WO2010138983A1

WO2010138983A1 - Method for contacting an electronic component and a heat-conducting element and for producing a printed circuit board

Info

Publication number: WO2010138983A1
Application number: PCT/AT2010/000187
Authority: WO
Inventors: Gregor Langer
Original assignee: At & S Austria Technologie & Systemtechnik Aktiengesellschaft
Priority date: 2009-06-02
Filing date: 2010-05-28
Publication date: 2010-12-09
Also published as: AT11628U1

Abstract

In a method for contacting or connecting an electronic component (5) generating heat, in particular during operation, to a heat-conducting, particularly metal, element (1), it is provided that the component (5) is connected to the heat-conducting element (1) to form an intermetallic diffusion layer (12), wherein in particular a connection at a surface that is different from a surface (6) provided with contacts or contact points (24) of the component (5) is provided for. In addition, a method for integrating a component (13), comprising an electronic component (5) generating heat, in particular during operation, and a heat-conducting, particularly metal, element (1) connected thereto, into a printed circuit board (14), and such a component and a printed circuit board (14), which comprises such a component (13), are provided. Overall, a component (13) having improved contacting and heat dissipation can be provided, particularly when integrated into a printed circuit board (14).

Description

Method for contacting an electronic component and a thermally conductive element and for producing a printed circuit board

The present invention relates to a method for contacting or connecting a heat generating in particular during operation electronic component with a heat-conducting, in particular metallic element. The present invention also relates to a method for integrating a component, consisting of a particular heat-generating in operation, electronic component and an associated, heat-conducting, in particular metallic element in a printed circuit board on a component consisting of a particular in operation Heat generating, electronic component and a heat-conducting, in particular metallic element and on a printed circuit board produced therewith.

In connection with the production of printed circuit boards and in particular the miniaturization and performance increase of electronic components of the same usually also increases their heat loss during operation. This additional heat loss can cause serious problems, especially in the field of contacting such an electronic component to the printed circuit board as well as in the discharge and / or in extreme conditions, such as increased temperatures and / or strong mechanical stresses due to vibrations, for example in the automotive sector Distribution of the heat generated by the electronic component lead to an associated heat-conducting element or heat sink.

In the embedding of such, in operation partially large amounts of heat generating components, which are in particular to be coupled with a heat-conducting element, it is known, for example, after embedding such an electronic component in a particular multi-layer circuit board, a heat-conducting element or a heat sink using a To contact solder or adhesive connection with the component, wherein the heat-conducting element is also integrated in a recess of the circuit board. Instead of the use of heat-conducting elements, which are in particular made of a metallic element, for example, the use of ceramic substrates, specially shaped, a heat conduction favoring elements or portions of a circuit board or the use of multi-layer components, for example, a combination of conductive and non-conductive layers known.

Moreover, it is known to arrange in recesses or openings of a printed circuit board cooling components or heat sink, which are coupled to be arranged in particular on the surface of printed circuit boards, electronic components with the interposition of heat transfer elements. In this context, for example to DE-A 102005047025, EP-A 1 592 288, DE-A 10 331 453 or EP-A 1 480 269. A disadvantage of these known embodiments is in particular the fact that a contact of the electronic, heat-generating component in operation with the heat sink, in particular under conditions of use under elevated temperature and / or increased vibration can not always be reliably maintained, and that in particular by the Substantial complete embedding of a thermally conductive element or heat sink in the circuit board of the electronic component must be arranged largely unprotected on the surface of the circuit board.

The present invention therefore aims to avoid the problems of the above-mentioned prior art starting from the methods of the type mentioned at the outset as well as a component comprising a component and a heating element and a printed circuit board containing such a component, and in particular a method for contacting or connection of an electronic component with a thermally conductive EIe- ment and a component formed thereby as well as a method for producing a printed circuit board embedding such a component to the effect that on the one hand the contact between the electronic component and the heat-conducting element is improved and a simple Embedding such, consisting of an electronic component and a thermally conductive element component is made possible in a printed circuit board.

To solve these problems, a method for contacting or connecting a particular heat-generating in operation electronic component with a heat-conducting, in particular metallic element of the type mentioned above essentially characterized in that the component is connected to form an intermetallic diffusion layer with the heat-conducting element , By forming or using an intermetallic diffusion layer between the electronic component and the heat-conducting element to form alloys or connections between adjoining connecting layers, it is possible to ensure a proper and high-strength connection between the elements or components to be connected to each other , In this case, compared with known production methods, increased tensile strengths and improved resistance to destruction or impairment of the connection between the electronic component and the heat-conducting element can be achieved, for example, under varying temperature conditions or stresses and / or the occurrence of vibrations or oscillations. It thus makes it possible to provide a reliable connection between the electronic component and the heat-conducting element which, even under harsh operating conditions, for example in automotive applications, reliably dissipates the heat generated by the electronic component during operation onto the heat-conducting element and, subsequently, after embedding in a printed circuit board, as will be discussed in detail below, can be achieved on the circuit board. Overall, it is possible to provide a high-strength connection between the electronic component and the heat-conducting element, whereby the provision of the intermetallic diffusion layer also favors or improves the heat conduction or the heat transfer between the electronic component and the heat-conducting, in particular metallic element.

While the connection of the component with the heat-conducting element to form an intermetallic diffusion layer improved heat transfer from the component to the heat-conducting element and to the external environment of the circuit board thus achievable according to the invention can, moreover, with appropriate choice of materials for the heat-conducting element as well the materials used to form the intermetallic diffusion layer may additionally be provided with electrical contact between the electronic component and the heat-conducting element likewise via the intermetallic diffusion layer.

For an optionally required or desired separation of the electrical contacting of the provided under formation of an intermetallic diffusion layer improved heat dissipation is proposed according to a preferred embodiment of the inventive method that the component at one of provided with contacts or contact points of the component surface different surface is connected to the heat-conducting element. In this way, in particular in the case of components which usually have small dimensions and which can be formed with an exceedingly high number of contacts or contact points, it is ensured that reliable dissipation of the heat generated by the component is achieved by the inventively proposed formation of an intermetallic diffusion layer in connection with the heat-conducting element Heat takes place, while independently contacting with contacts or contact points of the electronic component can be made on a different surface.

In order to achieve a correspondingly reliable and firm connection between the electronic component and the heat-conducting element, it is proposed according to a preferred embodiment of the method according to the invention that the component and / or the heat-conducting element to be connected or coupled to form the intermetallic diffusion layer are each provided with at least one solder layer and that the solder layers contacted with each other and are connected to one another using ambient pressure and elevated temperature to form the intermetallic diffusion layer. After building up at least one layer of solder on to be connected to each other or to be determined Areas or surfaces of the electronic component and / or the heat-conducting element, the solder layers are contacted with each other and connected together using increased environmental pressure and elevated temperature to form the intermetallic diffusion layer. The solder layers provided for forming the intermetallic diffusion layer can be provided substantially separately on areas or surfaces of both the electronic component and the heat-conducting element which are to be fixed to each other and subsequently connected together using elevated pressure and temperature to form the intermetallic diffusion layer , Alternatively, it can be provided that a corresponding number of solder layers is provided on the corresponding surface of the component or the heat-conducting element, followed by a subsequent formation of the intermetallic diffusion layer also directly contacting the respective adjacent solder layer with the component or the heat-conducting element , Thus, the formation of alloys or connections between the solder layers adjacent to one another or contacted with one another can provide the desired proper and high-strength connection between the electronic component and the heat-conducting element. By forming the intermetallic diffusion layer for connecting the electronic component to the heat-conducting element, an approximation or tuning of, for example, the thermal expansion coefficients of the materials used can also be achieved, so that thereby also in particular at elevated

Temperature stresses improves the connection of the electronic component with the heat-conducting element and thereby the heat dissipation can also be improved. By using a diffusion soldering or Schmelzdiffusionslötverfahrens under application of ambient conditions increased pressure and elevated temperature to form the intermetallic diffusion layer diffuses the materials or components of the contacted solder layers together, so that a high-strength compound by the diffusion of the solder layers into each other or with each other is achievable. Herein, intermetallic phases or alloys may occur between the materials used to form the intermetallic diffusion layer, it being understood that such diffusion of the materials into one another occurs at temperatures well below the melting temperatures of those for the solder layers, respectively raw materials used, as will be discussed in more detail below.

For carrying out the Djffusionslötverfahrens under pressure and temperature conditions, which are exposed to components and components of a circuit board without impairment and for simultaneous achievement of a proper connection or definition by diffusion of the materials used for the respective (n) solder layer or solder layers materials is according to a In a preferred embodiment of the method according to the invention, it is proposed that the at least one solder layer be made of an electrically conductive metal. selected from the group consisting of silver, gold, nickel and copper and / or tin, indium and bismuth. The materials mentioned have a corresponding good or high conductivity, which are required to achieve a proper contact between the areas or surfaces to be joined together and an improved thermal conductivity, and also ensure that, especially at a comparatively low temperature when using a corresponding pressure for a corresponding period, a reliable intermetallic connection between the solder layers of the component to be joined together and heat-conducting element can be achieved.

In order to prevent diffusion of the materials used for forming the intermetallic diffusion layer as a solder joint into the contact points or regions of the component to be connected or fixed to each other and the heat-conducting element, it is proposed according to a further preferred embodiment that before applying the at least one Lotschicht a barrier layer on the mutually connected or to be fixed to each other areas or surfaces of the component and / or the heat-conducting element is applied. This barrier layer prevents diffusion of the solder materials or of the elements of the resulting intermetallic compound or possibly resulting alloy into the region of the regions or surfaces of the component and / or of the heat-conducting element to be connected to one another or to one another.

In order to reliably form a barrier layer while at the same time maintaining a sufficient conductivity and a reliable connection with the adjoining surfaces of the component and heat-conducting element to be connected or bonded to one another and also the at least one solder layer to be additionally arranged, according to a further preferred embodiment proposed that the barrier layer of an electrically conductive metal selected from the group comprising nickel, iron or molybdenum and / or alloys containing nickel and / or iron is formed.

To support the melt diffusion process for connecting the areas to be joined or fixed to each other, in particular contact points, it is proposed according to a further preferred embodiment that two different solder layers are respectively applied to an area to be joined or fixed to each other. By arranging or applying two different solder layers, for example, initiation or initiation of the diffusion process can be carried out in a targeted manner after the contacting of the regions to be joined by appropriate selection of the directly adjacent solder layers, while a progressive or more advanced connection under formation of an intermetallic diffusion layer regulated or controlled by providing a further layer of solder can be achieved. In this context, the different solder layers can be selected, for example, with regard to their melting temperature, wherein, for example, in each case a solder layer of a material of low melting temperature is set at the top of the areas or surfaces to be joined, followed by a solder layer of a material of higher melting temperature and optionally improved or increased electrical conductivity is used, so that in addition during the diffusion process, for example, a eutectic alloy of the materials used for the solder layer is formed, which has a correspondingly high resistance to destruction of the compound and a correspondingly high and good in particular thermal conductivity having to be achieved contact or connection.

For a particularly reliable and simple application of the at least one solder layer in particular in connection with the production of a printed circuit board of small thickness or layer thickness, it is proposed according to a further preferred embodiment of the method according to the invention that the at least one solder layer and the barrier layer be electrochemically or chemically deposited or applied.

In connection with the production of a printed circuit board in which increasing

Miniaturization of the same correspondingly low layer thicknesses of the individual elements are used and in consideration of achieving a corresponding, resistant connection or contacting is proposed according to a further preferred embodiment that the at least one solder layer and / or the barrier layer has a thickness of at least 5 nm, in particular at least 100 nm to at most 100 microns, preferably at most 20 microns (have). Such layer thicknesses or thicknesses of the solder layer or solder layers to be used and / or the barrier layer are in a conventional manner in the production of printed circuit boards used areas of a layer thickness of individual elements or layers of such a circuit board, in which a to be connected to a heat-conducting member in Another consequence is to be integrated.

In order to achieve a reliable connection of the regions or elements to be contacted with each other to form an intermetallic diffusion layer is proposed according to a further preferred embodiment that the soldering at a pressure of less than 300 bar, in particular less than 250 bar and at temperatures of less than 400 ^0th C, in particular between 150 ⁰ C and 250 ^Q C is performed. In particular, taking into account the temperatures used for the melt diffusion soldering, it is immediately apparent that the soldering operation is carried out at temperatures which are partly are considerably below the melting temperatures of the materials used for the formation of the solder layers.

In order to increase the efficiency of the method according to the invention for contacting or connecting an electronic component with a thermally conductive element and taking into account the usually small dimensions, to be joined together elements or components is proposed according to a further preferred embodiment of the method according to the invention that a A plurality of electronic components is connected to a common heat-conducting member to form a respective intermetallic diffusion layer, and that the heat-conducting member is divided after connection with the plurality of components for separating the components respectively connected to a portion of the heat-conducting member. Thus, by simultaneously producing a plurality of components, each consisting of an electronic component and a thermally conductive element connected to form an intermetallic diffusion layer, the throughput in the production of such components can be increased, in particular in connection with the production of a printed circuit board or components of which the simultaneous production of a plurality of components or units and the subsequent subdivision or separation thereof is known per se.

In order to achieve the corresponding thermal conductivity or the provision of a sufficient cooling capacity by a heat-conducting element is also proposed that the heat-conducting element is formed by a relation to the at least one solder layer having an increased thickness, metallic layer, in particular of copper, as one weiters preferred embodiment of the method according to the invention.

For solving the above-mentioned objects, moreover, a method for integrating a component, comprising an electronic component, which generates heat in particular during operation, and a heat-conducting, in particular metallic, element connected thereto in a printed circuit board is essentially characterized by the following steps: providing a component consisting of an electronic component and an associated thermally conductive element according to a method according to the above-mentioned invention or a preferred embodiment thereof; In particular, providing a plurality of layers of a multilayer printed circuit board;

Bonding the layers of the multilayer printed wiring board and the component to be integrated therein by application of elevated pressure and temperature to environmental conditions, and Patterning at least one conductive layer of the circuit board for contacting contacts of the component embedded therein.

It can thus be in a simple manner, after providing a component, each consisting of an electronic component and an associated with formation of an intermetallic diffusion layer thermally conductive element, with known method steps for producing a printed circuit board such a component in a simple and reliable manner integrate a printed circuit board and achieve a contacting of the electronic component with a corresponding structured, conductive layer. By embedding the component produced according to the method of the invention or a preferred embodiment thereof by a connection between the electronic component and the thermally conductive element, an optimized dissipation of heat generated by the electronic component during operation can be achieved. In addition, can be provided by the embedding a corresponding protection, in particular for the electronic component, so that can be dispensed, for example, a housing for the electronic component. In addition, a corresponding reduction in space and also, in particular under harsh operating conditions, a higher reliability results from the correspondingly protected arrangement of the component consisting of the electronic component and the heat-conducting element. Furthermore, the embedding or integration of such a component into the printed circuit board after the connection or contacting between the electronic component and the thermally conductive element is established ensures that the diffusion or melting point required for the formation of the intermetallic diffusion layer is or are used. diffusion soldering regardless of used in the manufacture of a circuit board process steps and in particular, for example, independently of known Lötbondverfahren for contacting with other components or elements performed or can be used.

Instead of embedding or integrating into a multilayer printed circuit board during a bonding operation of the individual layers of a multilayer printed circuit board as stated above, embedding of a component formed of an electronic component and a thermally conductive element forming an intermetallic diffusion layer may be employed be made in a corresponding recess of a previously prepared circuit board. Also in such a method, after an embedding, a contacting of contacts or contact points of the electronic component with a particular structured conductive or conductive occurs

Layer of the printed circuit board. For structuring at least one conductive layer of the printed circuit board, it is proposed according to a preferred embodiment of the method according to the invention that structuring of at least one conductive layer of the printed circuit board is carried out by forming bores, in particular laser bores, by etching processes or the like.

In particular, to further improve the heat dissipation or to optimize the thermal management for electronic components that produce a very high heat loss, it is proposed according to a further preferred embodiment that the heat-conducting element with at least one further heat-conducting layer, in particular of metallic material, the PCB is connected. By connecting to at least one further heat-conducting layer, a further and, in particular, larger-area distribution of the heat generated or emitted by the electronic component in the printed circuit board is made possible and, when such an additional heat-conducting layer is provided, in particular on an outer surface of the printed circuit board, the heat output is further improved or supported.

As already indicated above, an additional assembly of a printed circuit board can be provided, in which a component consisting of an electronic component and a thermally conductive element associated therewith is received, wherein according to a further preferred embodiment it is proposed that in particular one of the structured conductive layers the printed circuit board is contacted with other electronic components.

To solve the above-mentioned objects beyond a component consisting of a particular heat during operation, electronic component and a heat-conducting, in particular metallic element, essentially characterized in that the component is connected to form an intermetallic diffusion layer with the heat-conducting element , Thus, as discussed in detail above, it is possible to provide a component consisting of an electronic component and a thermally conductive element, which also provides good and reliable heat dissipation and reliable maintenance of the contact between the component and the thermally conductive element Provides conditions of use.

While, as mentioned above, forming the intermetallic diffusion layer in addition to an improved heat transfer and an electrical contact between the component and the heat-conducting member may be provided which can be connected in particular subsequently with further conductive or conductive structures of a printed circuit board after embedding , Is proposed for decoupling the heat dissipation of an electrical contact of contacts or contact points of the electronic component according to a preferred embodiment, that the component at one of Contacts or contact points of the component surface provided with different surface is connected to the heat-conducting element.

In order to achieve a correspondingly good heat dissipation and an improved distribution of the heat generated by the electronic component to a larger portion, in particular after embedding in a printed circuit board is also proposed that the heat-conducting element relative to the electronic component has enlarged dimensions, as a preferred embodiment corresponds to the component of the invention.

To achieve the objects mentioned above, a printed circuit board is also provided, which contains at least one component according to the present invention or a preferred embodiment thereof.

The invention will be explained in more detail with reference to embodiments schematically illustrated in the accompanying drawings. In this show:

Figure 1 is a schematic view of an electronic component and a heat-conducting, in particular metallic element, which are to be joined together for the production of a component according to the invention according to the inventive method, wherein in each case a barrier layer and two solder layers are applied according to the inventive method;

FIG. 2 is a partial schematic view showing that a plurality of components are bonded to the thermally conductive member to form an intermetallic diffusion layer; FIG. FIG. 3 is a schematic view showing that the plurality of electronic components connected to the thermally conductive member are separated from each other; FIG.

4 shows a schematic view of an embedding or integration of a component comprising an electronic component and a thermally conductive element connected therewith to form an intermetallic diffusion layer into a multilayer printed circuit board according to the present invention; 5 shows a schematic partial view of the connection of a plurality of layers of a printed circuit board according to the invention using the method according to the invention with embedding of the component according to the invention;

FIG. 6 shows a schematic partial view of a structuring of conductive layers of the printed circuit boards according to FIG. 5; FIG. 7 shows a partial view of a further structuring of conductive layers of the printed circuit board according to the invention; and

Fig. 8 is a partial view of a further assembly of the circuit board according to the invention with additional components. In Fig. 1 it is shown that a barrier layer 2 is arranged or applied to a thermally conductive element 1, which is formed for example by a corresponding thickness copper plate, then followed by two layers 3 and 4 arranged and applied from mutually different solder material are.

In a similar manner, a barrier layer 7 is likewise arranged on an electronic component 5 on a surface facing away from a surface 6 on which contacts or contact points are not shown in detail for further contacting in FIG on the heat-conducting element 1, two mutually different solder layers 8 and 9 connect.

The thicknesses of the individual layers 2 to 4 and 7 to 9 shown in FIG. 1 are merely exemplary and not true to scale, with details of usable, possible ranges of layer thicknesses being discussed in detail below.

The barrier layers 2 and 7 are formed of nickel, for example. The solder layers 3 and 4 and 8 and 9 to be subsequently joined together to form an intermetallic diffusion layer are formed, for example, each of silver for the layer 3 and δ, and tin for the layers 4 and 9.

The application of the barrier layers 2 or 7 and the solder layers 3, 4 and 8 and 9 can be carried out by an electrochemical or chemical deposition or application.

In addition to applying at least one solder layer 3 and 4 or 8 and 9 both on the heat-conducting element 1 and on the component 5 may be provided, a corresponding plurality of solder layers either on the component 5 and in particular on the heat-conducting element facing surface or applied on a corresponding portion of the heat-conducting element 1, subsequently carried out using higher temperature and / or increased pressure to form the intermetallic Dif- fusion layer, a compound or contact with the respective other element, on which originally no or a small number the solder layers was provided, so that in turn a composite consisting of the electronic component 5 and the thermally conductive element 1 is provided to form an intermetallic diffusion layer.

Such an asymmetric structure of layers or solder layers before the formation of an intermetallic diffusion layer may be selected such that, for example, the barrier layer 7 and only a solder layer 8 are provided on the electronic component 5. In addition, on the thermally conductive element 1, the barrier layer 2 and Lotschichten 3 and 4 provided. In this embodiment, in contrast to the arrangement shown in FIG. 1, the solder layer 9 is dispensed with since, according to preferred embodiments, in particular the solder layers 4 and 9 consist of the same materials.

According to a further modified embodiment, only the barrier layer 7 is provided on the electronic component 5. To form the intermetallic diffusion layer 2 solder layers 3, 4 and 8 are provided in this case on the thermally conductive element 1 in addition to the barrier layer, so that under application of elevated pressure and / or elevated temperature with simultaneous formation of the intermetallic diffusion layer, a connection to the electronic component 5 is effected by a corresponding connection with the barrier layer 7 provided thereon.

Of course, in one of the above-exemplified asymmetrical arrangements of a different number of layers or solder layers, a change between the heat-conducting element 1 and the electronic component 5 may be provided prior to formation of the intermetallic diffusion layer.

As indicated in particular in FIG. 2, by using a press 10, shown schematically, using an elevated environmental pressure and elevated temperature according to an arrow 11, a formation of an intermetallic

Diffusion layer 12, wherein in Fig. 2, a plurality of components 5 is indicated, which are each to be connected to the heat-conducting element 1 using a common press 10. When using silver and tin for the layers 3 and 4 and 8 and 9, the intermetallic diffusion layer 12 is formed by a eutectic silver-tin alloy, which increased and improved tensile strength and contact between the components 5 and the heat-conducting element. 1 provides.

The thickness of the barrier layer 2 and 7 may for example be between 100 nm and 20 μm. The thicknesses of the individual solder layers 3 and 4 and 8 and 9 are in a range of about 100 nm to at most 100 microns.

The pressure used to form the intermetallic diffusion layers 12 is selected, for example, at most 250 bar, wherein in addition depending on materials used for the electronic component 5 temperatures between 150 ⁰ C and 250 ⁰ C, in particular about 220 ⁰ C are used.

Instead of nickel for the barrier layer 2 or 7, for example, iron or molybdenum and / or nickel and / or iron-containing alloys can be used. For the solder layers 3 and 4 as well as 8 and 9, in particular materials or metals with different melting point can be used, wherein the adjacent layers 4 and 9 are formed of a metal lower melting point and thus higher melting ability, while, for example, the layers and 8, of materials, and particularly metals, of, for example, generally increased conductivity, such as gold or copper instead of silver.

In addition, the selection of the materials used for the layers 3 and 4 and 8 and 9 is also taking into account achievable by using the appropriate temperature and pressure conditions by melt diffusion alloys, which subsequently the desired contact or connection high resistance, especially high Provide dexterity and thermal conductivity.

After the production of a contact or connection of the plurality of electronic components 5 with the heat-conducting element 1, which is formed in particular by a copper sheet of appropriate thickness, there is a subdivision or separation of each generally designated 13 components, each consisting of an electronic component 5 as well as a portion of the heat-conducting element 1 connected to form the intermetallic diffusion layer 12.

In Fig. 4, the inclusion or embedding of such a component 13 in a generally designated 14, multilayer or multilayer printed circuit board is indicated, wherein the individual, shown separately in Fig. 4 layers or layers of such a circuit board, for example, from an RCC Resin coated copper 15, a prepreg 16, a Gore or core 17 and a further RCC film 18 are formed.

In Fig. 4 it is indicated that according to the dimensions of the component 13, the individual layers or layers 16 to 18 are provided with corresponding recesses.

In Fig. 5 is schematically the preparation of a composite of the individual layers or layers of the multilayer printed circuit board 14 embedding the component 13 in turn using a schematic indicated press 19 and, as known per se, increased pressure and elevated temperature 20 for forming a printed circuit board indicated. From FIG. 5, the integration or embedding of the component 13, consisting of the electronic component 5 as well as the thermally conductive element 1 connected or coupled thereby to form the intermetallic diffusion layer 12, can be clearly seen.

According to the illustration in FIG. 6, a structuring takes place for a subsequent contacting of contacts or contact points of the electronic component 5 which are not shown in detail in the region of the electronic component 5, for example by the formation of laser bores 21. Furthermore, the heat-conducting element or heat sink 1 is looped back on the surface facing away from it.

In the region of the laser bores 21, as is indicated in FIG. 7, a contacting of the electronic component 5 with the structured layer or layer takes place within the framework of a further structuring and in particular an additional structure of structured, conductive or conductive layers 22 and 23 via contact points 24.

Moreover, from FIG. 7 it can be seen that the thermally conductive element formed, for example, from a copper sheet 1 also has a partial region 25 of a further heat-conducting layer, for example also made of copper, for improving heat dissipation, in particular by providing a further enlarged surface for heat dissipation. radiation is coupled.

FIG. 8 shows the arrangement or assembly of the structured conductive layers 22 and 23 with further components or components 26 and 27.

If desired, in addition to the provided under formation of the intermetallic diffusion layer 12 improved heat dissipation between the electronic component 5 and the heat-conducting member 1 with selection of appropriate materials in particular for the heat-conducting member 1 and an electrical contact using the intermetallic diffusion layer 12 are provided. In this case, the heat-conductive member 1, which is formed of, for example, a copper sheet, optionally not only with another heat-conductive layer 25 for improving

Heat dissipation, as indicated in Fig. 7, but also coupled to corresponding conductive or conductive structures of the circuit board, wherein the indicated in Fig. 7 further, heat-conducting layer 25 can take over an electrically conductive function simultaneously.

Thus, a component 13 consisting of a heat-generating electronic component 5 during operation and a heat-conducting, in particular metallic element 1 coupled or connected therewith to form an intermetallic diffusion layer 12 can be provided in a reliable manner, wherein this component 13 is particularly simple Way can be prepared in advance and separately, as indicated in Fig. 1 and 3 respectively.

After the preparation of such a component 13 can be in a simple and reliable way, the component 13 in a multi-layer circuit board 14 integrate, with subsequent structuring and assembly operations and contacting operations in simple and reliable way are possible and are not affected or obstructed by providing or forming the component 13.

By providing the intermetallic diffusion layer 12 between the component 5 and the heat-conducting element 1 can be a reliable contact between these elements of the component 13 as well as a corresponding good heat dissipation under harsh environmental conditions of, for example, elevated temperature and increased vibration or vibration, such as in the automotive sector, provide.

Furthermore, can be provided by the separate production of each consisting of a component 5 and a thermally conductive member 1 component 13 compatibility with different methods for the production of multilayer printed circuit boards 14 and substantially independent of assembly operations with additional components available.

By embedding particular of the component 5 in the multilayer printed circuit board 14, a corresponding protection of the component 5 can be achieved while minimizing the space, for example, by dispensing with a housing for the component 5.

In addition, can be made by the separate preparation of the component 13, each consisting of a component 5 and a connected or coupled, heat-conducting element 1, after the completion of the component 13, a review of the individual component 13, so that in particular a Committee can be reduced to finished, but not properly functioning printed circuit boards, which, for example, have an improper contacting of a component 5 with a heat-conducting element 1 or heat sink.

Claims

claims

1. A method for contacting or connecting a particular in operation heat generating electronic component (5) with a heat-conducting, in particular metallic element (1), characterized in that the component (5) to form an intermetallic diffusion layer (12) with the heat-conducting Element (1) is connected.

2. The method according to claim 1, characterized in that the component (5) at one of contacts or contact points (24) of the component (5) provided surface (6) different surface with the thermally conductive element (1) is connected.

3. The method according to claim 1 or 2, characterized in that for forming the intermetallic diffusion layer (12) of the component (5) and / or to be connected or to be coupled, thermally conductive element (1) each with at least one solder layer (3 , 4, 8, 9) and that the solder layers (3, 4, 8, 9) are contacted with each other and bonded to each other using environmental pressure and elevated temperature to form the intermetallic diffusion layer (12).

4. The method of claim 1, 2 or 3, characterized in that the at least one solder layer (3, 4, 8, 9) made of an electrically conductive metal selected from the group comprising silver, gold, nickel and copper and / or Tin, indium and bismuth is formed.

5. The method according to any one of claims 1 to 4, characterized in that prior to the application of the at least one solder layer (3, 4, 8, 9) a barrier layer (2, 7) on the mutually connected or to be determined areas or Surface of the component (5) and / or the heat-conducting element (1) is applied.

6. The method according to claim 5, characterized in that the barrier layer (2, 7) of an electrically conductive metal selected from the group comprising nickel, iron or molybdenum and / or alloys containing nickel and / or iron is formed.

7. The method according to any one of claims 1 to 6, characterized in that two different solder layers (3, 4, 8, 9) are respectively applied to a surface to be bonded or to be determined.

8. The method according to any one of claims 1 to 7, characterized in that the at least one solder layer (3, 4, 8, 9) and / or the barrier layer (2, 7) is electrochemically or chemically deposited or applied.

9. The method according to any one of claims 1 to 8, characterized in that the at least one solder layer (3, 4, 8, 9) and / or the barrier layer (2, 7) has a thickness of at least 5 nm, in particular at least 100 nm at most 100 microns, preferably at most 20 microns (have).

10. The method according to any one of claims 1 to 9, characterized in that the soldering process at a pressure of less than 300 bar, in particular less than 250 bar and at temperatures of less than 400 ⁰ C, in particular between 150 ⁰ C and 250 ⁰ C. is carried out.

11. The method according to any one of claims 1 to 10, characterized in that a plurality of electronic components (5) with a common heat-conducting element (1) to form a respective intermetallic diffusion layer (12) is connected and that the heat-conducting element (1) is divided after connection with the plurality of components (5) for the separation of each of a portion of the heat-conducting member (1) connected to components (5).

12. The method according to any one of claims 1 to 11, characterized in that the heat-conducting element (1) from an opposite the at least one solder layer (3, 4, 8, 9) has an increased thickness, metallic layer, in particular made of copper ,

13. A method for integrating a component consisting of a heat generating in particular during operation, electronic component (5) and an associated, heat-conducting, in particular metallic element (1) in a printed circuit board (14), characterized by the following steps:

Providing a component (13) consisting of an electronic component (5) and a thermally conductive element (1) connected thereto by a method according to one of claims 1 to 12; In particular, providing a plurality of layers (15, 16, 17, 18) of a multilayer

Printed circuit board (14);

Bonding the layers (15, 16, 17, 18) of the multilayer printed circuit board (14) and the component (13) to be integrated therein by application of increased environmental pressure and temperature; and patterning at least one conductive layer (15) of the circuit board for contacting

Contacts of the embedded component (5).

14. The method according to claim 13, characterized in that a structuring of at least one conductive layer (15) of the printed circuit board (14) by a formation of holes, in particular laser bores (21), by etching or the like. Is made.

15. The method according to claim 13 or 14, characterized in that the heat-conducting element (1) with at least one further heat-conducting layer (25), in particular of metallic material, the circuit board (14) is connected.

16. The method according to any one of claims 13 to 15, characterized in that in particular one of the structured conductive layers (15, 18, 22, 23) of the printed circuit board (14) with further electronic components (26, 27) is contacted.

17 component, consisting of a particular heat-generating in operation, electronic component (5) and a heat-conducting, in particular metallic element (1), characterized in that the component (5) to form an intermetallic diffusion layer (12) with the heat-conducting element (1) is connected.

18. Component according to claim 17, characterized in that the component (5) is connected to a surface provided with contacts or contact points (24) of the component (5) surface (6) with the heat-conducting element (1) ,

19. Component according to claim 17 or 18, characterized in that the heat-conducting element (1) relative to the electronic component (5) has enlarged dimensions.

20. Printed circuit board, comprising at least one component according to claim 17, 18 or 19.