GB2246728A - Support for a circuit board - Google Patents
Support for a circuit board Download PDFInfo
- Publication number
- GB2246728A GB2246728A GB9012441A GB9012441A GB2246728A GB 2246728 A GB2246728 A GB 2246728A GB 9012441 A GB9012441 A GB 9012441A GB 9012441 A GB9012441 A GB 9012441A GB 2246728 A GB2246728 A GB 2246728A
- Authority
- GB
- United Kingdom
- Prior art keywords
- support
- plate
- components
- substrate
- board
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K13/00—Apparatus or processes specially adapted for manufacturing or adjusting assemblages of electric components
- H05K13/0061—Tools for holding the circuit boards during processing; handling transport of printed circuit boards
- H05K13/0069—Holders for printed circuit boards
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Supply And Installment Of Electrical Components (AREA)
Abstract
The support is for double sided surface mount component circuit boards (1) and comprises a personality plate (20) to support the lower surface of the board to which components have already been mounted while components are mounted to the other side of the board. The personality plate includes a plurality of supporting pins (21) and a phototool which is glued to the plate. The phototool is used in locating pins in the plate (20) and to identify the plate with a particular board. The plate (20) has register holes (25a, b) for accepting dowels (6, 7) of a tooling bar (8) registered with a support frame (13) carrying the plate (20). <IMAGE>
Description
A SUPPORT FOR A CIRCUIT BOARD
The invention relates to a support for a circuit board.
Printed circuit substrates made from for example glass fibre or ceramic materials are often designed to receive surface material components on both sides.
Such substrates are provided with conducting tracks which define circuit patterns on both sides of the substrate, and with through paths which provide for side to side connections between the circuit patterns.
Tooling holes or laser scored edges are also provided in the circuit patterns to act as registration datums.
The patterns are substantially flat on each side of the substrate and the substrate once formed is used as a base of a circuit board.
During assembly, surface mount components are secured to the substrate by soldering the components to the conducting tracks. Components are presented to one surface of the substrate and a solder paste is applied to the joint between the component and the track. Solder pastes are generally thixotropic and until the paste between the components and the track is fixed by melting at high temperatures the connection between the component and the track is susceptible to damage by handling of the substrate or smearing of the solder paste. Surface mount component bodies may be secured to the substrate by way of an adhesive. Adhesive spots are provided at positions on the substrate and the components are then placed onto the substrate and are secured thereto by the adhesive spot.This requires both accurate positioning of the adhesive spot and accurate placing of the component to the substrate.
Once all of the required components have been secured to one side of the substrate by solder paste and/or adhesive, the substrate is placed in a high temperature oven causing the solder paste to flow and thereby to form soldered joints between the component and the track. Components can then be secured to the other side of the substrate in a similar process.
When components are being secured to the substrate it is important that the substrate is well supported and accurately presented (eg. level). When components are mounted only to or initially to one side of a substrate this does not present great difficulties because the substrate can for example be placed on a level receiving surface and held firmly in place during the mounting of components etc. However, when components are mounted to both sides of a substrate difficulties can be encountered in mounting components to the second side when components are already mounted to the first side. If for example the substrate is not accurately presented then automatic compound placement and/or the dispensing of adhesive may suffer in terms of reduced accuracy.Furthermore, if the substrate is allowed to bow the application of solder paste by for example screen printing will suffer and may well result in a misregistration and/or smearing of the solder paste pattern.
One known system of support for a circuit board having components already mounted to one side uses supporting blocks having recessed portions which accommodate the mounted components and having ridges surrounding the received portions which ridges are brought into contact with portions of the substrate between components and thereby provide support for the substrate. Alternatively, supporting blocks having local pads which provide a pocketed structure have been used.
Surface mounted components are often, of necessity, densely mounted to printed circuit substrates. This dense packing of components makes the manufacture of supporting blocks both time consuming and expensive because the blocks must be formed accurately to ensure accurate registration with the substrate and the mounted components.
Furthermore, such blocks are not well suited to adapting to changes in the layout of components on a substrate, which changes many occur for example as the result of a design change say to upgrade the circuit.
Under such circumstances it may be necessary to remanufacture the blocks thereby adding to the expense. Moreover, since blocks are normally made by a machine shop facility, further costs are incurred either in maintaining such a facility or in subcontracting the work to an outside firm.
The present invention aims to overcome the above discussed problems by providing a means of support for a double sided printed circuit substrate which support is both simple and cheap to manufacture and use.
According to one aspect of the invention therefore there is provided a support for a circuit board, the support comprising a supporting plate provided with a plurality of supporting pins extending away from one face of the plate and arranged to contact the lower surface of the circuit board.
The provision of the plurality of supporting pins obviates the need for accurate tooling and machining.
As will become clear from the detailed description of a preferred embodiment that follows, the use of supporting pin facilitates manufacture of supporting plates for different circuit boards by relatively unskilled personnel. Also, the supporting plate can be readily modified to accommodate changes in the layout of components on a circuit board resulting from for example design changes in the circuit of the circuit board.
The support plate can be made to engage with a fixed frame which is securable to an even and substantially immovable surface such as a machine bed.
The fixed frame may define an aperture to which the supporting plate can be placed, and the supporting plate can be arranged to be removably mounted therein.
The support may further comprise a registration arrangement by which the plate and/or the circuit board can be accurately registered in the support thereby enabling circuit boards to be assembled accurately. The registration arrangement can comprise a registration member provided with registration pegs or dowels which cooperate with bushes or other apertures in the fixed frame and the plate and/or circuit board.
The support plate may include markings, such as a photo tool, for identifying the layout of the circuit board for which the plate is to be used, and for facilitating construction of the plate.
According to another aspect of the invention there is provided a support for a circuit board, the support comprising a plurality of elongate members positioned to extend between components previously mounted to one side of a board to support the board while components are mounted to the other side of the board.
The invention also provides a method of manufacturing a circuit board to which components are mounted on opposing sides thereof, the method comprising mounting components to one side of the board and supporting that side of the board, by way of a supporting plate comprising a plurality of supporting pins arranged to extend between said components to contact said side of said board, while components are mounted to the other side of the board.
The above and further features of the invention are set forth with particularity to the appended claims and together with advantages thereof will become clearer from consideration of the following detailed description of an exemplary embodiment of the invention given with reference to the accompanying drawings.
In the accompanying drawings:
Figure 1 is an exploded perspective view of a support for supporting a substrate in a first configuration;
Figure 2 is a sectional view of the support of
Figure 1;
Figure 3 is an exploded perspective view of the support in a second configuration;
Figure 4 is a sectional view of the support of
Figure 3; and
Figure 5 shows stages in the manufacture of a personality plate for the support.
Referring now to the drawings, in Figure 1 there is shown a substrate 1 having two opposing faces or sides 2, 3 to which components can be mounted. It will be appreciated that, although not shown, each side 2, 3 of the substrate is provided with conducting tracks and the substrate may also include through paths for providing electrical connections between the tracks on each side 2, 3. The substrate also includes two locating datums, in this case datum holes 4, 5 which engage with respective datum dowels 6, 7 in a tooling bar 8, as can be seen in Figure 2 of the drawings. The tooling bar 8 also includes master dowels 9, 10 which are positioned to engage with respective bushes 11, defined in a laterally extending groove 12, in a master member 13.The master member 13 is in turn fixed by any suitable means to a flat machine bed 14 or the like and thereby provides support for the substrate during the mounting of components. The master member 13 defines an aperture 15, the purpose of which will become clearer from the following description.
Initially the substrate 1 will not have any components secured to it and both sides 2, 3 will be substantially flat. The conducting tracks (not shown) on the sides 2, 3 will of course have some depth but for all practical purposes this depth can be ignored. The substrate 1 can therefore be supported by a planar surface in contact with the lower side, say side 3, during the mounting of components to the upper side, say side 2. To this end, a bolster plate 16 is provided for supporting the substrate 1 during the first stage of production of the circuit board when components are secured to the first side 2 of the substrate. The bolster plate 16 engages in the aperture 15 such that the upper surface 17 of the bolster plate 16 lies in substantially the same place as the upper surface 18 of the master member 13, as can be seen in Figure 2 of the accompanying drawings.
It should be noted from Figure 2 that the datum dowels 6, 7 extend through the tooling bar 8 and beyond such that the upper surface 19 of tooling bar 8, when the tooling bar is engaged in position in the groove 12 in the master member 13, lies flush with the upper surface 18 of the master member.
As can be seen from Figure 2, with the datum holes 4, 5 engaged with the respective datum dowels 6, 7 and the second side 3 of the substrate 1 resting on the upper surface 17 of the bolster plate 16, the substrate 1 is registered in a predetermined position and firmly supported by the support arrangement.
Adhesive spots can then be placed on the upper side 2 of the substrate and/or components and solder paste presented thereto either manually or preferably by way of any suitable automatic assembly equipment.
During the assembly process, the substrate is held in its predetermined position by the datum dowels 6, 7 in cooperation with the datum holes 4, 5 in the substrate and this facilitates accurate positioning of adhesive spots, solder paste and components for the first side 2 of the substrate. Furthermore, the bolster plate 16 prevents bowing of the substrate during automatic operations such as screen printing of solder paste thereby further increasing the accuracy of manufacture and reducing the likelihood of solder paste being smeared over other portions of the substrate 1.
Once all components have been placed on the surface 2, the substrate is removed from the support arrangement and taken elsewhere for treatment, such as by high temperature oven, to form soldered joints between the components and the track.
While the substrate is being treated, the bolster plate 16 is removed from the aperture 15 in the master member 13 and is replaced by a different plate 20, referred to herein as a "personality plate" which has a form unique, though readily adaptable, to the layout of components on the first side 2 of the substrate 1.
As can be seen in Figures 3 and 4 of the accompanying drawings, the personality plate 20 comprises a plurality of precision small diameter support pins 21. The pins 21 are positioned on the personality plate 20 so as to extend past components such as 22 and 23, on the first side 2 of the substrate 1 when the substrate 1 is presented to the support arrangement with the first side 2 facing downwardly.
As can be seen from Figure 4 of the accompanying drawings, the support pins 21 are all of equal length.
The length of the support pins 21 is such that the substrate will be supported evenly by the upper surface 19 of the tooling bar 8, the upper surface 18 of the master member 13 and distal end surfaces 24 of the pins 21. In this way, the personality plate 20 supports the substrate 1 by way of the pins 21 cooperating with the downwardly facing first surface 2 during the positioning of adhesive spots, components and solder paste on the second surface 3. Since the pins 21 extend past the components 22, 23 and are in direct contact with the downwardly facing first surface 2 of the substrate, the substrate can be well supported during this stage of the circuit board assembly process.As with the arrangement shown in
Figures 1 and 2, the arrangement shown in Figure 3 and 4 enables the substrate to be held in a predetermined position by way of the datum dowels 6, 7 registering in the datum holes 4, 5 in the substrate, and the personality plate 20 prevents bowing of the substrate during automatic operations such as screen printing of solder paste etc.
It will be noted that the personality plate 20 includes datum holes 25a, 25b which are similar to the datum holes 4, 5 in the substrate 1 and also cooperate with the datum dowels 6, 7 to register the personality plate 20 accurately in the aperture 15 in the master frame 13. In this way an accurate alignment between the substrate 1 and the personality plate 20 can be achieved. Thus, the substrate is accurately positioned by the datum dowels 6, 7 in cooperation with the holes 4, 5 and firmly supported by the support pins 21 of the personality plate 20, which is also accurately positioned by the datum dowels 6, 7 in cooperation with the holes 25a, 25b, thereby facilitating manufacturing of the second side of the circuit board.
Once all components have been positioned on the second side 3 of the substrate 1 and solder paste has been applied for the second side, the substrate is again removed from the support arrangement for further treatment to form soldered joints for the components and the track (not shown) on the second side 3 of the substrate. Incidentally, components on the first side 2 are held in position by the surface tension of melted solder and do not separate from the first side 2 of the substrate during this second solder joint forming process.
One exemplary method by which the personality plate 20 is produced is shown in Figure 5 of the drawings. It is assumed for the purpose of explanation that the circuit and circuit board layout have already been designed and that a personality plate is to be made to enable the circuit board to be produced on a large scale. Thus, a phototool 26 will have been produced in the form of artwork for use in say etching or silk screen printing conducting tracks onto the above discussed substrate 1. Holes 27, 28 are first formed in a personality plate blank 29. The holes 27, 28 will serve as the above discussed datum holes 25a, 25b for aligning the personality plate in the frame 13 and in relation to the substrate 1. The blank 29 can be made from any dimensionally stable sheet material such as for example aluminium or glass reinforced plastics.Registration marks or datums 30, 31 on the phototool 26 are aligned with the holes 27, 28 as the phototool is brought to the blank 29 and secured to one side thereof by way of for example a suitable low adhesion adhesive to facilitate later removal of the phototool.
As shown in Figure 5(b) with the phototool secured to the blank 29 and trimmed to fit the blank, if required, the artwork 32 on the phototool serves to identify the location of conducting tracks, from which the position of components can be readily discerned, on the substrate 1 (not shown in Figure 5). With the phototool 26 in position the blank 29 is drilled with a plurality of drill holes 33 to accommodate the plural supporting pins 21. Any suitable pins may be used though we have found that needle rollers, which have a length and a diameter within a small tolerance, are particularly suitable. The pins 21 are inserted into the drill holes 33 and are secured therein by a friction fit.It will of course be appreciated that the pins 21 are placed in the blank 29 at positions corresponding to those at which there are no components on the circuit board so that the distal end of the pins will contact the substrate 1 and not the surface of the components mounted thereon.
In the event of a minor design change resulting say in a component being moved to a new position on the circuit board, a corresponding minor change can be made to the personality plate. As shown in Figure 5(d) of the accompanying drawings, a pin, or plural pins, can be removed from its drill hole, or their drill holes, eg. drill hole 34 and a new pin eg. pin 35 can be provided at a different location on the board if required.
Where a major design change is implemented and a new phototool is produced, the personality plate can be stripped down to the blank 29 by removing the pins 21 and the old phototool. Once the personality plate has been stripped down to the blank 29, as shown in
Figure 5(e), the new phototool can be placed onto the blank 29. Existing holes 33 can be used to accommodate new pins where appropriate and new holes can be drilled, using the new phototool as a guide, to accommodate further supporting pins as required.
Thus, the personality plate is cheap to make because it is constructed from readily available materials and because of its simple construction. The personality plate is also cheap to use because modifications to the circuit board can be readily accommodated without the need to build a completely new plate in most circumstances.
Having thus described the present invention by reference to a preferred embodiment it is to be well understood that the embodiment in question is exemplary only and that modifications and variations such as will occur to those possessed of appropriate knowledge and skills may be made without departure from the spirit and scope of the invention as set forth in the appended claims and equivalents thereof.
Claims (10)
1. A support for a circuit board, the support comprising a supporting plate provided with a plurality of supporting pins extending away from one face of the plate and arranged to contact the lower surface of the circuit board.
2. A support as claimed in claim 1, wherein the support plate is adapted to engage with a fixed frame which is securable to a level and substantially immovable surface.
3. A support as claimed in claim 2 wherein the surface is a machine bed.
4. A support as claimed in claim 2 or 3 wherein the fixed frame defines an aperture to which the supporting plate can be placed.
5. A support as claimed in claim 2 or 3 and wherein the supporting plate is adapted to be removably mounted to said fixed frame.
6. A support as claimed in any preceding claim, further comprising a registration arrangement by which the plate and/or the circuit board can be accurately registered in the support.
7. A support as claimed in claim 6 wherein the registration arrangement comprises a registration member provided with registration pegs or dowels which cooperate with bushes or other apertures in the fixed frame and the plate and/or the circuit board.
8. A support as claimed in any preceding claim, wherein the support plate includes markings, such as a photo tool.
9. A support for a circuit board, the support comprising a plurality of elongate members positioned to extend between components previously mounted to one side of a board to support the board while components are mounted to the other side of the board.
10. A method of manufacturing a circuit board to which components are mounted on opposing sides thereof, the method comprising mounting components to one side of the board and supporting that side of the board, by way of a supporting plate comprising a plurality of supporting pins arranged to extend between said components to contact said side of said board, while components are mounted to the other side of the board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9012441A GB2246728A (en) | 1990-06-04 | 1990-06-04 | Support for a circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9012441A GB2246728A (en) | 1990-06-04 | 1990-06-04 | Support for a circuit board |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9012441D0 GB9012441D0 (en) | 1990-07-25 |
| GB2246728A true GB2246728A (en) | 1992-02-12 |
Family
ID=10677047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9012441A Withdrawn GB2246728A (en) | 1990-06-04 | 1990-06-04 | Support for a circuit board |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2246728A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19808171A1 (en) * | 1998-02-26 | 1999-09-02 | Resma Gmbh | Arrangement for assembling printed circuit boards with integrated circuits |
| CN101472460B (en) * | 2007-12-27 | 2010-10-06 | 富葵精密组件(深圳)有限公司 | Carrying device and method for preparing two-sided sticking/loading circuit board using the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0157451A2 (en) * | 1984-03-20 | 1985-10-09 | Philips Patentverwaltung GmbH | Carrier for printed-circuit boards |
| EP0191905A2 (en) * | 1985-02-14 | 1986-08-27 | Ezio Curti | Device for positioning and steadying a carrying board for printed circuits by means of reference pins with variable diameters |
| EP0404577A1 (en) * | 1989-06-22 | 1990-12-27 | Sanyo Electric Co., Ltd. | Assembling apparatus using back-up pins for supporting printed circuit board |
-
1990
- 1990-06-04 GB GB9012441A patent/GB2246728A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0157451A2 (en) * | 1984-03-20 | 1985-10-09 | Philips Patentverwaltung GmbH | Carrier for printed-circuit boards |
| EP0191905A2 (en) * | 1985-02-14 | 1986-08-27 | Ezio Curti | Device for positioning and steadying a carrying board for printed circuits by means of reference pins with variable diameters |
| EP0404577A1 (en) * | 1989-06-22 | 1990-12-27 | Sanyo Electric Co., Ltd. | Assembling apparatus using back-up pins for supporting printed circuit board |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19808171A1 (en) * | 1998-02-26 | 1999-09-02 | Resma Gmbh | Arrangement for assembling printed circuit boards with integrated circuits |
| CN101472460B (en) * | 2007-12-27 | 2010-10-06 | 富葵精密组件(深圳)有限公司 | Carrying device and method for preparing two-sided sticking/loading circuit board using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9012441D0 (en) | 1990-07-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0415527A2 (en) | Printed circuit board fixture | |
| US5526974A (en) | Fine pitch electronic component placement method and apparatus | |
| JPH0347794A (en) | Screen printing method and method and apparatus for preparing printing plate | |
| US6161749A (en) | Method and apparatus for holding a printed circuit board during assembly | |
| GB2443659A (en) | Workpiece carrier for supporting a plurality of workpieces | |
| WO1998056218A1 (en) | Fine pitch component placement method and apparatus | |
| US5197888A (en) | Method of positioning flexible circuit members on a common circuit member | |
| GB2246728A (en) | Support for a circuit board | |
| JPS646450B2 (en) | ||
| JPH0220426B2 (en) | ||
| JPH04137795A (en) | Method and device for laser soldering | |
| JPH0320834Y2 (en) | ||
| KR100629907B1 (en) | Method for Replacing Bad Array Board in the Printed Circiut Board | |
| JP3366515B2 (en) | Positioning device | |
| JPH0837397A (en) | Method of positioning printed wiring board and component | |
| JP2677227B2 (en) | Manufacturing method of printed wiring board | |
| JP3025033B2 (en) | Screen printing machine | |
| JP3298302B2 (en) | Positioning method and apparatus | |
| KR100327124B1 (en) | Soldering apparatus for screen printer | |
| JPS62123793A (en) | Printed circuit board aligner | |
| JPS61131495A (en) | Printed circuit board | |
| JP3196662B2 (en) | Printed wiring board printing method and printed wiring board printing apparatus | |
| JPH0468625B2 (en) | ||
| JPH0529756A (en) | Printed board supporting jig | |
| JPS60161510A (en) | Aggregate positioning printed wiring board |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |