Reworkng a BGA Using a Stay in Place Stencil

This instructable will describe the proper method for placing a rework stencil. The stay-in-place feature greatly simplifies the rework process while providing a more reliable connection.

Materials Needed

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.