Electric component assembly

Abstract

A component assembly is disclosed. In an embodiment the assembly includes a carrier, a metallic structure arranged on the carrier, wherein the metallic structure comprises at least one cavity and an electrical component arranged at least in part in the cavity, wherein the metallic structure comprises at least two part regions which are not connected to each other by any further part of the metallic structure, and wherein the cavity is located between the two part regions. The assembly further includes two contact areas located on the carrier, wherein the component is located on the two contact areas such that each part region of the two part regions is located on one of the two contact areas.

Claims

1. A component assembly comprising: a carrier comprising an electrically insulating material, wherein the electrically insulating material forms a planar surface; a metallic structure arranged on the planar surface of the carrier such that the metallic structure is neither partially nor fully embedded in the electrically insulating material of the carrier, wherein the metallic structure defines at least one cavity such that a surface of an inner wall of the cavity is formed by the metallic structure; and an electrical component arranged at least in part in the cavity, wherein the metallic structure comprises at least two part regions which are not connected to each other by any further part of the metallic structure, wherein the cavity is located between the two part regions, wherein a thickness of the metallic structure in a direction perpendicular to the planar surface of the electrically insulating material is larger than a height of the electrical component in the direction perpendicular to the planar surface of the electrically insulating material, and wherein the metallic structure is neither in electrical connection with the electrical component arranged at least in part in the cavity nor in electrical connection with any further electrical component of the component assembly.

2. The component assembly according to claim 1, wherein the electrical component is a thermistor element, varistor element, TVS diode or light-emitting diode.

3. The component assembly according to claim 1, wherein the electrical component is a chip.

4. The component assembly according to claim 1, wherein the carrier comprises a ceramic or an organic material.

5. The component assembly according to claim 1, wherein the cavity is at least partially covered at least in part by a further element, wherein the further element is located on the metallic structure, wherein the carrier has a plain outer surface, and wherein the metallic structure and the electrical component are located on the plain outer surface.

6. The component assembly according to claim 1, wherein a width of each of the part regions is larger than a width of the electrical component such that the two part regions laterally project over the electrical component.

7. The component assembly according to claim 5, wherein the further element is a further electrical component or a further carrier.

8. The component assembly according to claim 5, wherein the metallic structure fastens the further element on the carrier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The objects described here are explained in more detail below by way of schematic exemplary embodiments that are not true to scale, in which:

(2) FIG. 1 shows a schematic cross section of a component assembly,

(3) FIG. 2 shows a perspective view of the component assembly from FIG. 1,

(4) FIGS. 3A to 3G show schematic cross sections of method steps during the production of a component assembly,

(5) FIGS. 4 to 7 show schematic cross sections of further component assemblies,

(6) FIGS. 8 to 10 show schematic cross sections of different design possibilities of component assemblies.

(7) The same references in the following figures preferably refer to parts of the different embodiments which correspond in a functional or structural manner.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(8) FIG. 1 shows a schematic cross section of a component assembly 1. The component assembly 1 comprises a carrier 2. The carrier 2, in particular a basic body 20 of the carrier, preferably comprises an electrically insulating material. For example, the carrier 2 comprises a ceramic material or an organic material.

(9) The carrier 2 comprises a metallic structure 3, in particular a layered metallic structure 3, on a first outside surface 4. The metallic structure 3 is formed, for example, by means of electroplating.

(10) The top surface 19 of the metallic structure 3 remote from the carrier 2 extends parallel to the first outside surface 4 of the carrier. For example, the first outside surface 4 is a bottom surface of the carrier 2. The metallic structure 3 comprises, in particular, a planar top surface 19 which makes it possible to locate the carrier evenly or to arrange a further element evenly on the top surface 19.

(11) For example, the structure 3 comprises copper. In addition, the metallic structure 3 can be provided with a thin layer, for example, a gold layer, on a top surface for improving the solderability. The structure can comprise, for example, a height within the range of between 80 m and 90 m. In this case, the height is preferably chosen in such a manner that an electrical component is able to be completely embedded into the metallic structure. For example, the height can also be within the range of 120 m. The structure 3 can be realized in a completely metallic manner.

(12) The structure 3 comprises several part regions 3a, 3b which are separated from one another. The part regions 3a, 3b are realized in each case in a layered manner and comprise the same height h.sub.1 which corresponds to the height of the structure. For example, the part regions 3a, 3b are realized as contact pads.

(13) A cavity 5, in which an electrical component 6 is arranged, is situated between the part regions 3a, 3b. The electrical component 6 is completely recessed in the cavity 5 such that the top surface of the component 6, which points away from the carrier 2, does not project beyond the metallic structure 3. The height h.sub.2 of the component 6 is in particular smaller than the depth t of the cavity 5.

(14) The electrical component 6 is a discrete component. For example, the electrical component 6 is realized as a varistor. In particular, the varistor can be realized in the form of a multiple layer varistor, also called a multi-layer varistor (MLV). For example, the varistor is realized as an ESD protective component. As an alternative to this, the electrical component 6 can also be realized as a TVS diode, as an NTC thermistor component, PTC thermistor component or as a light-emitting diode. The electrical component 6 can also be realized as a chip, in particular as a light-emitting diode chip.

(15) The electrical component 6 is preferably realized in an ultrathin manner. In particular, the electrical component 6 can comprise a height of less than 100 m, for example, a height of 80 m. In a corresponding manner, the cavity can comprise a depth t of less than 150 m, for example, of 120 m. The depth t of the cavity 5 can correspond to the height of the metallic structure 3.

(16) FIG. 2 shows a perspective view of the component assembly from FIG. 1. The carrier 2 is provided with contact faces 8 (not shown in FIG. 1), on which the part regions 3a, 3b of the metallic structure 3 of the carrier 2 are mounted. The contact faces 8 are preferably thin metallic layers and can comprise in particular copper with a thin gold layer for improving the solderability. For example, the contact faces 8 comprise thicknesses within the range of 20 m. The electrical component 6 is also mounted on the contact faces 8. The component 6 is preferably soldered on the contact faces 8.

(17) Vias 7, i.e., through-connections, are arranged in the carrier 2. The vias 7 serve for contacting the contact faces 8 electrically. In addition, the vias 7 can also be realized as thermal vias and serve for heat removal. The part regions 3a, 3b are contacted electrically in each case by a via 7. Consequently, the part regions 3a, 3b can be used for contacting a further element.

(18) The vias 7 comprise, for example, copper. As an alternative to this, the contact faces 8 can also comprise other materials with a high degree of thermal conductivity, such as, for example, silver or silver palladium.

(19) The metallic structure 3 comprises a third part region 3c (not shown in FIG. 1). Said part region 3c can also serve, for example, for contacting electrically and/or for heat removal and can be connected to electrical and/or thermal vias. Said part region 3a is preferably not contacted electrically and in particular is insulating with respect to thermal vias adjoining thereto. For example, the part region 3a is realized as a thermally conductive pad.

(20) For example, a heat-generating component is arranged on a second outside surface 9 of the carrier 2 which is located opposite the first outside surface 4. This can be a light-emitting diode chip 4 in particular. Vias which lead through the carrier 2 can remove the heat through the carrier 2 to the third part regions 3c. For example, the second outside surface 9 is a top surface of the component assembly 1.

(21) The third part region 3c comprises the same height as the first and second part regions 3a, 3b. Consequently, a further element can be arranged horizontally on the three part regions 3a, 3b, 3c.

(22) FIGS. 3A to 3G show schematic cross sections of method steps when producing a component assembly.

(23) The resulting component assembly shown in FIG. 3G is a further example of a component assembly and differs from the component assembly shown in FIGS. 1 and 2 in the specific arrangement of the different component parts, but the method can be applied analogously to the production of the component assembly shown in FIGS. 1 and 2 and to the component assembly shown in the following figures.

(24) A carrier 2 is prepared according to FIG. 3A. The carrier 2 is preferably realized from an insulating material, in particular the carrier 2 can be realized as described in conjunction with FIGS. 1 and 2.

(25) According to FIG. 3B, in a connecting method step through-holes 10 are provided, for example, stamped, in the carrier 2 for realizing vias. This can be affected, for example, in a mechanical manner, in particular with pins, or with a laser.

(26) According to FIG. 3C, the through-holes 10 are filled with a metallic material such that vias 7 are formed. In addition, contact faces 8 are mounted on first and second outside surfaces 4, 9 of the carrier 1 such that the contact faces 8 are contacted by the vias 7. In particular, the contact faces 8 can be mounted using a screen printing method. The contact faces 8 comprise, for example, copper or silver. For example, the contact faces comprise a height of about 20 m.

(27) According to FIG. 3D, electrical insulation 11 is applied on parts of the contact faces 8 and outside surfaces 4, 9 of the carrier 2. The insulation 11 is realized in a layered manner. The insulation 11 can be applied in a first step in such a manner that the contact faces 8 and the outside surfaces 4, 9 of the carrier 2 are completely covered by the insulation 11. The insulation 11 can then be structured in such a manner that part regions of the contact faces 8 and/or of the outside surfaces 4, 9 of the carrier 2 are exposed. The exposed regions of the contact faces 8 serve, for example, for contacting an electrical component.

(28) For example, a first insulation 11a is applied onto a contact face 8 which is arranged on a second outside surface 9. The first insulation 11a comprises, for example, a proportion of glass and can be imprinted as glass paste. As an alternative to this, the first insulation 11a can comprise silicon nitride (Si.sub.3N.sub.4) or aluminum nitride (AlN) and can be applied, for example, using plasma-enhanced chemical vapor deposition or using reactive sputtering. The first insulation 11a can then be structured by means of an etching mask.

(29) A second insulation 11b is applied on a contact face which is arranged on a first outside surface 4. The second insulation 11b comprises a material with a high degree of thermal conductivity. For example, the second insulation 11b comprises aluminum nitride. The second insulation 11b can be deposited.

(30) According to FIG. 3E, a metallic structure 3 is then applied, in particular electroplated, on the first outside surface 4. For example, the method of a semi-additive coating can be applied for this purpose where a structured resist, e.g., photoresist, is applied on a seed layer. As an alternative to this, a copper layer can be applied, provided with a structured acid resist and then be subtractively etched.

(31) The metallic structure 3 comprises a first and a second part region 3a, 3b. The first part region 3a is arranged on the second insulation 11b such that no electrical contact to the contact faces 8 is produced. On account of the high degree of thermal conductivity of the second insulation 11b, heat can be removed from the vias 7 that are arranged above the first part region 3a to the first part region 3a.

(32) In addition, a second part region 3b of the metallic structure 3 is applied onto an exposed contact face 8 on the first outside surface 4. The second part region 3b is in electrical contact with the via 7 that is arranged above it. The second part region 3b can serve for electrically contacting a further element which can be arranged on the second part region 3b.

(33) The second part region 3b covers the contact face 8, with which it is in electrical contact, only in part such that a region of the contact face 8 is exposed. Said region of the contact face 8 can be utilized for contacting a component.

(34) In the alternative embodiments, for example, several or all of the part regions 3a, 3b can be electrically contacted. As an alternative to this, it is also possible for none of the part regions 3a, 3b to be electrically contacted.

(35) The part regions 3a, 3b are spaced apart from one another such that a cavity 5 is realized between the part regions 3a, 3b.

(36) According to FIG. 3F, the exposed regions of the contact faces 8 as well as the part regions 3a, 3b of the metallic structure 3 are provided with a thin metallic layer 12. The layer 12 is, for example, a thin gold layer and can serve for improving solderability. As an alternative to this, the layer 12 can comprise nickel-palladium-gold or Ni-gold. The thin layer 12 can be seen as a component part of the part regions 3a, 3b of the metallic structure.

(37) According to FIG. 3G, an electrical component 6, in particular a discrete electrical component 6, is then arranged in the cavity 5. The electrical component 6 is arranged directly next to the second part region 3b. The electrical component 6 is arranged on part of the contact face 8 which is contacted by the second part region 3b and is not covered by the second part region 3b. The electrical component 6 is in electrical contact with the contact face 8 and the via 7 which is arranged above it.

(38) For example, the component 6 is soldered on the contact face 8, in particular on the thin layer 12 of the contact face 8. As an alternative to this, the component 6 can also be glued on, in particular using a conductive adhesive. A conductive adhesive containing silver is used for this purpose, for example. As an alternative to this, the component 6 can also be bonded onto the contact face 8. For example, the component 6 can be connected to the contact face 8 by means of thermosonic bonding, thermocompression bonding or an ultrasonic flip chip gold-to-gold interconnect.

(39) The electrical component 6 is completely recessed in the cavity 5 in the present case such that it does not project beyond the metallic structure 3 comprising the thin layer 12.

(40) One or several further components can be mounted on the second outside surface 9 of the carrier. For example, a further component, such as, for example, a light-emitting diode chip, can be arranged on the contact face 8, which is provided with a thin layer 12, and can be electrically contacted. The first part region 3a can serve for removing heat that is generated in the further component.

(41) The further FIGS. 4 to 10 show exemplary embodiments and design possibilities of a component assembly which are modifications and variants of the exemplary embodiments shown in FIGS. 1, 2 and 3G and which consequently will be explained above all with regard to the differences hereto.

(42) In the case of the component assembly 1 shown in FIG. 4, a metallic structure 3 including three part regions 3a, 3b, 3c is arranged on a carrier 2. It can be possible to contact the metallic structure 3 electrically or it cannot be possible to contact it electrically.

(43) A cavity 5a is realized between a first and a second part region 3a, 3b. A third part region 3c of the metallic structure 3 is arranged in the cavity 5a. The third part region 3c comprises a smaller height than the first and the second part regions 3a, 3b. Cavities 5b, 5c are realized between the first part region 3a and the third part region 3c as well as between the second part region 3b and the third part region 3c. The cavities 5b and 5c can also be seen as part regions of the cavity 5a.

(44) One electrical component 6a, 6b is arranged in each case in the cavities 5b, 5c. The cavities 5a, 5b, 5c are filled with a protective material 13, in particular an insulating material. The protective material 13 can be realized as a protective coating. As an alternative to this or in addition to it, the cavities 5a, 5b, 5c can be filled with a material for light conversion. For example, the protective material 13 can also serve for light conversion. In particular, blue light generated by an LED can be converted into white light. A phosphorous material is used for this purpose, for example.

(45) Each of the three part regions 3a, 3b, 3c can serve, for example, for contacting an electrical element or for heat removal.

(46) In the case of the component assembly 1 shown in FIG. 5, the metallic structure 3 includes four part regions 3a, 3b, 3c, 3d which are separated from one another. A first cavity 5a, in which a first electrical component 6a is arranged, is situated between the first and the second part regions 3a, 3b. A second cavity 5b, in which a second electrical component 6b is arranged, is situated between the third and the fourth part regions 3c, 3d. The first and second electrical components 6a, 6b are arranged on contact faces 8 and are contacted electrically by means of the contact faces 8. The part regions 3a, 3b, 3c, 3d of the metallic structure 3 are also arranged on the contact faces 8 and are electrically contacted by the contact faces 8.

(47) In addition, a third component 6c, in particular a chip 14, is arranged on the carrier 2. The chip 14 is, for example, a light-emitting diode chip. The chip 14 is arranged in a third cavity 5c which is formed by the second and third part regions 3b, 3c of the metallic structure 3. The chip 14 can be contacted electrically, for example, by means of contact faces, vias or wiring.

(48) In the case of the exemplary embodiment shown here, the electrical components 6a, 6b and the chip 14 are arranged on the same outside surface 9 of the carrier 2. The outside surface 9 is preferably a top surface of the carrier 2. Consequently, for example, in the case of a third component 6c which is realized as a light-emitting diode chip, light is able to be emitted upward. The recessing of the electrical components 6a, 6b in the cavities 5a, 5b prevents light emitted from the light-emitting diode chip being shadowed by the further electrical components 6a, 6b.

(49) The side faces of the part regions 3c, 3b which define the cavity 5c in which the chip 14 is arranged, are preferably reflective. A light yield can consequently be improved.

(50) The metallic structure 3 preferably comprises a high degree of thermal conductivity. The advantage of this is that heat generated in operation is easy to remove. As a result, the component assembly 1 comprises good thermal management. The service life of the component assembly 1 can be significantly extended by a reduced thermal load.

(51) The cavities 5a, 5b, 5c are filled with a protective material 13. The protective material 13 completely covers the metallic structure 3 and the components 6a, 6b, 6c. In particular, the protective material 13 forms a protective coating on the component assembly 1.

(52) The component assembly 1 shown in FIG. 6 comprises a carrier 2 on which a metallic structure 3 including a first, second and third part region 3a, 3b, 3c is arranged. The second part region 3b is arranged between the first and the third part region 3a, 3c. All the part regions 3a, 3b, 3c comprise the same height.

(53) A first component 6a is arranged in a first cavity 5a of the metallic structure 3. The first component 6a can be realized as a chip, for example, as a light-emitting diode chip. The first component 6a is contacted by means of vias 7. The vias 7 can be realized as thermal and/or electrical vias. A second component 6b which is contacted electrically by means of contact faces 8 is arranged in a second cavity 5b.

(54) A further element 15 is arranged on the metallic structure 3. The further element 15 covers the components 6a, 6b which are arranged in the cavities 5a, 5b. Consequently, the components 6a, 6b are embedded in the cavities 5a, 5b between the carrier 2 and the further element 15.

(55) The further element 15 is fastened, for example, soldered, on the metallic structure 3. Consequently, the metallic structure 3 serves, in particular, for fastening the further element 15. In addition, the metallic structure 3 also serves for contacting the further element 15 electrically. In addition to this or as an alternative to it, heat can also be transferred between the further element 15 and the carrier 2 by means of the metallic structure 3.

(56) The further element 15 forms a second plane of the component assembly. The carrier 2 with the components 6a, 6b arranged thereon can be seen as a first plane of the component assembly 1.

(57) Using the assembly shown, components 6a, 6b can be accommodated in a space-saving manner in the component assembly 1 as they are recessed in cavities 5a, 5b which are arranged between the planes.

(58) The further element 15 is realized, for example, as a carrier. In particular, further components can be mounted on the further element 15. The further element 15 can also be realized as a chip, in particular as a light-emitting diode chip.

(59) FIG. 7 shows a component assembly 1 with three planes. A first further element 15 is arranged on a carrier 2, which forms a first component plane, and a second further element 16 is arranged thereon. The first further element 15 forms a second component plane and the second further element 16 forms a third component plane.

(60) The first further element 15 is electrically and mechanically connected to the carrier 2 by means of a metallic structure 3 comprising two part regions 3a, 3b. The second further element 16 is electrically and mechanically connected to the first further element 15 by means of a further metallic structure 17, comprising two part regions 17a, 17b. The metallic structures 3, 17 can comprise the structural and functional characteristics as are described in conjunction with FIG. 6. The further elements 15, 26 can be realized, for example, as electrical components. The further elements can be realized as a chip, in particular as a light-emitting diode chip or as a carrier. In particular, the second further element 16 can be realized as a light-emitting diode chip.

(61) Cavities 5a, 5b are realized in each case in the metallic structures 3, 17. A first electrical component 6a is embedded in the cavity 5a of the first metallic structure 3 and a second electrical component 6b is embedded in the cavity 5b of the second metallic structure 17. In the present example, both electrical components 6a, 6b are fastened on the first further element 15. As an alternative to this, the first component 6a can be fastened on the carrier 2. The second component 6b can be arranged as an alternative to this on the second further element 16.

(62) FIGS. 8 to 10 show different design possibilities of metallic structures 3 and possible arrangements of discrete components 6a, 6b in component assemblies 1. The previously described exemplary embodiments of the component assemblies 1 can be converted in a corresponding manner.

(63) FIG. 8 shows an embodiment of a component assembly 1 where a discrete component 6 is arranged in a cavity 5 of a metallic structure 3. The component 6 is completely recessed in the cavity 5.

(64) FIG. 9 shows an embodiment of a component assembly 1 where two discrete components 6a, 6b are arranged in a cavity 5. The components 6a, 6b are completely recessed in the cavity 5.

(65) FIG. 10 shows an embodiment of a component assembly 1 where the metallic structure 3 comprises beveled side faces 18. This can lead, for example, to an improvement in the thermal characteristics. For the case where at least one of the components 6a, 6b is realized as a light-emitting diode chip, improved emission characteristics can be obtained as a result.