Electrical Contact

Abstract

A free-standing, guided entry metallic one-piece female spring contact is provided which has particular utility in conjunction with integrated circuits. The contact is intended to be mounted, together with a multiplicity of similar contacts, in plated holes in a printed circuit board. The contact is formed to define two opposing spring leaves which receive the pins or tab-like male contacts, for example, of an integrated circuit device. The contact also defines an integral apertured crown over the spring leaves which serves as a guide for the male contact.

Parent Case Text

This application is a continuation application based on Ser. No. 174,401, filed Aug. 24, 1971 and entitled "Electrical Contact."

Description

BACKGROUND OF THE INVENTION

Integrated circuits are being used in increasing numbers in electronic equipment. Integrated circuits usually take the form of a block in which the integrated electronic circuitry and active electronic elements are located, and contacts protruding outwardly from the block. These contacts usually have a pin or tab-like configuration.

As mentioned above, the contacts of the present invention may be conveniently mounted in plated holes in the circuit board on which the integrated circuit is to be mounted, and the contacts constructed in accordance with the invention provide female connectors for the male contacts from the integrated circuit. The contacts not only establish electrical connection between the integrated circuit and the external circuitry of the circuit board, but they also serve as a means for supporting and mounting the integrated circuit on the circuit board.

A feature of the contact of the invention, as previously pointed out, is the provision of a guide for each contact. This guide serves to direct the entry of the male contacts of the integrated circuit block between the corresponding spring leaves of the contact, and into electrical engagement with the contact.

The construction of the contact of the present invention, as will be described, is such that the contact may be installed economically in a circuit board using semi-automatic insertion equipment. When the contact is installed, its contour provides a gas-tight, reliable solderless joint to the printed circuit board. The spring leaves formed by the contact of the invention provide a low-resistance, high-pressure engagement with the integrated circuit contact. Moreover, the guided-entry element of the contact of the invention safeguards the contact and assures the most reliable interface between the integrated circuit and the contact.

DRAWING DESCRIPTION

The single FIGURE is a perspective representation of a contact constructed in accordance with the invention as received in a plated hole in a usual printed circuit board.

DETAILED DESCRIPTION

As shown in the drawing, the contact constructed in accordance with the invention is received in a plated hole 10 in a printed circuit board 12. It will be understood that a multiplicity of similar contacts may be so received, and arranged in parallel rows, so as to receive the pin-like or tab-like contacts of an associated integrated circuit module. The contact itself, as shown in the drawing, is designated generally as 14, and it comprises an integral socket portion 16, and a shank portion 18, having a one piece, integral, off-set construction.

The shank 18 of the contact in the illustrated embodiment is square in cross-section and designed for wire-wrap applications. At a point directly above the square shank 18, a tapered section 20 acts as a wedge when the contact is inserted in the plated hole 10 in the printed circuit board 12. A gas-tight reliable joint is thereby formed at the interface of the four corners of the wedge-shaped portion 25 of the contact and the electrically conductive bore of the hole 10. In this way, a gas-tight, reliable, solderless connection is made between the contact 14 and the circuitry on the printed circuit board 12.

Directly above the wedge-shaped portion 20, the contact 14 is formed into a pair of opposing strips 22 and 24, these strips being folded back on themselves, as shown in the drawing, to form two opposing spring leaves. The leaves receive the pin-like or tab-like contact of the integrated circuit, or other module, which makes intimate electrical engagement with the two leaves 22 and 24, and which is firmly supported between the leaves.

A further strip-like portion 26 is formed integral with the shank 18 adjacent to the wedge-like portion 20, the latter strip-like portion of the contact extending up adjacent to the leaves 22 and 24, and having a bent-over crown section extending over the top of the leaves. The crown section has an opening which, in the illustrated embodiment is rectangular and indented as shown. The indentations serve to further guide the male tab of the integrated circuit module. This opening also serves as a rigid support for the contact thereby preventing abuse of the spring leaves 22 and 24 below the contact, and insuring a well centered interface between the integrated circuit module and the contact.

The contact 14 may be composed of beryllium copper, or other appropriate resilient electrically conductive material.

The invention provides, therefore, an improved one-piece guided entry free-standing electrical contact which serves as an improved and positive electrical connector for an integrated circuit module, or the like. The contact of the invention not only is relatively simple and inexpensive to construct, but also may be inserted easily and by semi-automatic insertion machines into the printed circuit boards.

It will be appreciated that although a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the following claims to cover such embodiments as fall within the spirit and scope of the invention.

Claims

I claim:

1. An electrical contact adapted to be supported on a circuit board having a bore, comprising

a. an upright, elongated shank having main extent freely receivable through said bore to project at one side of said board, said shank main extent having a main polygonal cross section to define corners for engagement with the turns of a wire wrapping,

b. the shank also having a relatively short portion above said main extent, said short portion having a polygonal cross section larger than the cross section of the shank main extent and defining corners spaced apart to tightly engage said bore when said short portion extends therein, there being at least two downwardly tapering walls on the shank for merging said short portion thereof with said main extent,

c. an L-shaped flat metallic strip having an elongated portion extending upwardly from the shank and a laterally forwardly extending crown portion defining a central guide opening, and

d. a pair of like, V-shaped flat metallic spring strips each having an outer leg extending upwardly toward the crown portion and an inner leg extending downwardly away from the crown portion, and said legs merging at a sharp fold in relatively close proximity to said crown, said outer legs having rearwardly projecting lower extensions joined to said elongated portion of the L-shaped strip near said short portion of the shank, and said inner legs tapering downwardly and toward one another between said outer legs to define closely spaced free ends located closer to said extensions than to said crown for contacting a pin guidably inserted through the crown at the opposite side of said board and into position between said free ends.

2. The contact of claim 1 and including said circuit board defining said bore engaged by said corners of the shank short portion, said outer leg lower extensions having lower edges located adjacent said board.

3. The contact of claim 1 wherein said central guide open of the crown has rectangular configuration, the crown top surface extent bounding said opening tapering downwardly to guide said pin inserted downwardly through said opening.