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GAISER TOOL COMPANY

Gaiser Tool Company - Home Page

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GAISER SMALL WIRE WEDGE INFORMATION   

8. HOLE DIAMETER

The general design rule for the hole diameter (H) is: H = 2 x Wire Diameter (WD). For gold wire, the H can be smaller than 2 x WD so as to improve the

wire guiding capabilities. For aluminum wire, reducing the H to WD ratio can lead to excessive build-up in the hole area and possible wire scratching.

GTC Figure 45-26

Figure 26. This scratched wire can be due to:

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The wire being directed to the hole of the wedge at an incorrect angle

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A rough edge in the hole

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The hole being too small for WD

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The wire coming off the spool already scratched

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The wire clamp not being adjusted correctly

If the wire is intentionally being fed to the wedge at a different angle than the wire feed angle of the wedge, wire scratching may occur. It can be minimized by special polishing of the countersink area (see Wedge Finish below.) In many cases, the H dimension can

be maintained to the H = 2 x WD ratio and wire guiding can be improved by using a maxiguide wedge. Also, all Gaiser wedges are manufactured with a polished hole. This enhances wire feeding and reduces the chance of wire scratching.

GTC Figure 45-27

Figure 27. This photo shows a side view of a V-notch wedge. Note the relief notch between the bond foot and the wire feed hole.

 

GTC Figure 45-28

Figure 28. This photo shows the bottom view of the tool in Figure 27. The bond foot is in focus with the FR to the left. The dark circle in the center of the wedge is the hole.

 

GTC Figure 45-29

Figure 29. Pictured here is a side view of a maxiguide wedge. Note the lack of the relief notch from this view.

 

GTC Figure 46-30

Figure 30. This photo shows the bottom view of the maxiguide wedge. The side walls guide the wire beneath the bond foot.

 

GTC Figure 46-31 and 46-32

Figure 31 & 32. A comparison of wire guiding between a V-notch wedge and a maxiguide wedge is shown above. The V-notch wedge provides less wire control. Quite often, the wire exhibits memory retention from being wrapped on a spool. This causes the wire to want to feed to one side after exiting the hole. The maxiguide wedge helps align the wire under the center of the bond foot.

 

A design that provides enhanced wire guiding and looping characteristics is the oval hole.  

GTC Figure 46-33

Figure 33. Pictured above is an oval hold wedge. The oval hole design has a hole width that is narrower than the hole height. This hole design provides optimum wire placement control while still providing good looping. 

 

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Last modified: 2017-11-09