DE3510638C1 - Inductive miniature component, especially a miniature coil, and a method for producing such a component - Google Patents

Abstract

An inductive miniature component, especially a miniature coil, and a method for producing such a component. In the case of a method which can be fully automated, openings are stamped into a strip of metal, strip-shaped connecting contacts which are connected to the opening edge remaining. Each connecting contact consists of two strip sections which are arranged at right angles to one another and of which one represents the outer contact and the other the inner contact which is connected to a winding end. A core consisting of ferromagnetic material is bonded by means of its end surface onto the strip sections. The core is then wound and is extrusion-coated with a sheath. Finally, the component is cut off the strip by cutting the strip sections off from the edge of the opening.

Description

The known miniature component is used for mechanical fastening of the core on the connection contacts those in their transverse dimensions the core surpassing ferrite base plate required, which is detrimental to the achievable inductance, because the size ratio between the core and the entire component is limited.

By integrally formed with the roll-shaped core part Ferrite base plate, the core is asymmetrical and it must be used when feeding the Cores in the manufacturing process must be paid attention to the correct orientation. Farther the multiple bending of the connection contacts is to be regarded as a laborious process.

It is also known from GB-PS 21 08 769, connection contacts in the case of an inductive miniature component directly on the face of the core stick on. These connection contacts are made of a metal wire with a rectangular shape Cross section, which is cut into individual sections, which are then placed on the core can only be glued on. This has the disadvantage that a really durable connection between contact and core is not ensured and the production in one fully automated process is difficult.

It is also from DE-OS 30 36 913 and the "Patents Abstracts of Japan, E-284, December 13, 84, Vor.8, Nr.272 «known, inductive miniature components to be encapsulated as a whole with plastic.

The object on which the invention is based was to provide an inductive To create miniature component of the type mentioned, which is particularly easy is constructed, allows high inductance values and in a simple manner in one fully automated process can be produced, which in a cost-effective manner allows the production of large numbers of items per unit of time.

The solution to the first sub-task is done according to the invention with a inductive miniature component, which is in the characterizing part of claim 1 has specified features. Particularly advantageous embodiments of the invention Components are the subject of claims 2 to 3.

As explained in more detail below using an exemplary embodiment, the miniature component according to the invention is particularly simple in construction by the core is placed directly on the connection contacts without a base plate and the entire component is overmolded with plastic material. Gluing the core serves on the connection contacts, as explained in more detail below, only for temporary fixation during the manufacturing process. The final stability The component is produced by overmolding with plastic material. on this creates a hermetically sealed component. The inventive Component can be manufactured in extremely small dimensions, with because of the special structure good electromagnetic properties and a good one thermal decoupling between the lead out parts of the connection contacts and the contact points can be reached with the winding wire ends.

The invention also relates to a method for fully automatic Production of the component according to the invention with the in the characterizing part of the Patent claim-4 specified features. Advantageous embodiments of the invention The method is described in claims 5 and 6.

The arrangement of the components to be produced on the tape or tape section it also allows each process step of the process according to the invention to be carried out simultaneously for several components arranged one behind the other on the belt. To this Way, it is possible to produce large numbers in the unit of time.

An exemplary embodiment is described below with reference to the accompanying drawings for the component according to the invention and the method of production according to the invention of the component explained in more detail. In the drawings, F i g. 1 in side view in a schematic, greatly enlarged representation, an inductive miniature component; 2 shows the component according to FIG. 1 in a view from below; F i g. 3 in opposite F i g. 2 enlarged view of a partial plan view of a connection contact of the Component according to Figures 1 and 2; F i g. 4 a section in a view from above a metal strip for the production of a component according to FIG. 1 to 3 before Putting on the kernels; FIG. 5 in a sectional view along line V-V in FIG. 4 the tape after placing and winding the uncut shown cores and the connection of the winding wire ends; F i g. 6 in a schematic representation an overall device for carrying out the method for producing a component according to FIG. 1 to 3.

It will first be based on FIG. 1 to 3 the basic structure of the inductive miniature component to be produced, for example a choke coil or a transformer, described in more detail.

The component has a one-piece, massive, symmetrical too an axis, which is also the coil axis of the component, formed, End faces having core made of electrically non-conductive, or only a very Ferrite material exhibiting low electrical conductivity. With the one shown Embodiment is a core 1 is used, which in the longitudinal direction is essentially Has an H-shaped (roll-shaped) cross-section. But of course you can other one-piece cores with a symmetry axis can also be used. To the A winding 2 is arranged around the core, the ends of which are 2a and 2b in further below explained in more detail with connection contacts connected by soldering or welding are.

Of course, several windings can also be applied to the core will. The connection contacts of the component consist of metal strips on an end face of the core 1 are glued on. The component shown has a total of four connection contacts, of which if it is, for example, one Inductance with two electrical connections is two electrical connections can be conductively connected to each other.

Each connection contact consists of a one-piece metal strip with several adjoining strip sections, one of which in each case first strip section 3a, 3b, 3c, 3d is led out to the outside and to the outside Connection of the component is used. A second strip section 4a, 4b, 4c, 4d, the, as shown below, at the beginning of the manufacturing process in the plane of the first strip section and is arranged at right angles to this, closes integrally adjoins the first strip section. The third strip sections 4a, 4b, 4c, 4d serve for connecting the winding ends. In Fig. only one winding is indicated, the ends 2a and 2b of which with the strip sections 4a and 4b are connected. The strip sections 4c and 4d indicated in FIG either remain free or are connected to the ends of a further, not shown Winding connected. The third strip sections 4a, 4b, 4c and 4d are from FIG Level of the strip sections 3a, 3b, 3c, 3d bent out upwards. You wise also at their free ends a widening 5a, which prevents the - Prevents the winding ends from looping around before soldering.

The component is provided except for the external connection Parts of the first strip sections are surrounded by an indicated sheathing 21. This sheathing is done by overmolding or casting.

As shown in greater detail in FIG. 3, each terminal contact in the first strip section in the area of the transition of the first strip section 3c to the second strip section 4c has a punched hole 7, the diameter of which is slightly smaller than the width of the strip section 3c. This creates a certain thermal decoupling between the lead out first strip sections and the second strip section 4c soldered to the winding end and the Bonding point K achieved. In the following, FIG. 4 to 6 the manufacturing process for the production of a component according to FIG. 1 and 2 explained in more detail.

In the manufacturing process, one wound on a roll 11 can be used Metal strip, for example a strip material 0.125 mm thick and 12 mm wide, can be assumed from an alloy containing copper.

The tape 8 is first fed to a first device 12, in which it is brought into a shape by punching, which is shown in the fig. 4 and 5 shown is. Like F i g. 4, the band 8 is provided with punched openings 9, certain portions connected to the edge of the opening 9 within the opening 9 the tape stop. The remaining parts of the tape settle together from four first strip sections 3a, 3b, 3c, 3d, which are symmetrical to the The transverse center axis Q and the longitudinal center line M of the opening 9 are arranged. Included the first strip sections 3a and 3c run parallel to one another and extend in the transverse direction from in F i g. 4 upper edge of the opening 9 to just before the Center line M. The first strip sections 3a and 3c are two further first ones Strip sections 3b and 3d opposite, which differ from the one shown in FIG. 4 lower margin the opening 9 in the transverse direction until just before the longitudinal center line Merstreck.

Near the inner ends of the first strip sections are in each case second and third strip sections 4a, 4b, 4c, 4d arranged, which integrally adjoining the first strip sections in the longitudinal direction of the tape 8 extend over part of the opening width in the longitudinal direction.

The belt 8 is also provided with holes 10 in which transport devices can intervene.

After punching, the band 8 is used to carry out another Process stage of a device 13 supplied, which at the same time from a storage container 14 ferrite cores can be fed. By means of the devices 13, the ferrite cores 1 from above so placed on the tape 8 that each core 1 the inner ends of the first strip sections 3a, 3b, 3c, 3d about the same Chen surface parts covered. So that the device 13 does not first have to be differentiated when the core is put on must, which of the two end faces must be directed downwards, are cores used, which are symmetrical with respect to their transverse center plane. Of the The core is connected to the strip sections of the tape 8 by gluing.

From the device 13, the tape then runs on into the device 15, in which the winding is applied to the core 1. The winding wire will the device 15 is fed from a feed device 16. To carry out the winding can be used per se known machines in which the Winding wire is fed by means of a guide pin coming from above is guided around the core, with it on different, predeterminable orbits can be guided in space. At the beginning and at the end of the winding of the core 1 itself the winding ends around the third strip sections are by means of the same device 4a, 4b, 4c, 4d led around. The guide pin generally plunges during these movements more or less deeply into the openings 9 of the belt 8. The openings 9 must therefore be dimensioned in their width so that the path of the guide pin also with the winding of the second strip sections is not hindered.

After applying the winding, the connection points between the winding ends and the third strip sections 4a, 4b, 4c, 4d by soldering or another type of fastening is fixed in a device 17.

Subsequent to the soldering process, if necessary, in the device 17 the third strip sections 4a, 4b, 4c, 4d are completely or partially bent upwards so that the tape with the wound cores is in a state as shown in FIG. 5 shows the bending up of the third strip sections 4a, 4b, 4c, 4d has the advantage that the transverse dimensions of the finished component be reduced. If the winding ends are guided accordingly, achieved that between the point of attachment of the winding end to the second strip section and the point at which the winding end into the winding applied to the core 1 2 passes, a bent piece of wire forming a strain relief is formed.

In the state that has now been reached, the entire component is provided with a Sheath, for example made of epoxy resin, encapsulated. This can be done, for example, in the device 18, which is supplied with the material from a feed device 19 will. It is possible to either pass the tape as a whole through the device 18 or to divide the tape into individual sections, each of which is several Contain components and insert these sections individually in an injection molding machine.

After the overmolding, the finished component is removed from the tape 8 separated, in which the first strip sections 3a, 3b, 3c, 3d at the edge of the opening 9 can be cut off. This can take place in the device 20.

The process described can be fully automated and is extraordinary flexible in its design. So the movement of the belt 8 through the various Stations take place continuously or gradually.

Furthermore, it is easily possible to switch between different ones very quickly To switch types of components. If, for example, coils are produced, so can the parallel first strip sections 3a and 3c or 3b and 3d, respectively be connected by a bridge and the winding ends are only connected to the second strip sections 4a and 4b. On the other hand, they become transmitters produced, all four connection contacts are electrically isolated from one another.

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Claims (6)

Claims: 1. Inductive miniature component, with a one-piece, massive, symmetrical to an axis, which is also the coil axis of the component is formed, end face having core made of poorly electrically conductive, ferromagnetic material, in particular ferrite material, the core also is symmetrical to an imaginary plane perpendicular to the coil axis, with at least a coil winding arranged around the core, as well as two to one each Connection contacts belonging to the winding and consisting of one-piece metal strips, which first and second lying in one plane, at right angles to each other have arranged strip sections, the connection contacts on the one End face of the core are attached so that the external connection of the inductive Component provided first strip sections and the second strip sections are perpendicular to the coil axis and -whereby the connection contacts continue to be third, each have strip sections adjoining the second strip sections and the ends of the third strip sections each with one end of a coil winding are connected, characterized in that the connection contacts (3a-4a, 3b-4b, 3c-4c, 3d-4d) are glued directly onto one end face of the core (1), where at least 50% of the face of those resting on this face Areas of the connection contacts (3a-3d, 4a-4d) are covered and each of the to the outside Connection serving first strip sections (3a-3d) in the region of the transition between the first and second strip section (3a-4a to 3d-4d) at least one extending over part of its width through the metal strip Has recess (7) and that the core, coil windings and connection contacts in such a way are coated with plastic material (21), so that only the outer ends of the for the external connection of the component serving strip sections (3a, 3b, 3c, 3d) protrude laterally from the plastic material. 2. Component according to claim 1, characterized in that each the first strip sections (3a to 3d) serving for the external connection have a larger one Has length as the sum of the lengths of the respectively associated second and third Strip sections (4a -4d). 3. Component according to claim 1 or 2, characterized in that serving to connect the coil winding third strip sections in direction are angled towards the coil axis. 4. Process for the production of an inductive miniature component according to one of claims 1 to 3, in which a band or band section made of metal is continuously provided with punched openings, such that within each of the openings with at least two connection contacts connected to the edge of the opening first, second and third strip sections arise and the structure of the component furthermore takes place in that the coil core is connected to the strip sections, then is wound and the winding wire ends contacted with the third strip sections cut off the remaining winding wire and after completion of the construction the component is separated from the tape or tape section by punching, characterized by the following process steps: (a) The openings (9) are punched in such a way that that the first strip sections (3a-3d) extend immediately in front of the opening center line (M) extend and the second strip sections (4a-4d) only over a small one Part of the opening width extended and it will be in the first strip sections (3a-3d) in the area of the transitions between the first and second strip sections (3c-4c) recesses (7) -punched, extending over part of the width of the strip section extend; (b) the coil core (1) is immediately so on with an end face the strip sections placed so that the inner ends of all the first strip sections covered to equal parts of the surface and with these strip sections by gluing tied together; (c) the component is after winding the core (1) and contacting of the winding wire ends with the third strip sections except for the outer one Connection of the component provided parts of the first strip sections completely encapsulated with plastic material (21). 5. The method according to claim 4, characterized in that the tape (8) or the band section is provided with openings (9) in such a way that the with the Opening edge connected first strip sections (3a, 3b, 3c, 3d) in the transverse direction run to the band (8). 6. The method according to any one of claims 4 to 5, characterized in that that between the respective parallel first loop sections (3a, 3b, 3c, 3d) consist of a bridge extending over at least part of its length remain. The invention relates to an inductive miniature component with the features from the preamble of claim 1 and a method for Production of such a component according to the preamble of the claim 4th Such a component, the core, however, not being symmetrical to a plane perpendicular to the coil axis and a corresponding manufacturing process, are known from DE-OS 26 17 465. In the component known from DE-OS 26 17 465 there is the core made of poorly electrically conductive, ferromagnetic material. The known core has a roller-shaped core member and a base plate formed integrally therewith on; both are made of ferrite material. The connection contacts are with this base plate connected by resting on their underside and by having the winding ends the coil connected strip sections of the connection contacts the ferrite base plate grip around claw-like so that their ends on the top of the ferrite base plate rest outside of the roll-shaped core part.