GB2166998A - Extractor tool - Google Patents

Abstract

A tool for removing de-soldered I.C. components or "chips" from circuit boards shown in exploded view in Figure 1 and has a sleeve 10,12 to fit about the clip, spring claws 18,20 which can be closed together to engage below the chip, and a body 16 which carries the claws and which is spring 28 urged to retract away from the board and to automatically close the claws together so that the chip is drawn into the sleeve and removed from the board. <IMAGE>

Description

SPECIFICATION Extractor tool This invention relates to tools for extracting integrated circuit components ("chips") from circuit boards. The usual procedure with known tools is to engage claws provided on the tool below the chip, that is to say between the body of the clip and the PCB to which it is attached, and then de-solder the terminals, allowing a spring to pull the claws with the engaged chip away from the board.

The object of the invention is to provide an improved tool particularly suitable for use on crowded boards where there is relatively little room around each chip.

According to the invention an extractor tool comprises a tubular sleeve and a body which is slidable in the sleeve, the body including a chip abutting end, with spring means between the sleeve and body urging the same towards a position in which said end is drawn into the sleeve, the body carrying a pair of chip engaging claws which are resiliently urged apart, so that when the body is manually displaced in the sleeve against said spring means, the claws emerge from the sleeve and resiliently separate to allow positioning of the chip therebetween, and when the spring means is allowed to draw said body in the reverse direction the claws are closed together as well as withdrawn into the body so as to engage with the chip and draw the chip in the same direction.One preferred embodiment of the invention is now described with reference to the accompanying drawings in which: Figure 1 is an exploded perspective view of a tool, and Figures 2 to 4 are elevations showing the same in three different positions in use.

In the drawings the sleeve is made of rectangular cross-sectional metal tube with a relatively thin wall, and the dimensions of the rectangle (internally of the sleeve) are only slightly in excess of the plan dimensions of the chip with which the tool is to be used. The invention contemplates the use of a different tool for each (plan) size of chip.

As shown the tube may be made of two like pressings 10, 12 assembled together.

The sleeve is castellated by cutting away portions of the side and end walls except at the corners of the rectangle. Hence angle posts 14 are left, one at each corner, which can fit around the corners of the chip when the tool is in use.

The body 16 is generally rectangular in crosssection and of slightly smaller dimensions than the plan size of the chip: fixed to the body is a pair of blade springs 18, 20 which diverge away from one another as they extend in length along the body and have in-turned extremities 22 to provide the pair of claws. The blade springs may be adjustable in position on the body, for example by providing each spring with an elongated slot 24 through which a screw 26 passes into the body, for the purpose of accommodating the tool to chips of different thicknesses, although of the same plan size.

A compression spring 28 is located between the body and an abutment 30 fixed to the sleeve, and the body extends through the sleeve and out of the free end remote from the castellated end. The sleeve has projections 32 to enable the fingers of a hand to grasp the tool and manipulate it in use.

The springs lie in grooves 34 in the sides of the body.

In use, in the free position Figure 2, the end portions of the blade springs as well as the claws project beyond the sleeve, and the abutment end of the body is below the end of the sleeve. The abutment end is positioned on the chip which is to be removed and gentle pressure is applied to the sleeve so as to move the said end portions 22 of the blade springs past the end surfaces of the chip until the claws contact the board to which the chip is attached. In this movement the body is moved towards the abutment plate and its end is firmly pressed against the top surface of the chip.

The next step is a continuatuon of the same, to move the tubular sleeve relative to the tool and towards the board. This movement of the sleeve relative to the other parts of the tool takes the angle corner posts 14 past the corners of the chip until the end edges of the corner posts seat on the board. In this movement, the parallel walls of the sleeve move over the said end portions of the blade springs and effectively close them together so that the claws are moved to engage under the chip and are held in position by the sleeve. At this point further manual operation and manipulation ceases to be necessary, and the tool can be released. The claws are held in position relative to one another by the sleeve, and there is little or no spring action upon the sleeve tending to displace it relative to the claws. There is spring action on the body and hence on the claws, but it is ineffective at this point because the chip is (assumed to be) soldered in place to the board.

When the chip is de-soldered, the spring is able to displace the body away from the board leaving the sleeve in position, taking the blade springs with the body and hence lifting the chip off the board.

The tool and chip can be removed as a unit (Figure 4) and by appropriate manipulation of the stem and/or projections mentioned the parts of the tool can be returned to their original positions thus releasing the chip from the claws.

Claims (5)

1. An extractor tool comprising a tubular sleeve and a body which is slidable in the sleeve, the body including a chip abutting end, with spring means between the sleeve and body urging the same towards a position in which said end is drawn into the sleeve, the body carrying a pair of chip engaging claws which are resiliently urged apart, so that when the body is manually displaced in the sleeve against said spring means, the claws emerge from the sleeve and resiliently separate to allow positioning of the chip therebetween, and when the spring means is allowed to draw said body in the reverse direction the claws are closed together as well as withdrawn into the body so as to engage with the chip and draw the chip in the same direction.

2. A tool as claimed in Claim 1 wherein the sleeve is castellated to provide angle posts at the corners to fit about the chip.

3. A tool as claimed in Claim 1 or Claim 2 wherein the claws are adjustable in position on the body to suit different chip thicknesses.

4. A tool as claimed in any preceding claim wherein the body has grooves to accommodate the claws.

5. A tool substantially as described with reference to the accompanying drawings.