GB2263817A - Process for the production of service boxes for vehicles - Google Patents

Description

2-263817 IMPROVED PROCESS FOR THE PRODUCTION OF SERVICE BOXES This

Invention concerns an improved process for the production of service boxes and their parts having new construction characteristics, format and design which fulfill the purpose for which they were specifically conceived with maximum safety and efficiency.

A service box for cars can be defined as the central mechanism of the electrical connection system in the vehicle.

This service box acts as a support for protection equipment (fuses) as well as for various electrical components, such as relays, diodes, electronic control modules and connectors.

All the connections of the above mentioned components are effected in the box by means of one or various printed circuit boards (PCB's). The circuit boards and the terminals are covered with plastic which protects and secures them.

The service boxes act as connection centres, grouping together the electrical and electronic connections, and are capable of distributing power and control signals to and from the various parts of the vehicle.

Certain aspects of the boxes referred to in the production process below have been described in similarly entitled documents such as Spanish Model No. 228.789 entitled "Electronic distribution box for cars", Spanish Model No. 239.279 "Perfected Electrical Distribution Block", Spanish Invention Patent No. 533.433 "Perfected procedure for the production of electrical distribution boxes", Additional certificate No. 534.841 "Improvements in Invention Patent No. 533.433" and finally, Spanish Invention Patent No. 9001544 "Perfections to production procedure for electrical distribution boxes.

The documents above mentioned contain some of the improvements applicable to electrical distribution boxes developed by the present inventor. The technology has been protected over the years by these patents and the objective of this application is to amalgamate the improvements contained in the previous proposals into one construction which,as stated before would embody the various parts and processes concerned in the production of these service boxes.

The service boxes are connected to the exterior by means of intertconnections, which are metal parts embedded in copper and attached by solder. The main advantage of each new product (i.e. service box) lies in the versatility of its design, which allows adustments or 1 - 3 increase of function at low cost.

Amongst other advantages, these improvements, details of which are given below, include PCB technology, enabling:

a) Less weight than the traditional system b) Less volume than the traditional system c) Decrease in cost compared to present cable system d) Easy assembly of service box in vehicle e) f) g) Prevention of connection errors Access to both the user and mechanic Safe connections The object of this invention is to incorporate the improvements of the previous patents, together with the various parts comprising a general non-specifc service box. The product or the service box is created in the design phase and produced according to the customer's requirements, adapting it to the technology described, which is common to all boexs.

With this object in view, the present invention provides an improved process for the production"of service boxes comprised of a set of PCB's to which have been inserted and soldered the corresponding electrical components, and characterised in that the production process includes at least some of the following steps: printing of components, soldering of components, insertion of bridges, insertion of short pins and long pins, checking - 4 of plane circuits, angling of PCB's by milling of bases, 'Isew ng" of PCBIs along perimeter edges, assembly of covers and fuses, final checking, encasing.

The production process for service boxes begins with the study of the product, paying special attention to technical and dimensional requirements fo the customer. At this first stage, the printed circuit begins to take shape - whether on a simple of multiple board, double sided, angled or otherwise - together with the plastic parts which serve to assemble, seal, attach and separate the boards. The external assemblies in the box, such as connectors, fuses and relays, are also examined at this stage.

The production of the PCB stars from a base with a conducting lamina, generally copper, on top. The base used is normally paper with phenol resins, called FR-2, although FR-4 (glass fibre with epoxy resin) can also be used for car service boxes. The conducting material is chosen for its thickness, depending on the amperage it must withstand; thicknesses up to 400 mm are commonly used.

An anti-solder film or varnish is then applied to the conducting material; the edges of the conduction strips are also oxidised for this purpose, as the anti-rtist film does not reach them.

Electrical connectivity between the two sides of the circuit board is achieved by means of a short pin. Several layers joined together (a multiple board), which may be either single or double sided, are used to form service boxes. The boards are mechanically joined together by long pins, which also form an electrical connection. Four sides, each of copper, can then be connected by means of the long pins (two sides of one board connected to one of the other, the four sides together, or one of one board to one of the other).

The long pins are positioned around the external perimeter of the boards to achieve good mechanical connection, hence the insertion of these long pins is known as "sewing" It is also possible for reasons of volume to use an angled circuit, so that less volume is occupied using the same surface. In this way, PCB's angled at W, 45 and even 180 are possible.

The plastic parts used aredesigned according to the requirements of the customer and the design of the PCB.

The main plastic parts are the plastic supports (basically for fuses, connectors and relays).

The function of the plastic parts is to give mechanical 6 support to the connections, relays and fuses and also to house the PCB, as described below. For a service box to be operative it must be set into the vehicle using screws, which go directly into the body work, or to feethrough screws or suitable clips.

Separators are also used in the assembly for PCB's in the service box. Their purpose is to provide electronic insulation between opposing strips of multiple board PCBIS.

To house relays, fuses and connections each plastic support must be designed so that the corresponding component fits into its housing.

In this way a box is designed to provide a housing for fuses, connectors, relays and the extracting pincer.

The components of the PCB normally used in the recommended production processes are sockets. These are embedded in the board, and are pincer shaped. They generally hold the tab of a fuse, relay or other component, thus making an electrical connection. The tas are components inserted intot he board which act as an interconnection with the exterior, they are normally wide and long with respect to their depth. A group of tabs will form an external connection support socket. Bridges are mechanisms for connecting support socket.

3ridges are mechanisms or connecting the strips of a PCB, when it is impossible to make the same union using the strips themselves due to shortage of space.

Jumpers are also used and have the same function as a bridge, as previously described, but join strips which are angled at 45, 90 and 1800. They are soldered on the side in which they are inserted and do not cross the base.

Another element used is a busber, whih is any type of bridge inserted into the PCB when it is not possible to use the conventional bridge descibed above, whether due to electrical reasons or because of electrical requirements. Finally, conducting screws are also used, their geometry and function will depend on what purpose they are required for.

Other details and characteristics of this invention will be presented in the following description which refers to the accompanying drawings, in which the principal details of the recommended production process are schematically described. These details are given as examples, and refer to a production of a generic service box, but are not limited to the production details given here. This description should therefore be considered as an illustrative view of service box production. which does not exclude any other designs, incorporating part - 8 or all of the operations described.

In the drawings:

Figure 1 show a diagram of the production process for service boxes; Figure 2 shows an elevation of a partial section of a PCB, in which a short pin has been placed; Figure 3 shows a perspective of two PCB's joined by V1 sewing" of large pins around the perimeter; Figure 4 shows elevations of partial transverse sections of a series of PCB's, angled at right angles, acute angles, 1800 and 450; Figure 5 shows an elevation of a partial longitudinal section of a PCB which has been milled to divide multiple boards into single boards; Figure 6 shows an elevation of a longitudinal section of service box which consists of a connector support and fuse support; Figure 7 shows an elevation of a longitudinal section of a separator and its different sections with fastening and hinge details; 9 Figure 8 shows a plan of the fastening mechanism of the pincer mounted on the fuse support; Figure 9 shows a plan elevation and side view of a pincer; Figure 10 shows a plan and elevation of a partial section of the connector fastening system for the connector support, after the tabs have been introduced.

Figure 11 shows an elevation of a longitudinal section of the PCB in which a bridge has been inserted; Figure 12 shows a front elevation, lower plan and development of a bridge; Figure 13 shows elevations of partial sections of a conducting screw; Figure 14 shows an elevation of a partial section of a laser welding system; and Figure 15 shows an elevation of a partial section of an ultrasonic welding system.

A detailed summary of the various element of this invention is given below: (10) printing; (11) soldering components; (13) insertion bridges; (14) insertion pins; - 10 (15) soldering pins; (16) checking of plane circuit; (17) angling; (18) positioning of separators; (19) "sewing "; (20) lateral soldering; (21) fuse and cover assembly (21a) fuse support covers; (21b) relay support cover assembly; (21c) conector support cover assembly; (22) final check; (22a) encasing, (23) Base (24) conducting lamina; (24a) area near pin; (24b) area near component. (25) short pin;-(26) long pin; (27) connector supports; (27a) partitions; (29) service box; (30) tabs; (31) PCB; (32) sockets; (33) cavities; (34) cavities; (35) separator; (36) hinge; (36a) flexible lamina (37) arrow-head ends; (38) arms; (39) fuses; (40) extracting pincer; (40a) pincer sides; (40b) fidges; (40c) claws; (40d) projecting stem; (41) fins; (41a) fin-tip; (42) bridges; (42a) right-angle bends; (43) conducting screws; (43a) head; (43b) indented areas; (43c) polyhedral body; (44) laser beam; (45) mirror; (46) prism; (47) components; (48) laser beam; (49) luminous beams; (49) soldering material.

In one of the operations dealt with in this invention, the production process for a service box (29) with PCB's (31), angled or non-angled and sewn, will be composed of at least some of the following operations:

a) Cutting of short and long pins (25 and 26) to machining of the ends from a b) measure and continuous rod. Cutting of bridges (42), angling of the elbo c) d) e) g) h) i) j) k) bends (42) and machining of their ends. Insertion of short pins (25) or large pins (26) and bridges (42) Soldering of pins (25 and 26) to PCB (31) by tin soldering or by ultrasonic and/or laser welding. Insertion of components such as tabs (30) and sockets (32). Soldering of tabs and sockets (32). Checking of plan circuit Angling of circuit (31), placing a separator in the middle (35). "Sewing" by means of insertion of long pins (26) and subsequent angling. Assembly of the injection-moulded plastic covers for fuse and relay suports.

Assembly of the injection -moulded plastic covers for fuse and relay supports.

Assembly of the fuses and final check.

The production process for a service box whose PCB is angled and "sewn" is carried out on a production line composed of computer-programmed automatic inserters for the different components, a transport line and automatic solderers together with an artificial vision system wihch detects the different colours of the fuses in their corresponding positions, the assembly line is subsequently electronically controlled, printing the reference number and date on the service box (29), if - 12 the part is correctly assembled, or automatically discarding any faulty part.

Soldering is carried our in the following way depending on the type of soldering used. For example:- Soldering by dip: the unsoldered PCB is firstly passed through the "fix" to eliminate all dirt on the copper and thus achieve a better solder. Subsequently the circuit enters a pre-heating area where the ambient temperature is approximately 4000 in order to lessen the thermal shock which it will receive on contact with the tin and finally it is passed through the tin dip which is at a termperature of approximately 245C, and the tin reaches the area to be soldered.

The whole process can be controlled by changing certain variables, such as velocity of the conveyor belt carrying the board or the level of the tin dip covering the areas to be soldered. 60-40 tin should be used, i.e. 63 tin and 17 lead.

Laser welding as seen in Figure 14 is carried out by means of a laser beam (48) which strikes a prism (46), sending out luminous beams (49) to mirrors (45), which reflect these onto the areas (24a) near the pins, thus producing fusion. The laser (49) can be applied directly to the base or pin of the component_to be welded, or - 13 partly to the support and partly to the copper on the conducting lamina (24) which surrounds it, i.e. the surrounding area (24a).

Welding can also be carried out by ultrasound, as shown in Figure 15, in such a way that the bases (47) of the components are joined to the copper of the conducting lamina (24), by fusion. The advantage of ultrasound welding is that the opposite side of the board side is still usable.

The principal operations forming part of the improved production process are described below, with reference to the corresponding figures. Figure 2 shows a pin (25) on a PCB (31) with soldering material (49). The use of long pin (26) allows the electrical union of four sides of copper (24) which can be connected together, as required, by means of these long pins (26), with both sides of one board (31) connected to the conducting part (24) of the other board (31), the four conducting sides (24) connected together or one side (24) of one board (31) connected to one side (24) of the other.

The positioning of the long pins (26) is carried out as shown in Figure 3 along the whole perimeter of the PCBIs (31), so that they have an adequate mechanical connection between them.

- 14 It is also possible due to space shortages to transform the boards (31) by angling them, so that the same working surface of the strips occupies less volume or so that the boards can be adjusted to the exact shape required by the car manufacturer. The result is circuit boards (31) angled at 90, 45' and even 180'.

As can be seen in Figure 4 angling at 90' present two possibilities: angling outwards or inwards, for which the base (23) is milled down accordingly, as shown in Figure 4. Milling of the base varies according to the chosen angle (23). Milling at 900 produces a completely straight profile of the groove with parallel vertical sides, while in a different form of 90' angle milling creates sides which form an approximate 900 angle between them.

When angling is at 45 there are two possibilities: turning outwards or inwards. When angling is outwards, milling produces a groove with parallel vertical sides, while turning inwards produces a groove with sides which form an approximately 450 angle.

When angled at 1800, the distance betwen the two PCB's (31) is governed by the width of milling which should be twice the base width by TT.

- 15 It should be remebered that for all types of base angling (32), after milling the coper layer or conducting lamina (24) without cutting, a thin layer of base (23) should remain whose thickness will vary between 0.02 and 0.01 mm.

Another system used is angling and subsequent sewing through the edges which are not turned.

When PCB's (31) are of smaller dimensions, they can be grouped on a board of greater size and insertion and soldering operations may be carried out as for only one board. To divide the multiple board into single boards, milling as shown in Figure 5 is performed.

Plastic parts, such as the connector support (27) and the fuse suport (28), are designed according to the requirements of the customer, but generally they fit into each other with the PCB's held between them by short pins (25), long pins (26) or bridges (42) as shown in Figure 6. Both sides of the conducting lamina (24) have sockets (32) and tabs (30) which are positioned inside the cavities and designed so that they act as an entrance guide for the corresponding fuses and connectors.

Separators (35) are placed between two PCB's; the former as shown in Figure 7, are equippped with corresponding - 16 hinges (36), which have points of discontinuity, for example those encircled in the drawing. Such points possess a small flexible lamina (36a), in order to give them continuity. At the end of these separators (35) are some arrow-head ends (37) on the end of arms. These (36) hold the separator between the two PCB's (31).

The connector attachment systems requires the support (27) to have fins (41) with fin-tips (41a). These fins are soldered to the walls of the cavities (33) as shown in figure 10, which shows the connector support (30) with several fins (41) and tabs (30). Figure 10 also shows the connector suport with connectors held by the fin-tip (41a).

Bridges (42) which are automatically produced are formed by tin and copper rods, which are firstly cut so as to make bridge heads with a truncated prism configuration at the elbow bends.

Finally, the conducting screws (43) as shown in Figure 13, have a body (43c) with a polyhedral lateral surface which extends into a head at the top (43a) while at the bottom of the polyhedral body (43c) indented areas (43b) as shown in Figure 13, penetrate the PCB (31) and by means of this indentation hold the conducting screw (43) inside the service box (29) and also inside the conducting parts (24) of the PCB (31).

- 17 As will be seen after examining the drawings and accompanying explanations, this Invention Patent Application provides a simple and effective production process by means of a set of easy operations and doubtlessly constitutes a new industrial development.

The invention described in the accompanying figures may be subjected to any alteration of details considered suitable, as long as they do not affect the essence of the Patent, as summarised in the following claims.

- 18

Claims (1)

1. An improved process for the production of service boxes comprised of set of PCB's to which have been inserted and soldered the corresponding electrical components, and characterised in that the production process includes at least some of the following steps: printing of components, soldering of components, insertion of bridges, insertion of short pins and long pins, soldering of short pins and long pins, checking of plane circuits, angling of PCB's along perimeter edges, asembly of covers and fuses, final checking, encasing.

   A process as claimed in CLaim 1 in which to achieve electrical conductivity between the two conducting sides fo the PCB a short pin is used.

   A process as claimed in Claim 1 in which to achieve electrical conductivity between various PCB's with either single or double conducting sides long pins, which also form a mechanical union, are used and electrically connect four sides of conducting material together, or two sides of conducting material of one board with one conducting lamina of another board, or a conducting lamina on one board with another - 19 conducting lamina on another board.

   4.

   6.

   7.

   8.

   9.

   A process as claimed in Claims 1, 2 or 3 in which the mechanical connection between the PCBIs is achieved along the external perimeter of the boards by the insertion of long pins.

   A process as claimed in any preceding claim in which the PCBIs are turned outwards by 90, inwards by 90, outwards by 45, inwards by 45' and to 1800.

   A process as claimed in Claim 5 in which milling of the base layer when turned 900 outwards is carried out leaving the layer lowered and a groove with parallel vertical sides.

   A process as claimed in Claim 5 in which milling on the base layer when the PCBIs are turned 90 inwards produces a groove with vertical sides which form an approximately 90 angle.

   A process as claimed in Claim 5 in which milling on the base layer when the PCB's are turned 45 outwards produces a groove in which the vertical sides are parallel.

   A process as claimed in Claim 5 in which milling - 20 operations on the base layer when the PCB's are turned inwards by 450 produces a groove whose vertical sides form a 45' angle.

   10. A process as claimed in Claim 5 in which the width of milling operations on the base layer when the PCB's are turned by 180' governs the distance between the boards, so that this distance equals twice the base width by TT.

   A process as claimed in any preceding claim in which to divide a multiple PCB into single PCB's the layer of base material is milled following a groove whose vertical sides form an angle between 60 + 50.

   12. A process as claime in Claim 1 which a service box comprises at least a connector support and a fuse and relay support, respectively equipped with partitions and dividing them into groups of cavities and respectively.

   13. A process as claimed in any preceding claim in which separators are placed between two PCB's which are composed of a sheet of thin dielectric material on whose ends are placed, alternately emerging perpendicularly from each side, arrowhead ends supported by arms, the hinge with - 21 flexible lamina being positioned at a predetermined distance from both.

   14. A process as claimed in any preceding claim in which extracting pincers are located for the extraction of fuses, the pincers sides have ridges projecting from the middle of their outer surface and claws at the end of their inside surface. At the pincers' vertex there is a projecting stem.

   15. A process as claimed in an preceding claim in which fins with fintips at their ends emerge perpendicularly from the connector support as a means of holding the connectors to be introduced into the cavity from connection with the tabs.

   16. A process as claimed in any preceding claim in which the insertion of bridges in PCB's is carried out after the development of these bridges by means of cutting rods of tin and copper at predetermined distances and turning them according to elbow bends and after the production of truncated pyramid areas at the end points.

   17. A process as claimed in any preceding claim in which conducting screws have a polyhedral body - 22 whose upper areas extends into a head with screw thread and whose lower area has indented areas.

   18. A process as claimed in any preceding claim in which laser welding operations are carried out by means of a prism which splits light beams and refracts them in mirrors causing the area close to the pins to melt and form two solder areas.

   19. A process as claimed in Claim 1 in which in the ultrasonic welding operation the component bases are joined to the conducting lamina by fusion with these elements and the area.

   An improved process for the production of service boxes for motor vehicles substantially as hereinbefore described with reference to and is illustrated in the accompanying drawings.

   z