EP0949640A1 - Method for producing electronic components comprising a winding - Google Patents

Abstract

A center section wiring spool wire wound coil (2) is used, with ionized air flux blowing during production, which removes static discharges.

Description

The present invention relates to a method advanced electronic components manufacturing comprising a winding.

Many electronic components include a coil formed by a generally ferrite core around from which is wound a very fine wire, with a diameter of the order of a few hundredths of a millimeter.

A method of manufacturing such circuits is known of patent WO 91/00603. This process includes a certain number of steps which will be briefly described here with reference to Figure 1 appended to this application.

An electronic component, designated as a whole by general reference numeral 1, includes a core made of ferrite 2 which is applied against an integrated circuit 4 by means of a mechanical holding device not shown in Figure 1. A dispensing device carrying a reel on which a wire is wound winding 6 is brought into position in order to proceed with the winding of the core 2. The distributor device is moving longitudinally at core 2 and rotating around it, allows regular laying in turns contiguous such as 8 of wire 6 on core 2. After winding of a coil 10 on the core 2, the wire 6 is cut and the dispensing device is brought in front of the next ferrite core. Free ends 12 and 14 wire 6 wound on the core 2 are then taken up by an appropriate device and applied to the studs contact such as 16 of the integrated circuit 4.

Electronic coil components of the kind described above are especially employed in the industry watchmaking and in the automotive industry where they are used in combination with immobilizer systems coded vehicles. In the latter case, the circuit integrated 4 and its associated coil 10 which forms an antenna reception are integrated in a glass tube 18 or in a similar material as shown in Figure 2 attached to this request. Tube 18 is initially opened at one of its ends, and contains an epoxy resin 20 thermosetting. After a centrifugation step which allows the electronic component 1 to be precipitated towards the bottom of tube 18, this is conventionally sealed using a high energy laser beam. The last process step is to polymerize the resin 20 into placing the sealed tube 18 in a baking oven. The tube 18 is then molded for example in the thickness of the handle of an ignition key for a motor vehicle. The integrated circuit 4 enclosed in the tube 18 comprises a identification code which is transmitted by link radio frequency to the central electronic management unit of the vehicle. After receiving the identification code and checking its authenticity, the central unit controls the unlocking of the vehicle immobilizer system.

The above process has advantageously made it possible to mechanize and automate component manufacturing electronics with a winding, thus contributing to a significant drop in the cost price of the coils completed. However, it has been found that this new process manufacturing was accompanied by significant problems of electrostatic discharges. Indeed, the 8 turns of wire 6 are wound on the core 2 at high speed, typically around 50,000 revolutions per minute. However, when of the winding of the wire 6, the turns 8 of the coil 10 rub on each other, which results the appearance of electrostatic charges on the surface of the wire 6. The outer envelope of wire 6 being electrically insulated by means of an insulating lacquer so not to create short circuits between the turns contiguous 8, the electrostatic charges accumulate in coil 10 and cannot be discharged. In the last step of the process where the free ends 12 and 14 of the coil 10 are applied to the pads of contact 16 of integrated circuit 4, static electricity abrupt discharge in the integrated circuit 4 and the destroy. Electrostatic discharge losses commonly seen are in the range of 20-30% of integrated circuits 4.

The object of the present invention is to remedy the problems and disadvantages above by proposing a winding manufacturing process for canceling the electrostatic charges which appear during winding of the turns.

To this end, the present invention relates to a electronic components manufacturing process comprising a winding, in which a device distributor carrying a reel on which is wound a winding wire lays the wire in contiguous turns and regular on a nucleus, this process being characterized by what we force the circulation of an ionized air flow on the winding during manufacture.

Thanks to these characteristics, the present invention provides a manufacturing process in which the fillers electrostatic which appear by friction of turns on each other when winding a wire on a ferrite core are canceled by charges electrics of opposite sign coming from ionized air produced by an air ionizer device. The winding of wire thus becomes electrically neutral, so that its free ends can be welded to the studs contact of an integrated circuit without risk of destroying it by electrostatic discharge.

The present invention also makes it possible to resolve the very delicate problem of load control electrostatics of a moving device. Indeed, it hardly seems possible, given the extremely high distributor speed carrying the reel on which the wire is wound, connect this distributor to earth by means, for example, an electrically conductive strand. Thanks to this invention it becomes possible to control without contact and without a fixed link the electrostatic state of charge of a winding manufacturing bench.

The present invention also relates to a device for implementing the method according to the invention, comprising a reel on which a wire is wound winding and a distributor device which moves longitudinally at and rotating around a core for allow regular installation according to contiguous turns of a winding on the core, characterized in that a air ionizer device arranged inside a frame diffuses on the winding during air manufacturing ionized whose electrical charges cancel out electrostatic charges of opposite sign induced by friction in said winding.

• la figure 1, déjà citée, est une vue générale en perspective d'un bobinage utilisé comme composant d'un circuit intégré ;
• la figure 2, déjà citée, est une vue en perspective d'une variante d'application du circuit électronique de la figure 1, et
• la figure 3 est une vue schématique du dispositif de mise en oeuvre du procédé selon l'invention.

Other characteristics and advantages of the present invention will appear more clearly on reading the detailed description which follows of an example of implementation of the method according to the invention, this example being given purely by way of non-limiting illustration, link with the attached drawings in which:

• Figure 1, already cited, is a general perspective view of a winding used as a component of an integrated circuit;
• FIG. 2, already cited, is a perspective view of an alternative application of the electronic circuit of FIG. 1, and
• Figure 3 is a schematic view of the device for implementing the method according to the invention.

In all that follows, the elements identical to those described above will be designated by the same digital references.

The device for implementing the method according to the invention, designated as a whole by the reference general numeric 22 in Figure 3, includes a reel 24 on which the winding wire 6 is wound. wire 6 enters through an opening 26 in a frame 28 to the interior of which it is guided in translation by means a directional guide device 30. This device guide 30 is for example made up of two buffers felt such as 32 which guide and clean the wire 6 by friction. It should be noted that this first step in guidance and cleaning can be a source generator of electrostatic charges in wire 6.

The wire 6 is then taken up by a device distributor 34 in position above the ferrite core 2. The dispensing device 34 which moves longitudinally to the core 2 and rotating around this allows regular laying in contiguous turns 8 wire 6 on core 2. After winding, wire 6 is cut and its free ends 12 and 14 will be applied by thermocompression on the contact pads 16 of the integrated circuit 4.

According to the present invention, a device air ionizer 36 is disposed inside the frame 28 in which it diffuses ionized air carrying charges electrics which cancel the charges electrostatic of opposite sign induced by friction in wire 6. This becomes electrically again neutral and its free ends 12, 14 can be soldered to the contact pads 16 of the integrated circuit 4 without risk of destroying it by discharge electrostatic.

It goes without saying that various modifications and variants simple fall within the scope of the present invention.

Claims (2)

Component manufacturing process electronic (1) comprising a winding (10), in which a dispensing device (34) carrying a reel (24) on which a winding wire (6) is wound, lays the wire (6) in contiguous (8) and regular turns on a core (2), this process being characterized in that one forces the circulation of an ionized air flow on the winding (10) in manufacturing course. Device for implementing the method according to claim 1, comprising a reel (24) on which is wound a winding wire (6) and a device distributor (34) which moves longitudinally at core (2) and rotating around it to allow a regular installation according to contiguous turns (8) of a winding (10) on the core (2), characterized in that a air ionizer device (36) disposed within a frame (28) diffuses on the winding (10) during manufacture of ionized air including electrical charges come to cancel the electrostatic charges of sign opposite induced by friction in said coil (10).

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