Minnesota Mining and Manufacturing Company

Martin C Ignasiak

John N Tengler

John E Hartman

Remi D Swierczek

Horst E Moll

A novel electrical connector and fixture for surface mounted leaded chip carriers, particularly for quad pack integrated circuit packages. The fixture includes a rectangular frame that supports the leads extending from the four sides of the integrated circuit package. The connector includes a plurality of contact members securely mounted in an outer housing member. The contact members have flexible contacting portions arranged for registration with the leads. Each contacting portion projects slightly from and is surrounded by an insulating wall that protects the contacting portions from touching each other when they are subjected to an axial buckling stress. The ends of the contact members opposite the contacting portions project from the outer housing member sufficiently separated for connection with other apparatus such as a test probe, electrical connector, etc. The outer housing member slides on an inner support member along an axis generally perpendicular to the IC package with which the connector is used. The inner support member includes registration pins that engage a registration index on the fixture. The outer housing member is urged towards the IC package to establish electrical contact between the leads and contact members. The connector applies force to the leads substantially perpendicular to the leads where they are supported by the fixture. A latch mechanism is provided to hold the connector engaged with the IC package.

Electrical connector and fixture for four-sided integrated circuit device

An electrical clip connector for a PLCC or the like comprises a plurality of electrical contacts for electrically connecting with respective leads of the PLCC, a main support body, and two pairs of oppositely disposed latching elements supported by the body for inward and outward movement. The latching elements are inwardly urged for engaging respective different sides of the PLCC thereby to hold the clip connector in operative position. The latching elements of one pair include lower end portions of respective levers pivotally secured to the main support body at respective opposite sides thereof, and the latching elements of the other pair include respective legs depending from the main body portion in cantilever-like fashion. Cam surfaces on the legs are engageable by a wedge-like portion of the lever arms when pivoted to force the legs outwardly in a direction generally parallel to the pivot axes of the lever arms.

Test clip for PLCC

A connector for making self-retaining, disconnectable electrical contacts to each of the leads of a surface mount leaded chip carrier disposed in a socket includes a plurality of contact members arranged geometrically similarly to the carrier leads. Each contact member includes a coupling portion for establishing a connection to an external device, a mounting portion mounted in a non-electrically conducting body and a blade-like contacting portion for insertion between a carrier lead and a socket contact finger resiliently bearing on the carrier lead. The non-conducting body slidably engages an insulating anvil that bears on the carrier to hold it in position in the socket when the contacting portion blades are withdrawn from between the carrier leads and socket contact fingers. A collar extending from the anvil includes a hole closely surrounding each blade to guard against excessive bending of the blades.

Electrical connector for surface mount chip carrier installed in a socket

A retainer post for tightly engaging a printed circuit board employing surface mounted technology. The retainer post has a hollow neck portion for insertion in a hole in a printed circuit board, an adjoining shoulder section for engaging the surface of the printed circuit board and, preferably, a retaining means for retaining said post in the printed circuit board. The retaining means preferably is formed of a circumferential, radially projecting barb containing longitudinal notches so that it may be inwardly compressed as the retaining post is inserted in a hole in a printed circuit board. The neck section contains a plurality of longitudinal spaced (i) grooves on its outer surface forming opposing frangible webs or (ii) cuts through said neck section. The neck section contains a cavity in which is disposed a material that expands upon heating. Expanding materials include shape memory effect alloys, such as nitinol, and a structure in which a material having a relatively high thermal coefficient of expansion is coated with a material having a lower thermal coefficient of expansion. Upon heating a retainer post in a vapor phase soldering step, the expanding material creates an internal bursting pressure that expands portions of the neck section. The portions are defined by the longitudinal cuts or by the webs that are fractured by the bursting pressure. The expanded neck portions tightly engage the printed circuit board through which the retainer post is inserted. A stable mechanical contact between the post and circuit board is achieved so that the retainer post may be used to attach electrical connectors and other components to the printed circuit board without threatening the integrity of electrical connections.

Expanding surface mount compatible retainer post

A test clip for a plastic leaded chip carrier (PLCC) includes a plurality of electrical contacts for electrically connecting with respective leads of the PLCC, an electrically non-conductive body for supporting such contacts in spaced-apart positions, and a retaining mechanism for holding the test clip in operative position with respect to the PLCC. The retaining mechanism includes plural latching arms at respective corners of the test clip and a slide actuator therefor. The slide actuator also is operative to deflect the contacts from a normally open position to a closed position engaging respective leads of the PLCC.

An electrical component for electrical interconnection of electrical elements includes an electrically non-conducting body containing at least one cavity for receiving an electrically conducting member, an opening for access to the cavity, a solder mask disposed proximate the opening for preventing the flow of molten solder through the opening and a frangible connection between the mask and the body. An electrical contacting member disposed within the cavity, preferably through a second opening, includes a solder tail that passes through the opening adjacent the mask. The component, containing the contacting member, is disposed on the top side of a printed circuit board with the solder tail, and preferably the mask, inserted into a plated-through hole in the board and protruding from the bottom side of the board. The solder tail is soldered to the board in a wave soldering process during which the mask prevents molten solder from entering the cavity. Thereafter, the solder mask may be removed by breaking the frangible connection so that an electrical lead can be inserted into the cavity from the bottom side of the board.

Growing community of inventors

Mentor, OH, United States of America

Martin C Ignasiak