JPS6015160B2 - Method and device for forming an electric circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention thus relates to a method of interconnecting electronic components to form an electrical circuit, said components being secured to a suitably prepared insulating substrate.

The invention also relates to an apparatus for carrying out the method according to the invention.

Apart from the problem of assembling active components on a substrate, it is known that the assembly of miniature designed circuits requires the interconnection of these elements by means of connecting lines.

It is an object of the invention to obtain a highly flexible method for the interconnection of electronic components as described above, in particular for the assembly of prototypes and standard assembly parts by means of a method and a machine for modifying the design as required and in a very short time. It is in.

One design employed in the prior art, the so-called "multi-wire J" type, uses a printed circuit insulated board of the type on which the insulated wires are placed.

After steps including pressing the wire into the synthetic resin, drilling the holes, chemically electrodepositing the copper, tinting, and etching and corroding the connecting studs,
A completed and assembled set of connections ready to receive electronic components is thus obtained.

However, the aforementioned "multi-wire" design has the following drawback: The insulated wires are first routed onto the insulating substrate by a "multi-wire" type tracing machine, which is programmed by an electronic computer. Involves high capital costs. This machine must be installed in the manufacturer's premises and any circuit modifications must be made to the machine. resulting in a modification of the gram. Since the final process of the above-mentioned multi-wire one method is incorporated soon after the insulated wires are installed, it is difficult to modify any of the wiring diagrams.Furthermore, the standard card type board is manufactured by sambling, chemical electrodeposition of copper, etc. The present invention provides a method for preparing interconnect insulated wires in advance by a process consisting of tinting, etching, and in some cases applying adhesive. It is advantageous that the steps consisting of can be carried out at the end of the circuit assembly process, thus making it possible to quickly modify the wiring diagram with great flexibility.Furthermore, it is possible to perform the process consisting of drilled metal holes, flush-mounted connection studs (square legs). , circular pastels, standardized cards with etched tracks are prepared by a process consisting of milling, chemical electrodeposition of copper, tinting, etching and in some cases application of adhesive, and preferably can be pre-prepared in a specialized manufacturer's factory, so that the user has at his disposal an inventory of standardized cards ready for interconnection.

Finally, according to the method according to the invention, the machinery for the arrangement of electrical wires or in other words the interconnection of separate circuits can be installed in the user's factory, so that the design of the wiring diagram can be modified immediately before use. .

More specifically, the present invention is directed to a method for interconnecting components on an insulated substrate by means of insulated wires, which substrate includes metallized holes, etched tracks, pastels and the like from one side of the substrate. having conductive spheres such as connecting studs spaced apart and insulated from other components;
These etched tracks, metallization holes, pastels and connecting studs are preferably tinned; according to the invention, one side of said substrate is coated with a thermosetting adhesive film, which film is coated with metallization. covering the entire surface of the board except for the holes, etched track points where contact occurs, pastels and connecting studs, where each of these conductor circles is automatically joined by an insulated wire inserted into the resin; Electrical connections are made by stripping the wires, soldering them to the aforementioned conductive spheres, and cutting said wires after soldering, these three steps yielding a multi-wire circuit ready for use. Therefore, it is carried out by numerical control.

In the method according to the invention, the insulating substrate is the same as the substrate employed in printed circuits.

The thermosetting adhesive film is attached to one surface of the substrate to provide mechanical strength to the insulated wire. The adhesive film covers the entire surface except the pastel, metallization holes, connecting studs and connector pieces. Adhesive membranes can be attached in several ways. a Dry membrane type in which holes (holes corresponding to conductive spheres) are formed by stamping.

The film adheres to the substrate as a result of slight heating or evaporation of a suitable solvent and passing between two rubber rollers. The membrane is precisely applied by conventional methods. b The film can be applied without special adjustment of the position of the substrate or drilling of holes beforehand; the holes are then formed by chemical attack of the adhesive, which is then screened by a screening method at points where it is not desired to attack the thermoset film. This is done while the adhesive is being protected by the photosensitive resin being coated.

This protective resin is then dissolved after attacking the adhesive film. c The adhesive resin is used in solution and placed directly on the circuit by the screen method.

Each of these steps is performed prior to the wire deployment step itself, and the advantage of this method according to the invention is again the possibility of constructing an inventory of substrates that can be used in several types of circuits. It is clear that the use of a film layer of thermosetting resin is not essential for the practical application of the invention and could be replaced, for example, by a radiation-cured film; it is only necessary that this film be insulating. It has the effect of bonding the line to the substrate and then preferably loses its adhesion to the remaining surface as a result of a transformation of its physical properties by suitable treatment (e.g. removal by heating, radiation or melting). It's about making sure.

In another embodiment of the invention, if the machine for placing the insulated wire simultaneously applies the adhesive locally, or if the wire is coated with an adhesive or a layer which may suitably become an adhesive immediately before installation. Therefore, if the wires could be attached to the substrate with some other adhesive, this film could be made unnecessary.

The invention also relates to an apparatus for implementing said method.

This device has the following components: 'a} A horizontal table and a fixing device for firmly fixing the insulating substrate to the horizontal table.

{b} A translation control device for controlling translation of the horizontal table in two orthogonal directions within the plane of the horizontal table.

'c - A head disposed above a horizontal table, which has a fixed body and a rotating frame connected to the fixed body.

'd} A rotation control device for controlling rotation of the rotating frame around an axis perpendicular to the insulating substrate.

[e' A feeding device for unwinding and feeding insulated wire, the feeding device being coupled to a fixed lug.

'f) A removal device for removing insulation coating from an insulated wire, which is capable of removing insulation coating of an insulated wire corresponding to the position of a conductive sphere connected to the insulated wire, and is connected to an insulating substrate. Device.

A pressing device for pressing an insulated wire onto an insulating substrate, the pressing device being coupled to a rotating frame.

(v) A soldering device for soldering an insulated wire onto a conductive sphere, the device being coupled to a rotating frame.

(i) A cutting device for cutting an insulating wire after soldering an insulated wire, the cutting device being coupled to a rotating frame. Other properties and advantages of the invention will become more apparent from the following description of illustrative embodiments.

The examples described above are not intended to be limiting in any way, but are given for the purpose of explanation with reference to the accompanying drawings. FIG. 1 shows a diagram of an insulating substrate 2, which has a considerable number of electrical wires and etched connection studs.

The entire surface of this board 2 is covered with an adhesive resin, except for insulating connection studs 6, pastels 8, and metal holes 10. Provision is also made for connections, such as connections 14, which are not coated with resin and consist of etched conductive strips formed on the substrate 2.
The tracks or etched lines serve as ground and feed lines.

For example, the ground wire in FIG. 1 is line 12 and etched line 13 is the feed line. Insulated connection studs and metal lined holes, such as those designated by reference numerals 6 and 10,
They are used to form a relay point for wired connections or to insert separate components such as resistors or capacitors inserted between the respective connection studs and the holes. FIG. 2 shows a rotating head in which the feeding, heating and insulated wire stripping, tying, soldering and cutting devices are associated.

The rotating head portion has a fixed barrel 20 that is electrically connected to a rotating frame 24 by a rotating contact member such as a contactor 22;
Said frame is driven by an electric motor 26 acting on a gear 28 fixed thereto and is connected to a fixed Tsukioka 20 by bearings 30,32. The stationary shell 20 has a set of electric wires 34 for supplying the current, an auxiliary device 36 for feeding the insulating conductor, and a solder feed device 27 in which the solder strip passes via the stationary tube 29. a trowel 41 for stripping the wire and at the same time moving said trowel between the position shown in solid lines and the position 43 (these positions are shown in more detail in FIG. 4); and The tip of the soldering iron at position 43 has a blowpipe that directs the air emitted from tube 54. The arm 44 is attached to the rotary frame 24 as a fulcrum and is provided with a spring 46 that presses the reduction wheel 48 against the XY table 50.

Also mounted on the frame 24 are a soldering iron 51 and a cutting knife 52, which serve in some cases for soldering the electric wire 40 to the connecting stud 53 and in other cases for cutting said electric wire after soldering. . Arms 44, 52 are moved by electromagnetic devices designated by reference numerals 55, 57, respectively. The tips of soldering irons 41, 51 will be explained in more detail later. The rotating head in Figure 2 is as follows: For example, a numerical automatic controller operates each member synchronously;
The controller operates electric motor 26, which directs frame 24 in the desired direction of wire movement.

The wire is heated by the coil 38 just before insertion:
Actuation of the control device causes the tip of soldering iron 41 to strip the enamelled wire while applying a predetermined amount of solder fed from tube 29 to the wire. When this portion of wire 40 reaches close to the connecting stud, its movement is
The Y-table 5 is then stopped and the control device applies the solder iron 51 to the wire and the connecting stud to make the solder joint. When this bond is made, knife 52 cuts the wire. Then, by starting the rotary movement of the rotary frame 24 of the head by the electric motor 26 and controlling the movement of the XY table, it is possible to connect the insulated wire to another connection stud. A rolling wheel 48 between the two connecting studs to be connected inserts the wire 40 into the resin 4 of the substrate 2. The rotating head performs an upward displacement movement to move the insulated wire to the connecting stud. Figure 3 shows table 501
FIG. 2 is an enlarged view showing a device for inserting electric wires into the adhesive resin 4 of the substrate 2 to be fixed and bonding them.

The arm 44 to which the rolling wheel 48 is mounted is resiliently coupled to the frame 24 by a spring 46 so that the rolling wheel 48 can be pressed against the insulating substrate with a certain degree of elasticity. The wire 40 is aged just before being inserted into the adhesive resin of the substrate by a coil 38 in which a current is applied between the terminals 101 and 103. For example, the reduction wheel has a diameter of three ribs. The spring 46 ensures that the reduction wheel is applied elastically under pressure so that the connection is satisfactorily made when passing the wire. The rolling wheel is coated with a deformable, non-adhesive elastic membrane on one side 60, so that the transmission of translational, circuit movements is ensured, on the one hand, between the groove and the substrate, and on the other hand, between the groove and the wire. Said groove is in contact with the wire 40 to ensure that contact occurs. In this way, the wire is unwound without any tensile stress,
Otherwise such stresses may result in shearing during a change of direction. The insertion of the wire 40 into the resin 4 is a function of the speed of translation, the heating temperature of the wire, the pressure on the substrate exerted by the reduction wheel 48 and the nature of the adhesive (resin 4).

The operation of stripping and stripping the wires is accomplished with the apparatus shown in FIG. This device has a soldering iron 41, the tip of which is comprised of a suitably shaped tip 42 as shown in FIG. A heater that contributes to heating the tip 42 is composed of an electric wire 70 connected to a power source 72. The tip 42 is in a first position shown in solid line, here at 74, in contact with the wire 40 to be stripped: the solder contained in the tube 29 tines the wire and at the same time It reaches the same height as the tip 42 for stripping. In the second position 43,
The soldering iron is in a horizontal position and the nozzle 76 directs a jet of air to the tip of the tip to dislodge excess tin alloy therefrom. This has become oxidized and can no longer be used for the next stripping operation. The lead-tin alloy contains burnt enamel algae and is emitted at point 78 by an air jet emitted from nozzle 76. This air jet is intense and lasts only a very short time. The lead-tin particles are stored in eight reservoirs, which can be emptied when necessary or replaced at regular intervals. This is controlled by an electromagnet 77. This stripping and tinting operation may be carried out on wires that are either in motion or at rest, depending on the relative speed of stripping the wire and the forward movement of the wire over the substrate 2.

The length of the wire that is stripped depends on the shape and size of the soldering iron tip 42, the wire feed speed, and the contact time between the wire 40 and the tip 42. The tip is heated by the Joule effect under temperature regulation. The outer part of the tip village is covered with metal,
This protects the tip against oxidation at continuous operating temperatures of 400°C. It must furthermore be ensured that this protective layer of metal cannot be tinned, and therefore either a ferrous steel or chromium membrane is chosen for this purpose. FIG. 5 shows a device for soldering a stripped and tinned wire 40 to a connecting stud 53 by means of a tip 51 moved by an electromagnetic device (not shown).

This device connects the tip 51 to the electric wire 40 and the connecting stud 5.
Step 3: Solder the electric wires. This tip is directly heated by conduction because an alternating current (L) of a predetermined duration and amplitude is passed through the tip. In this case, the heating mode is intermittent, and therefore the thermal inertia of the tip 51 must be as low as possible to ensure a very rapid rise and fall of the temperature of the tip 51. The tip is cut to ensure that the heating zone 82 has a shape that provides the best resistance. The heating circuit delivering the current (1) is a voltage-reducing transformer 84, which makes it possible to obtain very high values of current as a secondary at low voltages. Very high frequencies, for example 100 ratio/s, are used to reduce the volume of the air gap. The tip 51 is moved by an electromagnet into two operating positions, namely the top layer and the wire 4 shown in FIG.
0 is moved between the bottom position where the connecting studs are soldered. The tip 51 of the soldering iron is composed of a non-stick material, which provides high chemical resistance and does not form oxides below 400 oo, has high thermal conductivity and good heat capacity.

Preference is given to using tungsten or molybdenum. From the point of view of saving time during stripping, it is advantageous to process wires with a length equal to twice the length of the solder seam (L) (stripped bare length) .

In fact, the wire is soldered under the bare first half and cut there, and the second part of the bare wire is furthermore particularly soldered without tinting to the other connecting stud W. It can be used for. After soldering, the electric wire is cut immediately near the tip 51 of the soldering iron.

The cutting knife consists of a predetermined shaped steel blade that can be actuated by an electromagnet to cut the wire immediately after the solder joint formed between the wire and the connecting stud of the circuit. FIG. 6 shows a tip 42 used for stripping and crimping wire with the apparatus shown in FIG.

A heating device 92 surrounds the tip 42, which is brought to a temperature of approximately 400°C by a source 72 shown in FIG.
The tip 42 has a rectangular parallelepiped shape, into which a wedge-shaped depression formed by two planes is cut, and the intersection line 94 of the two planes is oblique to the edge 96 of the rectangular parallelepiped. The solder 90 (lead-tin solder) is applied to the enamelled wire 4 by the operation of the device 27 shown in FIG.
It is conveyed in a tube 29 to a height of 0. The tip 42 must be tinable, must be resistant to chemical attack, and must not dissolve into the lead-tin alloy as is the case with copper. The tip is made of solid nickel or copper coated with a nickel-iron or nickel armor layer of considerable thickness. The shape of the tip of the tip is designed so that the volume of the lead-tin alloy is small compared to the volume of the tip and does not flow under the tip of the soldering iron (the wire is vertical) due to the action of gravity. be done. The wedge-shaped recess, composed of two planes, forms a crucible that narrows toward the bottom.

In the stripped position, the wire is confined within the volume of lead-tin contained within the recess of the tip 42. 7th
The figure shows a cross-section of a striped substrate to which electrical connections are made by the method and apparatus according to the invention, the epoxy glass substrate 2 being coated with an adhesive thermosetting resin 4.

The metallized holes are coated with a layer 54 of copper and a layer 106 of lead-tin 20 µm thick. An enameled wire 40 connects the two connection stands by means of solder seams 108, 110 obtained according to the invention. Components such as resistors or capacitors may be placed into holes as shown in Figure 7 or soldered flat, in which case the components may be placed on both sides of the circuit and metallized. Holes are not used.
The operations adopted in both cases follow conventional techniques for connecting the components of printed circuits: the ablated substrate formed according to the invention corresponds in nature to a conventional printed circuit. In another embodiment of the invention, a laser is used to solder the insulated wire to the connection stud.

In this example, the laser head is installed at the position of the soldering iron 51 next to the reduction wheel. This alternative embodiment eliminates the need for a spotting and stripping device. Another noteworthy feature is that the cutting operation can also be performed by a laser; said laser can be used in two different ways: with long pulses of small amplitude for soldering, or with short pulses of considerable amplitude for cutting. can be controlled. The cutting device shown at 52 is then also unnecessary. Finally, adhering the Zekken statue would not involve the need to apply an adhesive layer over virtually the entire insulating substrate as contemplated in the previously described embodiments.

In fact, and according to a variant of the invention, the machine includes a device for applying an adhesive layer to the entire track of the insulated wire.

For example, such a device may consist of a bonding needle controlled by the machine to bond with the insulating substrate immediately before applying the wire. The adhesive can also be applied locally by the wire while it is being unwound. In a final alternative embodiment, the insulating substrate is not provided with any adhesive layer at all, in which case the insulating wire is provided with a dry film which becomes self-adhesive by suitable pretreatment (e.g. heating or passing through a suitable solvent). covered with.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of the board before inserting the insulated wire, Fig. 2 is an overall view of the rotary head of the device according to the present invention, Fig. 3 is a diagram of the device according to the present invention for heating the insulated wire and bonding it to the board; Figure 4 is a diagram of a device for stripping and soldering insulated wires, and Figure 5 is a diagram of a device for soldering studded wires.
FIG. 6 shows a perspective view of the tip of a soldering iron for tinting and stripping enamelled insulated wires, and FIG. 7 shows a cross-sectional view of a substrate on which connecting wires and various electronic components according to the invention are provided. 2... Insulated substrate, 20... Fixed body, 24... Rotating frame, 26... Electric motor, 29... Tube, 36... Auxiliary device, 40... Insulated wire, 41, 51 ...Soldering iron, 44...Arm, 48...Reducing wheel, 50...XY table, 52...Cutting device, 53...Connecting stud. FIG. l YenG. 3 FIG- FIG. 2 F old 4 FIG. S FIG. 6

Claims (1)

[Scope of Claims] 1. A method for forming an electric circuit by interconnecting separate conductive spheres formed on an insulating substrate, the method comprising the following steps. (a) Providing an insulated wire and soldering one end thereof, which is not coated with insulation, to one of the conductive spheres. (b) A step of advancing the insulated wire toward the second conductive sphere and removing the insulation coating of the portion of the insulated wire that will be connected to the second conductive sphere. (c) A step in which the insulated wire is brought into contact with the insulated substrate as the insulated wire is advanced, and at this time, the portion of the insulated wire from which the insulation coating is not removed is fixed to the insulated substrate. (d) The part of the insulated wire from which the insulation coating has been removed is
A process that also brings the conductive sphere onto the conductive sphere. (e) Soldering the portion of the insulated wire from which the insulation coating has been removed to the second conductive sphere. (f) cutting the insulated wire so that the portion of the insulated wire that extends beyond the second conductive sphere is separated from the portion that is soldered to the second conductive sphere; 2. In the method according to claim 1, the step of fixing the insulated wire to the insulating substrate is a step of providing a layer of thermosetting resin on all parts of the insulating substrate except for the conductive area, A method comprising the steps of heating the wire and pressing the insulated wire against an insulating substrate in order to embed the wire in a layer of thermosetting resin. 3. In the method according to claim 1, the step of fixing the insulated wire to the insulated substrate includes a step of applying an adhesive only to a portion of the insulated substrate through which the insulated wire passes. Method. 4 In the method according to claim 3, the step of fixing the insulated wire to the insulated substrate includes a step of first applying an adhesive to the insulated wire, and a step of first applying an adhesive to the insulated wire, and a step of applying an adhesive to the insulated wire when bringing the insulated wire into contact with the insulated substrate. A method comprising the step of applying an adhesive onto a substrate. 5. A device for forming an electric circuit by connecting separate conductive spheres formed on an insulating substrate to each other with insulated wires, the device having the following components: (a) A horizontal table and a fixing device for firmly fixing the insulating substrate to the horizontal table. (b) A translational movement control device for controlling the translational movement of the horizontal table in two orthogonal directions within the plane of the horizontal table. (c) A head disposed above the horizontal table, which has a fixed cylinder and a rotating frame connected to the fixed cylinder. (d) A rotation control device for controlling rotation of the rotating frame around an axis perpendicular to the insulating substrate. (e) A feeding device for unwinding and feeding the insulated wire, the feeding device being connected to a fixed cylinder. (f) A removing device for removing insulation coating from an insulated wire, which is capable of removing the insulation coating of the insulated wire in accordance with the position of the conductive sphere connected to the insulated wire, and is connected to an insulating substrate. Device. (g) A pressing device for pressing an insulated wire onto an insulating substrate, the pressing device being coupled to a rotating frame. (h) A soldering device for soldering an insulated wire onto a conductive sphere, the device being coupled to a rotating frame. (i) A cutting device for cutting an insulated wire after soldering the insulated wire, the cutting device being coupled to a rotating frame. 6. The electric circuit forming apparatus according to claim 5, wherein the removing device includes a tinting device for applying tinting to the portion of the insulated wire from which the insulation coating has been removed. Electric circuit forming device. 7. The electric circuit forming apparatus according to claim 5, wherein the pressing device includes a heating device for heating the insulated wire before pressing the insulated wire onto the insulated substrate. Circuit forming device. 8. In the electric circuit forming apparatus according to claim 6, the removing device includes a soldering iron for soldering,
A moving mechanism for bringing this tin soldering iron to the part of the insulated wire where the insulation coating is to be removed, and a moving mechanism for bringing the tin soldering iron to the part of the insulated wire where the insulation coating is to be removed, and a moving mechanism for bringing the tin soldering iron to the part of the insulated wire where the insulation coating is to be removed, and a moving mechanism that applies tin solder material in the vicinity of the point where the tin soldering iron acts on the insulated wire. An electric circuit forming device characterized by having a sparrow solder supply mechanism for supplying solder to insulated wires. 9. In the electric circuit forming apparatus according to claim 8, the removing device includes a retracting device for retracting the soldering iron from the insulated wire until the next removal step; 1. An electrical circuit forming device comprising: a nozzle connected to a pressurizing source for injecting a short-time gas jet to a soldering iron at a position. 10 In the electric circuit forming apparatus according to claim 8, the soldering iron has a tip made of either nickel or copper, and the tip has a considerably thick electrodeposited tip. 1. An electrical circuit-forming device characterized in that the electrodeposited layer is formed of a metal, either a nickel-iron alloy or nickel. 11. In the electric circuit forming apparatus according to claim 8, the soldering iron has a tip in the shape of a rectangular parallelepiped, and the tip has a wedge-shaped groove consisting of two planes, An electric circuit forming device characterized in that the line of intersection of the two planes is inclined with respect to the edge of the rectangular parallelepiped. 12. In the electric circuit forming device according to claim 7, the heating device has a coil wound around an insulated wire and supplied with current, and the coil is arranged so that the insulated wire is placed on an insulated substrate. An electric circuit forming device characterized in that it is placed in close proximity to a point pressed against it. 13. In the electric circuit forming apparatus according to claim 5, the pressing device has a rolling wheel attached to the rotating frame by a spring, and the rolling wheel has a groove for receiving the insulated wire. An electrical circuit forming device characterized in that the groove is formed of a plastic material.