GB2209132A

GB2209132A - Soldering electric circuits

Info

Publication number: GB2209132A
Application number: GB8820198A
Authority: GB
Inventors: James * Topping Richard
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-08-27
Filing date: 1988-08-25
Publication date: 1989-05-04
Anticipated expiration: 2008-08-25
Also published as: GB8720226D0; GB2209132B; GB8820198D0

Abstract

An electrically heated soldering iron (16) having a copper head (17) configured to match the set of pins of a component (23) mounted on a circuit board (22) is carried by a traveller (12) mounted below an aperture (11) in a support table (10). A foot-pedal controller (20) effects raising and lowering of the traveller (12), and an adjustable locator member (25) enables accurate repeated location of a circuit board in the table. In operation, a circuit board is located so that the copper head (17) can be raised into engagement with a set of pins and the component can be withdrawn as soon as the solder has melted and a replacement immediately inserted. The apparatus improves the efficiency of this type of soldering operation. <IMAGE>

Description

SOLDERING APPARATUS AND ETHOS This invention relates to an apparatus for use in and a method of soldering.

In this specification, the term n soldering" refers generally in appropriate context to operations involving soldered electrical connections, and embraces both the fixing of such connections (soldering or resoldering) and the freeing of such connections (desoldering).

The invention is concerned particularly with soldering in relation to circuit boards using "throughhole" componentry in which many components eg integrated circuits, modules, connectors etc have a relatively large number of electrical connection pins. The pattern of pins on any one component is matched by a set of pre-drilled holes in the circuit board so that the component can be mounted on the circuit board with its connection pins extending through the holes. The surface of the circuit board remote from the component carries conductors defining circuit connections produced by etching a copper foil surface layer in known manner.

The connection pins (or selected "in-use" ones thereof) are soldered to the conductors at the board surface where the free ends of the pins emerge from their holes. Disadvantages of this type of construction arise when multi-pin components already soldered have to be removed or replaced or re-positioned. If each soldered connection has to be freed by de-soldering using known wicking or suction techniques, then the operation is time-consuming and/or calls for a high level of skill. The operational efficiency is further impaired if re-soldering is required. If the time factor is improved by applying a solder bath to a set of connections for simultaneous freeing thereof, then there is an accompanying risk of heat damage to the circuit board and/or adjacent components. Also, molten solder from the solder bath may flow through the holes and flood part of the component side of the board.

An object of the present invention is to provide a soldering appliance and method by means of which the above mentioned disadvantages are obviated or mitigated.

According to one aspect of the present invention, there is provided a method of soldering a component on a circuit board, comprising the steps of: offering the circuit board up to a support means associated with a heat source and operating means operable to guide the support and the heat source together and apart, adjusting the position of the circuit board on the support means so that the heat source can register with a selected set of connection points on the soldered side of the board, holding the circuit board on the support means at the adjusted position thereon, and causing the heat source to engage said set of connection points.

Preferably, the method includes the step of setting a locating means to enable repeat locating of the circuit board or similar circuit boards at the adjusted position.

According to a further aspect of the invention, there is provided a method of soldering a component on a circuit board, comprising the steps of: locating the circuit board on a support means associated with a heat source and operating means operable to guide the support and the source together and apart, holding the circuit board on the support means, and causing the heat source to engage a preselected set of contact points on the soldered side of the circuit board.

According to yet a further aspect of the present invention, there is provided apparatus for soldering a component on a circuit board comprising: a support means supporting a circuit board so that part of the soldered side thereof is accessible, and a heat source associated with the support means, the support and the heat source being mounted for guiding together and apart so that the heat source can be engaged with the accessible part of the circuit board, the heat source being adapted for registration with a pre-selected set of contact points at said accessible part.

Preferably, the heat source is movable towards and away from the support means by means of a foot-pedal controller.

Preferably, the apparatus includes a locating means mounted on the support means for registration with a component or other datum on the circuit board to enable repeat positioning of the circuit board or similar circuit boards on the support means.

Preferably, the apparatus includes clamp means for holding the circuit board in supported engagement with the support means.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic part-sectional elevation of soldering apparatus in-accordance with the present invention; and Fig. 2 is a plan view of part of the apparatus of Fig. 1.

In the drawings, the soldering apparatus consists of a support means in the form of a work-table 10 having a through aperture 11. On its underside, the table 10 carries a traveller 12 which is vertically shiftable on a guide bar 13 secured to the underside of the table 10 by means of a base plate 14. The traveller 12 carries a heat source 15 consisting of an electrically-operated heating element 16 and a copper adapter 17.

The traveller 12 is operable to shift the heat source 15 towards and away from the aperture 11 by means of a cable drive 18 of which a guide wire 19 is anchored at one end to the base plate 14 and at the other end to the base 20 ofa foot-pedal mechanism.

The arrangement is such that operation of the pedal mechanism lifts the traveller 12. A compression spring 21 is interposed between the traveller 12 and the base plate 14, the length of the spring 21 being chosen so that the spring force is encountered only if the adapter 17 of the heat source 15 moves beyond the top limit of the aperture 11.

The table 10 is shown with a circuit board 22 thereon and having a "through-hole" mounted component 23.

The apparatus includes a locating means 24 consisting of a locator member 25 adapted to locate on an end portion of the component 23, and adjustable with respect to a supporting arm 26 which carries a clamp screw 27.

Operation of the soldering apparatus is as follows.

The copper adapter 17 is chosen to match the set of pin connections of the component 23 to be removed from the circuit board 22 and replaced by a fresh component. The board 22 is offered up to the table 10 with the component 23 in the vicinity of the aperture 11. The foot pedal is operated to raise the traveller 12, and simultaneously the board 22 is adjusted in position so that the adapter 17 can be brought into registration with the set of connection pins of the component 23. The board 22 is then held at the set position whilst the pedal is operated to move the heat source 15 into engagement with the set of connection pins. As soon as the pins are freed by melting of their solder, the component 23 can swiftly be removed and a new component fitted.

If the soldering operation calls for repetitive work, the locating means 24 is brought into engagement with the component 23 (or some other datum) on the circuit board 22 immediately after the correct position of the circuit board has been established.

Thereafter, each soldering operation can be accomplished as soon as the component (or other datum) has been registered with the locating means 24 without any preliminary positioning effort.

The adapter for the heat source 15 may constitute a small solder bath for use in soldering components having a very large number of connection pins.

In one modification of the apparatus above described included within the scope of the appended claims, a clamp means (not shown) is provided to hold the circuit board 22 at the set position on the table 10, thus leaving an operator with both hands free to deal with the manipulation of the component.

In another such included modification, the arrangement is such that the heat source and the adapter are always stationary and the support means or table is mounted for movement towards and away from the heat source.

In yet another such included modification, the locating means consists of an image optically projected on to the circuit board for repeatable visual registration with a mark or component or area of the board.

Claims

1. A method of soldering a component on a circuit board, comprising the steps of: offering the circuit board up to a support means associated with a heat source and operating means operable to guide the support and the heat source together and apart, adjusting the position of the circuit board on the support means so that the heat source can register with a selected set of connection points on the soldered side of the board, holding the circuit board on the support means at the adjusted position thereon, and causing the heat source to engage said set of connection points.

2. The method claimed in claim 1, including the step of setting a locating means to enable repeat locating of the circuit board or similar circuit boards at the adjusted position.

3. A method of soldering a component on a circuit board, comprising the steps of: locating the circuit board on a support means associated with a heat source and operating means operable to guide the support and the heat source together and apart, holding the circuit board on the support means, and causing the heat source to engage a pre-selected set of contact points on the soldered side of the circuit board.

4. Apparatus for soldering a component on a circuit board comprising: a support means supporting a circuit board so that part of the soldered side thereof is accessible, and a heat source associated with the support means, the support and the heat source being mounted for guiding together and apart so that the heat source can be engaged with the accessible part of the circuit board, the heat source being adapted for registration with a pre-selected set of contact points at said accessible part.

5. Apparatus as claimed in claim 4, wherein the heat source is movable towards and away from the support means by means of a foot-pedal controller.

6. Apparatus as claimed in claim 4 or 5, including a locating means mounted on the support means for registration with a component or other datum on the circuit board to enable repeat positioning of the circuit board or similar circuit boards on the support means.

7. Apparatus as claimed in claim 6, wherein the locating means comprises a locating member for locating engagement with said component or datum.

8. Apparatus as claimed in claim 7, wherein the locating member is carried by an arm which is pivotally mounted to allow the locating member to be swung clear of a circuit board during mounting and demounting thereof on the support means.

9. Apparatus as claimed in any one of claims 4 to 9 including clamp means for holding the circuit board in engagement witht he support means.

10. A method of soldering a component on a circuit board, substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus for soldering a component on a circuit board, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.