GB2084068A

GB2084068A - A handling system for printed circuit boards

Info

Publication number: GB2084068A
Application number: GB8031301A
Authority: GB
Original assignee: Marconi Co Ltd
Current assignee: BAE Systems Electronics Ltd
Priority date: 1980-09-27
Filing date: 1980-09-27
Publication date: 1982-04-07
Also published as: GB2084068B

Abstract

Printed circuit boards are arranged to be slidably mounted in a pair of elongate guides 5 and 6. The upper surface of the printed circuit board is inclined towards an operator to facilitate the insertion of component leads into prepared holes in the board. Each guide contains a small recess 11, 12 which locates the printed circuit board and enables it to slide easily from one work station to the next. The spacing between the guides is adjustable so as to accommodate boards of different widths. <IMAGE>

Description

SPECIFICATION A handling system for printed circuit boards This invention relates to a handling system for printed circuit boards and is specifically concerned with such a system which facilitates the manufacture of relatively large numbers of similar boards. The term printed circuit board is used to denote a thin lamina, generally of an insulating nature, having conductive pads and/or tracks on one of its major faces which serve to interconnect components mounted on the opposite major face of the lamina.

Generally, the tracks and pads consists of an etched copper layer, and the electrical leads of the components are mounted on that side of the board which is remote from the tracks. The electrical leads of the components pass through small holes in the thickness of the board, with the leads being soldered to the conductive tracks and pads. Printed circuit boards of this kind are now very common, but it is still generally necessary to mount the components on the board individually by the hand so that the electrical leads are inserted correctly in the right holes. The increasing complexity of printed circuit boards (a printed circuit board may contain a hundred or more individual components) and the increasingly large numbers in which the printed circuit boards are required, poses difficulties in manufacture and assembly.It is often no longer practicable for the whole printed circuit board to be assembled by a single operator, but instead a partially completed board is passed on to another operator to insert further components and then the board is in turn passed on yet again for the remaining components to be mounted on the board.

The present invention seeks to provide a handling system which facilitates this mode of operation in a particularly simple and economical manner.

According to this invention, a handling system for printed circuit boards includes two members each having an elongate guide arranged to contact and receive directly opposite edges of a printed circuit board, the system being arranged to be mounted on a horizontal work surface so that one of the guides is higher than the other, whereby the upper surface of a printed circuit board when mounted in the guides is inclined towards an operator, the board being arranged to co-operate with said members so that it is slidable along the length of the guides.

Preferably the spacing between the guides is adjustable so as to enable printed circuit boards of different widths to be accomodated. It will be appreciated that printed circuit boards having only a single width can be accomodated at any one time, but this is generally quite satisfactory where a large number of identical boards are to be assembled.

When one production run has been completed, the spacing of the guides can be altered to accomodate the size of boards to be used in the next production run.

Preferably each elongate guide comprises a recess formed in the upper edge of each member with the base of each recess being arranged to carry the weight of the printed circuit board and the side of the recess being arranged to prevent excessive movement of the printed circuit board in a direction perpendicular to the direction of the elongate guide.

Conveniently, the members themselves are of an elongate nature and are formed of an extruded alloy with the recesses being either formed at the extrusion stage or subsequently being formed in a machining operation.

Preferably both members are carried by an inclined support with the lower guide being fixed in a non-adjustable manner and the upper guide being arranged to co-operate with a slot formed in the support so that movement of the upper guide along the slot serves to adjust the spacing between the two guides. In practice, the lower end of the support can be clamped to the front edge of the work surface so that it is closely adjacent to an operator. The length of each guide can conveniently correspond to the width of a normal work station. Additional lengths of guides together with their associated supports can then be connected end to end to form a handling system of any required length.In general, the greater the complexity of the printed circuit board, the greater number of handling stations required and consequently the length of the handling system will be increased in accordance with the appropriate number of operator portions.

Because the printed circuit boards sit directly in recesses formed in the guides there is no need to provide separate carriers to secure or protect the printed circuit boards or to facilitate their movement along the guides. The system is therefore particularly simple and unskilled operators can insert printed circuit boards into the handling system without difficulty.

The invention is further described by way of example with reference to the accompanying drawings in which, Figure 1 shows a perspective view of the handling system and Figure2 is a sectional view.

Referring to the drawings, the handling system for printed circuit boards consists of a number of sections connected end to end. Each section represents an operator station and is bounded by two inclined supports 1 and 2 each having a lower end 3 formed so as to abut against the front edge of a work surface (not shown) with clamping screws 4 serving to secure the support firmly to the underside of the worksurface. Each pair of supports 1, 2 are linked by two adjustable elongate guide rails 5 and 6. The lower rail 6, which in operation is the nearer to an operator, is fixed in a non-adjustable manner to the lower end of the inclined surface of the supports 1 and 2. However, the upper rail 5 is mounted on slots 7 and 8 which permit the spacing between the two rails to be readily adjusted.It is importantthatthe two rails 5 and 6 are maintained parallel and this is achieved by means of spacers rods 9 and 10. It will be seen from Figure 2 that these spacer rods fit into recesses in the rails 5 and 6, and in practice the length of the spacer rods corresponds to the width of a printed circuit board plus a nominal clearance (.015") which is carried by the handling system. Once the position of the rail 5 has been set, the rail is firmly secured to the supports 1, 2 but bolts (not shown).

The upper edge of each rail carries a guide in the form of a shallow recess 11 and 12 respectively. The shape of these recesses can best be seen in Figure 2 and it will be seen that the base 13 of each recess carries predominantly the weight of a printed circuit board 14, whereas the sides 15 of the recesses prevent excessive lateral movement of the board 14.

The sides 15 are spaced apart so as to permit sufficient clearance to enable the printed board to slide easily along the length of the rails with a minimum of applied hand force. In practice, an operator would simply push a printed circuit board along the guide to the next adjacent work station when a particular sequence of assembly operations has been completed.

The lower rail 6 is spaced apart from the front edge of the work surface (i.e. from the front end of the supports 1, 2) so as to provide a work space immediately in front of an operator to accomodate tools and the like. The components to be inserted in each printed circuit board 14 are conveniently located above and behind the upper rail 5 so that they can be easily reached.

An operator inserts components, such as are indicated diagrammatically at references 20,21,22 and 23 into previously prepared holes in the board 14 so that the electrical leads 24 extend below the lower surface of the board. It will thus be appreciated that the height of the recesses 11 and 12 above the supports 1 and 2 must be sufficient to allow clearance of the lower ends of the electrical leads.

Claims

1. A handling system for printed circuit boards including two members each having an elongate guide arranged to contact and receive directly opposite edges of a printed circuit board, the system being arranged to be mounted on a horizontal work surface so that one of the guides is higher than the other, whereby the upper surface of a printed circuit board when mounted in the guides is inclined towards an operator, the board being arranged to co-operate with said members so that it is slidable along the length of the guides.

2. A system as claimed in claim 1 and wherein the spacing between the guides is adjustable so as to enable printed circuit boards of different widths to be accomodated.

3. A system as claimed in claim 1 or 2 and wherein each elongate guide comprises a recess formed in the upper edge of each member with the base of each recess being arranged to carry the weight of the printed circuit board and the side of the recess being arranged to prevent excessive movement of the printed circuit board in a direction perpendicular to the direction of the elongate guide.

4. A system as claimed in claim 1,2 or 3 and wherein said members are of an elongate nature and are formed of an extruded alloy.

5. A system as claimed in any of the preceding claims and wherein both members are carried by an inclined support with the lower guide being fixed in a non-adjustable manner and the upper guide being arranged to co-operate with a slot formed in the support so that movement of the upper guide along the slot serves to adjust the spacing between the two guides.

6. A handling system for printed circuit boards substantially as illustrated in and described with reference to the accompanying drawings.

New claims or amendments to claims filed on 15.9.81.

Superseded claim 1 New or amended claims:

1. A handling system for printed circuit boards in which a printed circuit board can be successively presented to a plurality of work stations including two members each having an elongate guide arranged to contact and receive directly opposite edges of a printed circuit board, the system being arranged to be mounted on a horizontal work surface so that one of the guides is higher than the other, whereby the upper surface of a printed circuit board when mounted in the guides is inclined towards an operator, the board being arranged to co-operate with said members so that it is slidable along the length of the guides from one work station to the next.