Electronic Component and Process for Producing Same

Abstract

The invention relates to an electronic component with a cavity in which a magnetic circuit is arranged, the magnetic circuit being formed by the first and second magnetic conductor elements, which have at least one planar coil located between them, each of the magnetic conductor elements having at least one bridge-shaped area, and the turns of the planar coils passing through between the bridge-shaped areas of the magnetic conductor elements, each of the bridge-shaped areas having a first end, the first ends that are opposite one another forming a coil core for the planar coil, and the bridge-shaped areas each having a second end, the opposite second ends closing the magnetic circuit on the periphery of the planar coil.

Claims

1. An electronic component comprising: a cavity; a magnetic circuit arranged within the cavity, the magnetic circuit being formed by first and second magnetic conductor elements including a plurality of planar coils located between the first and second magnetic conductor elements, each of the first and second magnetic conductor elements including: bridge-shaped areas; and turns of the plurality of planar coil passing through between the bridge-shaped areas of the first and second magnetic conductor elements, each of the bridge-shaped area including first ends and second ends, the first ends that are opposite one another forming a coil core for one of the plurality of planar coils the second ends that are opposite one another closing the magnetic circuit on a periphery of the one of the plurality of planar coils.

2. The electronic component according to claim 1, wherein each of the first and second magnetic conductor elements is bow-shaped, star-shaped, or x-shaped and includes multiple bridge-shaped areas, which are arranged around the first ends at same or different angular distances.

3. The electronic component according to claim 1, wherein at least one of the plurality of planar coils is formed on a printed circuit board layer.

4. The electronic component according to claim 3, wherein a first planar coil of the plurality of planar coils forms a primary side of a transformer and a second planar coil of the plurality of planar coils forms a secondary side of the transformer, the first and second planar coils being arranged to be mirror symmetric to one another.

5. The electronic component according to claim 4, wherein a first part of at least one of the plurality of planar coils is arranged on a first side of the printed circuit board layer and a second part of the at least one of the plurality of planar coils is arranged on a second side of the printed circuit board layer opposite the first side, the first and second parts of the planar coil being electrically connected with one another by a via passing through the printed circuit board layer.

6. The electronic component according to claim 5, wherein: the printed circuit board layer includes a plurality of printed circuit board layers including a first printed circuit board layer and a second printed circuit board layer; and the first and second planar coils are formed on first and second printed circuit board layers, insulation layers being arranged between the first and second printed circuit board layers and on at least one surface of each of the first and second printed circuit board layers, the first and second printed circuit board layers and the insulation layers forming a coil package as a structural unit.

7. The electronic component according to claim 6, the coil package being arranged between the first and second magnetic conductor elements, the cavity being designed so that the magnetic circuit is fixed in the cavity, so that at least the second ends of the opposite conductor elements touch one another, the bridge-shaped areas of the conductor elements each extending parallel to the first and second planar coils.

8. The electronic component according to claim 7, wherein an air gap is formed between the first ends.

9. The electronic component according to claim 1, wherein the cavity is formed by one or more printed circuit board layers.

10. The electronic component according to claim 9, wherein the one or more printed circuit board layers have a coefficient of thermal expansion that is greater than that of ferrite of which the first and second magnetic conductor elements are formed; and the magnetic circuit further including at least one elastic element arranged in the cavity, the at least one elastic element configured to press the first and second magnetic conductor elements against one another to compensate for different coefficients of thermal expansion.

11. The electronic component according to claim 10, wherein the at least one elastic element is formed by a spring element.

12. The electronic component according to claim 11, wherein spring travel of the spring element is 10 m to 30 m.

13. The electronic component according to claim 11, wherein the electronic component is in the form of a multilayer component, and a printed circuit board layer of the multilayer component comprises the spring element.

14. The electronic component according to claim 10, wherein the at least one elastic element is formed by foam arranged in the cavity.

15. The electronic component according to claim 1, wherein an end face of the first end is equal to sum of end faces of the second ends of one of the first and second conductor elements, the first and second conductor elements preferably having an identical shape.

16. A printed circuit board comprising: at least one printed circuit board layer; and an electronic component arranged on or in the at least one printed circuit board layer, the electronic component including: a cavity; a magnetic circuit arranged within the cavity, the magnetic circuit formed by first and second magnetic conductor elements including a plurality of planar coils located between the first and second magnetic conductor elements, each of the first and second magnetic conductor elements including: bridge-shaped areas; and turns of the plurality of planar coils passing through between the bridge-shaped areas of the first and second magnetic conductor elements, each of the bridge-shaped areas including first ends and second ends, the first ends that are opposite one another forming a coil core for one of the plurality of planar coils, the second ends that are opposite one another closing the magnetic circuit on a periphery of the one of the plurality of planar coils.

17. The printed circuit board according to claim 16, including an electronic circuit that has an operating voltage, the electronic component being electrically connected to the electronic circuit and configured to make the operating voltage available.

18. The printed circuit board according to claim 16, further including a circuit with an interference suppression choke and the electronic component, the interference suppression choke including at least one of a current-compensated choke or a common mode choke.

19. The printed circuit board of claim 18, wherein the circuit includes a switched mode power supply or network filter.

20. The printed circuit board of claim 16, further including a DC-DC converter with the electronic component.

21. A production process for an electronic component, the production process comprising: producing at least one planar coil on a substrate; applying insulation layers onto the substrate to form a coil package; forming a magnetic circuit with the coil package arranged between first and second magnetic conductor elements formed within a cavity that is formed in at least one printed circuit board structure.

22. The production process according to claim 21, wherein the cavity is formed by at least one of a forming tool, a stamping tool, and an embossing roller.

23. The production process according to claim 21, wherein the printed circuit board structure and the magnetic circuit form a stack structure, which is formed by applying pressure to a structural unit in a multilayer process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the invention will be explained in detail below with reference to the figures. The figures are as follows:

[0030] FIG. 1 a cross section through a stack structure of a first embodiment of an inventive electronic component;

[0031] FIG. 2 depicts an embodiment of the primary and secondary coils;

[0032] FIGS. 3a-3d depict an embodiment of the production of the primary and secondary coils;

[0033] FIGS. 4a-4d depict an embodiment of the first and second magnetic conductor elements;

[0034] FIG. 5 depicts an embodiment of an electronic component with a spring mechanism;

[0035] FIG. 6 depicts an embodiment of a stack structure of the electronic component with a spring mechanism;

[0036] FIG. 7 depicts the stack structure of FIG. 6 after a multilayer process is carried out;

[0037] FIG. 8 depicts an embodiment of an electronic component with a foam;

[0038] FIG. 9 depicts another embodiment of an electronic component with a foam;

[0039] FIG. 10 depicts an embodiment of a printed circuit board with an embodiment of a discrete electronic component arranged on it;

[0040] FIG. 11 depicts an embodiment of a LAN transformer with common mode choke; and

[0041] FIG. 12 depicts an embodiment of a SEPIC converter.

[0042] In the following description of the embodiments, elements that correspond to one another or are the same are always labeled with identical reference numbers.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0043] FIG. 1 shows a cross-sectional view of an embodiment of an inventive discrete electronic component 1. The component 1 has, for example, a lower printed circuit board layer 2 and an upper printed circuit board layer 3, which are shaped so that a cavity 4 results between the printed circuit board layers 2 and 3. The cavity can be milled or, if produced in larger numbers, it can be put into both printed circuit board layers, or at least into one printed circuit board layer, with a corresponding forming tool, e.g., it can be embossed, e.g., by means of an embossing roller.

[0044] Each of the printed circuit board layers can be a so-called prepreg. In particular, it can be a glass fiber mat soaked with epoxy resin (for example, FR-4 materials).

[0045] The cavity 4 has a magnetic circuit arranged in it, which is formed by a first magnetic conductor element 5, a second magnetic conductor element 6, and a coil package 7 arranged between the conductor elements 5 and 6, this coil package 7 having at least one planar coil. The magnetic conductor element 5 has a first end 8, which projects in the axial direction into a central opening of the coil package 7. The magnetic conductor element 5 also has two second ends 9 and 9 on the periphery of the coil package 7.

[0046] The magnetic conductor element 6 has a corresponding first end 10, which is opposite the first end 8 in the central opening of the coil package 7, and second ends 11 and 11, which are opposite the second ends 9 and 9. For example, the magnetic conductor elements 5 and 6 are identical, so that if the component 1 is mass produced, the same components can be used to realize the conductor elements 5 and 6.

[0047] The conductor elements 5, 6 can be bow-shaped, for example. In the embodiment of FIG. 1, each of the conductor elements 5, 6 has two bridge-shaped areas, i.e., the conductor element 5 has the bridge-shaped areas 12 and 12, which connect the first end 8 with each of the second ends 9 and 9 and the magnetic conductor element 6 has the bridge-shaped areas 13 and 13, each of which connects the first end 10 with the second ends 11 and 11.

[0048] Each of the magnetic conductor elements 5, 6 consists of a ferrite having a high magnetic permeability.

[0049] In the representation according to FIG. 1, the turns of the planar coil of the coil package 10 run in a circle around the first ends 8 and 10, perpendicular to the plane of projection. The first ends 8, 10 form the coil core. The magnetic circuit is closed by the bridge-shaped areas that span the coil package 7, on one side by the second ends 9 and 11 that are opposite one another and, on the other side, by the ends 9 and 11 that are opposite one another.

[0050] FIG. 1 shows component 1 in a stack structure, in which the printed circuit board layers 2 and 3 are connected together into a structural unit, which can be done by a printed circuit board process known in the art. For example, this can be accomplished by pressing the printed circuit board layers 2 and 3 onto one another at an elevated temperature.

[0051] According to embodiments of the invention, the end faces of the second ends 9 and 11 or 9 and 10 lie on top of one another, while an air gap 14 remains between the end faces of the first ends 8 and 10.

[0052] FIG. 2 shows an embodiment of the invention for producing the coil package 7 with a primary coil 15 and a secondary coil 16.

[0053] The procedure to produce the primary coil 15 involves first applying a first part 17 of the turns of the primary coil 15, for example on the top of a printed circuit board layer 18, for example using a lithographic process, and, by contrast, applying a second part 19 of the turns of the primary coil 15 on the bottom of the printed circuit board layer 18. The parts 17 and 19 of the primary coil 15 are electrically connected with one another by a feedthrough 20, that is, a so-called via through the printed circuit board layer 18. The resulting primary coil 15 has connection contacts 21 and 22.

[0054] The procedure to produce the secondary coil 16 is analogous, and involves applying a part 23 of the turns of the secondary coil 16, for example on the top of a printed circuit board layer 24, and applying a second part 25 of the secondary coil 16 on the bottom of the printed circuit board layer 24, the parts 23 and 25 being electrically connected with one another by a feedthrough 26 (cf. FIG. 3b). The resulting secondary coil 16 has connection contacts 27 and 28.

[0055] FIG. 3 shows the corresponding process steps. In the first step (FIG. 3a), the printed circuit board layers 18 and 24 are made available. In the second step (FIG. 3b) the printed circuit board layers 18 and 24 have the feedthroughs 20 and 26 put in them, which can be done using processes known in the art for producing so-called vias. According to one embodiment of the invention, first the feedthroughs 20 and 26 are produced and then the conductor tracks are created.

[0056] In the third step (FIG. 3c) the primary coil 15 and the secondary coil 16 are produced by applying the parts 17 and 19 or 22 and 23, respectively, on the top or bottom of the respective printed circuit board layers 18 and 24. That is, the primary coil 15 is produced by first providing the printed circuit board layer 18 with the feedthrough 20, and then applying the conductor track of part 17 of the turns of the primary coil 15 onto the top of the printed circuit board layer 18 and part 19 of the turns of the primary coil 15 onto the bottom of the printed circuit board layer 18, the parts 17 and 19 of the turns being connected with one another through the feedthrough 20. An analogous procedure is used to produce the secondary coil 16 with the parts 23 and 25 of the turn of the secondary coil 16, by applying part 23 onto the top of the printed circuit board layer 24 and part 25 onto the bottom of the printed circuit board layer 24, after the feedthrough 26 has been produced.

[0057] In the fourth step, the coil package 7 is then formed (FIG. 3d), by putting another layer 29 between the printed circuit board layers 18 and 24, another layer 30 under the printed circuit board layer 24, and another layer 31 onto the printed circuit board layer 18, the other layers 29, 30, and 31 acting as electrical insulators. A printed circuit board process known in the art creates, from the layers 30, 24, 29, 18, and 31, a multilayer printed circuit board (MLPCB) as a structural unit to realize the coil package 7.

[0058] FIG. 4a is a top view of another embodiment of a magnetic conductor element 5, which here is X-shaped with four bridge-shaped areas 12. Here each of the individual bridge-shaped areas includes a right angle with other bridge-shaped areas. Embodiments are also possible in which the bridge-shaped areas include the same or different angles with other bridge-shaped areas. Likewise, the number of bridge-shaped areas that an individual conductor element 5, 6 has can vary, and can be, e.g., 2, 3, 4, 5, or 6. Both conductor elements 5, 6 have an identical number of the number of bridge-shaped areas.

[0059] In the embodiment according to FIG. 4a, the sum of the end faces of the second ends 9, i.e., 9, 9, 9, and 9, is the same as the end face of the first end 8, which is advantageous for conducting the magnetic flux, which is not narrowed by the effective cross section.

[0060] FIG. 4b shows a lateral section of the magnetic conductor element 5 of FIG. 4a.

[0061] FIG. 4c is a perspective view showing the magnetic conductor elements 5 and 6, which are identical to one another in the embodiment seen here.

[0062] FIG. 4d is a top view of the resulting finished construction of the magnetic circuit with the conductor elements 5 (at the top, not shown) and 6 arranged on top of one another and the coil package 7 located between them.

[0063] FIG. 5 shows an embodiment of the component 1 with spring elements 32, 33, which are arranged in the cavity 4, to press the magnetic conductor elements 5 and 6 against one another. This ensures that even if there are changes in temperature accompanied by changes in the length of the cavity 4 and the ferrite cores, the magnetic conductor elements 5 and 6 remain in mechanical contact with one another, so that the magnetic circuit remains intact.

[0064] FIG. 6 shows a detail of an embodiment of component 1, which has a coil package 7 with three pairs of primary and secondary coils in it. Spring elements 32 and 33 can be formed in a layer of material, e.g., a glass fiber mat or a prepreg material, this layer being part of the layer structure of component 1. Spring elements 32 and 33 are designed to press the magnetic conductor elements 5 and 6 against one another after the multilayer process is carried out, as is shown in FIG. 7, in particular to do so even if there are changes in temperature accompanied by changes in the length of the cavity 4 and the ferrite cores.

[0065] FIG. 6 shows component 1 as a stack structure before the multilayer process is carried out; FIG. 7 shows the component 1 in the finished state, after the multilayer process has been carried out, creating a structural unit of the component 1.

[0066] FIG. 8 shows an embodiment that is an alternative to that of FIG. 5; in this alternative embodiment the spring elements 32, 33 have been replaced by a foam filling at the top and bottom of cavity 4. For example, polyurethane foam 35 is used for this purpose.

[0067] FIG. 9 shows a further development of the embodiment according to FIG. 8, the embodiment according to FIG. 9 having electronic components 36 arranged on or in the printed circuit board layer 3. These electronic components 36 can be connected with the coil package 7.

[0068] FIG. 10 shows a printed circuit board 37 with an electronic circuit 38 and an embodiment of an inventive electronic component 1. For example, the component 1 is in the form of a transformer and is connected with the electronic circuit through conductor tracks 39 of the printed circuit board 37, to supply the circuit 38 with an operating voltage when a voltage source (not shown) is connected to the component 1.

[0069] For example, the circuit 38 is a drive circuit for an automobile headlight.

[0070] Embodiments of an inventive electronic component can be used as an interference suppression choke, in particular a current-compensated choke or a common mode choke (CMC). Such current-compensated chokes are known in the prior art and are used to suppress emitted interference. For common-mode interference, a current-compensated choke forms a very high inductance, since the interfering currents are not compensated in it. To accomplish this, current-compensated chokes are used at the inputs and outputs of switched mode power supplies and in network filters, especially also in LAN transformers.

[0071] FIG. 11 shows an embodiment of a LAN transformer 40 that comprises a transformer 41 and an embodiment of the component 1, which here is in the form of, and is connected as, a common mode choke (CMC).

[0072] Here component 1 has 4 terminals and, according to the embodiment according to FIGS. 2-9 two planar coils, which belong to the magnetic circuit 44 formed by the magnetic conductor elements 5 and 6. The first planar coil 42 (cf. primary coil 15) has the connections a (corresponding to connection contact 21) and a (corresponding to connection contact 22), and the second planar coil 43 has connection contact b (corresponding to connection contact 27) and connection contact b (corresponding to connection contact 28).

[0073] The transformer 41 has the signal inputs d and f and the ground conductor e. On the output side, the transformer 41 has the ground conductor c and is connected with the connection contacts a and b of component 1, in order, for example, to couple in an input signal applied to the signal inputs d and f through the transformer 41 and the common mode choke formed by the component 1 into a LAN cable, which is located on the side of the common mode choke 1.

[0074] According to embodiments of the invention, an inventive component 1 is used to realize a DC-DC converter, in particular a capacitor-coupled switching regulator, in particular for a SEPIC converter (abbreviation for single ended primary inductance converter), a CUK converter, or a zeta converter.

[0075] FIG. 12 shows the circuit diagram of a SEPIC converter, as it is known in principle from the prior art (https://de.wikipedia.org/wiki/sepic). In contrast to the prior art, according to the invention the inductances L1 and L2 are realized by an embodiment of the inventive component 1, the inductances L1 and L2 belonging to the magnetic circuit 44, which is formed by the conductor elements 5 and 6. The coupling coefficient of the inductances L1 and L2 can be, for example, 0.5 to 0.9, especially 0.6 to 0.8. The electronic components of the SEPIC converter can be arranged according to the embodiment according to FIG. 9; cf. the electronic components 36 shown there.

[0076] The SEPIC converter according to FIG. 12 can be used as a DC/DC converter to operate LEDs as driving light in the automobile. The input voltage UE can be the motor vehicle electrical system voltage of about 12 V and the output voltage UA can be the operating voltage of about 6.6 V required for operation of an LED module, for example.

LIST OF REFERENCE NUMBERS

[0077] 1 Component [0078] 2 Printed circuit board layer [0079] 3 Printed circuit board layer [0080] 4 Cavity [0081] 5 First magnetic conductor element [0082] 6 Second magnetic conductor element [0083] 7 Coil package [0084] 8 First end [0085] 9 Second end [0086] 9 Second end [0087] 10 First end [0088] 11 Second end [0089] 11 Second end [0090] 12 Bridge-shaped area [0091] 12Bridge-shaped area [0092] 13 Bridge-shaped area [0093] 13Bridge-shaped area [0094] 14 Air gap [0095] 15 Primary coil [0096] 16 Secondary coil [0097] 17 Part [0098] 18 Printed circuit board layer [0099] 19 Part [0100] 20 Feedthrough [0101] 21 Connection contact [0102] 22 Connection contact [0103] 23 Part [0104] 24 Printed circuit board layer [0105] 25 Part [0106] 26 Feedthrough [0107] 27 Connection contact [0108] 28 Connection contact [0109] 29 Printed circuit board layer [0110] 30 Printed circuit board layer [0111] 31 Printed circuit board layer [0112] 32 Spring element [0113] 33 Spring element [0114] 34 Connection pad [0115] 35 Polyurethane foam [0116] 36 Electronic component [0117] 37 Printed circuit board [0118] 38 Electronic circuit [0119] 39 Conductor tracks [0120] 40 LAN transformer [0121] 41 Transformer [0122] 42 Planar coil [0123] 43 Planar coil [0124] 44 Magnetic circuit