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Online probe cleaning method

IP.com Disclosure Number: IPCOM000004911D
Publication Date: 2001-Jul-11
Document File: 3 page(s) / 57K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method of cleaning probes online. Benefits include reduced test time, extended probecard longevity, and improved yield.

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This is the abbreviated version, containing approximately 100% of the total text.

Online probe cleaning method

Disclosed is a method of cleaning probes online. Benefits include reduced test time, extended probecard longevity, and improved yield.

The disclosed method addresses the problem of providing very low contact resistance to preserve test signal integrity during a wafer sort test.

During sort, a wafer is loaded on a Z stage. This stage aligns the die on the wafer with the stationary probe array. After alignment is completed, the stage overdrives the die on the water into the probe array to insure that good electrical contact is achieved. The conventional process is described as in the following sequence (see Figure 1):

1. Prober loads wafer on Z stage

2. Z stage aligns wafer to probe array

3. Z stage overdrives wafer into probe array

4. Testing starts after a specified amount of time

The disclosed method adds a controlled lateral movement of the stage after the last step to generate a scrub between the probe tips and the probed devices. This scrub cleans the oxides build up on the probe tips. The new process is described as in the following sequence:

1. Prober loads wafer on Z stage

2. Z stage aligns wafer to probe array

3. Z stage overdrives water into probe array

4. Z stage moves laterally after a specified amount of time to scrub device under test on probe tips

5. Testing starts after a specified amount of time

The conventional method (see Figure 2) generates the scrub at contact with the test device through the geometry designed into the probe spring. Cantilever probe spring translates vertical tip motion into lateral tip motion so the scrub is generated as the tip is overdriven into the probed device.

The disclosed method (see Figure 3) uses a secondary device to generate the lateral tip scrub for spring designs that do not have an inherent vertical-lateral tip translation motion such as a vertical spring.

Fig. 1

Fig. 2

Fig. 3

Disclosed anonymously