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Wafer Ball Placement Tooling
 BGA ball placement at the wafer level has gained popularity and acceptance in recent years. Ball Placement Delivery Systems vary in sophistication from a simple brush sweeping balls into apertures in the Stencil Placement Tool to devoted stencil printing machines with a self-contaned ball delivery head. As the delivery system sweeps over the Ball Placement Stencil, BGA balls fill the apertures and are transferred to the wafer when the wafer separates from the Stencil Placement Tool. Normally the Ball Placement Stencil is in direct contact with the wafer during the ball delivery process. Pads on the wafer have tacky flux to hold the balls in place prior and during the reflow process. A photoresist layer is imaged and developed on the back side of the Ball Placement Stencil Tool to prevent contact with the tacky flux during the ball delivery cycle.
Ball Size |
Aperture Size |
Stencil Thickness |
Resist Build-Up Thickness |
| 12 |
14.5 |
8 |
4 |
| 20 |
23 |
14 |
6 |
| 25 |
27 |
19 |
6 |
| 30 |
34 |
21 |
9 |
| 35 |
40 |
23 |
12 |
Note: All dimensions are in mils (0.001") |
Download product sheet.
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