GB2369250A

GB2369250A - Method and apparatus for reinforcing a ribbon cable adjacent a joint to a PCB

Info

Publication number: GB2369250A
Application number: GB0104181A
Authority: GB
Inventors: Enda Joseph Moran
Original assignee: Hi Key Ltd
Current assignee: Hi Key Ltd
Priority date: 2000-11-21
Filing date: 2001-02-20
Publication date: 2002-05-22
Anticipated expiration: 2021-02-20
Also published as: GB2369250B; GB0104181D0

Abstract

Reinforcement of a joint (3, 4) between a ribbon cable (2) and a PCB (5, 6) is provided by forming fillets of laquer (23) on respective opposite sides of the cable (2) adjacent the joint where the cable is connected to tracks (17) directly by solder connections (20). An apparatus comprises laquer spraying means for applying laquer onto the PCB and the cable. The fillets of laquer help prevent bending of the cable and possible fracture of the solder joint between the cable and circuit board.

Description

"A method and apparatus for reinforcing a ribbon cable adjacent a joint to a PCB" The present invention relates to a method and apparatus for reinforcing a ribbon cable adjacent a joint to a printed circuit board (PCB), and in particular, for reinforcing the ribbon cable to the PCB adjacent a joint where electrical conductors of the ribbon cable are connected by solder connections to electrically conductive tracks of the PCB.

In certain cases it is desirable to connect components external of a PCB to the PCB by a ribbon cable which is permanently connected to the PCB by soldering electrical conductors of the ribbon cable to electrically conductive tracks of the PCB. However, a disadvantage of such connections is that the ribbon cable is essentially secured to the PCB only by the soldered connections of the conductors of the ribbon cable to the tracks of the PCB. Conductors of a ribbon cable tend to be of relatively thin cross-section and thus weak and prone to breakage. In particular, the crosssectional area of such conductors extending from the solder connections tend to be significantly less than the cross-sectional area of the corresponding solder connection, and thus, a particularly weak point is generated in each conductor of the ribbon cable adjacent the solder connections. Should the ribbon cable be subjected to bending at the joint of the conductors to the tracks of the PCB, in other words, should the conductors of the ribbon cable be subjected to bending adjacent the joint, one or more of the ribbon cable conductors may be severed. Indeed, even if the ribbon cable is subjected to bending relative to the PCB adjacent the joint only a few times, it is possible for one or more, and indeed, all the ribbon cable conductors to

be severed. This, it will be appreciated presents a major problem since even if only one of the ribbon cable conductors were severed the connection between the external components and the PCB would be effectively rendered inoperable.

There is therefore a need for a method and apparatus for reinforcing a ribbon adjacent a joint to a PCB which minimises the danger of severing of the electrical conductors of the ribbon cable.

The present invention is directed towards providing such a method and apparatus.

According to the invention there is provided a method for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, electrical conductors of the ribbon cable being connected by soldered connections to electrically conductive tracks of the PCB adjacent the joint, the method comprising the step of applying a lacquer to the ribbon cable and to the PCB adjacent the joint between the ribbon cable and the PCB so that the lacquer forms a fillet between the ribbon cable and the PCB adjacent the joint.

In one embodiment of the invention the lacquer is applied to at least one side of the ribbon cable for forming the fillet on one side thereof. Preferably, the lacquer is applied to both sides of the ribbon cable for forming respective fillets on respective opposite sides of the ribbon cable. Advantageously, each fillet extends along the entire width of the ribbon cable adjacent the joint.

In one embodiment of the invention the depth of each fillet measured along a line

extending perpendicularly from a tangent to the surface of the fillet to the joint of the cable with the PCB lies in the range of 0. 25 mm to 3. 0 mm, and preferably, in the range of 0.5 mm to 2.5 mm, and advantageously, is approximately 1.5 mm.

Preferably, the lacquer is applied to the ribbon cable adjacent the joint so that the lacquer extends longitudinally along the ribbon cable for a distance from the joint in the range of 1 mm to 6 mm, and advantageously, in the range of 2 mm to 4 mm.

In one embodiment of the invention the lacquer extends longitudinally along the ribbon cable from the joint for a distance on one side of the ribbon cable which is longer than the distance along which the lacquer extends on the other side of the ribbon cable from the joint.

In another embodiment of the invention the lacquer is cured, and preferably is cured in a curing oven, which preferably is an infra-red curing oven.

In one embodiment of the invention the lacquer is applied to the ribbon cable and the PCB by spraying. Advantageously, the lacquer is pressurised for urging the lacquer through a spraying nozzle for spraying the lacquer onto the ribbon cable and the PCB.

In one embodiment of the invention the lacquer is an acrylic lacquer sold under the Trade Mark HUMISEAL type 1 R32A Acrylic Coating.

In another embodiment of the invention the lacquer is applied to the ribbon cable and

the PCB in a lacquering station.

In a further embodiment of the invention the PCB is placed on a main support means in the lacquering station and is clamped thereon by a pair of primary clamping means the primary clamping means being operable between a clamping position cooperating with the main support means for clamping the PCB thereon and a release position for disengaging the PCB.

In a further embodiment of the invention the PCB is clamped on the main support means by a pair of secondary clamping means operable between a clamping position co-operating with the main support means for clamping the PCB thereon and a release position for disengaging the PCB.

Advantageously, each secondary clamping means is pivotally mounted relative to the main support means, and is pivotal between the clamping and release positions.

Preferably, the respective secondary clamping means engage a first major surface of the PCB adjacent respective opposite side edges thereof, and are pivoted away from each other from the clamping to the release position for facilitating disengagement of the secondary clamping means from the PCB.

Advantageously, the primary clamping means are slideably mounted relative to the main support means, and are moveable with rectilinear motion between the clamping position and the release position. Preferably, the primary clamping means engage the first major surface of the PCB adjacent the respective opposite side edges thereof.

Ideally, the primary and secondary clamping means are operable from the clamping position to the release position in sequence, whereby the primary clamping means is initially operable from the clamping to the release position and the secondary clamping means is subsequently operable from the clamping to the release position for minimising disturbance of the PCB on the main support means during release of the respective clamping means.

In one embodiment of the invention the PCB is conveyed into and out of the lacquering station on a conveying means.

In another embodiment of the invention the conveying means forms the main support means.

In a further embodiment of the invention the conveying means comprises a pair of spaced apart parallel horizontally extending conveying chains for engaging a second major surface of the PCB adjacent the respective opposite side edges thereof.

Additionally, the invention provides apparatus for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, electrical conductors of the ribbon cable being connected by soldered connections to electrically conductive tracks of the PCB adjacent the joint, the apparatus comprising a main support means for supporting the PCB, a lacquer applying means for applying a lacquer to the ribbon cable and the PCB adjacent the joint for forming a lacquer fillet between the ribbon cable and the PCB adjacent the joint.

In one embodiment of the invention a pair of primary clamping means for clamping the PCB on the main support means are provided, the primary clamping means being operable between a clamping position co-operating with the main support means for clamping the PCB on the main support means and a release position for disengaging the PCB.

In another embodiment of the invention a pair of secondary clamping means for clamping the PCB on the main support means are provided, the secondary clamping means being operable between a clamping position co-operating with the main support means for clamping the PCB on the main support means and a release position for disengaging the PCB.

Preferably, each secondary clamping means is pivotally mounted relative to the main support means and is pivotal between the clamping and release positions.

Advantageously, the respective secondary clamping means are engageable with a first major surface of the PCB adjacent respective opposite side edges thereof and are pivotal away from each other from the clamping to the release position for facilitating disengagement of the secondary clamping means from the PCB.

Preferably, the respective primary clamping means are engageable with the first major surface of the PCB adjacent the respective opposite side edges thereof.

Preferably, each primary clamping means is mounted relative to the main support means to be moveable with rectilinear motion between the clamping and the release

positions.

Ideally, the primary and secondary clamping means are operable in sequence such that the primary clamping means are operable from the clamping to the release position before the secondary clamping means are operable from the clamping to the release position for releasing the PCB from the main support means.

In one embodiment of the invention each clamping means comprises a clamping member for engaging the first major surface of the PCB adjacent the corresponding side edge thereof. Advantageously, each clamping means is operable between the clamping and release positions by an operating ram. Preferably, each operating ram is a pneumatic ram.

In one embodiment of the invention the main support means is located in a lacquering station.

In another embodiment of the invention a conveying means is provided for conveying the PCB to and from the main support means. Preferably, the conveying means forms the main support means. Advantageously, the conveying means comprises a pair of spaced apart parallel horizontally extending conveying chains for engaging a second major surface of the PCB adjacent respective opposite side edges thereof.

In one embodiment of the invention the lacquer applying means comprises a nozzle communicating with a lacquer reservoir for storing the lacquer, and a means for

urging the lacquer through the nozzle. Advantageously, the lacquer applying means is moveable under the control of a control means for applying the lacquer. In one embodiment of the invention the control means controls the movement of the lacquer applying means for applying the lacquer to a substantial area of the PCB and to components mounted thereon.

In another embodiment of the invention an alignment means is provided for aligning the PCB on the main support means with the lacquer applying means. Preferably, the alignment means acts as a stop means for stopping the PCB in alignment with the lacquer applying means when the PCB is being conveyed by the conveying means onto the main support means. Advantageously, the alignment means is moveable between a stop position for engaging and stopping the PCB in alignment with the lacquer applying means, and a release position for facilitating conveying of the PCB from the main support means by the conveying means.

In one embodiment of the invention a curing oven is provided for curing the lacquer on the PCB and on the ribbon cable. Preferably, the curing oven is an infra-red curing oven.

Further the invention provides a PCB comprising a ribbon cable reinforced adjacent a joint of the ribbon cable to the PCB wherein the joint is reinforced by the method according to the invention.

Preferably, the joint is reinforced using the apparatus according to the invention.

The invention will be more clearly understood from the following description of an embodiment thereof which is given by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a panel comprising a plurality of PCBs according to the invention, Fig. 2 is a perspective view of a pair of PCBs according to the invention, Fig. 3 is a transverse cross-sectional view of a portion of the PCBs of Fig. 2, Fig. 4 is an enlarged transverse cross-sectional view of the portion of the PCB of Fig. 3, Fig. 5 is a schematic plan view of apparatus according to the invention for reinforcing a ribbon cable of the PCBs of Fig. 1, Fig. 6 is a diagrammatic perspective view of the apparatus of Fig. 5, Fig. 7 is a plan view of a portion of the apparatus of Fig. 5, Fig. 8 is a transverse cross-sectional end elevational view of the apparatus of Fig. 5 on the line VIII-VIII of Fig. 7,

Fig. 9 is a view similar to Fig. 8 on the line IX-IX of Fig. 7, and Fig. 10 is a perspective view of a portion of the apparatus of Fig. 5.

Referring to the drawings there is illustrated apparatus according to the invention indicated generally by the reference numeral 1 for reinforcing a ribbon cable 2 adjacent joints 3 and 4 to respective PCBs 5 and 6 formed in a panel 7 of the PCBs 5 and 6. Before describing the apparatus 1 the PCBs 5 and 6 and the panel 7 will first be described. Referring in particular to Figs. 1 to 4, the panel 7 comprises four of the PCBs 5 and four of the PCBs 6, each of which have a first major surface, namely, a top surface 8 and a second major surface, namely, a bottom surface 9. A peripheral edge 10 of the panel 7 extends around the PCBs 5 and 6, and the PCBs 5 and 6 are perforated from the peripheral edge 10 and from each other by elongated perforating slots 12. Lugs 14 extending between the peripheral edge 10 and the PCBs 5 and 6, and between the PCBs 5 and 6 in the slots 12 secure the PCBs 5 and 6 to each other and to the peripheral edge 10. On completion of manufacture and before or after testing of the PCBs 5 and 6 the PCBs 5 and 6 are separated from each other and from the peripheral edge 10 by severing the lugs 14. This aspect of the manufacture of PCBs will be well known to those skilled in the art. The PCBs 5 and 6 each comprise a plurality of components (not shown) mounted on the PCBs, and electrically conductive tracks 17, only one of which is illustrated in Fig. 3 of the respective PCBs interconnect the components of the corresponding PCBs, and also connect some of the components to the corresponding ribbon cable 2 at the corresponding joint.

Each ribbon cable 2 comprises a plurality of electrical conductors 15 only one of which is illustrated in Figs. 3 and 4. However, such ribbon cables and their conductors will be well known to those skilled in the art. At respective opposite ends 18 of the ribbon cables 2 insulation is stripped from the conductors 15, which are passed through corresponding bores 19 in the respective PCBs 5 and 6 at which the tracks 17 terminate for connecting to the corresponding conductors 15 of the ribbon cable 2 to the tracks 17. The conductors 15 are soldered to the tracks 17 by solder connections 20 adjacent the bores 19 for making electrically conductive connections between the conductors 15 of the ribbon cables 2 and the corresponding tracks 17.

In this way components on each PCB 5 are electrically connected to components on the corresponding PCB 6.

By virtue of the fact that the conductors 15 of the ribbon cables 2 are soldered directly to the tracks 17 of the PCBs 5 and 6, the conductors 15 adjacent the solder connections 20 are relatively weak and prone to severing if subjected to repeated bending. In particular, when the PCBs 5 and 6 are separated from each other the ribbon cable 2 of each pair of PCBs 5 and 6 is vulnerable to repeated bending at the joints 3 and 4 adjacent the solder connections 20. In order to minimise the danger of severing the conductors 15 of the ribbon cables 2 adjacent the solder connections 20, the ribbon cables 2 are reinforced at the joints 3 and 4 by a method according to the invention carried out in the apparatus 1, whereby a lacquer is applied to the ribbon cables 2 and the PCBs 5 and 6 adjacent the joints 3 and 4 for forming respective fillets 23 on respective opposite sides of each ribbon cable 2 at the joints 3 and 4. The fillets 23 formed by the lacquer reinforce the ribbon cables 2 adjacent the joints 3 and 4 and thereby substantially prevent bending of the ribbon cables 2

adjacent the joints 3 and 4. Any bending of the ribbon cables 2 occurs above and between the fillets 23, so that any bend formed in the ribbon cables 2 has a relatively large radius, and thereby severing of the conductors 15 is avoided. In this embodiment of the invention, the fillets 23 extend completely along the width of each ribbon cable 2 adjacent the joints 3 and 4 on respective opposite sides of the ribbon cable 2. Additionally, the fillets 23 are formed so that the distance A, see Fig. 4 measured along a line extending from a tangent to the surface 25 of each fillet 23 to the corresponding joint 3 and 4 of the ribbon cable 2 is approximately 1.5 mm.

Ideally, the lacquer forming each fillet 23 extends longitudinally along the ribbon cable 2 beyond the fillets 23 on each side of the ribbon cable 2. The lacquer extends longitudinally along the ribbon cable 2 a distance B of approximately 5 mm from the PCB on one side of the ribbon cable 2, and on the other side the lacquer extends longitudinally a distance C of approximately 2 mm from the PCB, see Fig. 3. In this embodiment of the invention, the lacquer is an acrylic lacquer sold under the Trade Mark HUMISEAL type 1 R32A Acrylic Coating, and is applied to the PCBs 5 and 6 and the components thereon to a depth of 50 microns plus or minus 20 microns.

Referring now in particular to Figs. 5 to 10, the apparatus 1 for applying lacquer to the PCBs 5 and 6 and the ribbon cables 2 for forming the fillets 23 in the joints 3 and 4 of the ribbon cables 2 will now be described. The apparatus 1 comprises a housing 30 defining a hollow interior region 31 therein within which a lacquering station 34 is located, wherein the lacquer is applied to the PCBs 5 and 6 and to the ribbon cables 2, see Fig. 6. The housing 30 is open at both ends having an entry opening 35 for accommodating panels 7 of PCBs 5 and 6 into the lacquering station 34 and an exit opening (not shown) for accommodating the panels 7 from the lacquering station 34.

A conveying means comprising a chain conveyor 37 sequentially conveys panels 7 of PCBs 5 and 6 through the lacquering station 34, and from the lacquering station 34 to a curing oven 36 for curing the lacquer, see Fig. 5. The curing oven 36 is an infra-red curing oven 36. The conveyor 37 continues from the curing oven 36 for conveying the panels 7 of the PCBs 5 and 6 for testing and separation.

The conveyor 37 comprises a pair of spaced apart parallel side supports 38, which support respective pairs of parallel horizontally extending endless chains 39 for receiving the panels 7 and for conveying the panels 7 through the lacquering station 34 and the oven 36 in the direction of the arrow D. Drive and idler sprockets (not shown) rotatably carried in the side supports 38 drive the chains 39, drive sprockets (not shown) are driven by a drive motor (not shown). The conveyor 37 forms a main support means at a support area 44 for supporting the panels 7 of PCBs 5 and 6 in the lacquering station 34 during lacquering of the PCBs 5 and 6 and the joints 3 and 4.

A lacquer applying means for applying lacquer to the PCBs 5 and 6 and the ribbon cables 2 adjacent the joints 3 and 4 comprises a spray nozzle 45, which is mounted on a nozzle carrier 46, which in turn is carried on a framework 50. The nozzle carrier 46 and the framework 50 facilitate movement of the nozzle 45 in X, Y and Z directions, namely, longitudinally in the directions of the arrows E and F, transversely in the directions of the arrows G and H, and vertically in the directions of the arrows K and L. A reservoir 47 mounted on the framework 50 stores the lacquer, and a communicating means, namely, a flexible communicating tube 49 extending from the reservoir 47 to the nozzle 45 accommodates lacquer from the reservoir 47 to the

nozzle 45. A pump 43 pumps the lacquer from the reservoir 47 to the nozzle 45, and pressurises the lacquer for urging the lacquer through the spray nozzle 45 in the form of a spray.

The framework 50 in the hollow interior region 31 is slideable on a pair of parallel spaced apart longitudinally extending guide rods 48 in the directions of the arrows E and F for providing movement of the nozzle 45 in the X direction. A pair of parallel spaced apart transversely extending guide rods 51 mounted on the framework 50 slideably carry the nozzle carrier 46 and permit sliding movement in the directions of the arrows G and H for providing movement of the nozzle 45 in the Y direction. A pair of drive motors (not shown), one mounted on the framework 50 and the other mounted on the nozzle carrier 46 drive the framework 50 and nozzle carrier 46, respectively, and in turn the nozzle 45 in the respective X and Y directions. The nozzle 45 is slideably mounted in the carrier plate 46, and is slideable through the carrier plate 46 in the directions of the arrows K and L. A drive motor (not shown) mounted on the nozzle carrier 46 drives the nozzle 45 in the directions of the arrows K and L for driving the nozzle 45 in the Z direction. A control means provided by an electrical control circuit (not shown) controls the operation of the three drive motors (not shown). The operation of such drive motors for imparting drive in X, Y and Z directions will be well known to those skilled in the art.

An alignment means, namely, a pair of stop members 52 are mounted on respective opposite sides of the conveyor 37 on the side supports 38 for stopping and aligning each panel 7 in the support area 44 in alignment with the nozzle carrier 46. Each stop member 52 comprises an L-shaped member 53 having a transversely

extending portion 54 terminating in a downwardly extending abutment member 55 for engaging each panel 7 when it is in the support area 44. A guide rod 56 slideably carried in a linear bearing 57 mounted on the corresponding side support 38 of the conveyor 37 carries each stop member 52. A piston rod 58 of a corresponding pneumatic ram 59 which is mounted on the conveyor 37 adjacent the corresponding linear bearing 57 is secured to the corresponding stop member 52 for urging the stop member 52 in the directions of the arrows P and Q between a stop position for engaging and aligning each panel 7, and a release position for accommodating release and transfer of each panel 7 from the support area 44. In this embodiment of the invention, the guide rods 56 and the linear bearings 57 co-operate with the pneumatic rams 59 for urging the stop members 52 between the stop and release positions with rectilinear motion. Mounting brackets 60 secure the linear bearings 57 and the rams 59 to the corresponding side support 38 of the conveyor 37.

A sensing means comprising a photosensor 61 is located upstream of one of the stop members 52 for detecting a panel 7 arriving in the support area 44. The control circuit (not shown) in response to the photosensor 61 detecting a panel 7 arriving in the support area 44 operates the pneumatic rams 59 from the release to the stop position for abutting and aligning the arriving panel 7 in the support area 44.

A primary clamping means for clamping a panel 7 in the support area 44 to the conveyor 37 during application of the lacquer comprises four primary clamps 65, two primary clamps 65 being mounted on each support member 38 of the conveyor 37 at spaced apart locations as will be described below. A secondary clamping means comprising four secondary clamps 67 are also provided for clamping the panel 7 on

the conveyor 37 in the support area 44 during application of the lacquer. Two secondary clamps 67 are provided on each side support 38 at spaced apart locations. Each primary clamp 65 comprises a primary clamping member 68 which is carried on a clamp carrier 69 for engaging the top surface 8 of the panel 7 adjacent the peripheral edge 10. A guide rod 71 extending downwardly from each clamp carrier 69 is slideable in a linear bearing 72 mounted on the corresponding side support 38. A piston rod 73 extending from a primary clamp drive means, namely, a primary pneumatic ram 74 is connected to the corresponding clamp carrier 69 of each primary clamp 65. The rams 74 urge the clamp carriers 69 and in turn the corresponding primary clamping members 68 in the directions of the arrows R and S with rectilinear motion between a clamping position illustrated in full lines in Figs. 8 and 10 engaging the top surface 8 of the panel 7 for clamping the panel 7 to the conveyor 37, and a release position illustrated in broken lines in Fig. 8 with the clamping members 68 disengaged from the panel 7 for facilitating transfer of the panel 7 from the support area 44 to the curing oven 36. Mounting brackets 75 secure the rams 74 and the linear bearings 72 to the corresponding side supports 38 of the conveyor 37.

The secondary clamps 67 each comprise a secondary clamping member 77 for engaging the top surface 8 of the peripheral edge 10 of the panel 7. Each clamping member 77 is carried on a pivotal carrier arm 78 which is pivotally connected to the corresponding side support 38 by a pivot mounting bracket 79. A secondary drive means comprising a secondary pneumatic ram 80 mounted on the corresponding side support 38 is provided for pivoting the corresponding pivotal carrier arm 78 for in turn operating the corresponding secondary clamping member 77 in the direction

of the arrows T and U between a clamping position illustrated in full lines in Figs. 9 and 10 engaging the peripheral edge 10 of the panel 7 for clamping the panel 7 on the conveyor 37 in the support area 44 and a release position illustrated in broken lines in Fig. 9 with the clamping member 77 disengaged from the panel 7 for accommodating transfer of the panel 7 from the support area 44. Mounting brackets 81 secure the rams 80 to the corresponding side supports 38 of the conveyor 37.

The primary and secondary rams 74 and 80 are operated under the control of the control circuit (not shown) and are simultaneously operated for urging the primary and secondary clamping members 68 and 77 from the release to the clamping position for clamping a panel 7 on the conveyor 37 in the support area 44. The control circuit (not shown) operates the primary and secondary rams 74 and 80 from the clamping to the release position in sequence. The control circuit initially operates the primary rams 74 for operating the primary clamping members 68 from the clamping to the release position, and then after the primary clamping members 68 are in the release position, the secondary rams 80 operate the secondary clamping members 77 from the clamping to the release position. This has the advantage of minimising any danger of the panel 7 remaining adhered to the primary clamping members 68 and being raised upwardly from the conveyor 37 as the primary clamping members 68 are being operated from the clamping to the release position.

By virtue of the fact that the secondary clamps 67 continue to clamp the panel 7 to the conveyor 37 in the support area 44 while the primary clamping members 68 are being moved upwardly with rectilinear motion from the panel 7 into the release position, there is no danger of the panel 7 being carried with the clamping members 68. By virtue of the fact that the secondary clamps 67 are pivotally operated and the

secondary clamping members 77 on respective opposite sides of the conveyor 37 are pivotally operated away from the panel 7 and away from each other into the release position, the secondary clamps 67 on respective opposite sides of the conveyor 37 effectively co-operate with each other as they are being pivoted from the clamping to the release position for disengaging the panel 7 in the support area 44. This co-operating action is caused by virtue of the fact that as the secondary clamping members 77 are pivoting from the clamping to the release positions, the secondary clamping members 77 are urged outwardly from each other and in turn from the panel 7 thereby causing disengagement of the panel 7 by the secondary clamping members 77. This is a particularly important advantage due to the fact that the lacquer tends to be deposited on the panel 7 adjacent the primary and secondary clamping members 68 and 77 which thus tends to cause the primary and secondary clamping members 68 and 77 to adhere to the panel 7. In the absence of the secondary clamps 67, the panel 7 in the support area 44 would tend to remain adhered to the primary clamping members 68 as the primary clamping members 68 were being urged from the clamping to the release position and thus the panel 7 would be raised from the conveyor 37. The clamping members 68 and 77 are tapered to a tip portion 82 for engaging the top surface 8 of the panels 7 for minimising the area of the clamping members 68 and 77 in engagement with the panel 7, thereby further facilitating disengagement of the clamping members 68 and 77 from the panel 7 as the clamping members 68 and 77 are being urged from the clamping to the release position.

In use, panels 7 are placed on the conveyor 37 and are sequentially conveyed by the conveyor 37 into the lacquering station 34. As each panel 7 is approaching the

supporting area 44, it is detected by the photosensor 61. The control circuit (not shown) operates the pneumatic rams 59 for urging the stop members 57 from the release to the stop position for engaging and aligning the panel 7 in the support area 44 with the nozzle carrier 46. On engagement with the stop members 52, the primary and secondary rams 74 and 80 are operated for urging the primary and secondary clamps 65 and 67 from the release to the clamping position for clamping the panel 7 in the support area 44 on the conveyor 37.

Under the control of the control circuit (not shown), the pump 43 pumps lacquer from the reservoir 47 to the nozzle 45, and the nozzle 45 is urged in the X, Y and Z directions by urging the nozzle carrier 46 in the appropriate X and Y directions and the nozzle 45 in the appropriate Z direction, as the lacquer is being applied to the PCBs 5 and 6 and to the components on the PCBs 5 and 6. The nozzle carrier 46 is operated so that the PCBs 5 and 6 are lacquered in pairs, and the pairs of PCBs 5 and 6 are sequentially lacquered. While each pair of PCBs 5 and 6 is being lacquered, the nozzle carrier 46 is urged into appropriate positions for applying lacquer to the joints 3 and 4 of the ribbon cables 2 with the PCBs 5 and 6 on respective opposite sides of the ribbon cables 2 for forming the fillets 23 on the respective opposite sides of the ribbon cables 2. The time the nozzle carrier 46 aligns the nozzle 45 with the respective joints 3 and 4 is controlled by the control circuit (not shown) so that the appropriate quantity of lacquer is dispensed on each side of each ribbon cable 2 at each joint 3 and 4.

On completion of lacquering of the PCBs 5 and 6 the primary clamps 65 are initially operated from the clamping to the release position, and then the secondary clamps

67 are operated from the clamping to the release position. The stop members 52 are then operated from the stop to the release position, and the conveying chains 39 of the conveyor 37 are operated for transferring the panel 7 from the support area 44 through the exit opening (not shown) to the curing oven 36. As the lacquered panel 7 is being transferred from the support area 44, the next panel 7 on the conveyor 37 is being transferred through the entry opening 35 into the support area 44.

Each cured lacquered panel 7 is conveyed from the curing oven 36 by the conveyor 37 to the next appropriate station which may be a test station or a routing station where the lugs 14 are severed so that the PCBs 5 and 6 may be separated from each other and removed from the peripheral edge 10.

The advantages of the invention are many. By virtue of the fact that the fillets 23 extend continuously along the width of each ribbon cable 2 on respective opposite sides thereof adjacent the joints 3 and 4 with the PCBs 5 and 6, the fillets 23 reinforce the ribbon cables 2 at the area where the conductors 15 of the ribbon cables 2 are weakest, and would be vulnerable to severing as a result of repeated bending adjacent the joints 3 and 4.

Claims

Claims 1. A method for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, electrical conductors of the ribbon cable being connected by soldered connections to electrically conductive tracks of the PCB adjacent the joint, the method comprising the step of applying a lacquer to the ribbon cable and to the PCB adjacent the joint between the ribbon cable and the PCB so that the lacquer forms a fillet between the ribbon cable and the PCB adjacent the joint.
2. A method as claimed in Claim 1 in which the lacquer is applied to at least one side of the ribbon cable for forming the fillet on one side thereof.
3. A method as claimed in Claim 1 or 2 in which the lacquer is applied to both sides of the ribbon cable for forming respective fillets on respective opposite sides of the ribbon cable.
4. A method as claimed in any preceding claim in which each fillet extends along the entire width of the ribbon cable adjacent the joint.
5. A method as claimed in any preceding claim in which the depth of each fillet measured along a line extending perpendicularly from a tangent to the surface of the fillet to the joint of the ribbon cable with the PCB lies in the range of 0.25 mm to 3.0

mm.
6. A method as claimed in any preceding claim in which the depth of each fillet measured along a line extending perpendicularly from a tangent to the surface of the

fillet to the joint of the ribbon cable with the PCB lies in the range of 0. 5 mm to 2. 5 mm.
7. A method as claimed in any preceding claim in which the depth of each fillet measured along a line extending perpendicularly from a tangent to the surface of the fillet to the joint of the ribbon cable with the PCB is approximately 1.5 mm.
8. A method as claimed in any preceding claim in which the lacquer is applied to the ribbon cable adjacent the joint so that the lacquer extends longitudinally along the ribbon cable for a distance from the joint in the range of 1 mm to 6 mm.
9. A method as claimed in any preceding claim in which the lacquer is applied to the ribbon cable adjacent the joint so that the lacquer extends longitudinally along the ribbon cable for a distance from the joint in the range of 2 mm to 4 mm.
10. A method as claimed in any preceding claim in which the lacquer extends longitudinally along the ribbon cable from the joint for a distance on one side of the ribbon cable which is longer than the distance along which the lacquer extends on the other side of the ribbon cable from the joint.
11. A method as claimed in any preceding claim in which the lacquer is cured.
12. A method as claimed in any preceding claim in which the lacquer is cured in a curing oven.
13. A method as claimed in any preceding claim in which the lacquer is cured in an infra-red curing oven.
14. A method as claimed in any preceding claim in which the lacquer is applied to the ribbon cable and the PCB by spraying.
15. A method as claimed in Claim 14 in which the lacquer is pressurised for urging the lacquer through a spraying nozzle for spraying the lacquer onto the ribbon cable and the PCB.
16. A method as claimed in any preceding claim in which the lacquer is an acrylic lacquer sold under the Trade Mark HUMISEAL type 1 R32A Acrylic Coating.
17. A method as claimed in any preceding claim in which the lacquer is applied to the ribbon cable and the PCB in a lacquering station.
18. A method as claimed in Claim 17 in which the PCB is placed on a main support means in the lacquering station and is clamped thereon by a pair of primary clamping means the primary clamping means being operable between a clamping position co-operating with the main support means for clamping the PCB thereon and a release position for disengaging the PCB.
19. A method as claimed in Claim 18 in which the PCB is clamped on the main support means by a pair of secondary clamping means operable between a clamping position co-operating with the main support means for clamping the PCB

thereon and a release position for disengaging the PCB.
20. A method as claimed in Claim 19 in which each secondary clamping means is pivotally mounted relative to the main support means, and is pivotal between the clamping and release positions.
21. A method as claimed in Claim 20 in which the respective secondary clamping means engage a first major surface of the PCB adjacent respective opposite side edges thereof, and are pivoted away from each other from the clamping to the release position for facilitating disengagement of the secondary clamping means from the PCB.
22. A method as claimed in Claim 21 in which the primary clamping means are slideably mounted relative to the main support means, and are moveable with rectilinear motion between the clamping position and the release position.
23. A method as claimed in Claim 21 or 22 in which the primary clamping means engage the first major surface of the PCB adjacent the respective opposite side edges thereof.
24. A method as claimed in any of Claims 18 to 23 in which the primary and secondary clamping means are operable from the clamping position to the release position in sequence, whereby the primary clamping means is initially operable from the clamping to the release position and the secondary clamping means is subsequently operable from the clamping to the release position for minimising

disturbance of the PCB on the main support means during release of the respective clamping means.
25. A method as claimed in any of Claims 17 to 24 in which the PCB is conveyed into and out of the lacquering station on a conveying means.
26. A method as claimed in Claim 25 in which the conveying means forms the main support means.
27. A method as claimed in Claim 25 or 26 in which the conveying means comprises a pair of spaced apart parallel horizontally extending conveying chains for engaging a second major surface of the PCB adjacent the respective opposite side edges thereof.
28. A method for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.
29. Apparatus for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, electrical conductors of the ribbon cable being connected by soldered connections to electrically conductive tracks of the PCB adjacent the joint, the apparatus comprising a main support means for supporting the PCB, a lacquer applying means for applying a lacquer to the ribbon cable and the PCB adjacent the joint for forming a lacquer fillet between the ribbon cable and the PCB adjacent the joint.
30. Apparatus as claimed in Claim 29 in which a pair of primary clamping means for clamping the PCB on the main support means are provided, the primary clamping means being operable between a clamping position co-operating with the main support means for clamping the PCB on the main support means and a release position for disengaging the PCB.
31. Apparatus as claimed in Claim 30 in which a pair of secondary clamping means for clamping the PCB on the main support means are provided, the secondary clamping means being operable between a clamping position cooperating with the main support means for clamping the PCB on the main support means and a release position for disengaging the PCB.
32. Apparatus as claimed in Claim 31 in which each secondary clamping means is pivotally mounted relative to the main support means and is pivotal between the clamping and release positions.
33. Apparatus as claimed in Claim 32 in which the respective secondary clamping means are engageable with a first major surface of the PCB adjacent respective opposite side edges thereof and are pivotal away from each other from the clamping to the release position for facilitating disengagement of the secondary clamping means from the PCB.
34. Apparatus as claimed in Claim 33 in which the respective primary clamping means are engageable with the first major surface of the PCB adjacent the

respective opposite side edges thereof.
35. Apparatus as claimed in Claim 33 or 34 in which each primary clamping means is mounted relative to the main support means to be moveable with rectilinear motion between the clamping and the release positions.
36. Apparatus as claimed in any of Claims 33 to 35 in which the primary and secondary clamping means are operable in sequence such that the primary clamping means are operable from the clamping to the release position before the secondary clamping means are operable from the clamping to the release position for releasing the PCB from the main support means.
37. Apparatus as claimed in any of Claims 33 to 36 in which each clamping means comprises a clamping member for engaging the first major surface of the PCB adjacent the corresponding side edge thereof.
38. Apparatus as claimed in any of Claims 33 to 36 in which each clamping means is operable between the clamping and release positions by an operating ram.
39. Apparatus as claimed in Claim 38 in which each operating ram is a pneumatic ram.
40. Apparatus as claimed in any of Claims 29 to 39 in which the main support means is located in a lacquering station.
41. Apparatus as claimed in any of Claims 29 to 40 in which a conveying means is provided for conveying the PCB to and from the main support means.
42. Apparatus as claimed in Claim 41 in which the conveying means forms the main support means.
43. Apparatus as claimed in Claim 41 or 42 in which the conveying means comprises a pair of spaced apart parallel horizontally extending conveying chains for engaging a second major surface of the PCB adjacent respective opposite side edges thereof.
44. Apparatus as claimed in any of Claims 29 to 43 in which the lacquer applying means comprises a nozzle communicating with a lacquer reservoir for storing the lacquer, and a means for urging the lacquer through the nozzle.
45. Apparatus as claimed in any of Claims 29 to 44 in which the lacquer applying means is moveable under the control of a control means for applying the lacquer.
46. Apparatus as claimed in Claim 45 in which the control means controls the movement of the lacquer applying means for applying the lacquer to a substantial area of the PCB and to components mounted thereon.
47. Apparatus as claimed in any of Claim 29 to 46 in which an alignment means is provided for aligning the PCB on the main support means with the lacquer applying means.
48. Apparatus as claimed in Claim 47 in which the alignment means acts as a stop means for stopping the PCB in alignment with the lacquer applying means when the PCB is being conveyed by the conveying means onto the main support means.
49. Apparatus as claimed in Claim 47 or 48 in which the alignment means is moveable between a stop position for engaging and stopping the PCB in alignment with the lacquer applying means, and a release position for facilitating conveying of the PCB from the main support means by the conveying means.
50. Apparatus as claimed in any of Claims 29 to 49 in which a curing oven is provided for curing the lacquer on the PCB and on the ribbon cable.
51. Apparatus as claimed in Claim 50 in which the curing oven is an infra-red curing oven.
52. Apparatus for reinforcing a ribbon cable adjacent a joint of the ribbon cable to a PCB, the apparatus being substantially as described herein with reference to and as illustrated in the accompanying drawings.
53. A PCB comprising a ribbon cable reinforced adjacent a joint of the ribbon cable to the PCB wherein the joint is reinforced by the method as claimed in any of Claims 1 to 28.
54. A PCB as claimed in Claim 53 in which the joint is reinforced using the apparatus as claimed in any of Claims 29 to 52.
55. A PCB substantially as described herein with reference to and as illustrated in the accompanying drawings.