GB2305018A

GB2305018A - Printed circuit boards having circuitry on an insulating sheet

Info

Publication number: GB2305018A
Application number: GB9517225A
Authority: GB
Inventors: Brian Hallett
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-23
Filing date: 1995-08-23
Publication date: 1997-03-26
Also published as: GB9517225D0

Abstract

A circuit (12) generated, for example, on a computer work station is applied to a sheet of insulating material (13) such as plastic. The lines making up the circuitry may be made of a material which is either inherently electrically conductive or which can be made conductive by further processing steps. The sheet is then secured to a substrate (11) by adhesive, holes are drilled at appropriate terminal positions and components are secured to the circuit board by soldering. The circuitry may be arranged to provide a location for a chip device (14, Fig. 2, not shown) so that terminals on the chip align and are in electrical contact with circuitry on the sheet.

Description

CIRCUIT BOARD PRODUCTION This invention relates to circuit board production.

Designers and manufacturers who assemble electronic components together do so on a printed circuit board ('pcb') with copper tracks linking the components into the appropriate circuitry. For design, development or experimental purposes it is expensive and time consuming to have a pcb made by a similar process to that used for mass production. A number of 'do-it-yourself' kits have been developed to enable a pcb to be made on a one-off basis fairly cheaply, quickly and of acceptable tolerances. Such kits usually involve the use of ultra violet cut') light to produce an image on a copper clad board. Copper is then chemically etched away from the board leaving the required copper image on the board. Such methods can be quick and cheap for one-off production.

According to the present invention there is provided a method of fabricating a printed circuit board comprising the steps of: 1 generating by means of a data processing system an image of a required circuit; 2 causing a representation of the image to be placed as a deposited image on a carrier of insulating material; the deposited image being composed either of a layer of an inherently electrically conductive compound or being adapted to provide for the creation of such a layer following a further step or further steps; 3 adapting the carrier and the deposited image, such as by piercing, to enable circuit elements to be located on the carrier; 4 securing circuit elements or parts thereof to a part of carrier by as retaining process such as soldering so as to provide at least in part for a good electrically conducting relationship between the circuit elements or parts with the deposited image.

According to a first preferred version of the present invention the step of causing a representation of the image to be placed as a deposited layer in turn comprises the steps of placing the deposited layer on a sub-carrier and thereafter securing the subcarrier to the carrier by means of an adhesive.

According to a second preferred version of the present invention the step of causing a representation of the image to be deposited involves the provision of an initially deposited image on the carrier, which initially deposited image is a layer of non-electrically conducting material, followed by a further step wherein the initially deposited image and the carrier are subjected to processing such that the initially deposited image leads to the generation of a layer of electrically conducting material conforming to the image but leaves the remainder of the carrier apart from that bearing the image in a non-conducting state.

An exemplary embodiment of the invention will now be described with reference to the accompanying drawing of a method of manufacture at two different stages with the same components in different relative positions.

Figure 1 shows a circuit board 11 on which a print 12 bearing a circuit image has started to be attached by means of an adhesive.

Figure 2 shows the print 12 fully secured to the board 11. The print 12 is made up of a insulating plastic film 13 on which has been printed a sequence of conducting lines (shown black) of copper. The print 12 provides a location 14 for a processor chip so that electrodes on the chip will align with, and be in good electrical conducting contact with, the twenty four circular terminations A, B aligned on either side of the location 14.

To manufacture the board shown in Figure 2 the design corresponding to that shown on print 12 in Figure 2 is drawn up by means of a computer work station at which the developing design is shown on a video display unit. Once the design is completed the design is printed out onto plastic film 13 so that electrically conducting lines shown in black in both figures. In addition to the printing of electrical conductors identifying indicia can also be included.

Once completed the print 12 is coated on its reverse side (the side not printed with conducting material) with an adhesive and the print 12 is initially positioned on the board 11 as shown in Figure 1 and is then drawn down until mounted in its entirety on the board 11 as shown in Figure 2.

The mounted board is then suitably drilled or otherwise pierced and the required components are then located on the board in accordance with the layout shown.

The assembled board and components are then subjected to a conventional soldering process to secure the components in place on the board.

The described method provides for the ready design and manufacture of one or a small number of a version of a printed circuit making use of widely available data processing and printing systems to provide for the ready design of the required circuit and for its subsequent transfer and production on a one-off basis.

Claims

CLAIMS 1A method of fabricating a printed circuit board comprising the steps of:

1 generating by means of a data processing system an image of a required circuit;

2 causing a representation of the image to be placed as a deposited image on a carrier of insulating material; the deposited image being composed either of a layer of an inherently electrically conductive compound or being adapted to provide for the creation of such a layer following a further step or further steps;

3 adapting the carrier and the deposited image, such as by piercing, to enable circuit elements to be located on the carrier;

4 A method of fabricating a printed circuit board as herein before described with reference to and as illustrated in the accompanying drawings.

4 securing circuit elements or parts thereof to a part of carrier by as retaining process such as soldering so as to provide at least in part for a good electrically conducting relationship between the circuit elements or parts with the deposited image.

2 A method as claimed in claim 1 wherein the step of causing a representation of the image to be placed as a deposited layer in turn comprises the steps of placing the deposited layer on a sub-carrier and thereafter securing the subcarrier to the carrier by means of an adhesive.

3 A method as claimed in any preceding claim wherein the step of causing a representation of the image to be deposited involves the provision of an initially deposited image on the carrier, which initially deposited image is a layer of non-electrically conducting material, followed by a further step wherein the initially deposited image and the carrier are subjected to processing such that the initially deposited image leads to the generation of a layer of electrically conducting material conforming to the image but leaves the remainder of the carrier apart from that bearing the image in a non-conducting state.