: Reworking a BGA Using a Stay in Place Stencil
BGA rework stencil featuring a stay in place feature to simplify the process and repair damaged solder mask. It improves first pass yields and repairs solder mask that may have been damaged by the device. See more information about BGA rework at back link. Here this instructable will describe the proper method for placing a StencilQuik (TM) rework stencil. The StencilQuik(TM) stay-in-place feature greatly simplifies the rework process while providing a more reliable connection.
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- New device to be placed
- Solder paste
- Isopropyl alcohol and lint-free wipes for cleaning the stencil
- Miniature Squeegee
- StencilQuik Stencil
- Reflow source
Step 1: Clean the Site
After removing the original part, prepare the site after wicking the site clean with isopropyl alcohol and a lint free wipe to get rid of any contaminants .
Step 2: Peel the Adhesive Backing Off the Stencil
Peel the adhesive backing off of the stencil.
Step 3: Place the Stencil
To place the stencil, align the apertures in the stencil with the pads on the board. Starting at one corner, place the stencil and slowly work towards the opposite corner. Smooth down the stencil afterwards.
Step 4: Apply Solder Paste
After allowing the solder paste to come to room temperature, stir the paste and apply it to the stencil with a miniature squeegee. Hold the squeegee at a forty-five degree angle to the board and apply the paste using enough force to ensure that sufficient solder is compressed into the apertures. The nice thing is that this stencil allows you to go back and forth numerous times in order to insure that all of the apertures are filled up.
Step 5: Remove Edges, Clean, and Inspect
Remove the tape edges around the stencil and wipe off any excess paste from the board with a lint free wipe. Afterwards, inspect the stencil to ensure that solder is distributed evenly and consistently in all of the apertures.
Step 6: Place the Device
Align the device to the stencil and press down on it lightly to ensure that the part lays flat. You will feel the BGA slide into place when it is aligned.
Step 7: Reflow, Clean, and Inspect
Reflow the part. Afterwards, clean it with isopropyl alcohol and a lint free cloth. Inspect the part for any errors.