Browse Prior Art Database

Electrical Probes

IP.com Disclosure Number: IPCOM000094038D
Original Publication Date: 1966-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 3 page(s) / 60K

Publishing Venue

IBM

Related People

Graner, FL: AUTHOR

Abstract

These electrical probes are suitable for making electrical resistivity measurements on a planar surface of microminiature circuitry. Requirements of the probes are: many contact points; all points to make contact on a very small sampling area, e.g., 0.032 in. x 0.032 in.; very small spacing between points, e.g., 0.005 in.; very close tolerances, e.g., 0.0005 in. Further, each probe is rugged enough to permit precision measurement during numerous cycles of operation. The contact area can be viewed under a microscope while contacts are being positioned on a test surface.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Page 1 of 3

Electrical Probes

These electrical probes are suitable for making electrical resistivity measurements on a planar surface of microminiature circuitry. Requirements of the probes are: many contact points; all points to make contact on a very small sampling area, e.g., 0.032 in. x 0.032 in.; very small spacing between points, e.g., 0.005 in.; very close tolerances, e.g., 0.0005 in. Further, each probe is rugged enough to permit precision measurement during numerous cycles of operation. The contact area can be viewed under a microscope while contacts are being positioned on a test surface.

The probes have relatively large, rigid, strong contact elements each with integral point, body, and connecting arm. The contact elements are mounted in V-grooves or slots in a supporting and guiding member. The contacts move along the V-grooves or slots in a supporting and guiding member. The contacts move along the V-grooves or slots in a direction perpendicular to the sampling area plane. The points are individually adjustable in this direction so that they simultaneously make contact on the sampling area plane. Flat surfaces on the contact element bodies engage the sides of the V-grooves or slots to prevent rotation of the contact elements and position them. Contact points are at relatively large distances from the relatively large contact bodies and are joined to them by integral arms whose sections become small as they approach the points. This makes possible the location of many points closely spaced in a very small sampling area.

The contact points are machined to precision tolerances in relation to the contact bodies and to the V-grooves or slots which position the contact elements so as to make contact in a selected pattern on the sampling area. In drawing A there is a four-point probe. In drawing B there is a sectional view of a twelve- point probe. The probe of drawing B is particularly described, corresponding elements in the probe of drawing A being similarly identified. In drawing B contact elements radiate radially from the center of a circle which encompasses the contact supporting element. All the contact points are within a very small area surrounding the center. Provision is made for the sampling area and the contact points to be viewed by a microscope through an opening in the center of the supporting element.

The probe of drawing B, of which an enlarged fragmentary bottom view of the probe is shown in drawing C illustrating the lateral positioning of a contact member, has a supporting and guiding member 1 for contact members 2. Member I has TEFLON* coated axial guiding ways 1A for each member 2 to position it accurately and prevent rotation but still permit axial movement. Member 1 can be made of electrically insulating material. If such is the case, a low friction and electrically insulating material TEFLON 1B or other similar insulation, is provided between members 2 and member 1.

An urging member 3, such as a spring or othe...