Browse Prior Art Database

Hall Effect Semiconductor Sample Mounting Techniques

IP.com Disclosure Number: IPCOM000077441D
Original Publication Date: 1972-Jul-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Philbrick, JW: AUTHOR [+4]

Abstract

The carrier concentration of a semiconductor material is often measured by the Hall effect and often requires mounting samples which are very thin and fragile, as well as odd shaped. Therefore, a suitable mount for soldering such samples is desirable especially where multiple alloy or solder contact are required.

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Hall Effect Semiconductor Sample Mounting Techniques

The carrier concentration of a semiconductor material is often measured by the Hall effect and often requires mounting samples which are very thin and fragile, as well as odd shaped. Therefore, a suitable mount for soldering such samples is desirable especially where multiple alloy or solder contact are required.

Hall effect or other multiple point measurements require making contacts at the sample perimeter. Fig. 1 illustrates a sample 1 and contacts 2. The sample mount proposed is shown in Fig. 2, consists of a piece of ceramic or other insulating material 3 with four regions of solderable material, for example, fired silver palladium paste 4 separated from each other by a narrow "cross" region. Solderable regions 4 may be connected to the electrical measuring equipment with wires, pressure contact, or by pins pressed through the insulating material and extending into or above the solderable regions 4. The sample 1 with solder balls 2 is then mounted onto the substrate by inverting the sample. The four solder balls touches or is over a separate solderable region 4. The substrate is then heated till the solder on the sample melts and makes contact to and is soldered to the substrate. By using the configuration shown on the substrate, one is assured of being able to solder to a sample of arbitrary shape, constrained in size only to being large enough that the separation between the contacts is greater than the width of the insulating region on the substrate, and small enough so that the sample will fit within the area defined by the pins.

Samples about 25-100 micrometers thick may be contacted as described above but may present certain difficult...