DE102013225805A1 - Method of manufacturing an assembly and assembly - Google Patents

Abstract

The invention relates to a method for producing an assembly, wherein a number of electrical components is applied to a substrate and some contacts of the electrical components are electrically connected by means of a arranged over the electrical components contact rail. The invention further relates to a corresponding assembly.

Description

The invention relates to a method for producing an assembly comprising a substrate and a number of electrical components. The invention further relates to such an assembly.

The electrical components are typically power transistors. Assemblies with such power transistors are used, for example, to supply electrical motors, for example in a motor vehicle, with controlled electrical power.

Generic modules are offered, for example, as gehauste modules. These are typically electrically tested and can be installed on mechanics by their design without complex aids. The electrical components, so typically power transistors, are often connected by means of a solder to the substrate, which leads to a good heat dissipation. On a side facing away from the substrate, the electrical components are typically electrically contacted by the technique of bonding, for example using an aluminum wire. To protect the assembly this is usually provided with a sheath made of silicone or a polymer.

A disadvantage of generic modules is in particular that the bonding technique of bonding requires a tool-based large-area space. For example, need wire guide and cutting device on the tool a defined space, which usually means the provision of additional surface for each outer so-called bond feet. Restrictions result from the fact that it is to be avoided aufzuspannen wires used for bonding over long distances. In fact, this could cause them to be damaged by vibrations or to sag, thus forming short circuits to other electrical potentials. Therefore, in generic assemblies often bases on the substrate or on an electrical component applied to keep short by the wires to be bridged routes and thus mechanically stable. These measures also mean that additional space must be provided. The corresponding modules are therefore particularly large area. An additional disadvantage of the bonding technique of bonding is the requirement of various protection measures to avoid electrochemical corrosion and mechanical damage to the bonds.

The document DE 10 2011 083 627 A1 shows an improved compared to the bonding technique manufacturing method for such assemblies. In this case, electrical connections above the substrate are no longer produced by means of bonding, but rather by structured application of conductive and insulating layers. Preferably, the technique of screen printing is used. This mechanically more stable connections are generated and it can also be saved area.

Starting from the known prior art, it is an object of the invention to provide a method for producing an assembly, which allows the production of such an assembly on an even smaller area. Furthermore, it is an object of the invention to provide a corresponding assembly.

This is achieved by a method according to claim 1 and by an assembly according to claim 13. Advantageous embodiments can be taken, for example, the respective subclaims. The content of the claims is made by express reference to the content of the description.

• – Bereitstellen eines Substrats,
• – Aufbringen einer Anzahl von elektrischen Bauelementen auf das Substrat, wobei jedes elektrische Bauelement auf einer dem Substrat abgewandten Oberfläche zumindest eine elektrische Kontaktfläche aufweist,
• – Bereitstellen einer elektrisch leitfähigen Kontaktschiene,
• – Aufbringen der Kontaktschiene auf die elektrischen Bauelemente, und
• – Ausbilden eines elektrischen Kontakts zwischen den Kontaktflächen der elektrischen Bauelemente und der Kontaktschiene.

The invention relates to a method for producing an assembly, which comprises the following steps:

• Providing a substrate,
• Applying a number of electrical components to the substrate, each electrical component having at least one electrical contact surface on a surface facing away from the substrate,
• Providing an electrically conductive contact rail,
• - Applying the contact rail to the electrical components, and
• - Forming an electrical contact between the contact surfaces of the electrical components and the contact rail.

In the embodiment of the method according to the invention, at least one electrical potential is not conducted on the substrate, but above the electrical components. In other words, the method allows the use of all three spatial dimensions to form electrical connections and to distribute electrical potentials, wherein at least one electrical potential is removed from a two-dimensional surface of the substrate and instead is displaced upwards. The footprint of a particular assembly can be significantly reduced in this way, for example, it can be halved. If the size of the substrate is determined on the basis of external parameters, more assemblies can be accommodated on the same substrate size. For example, twice as many assemblies can be accommodated on a substrate of a given size become. These advantages lead in particular to a saving of costs.

In addition to the provision of an electrical potential, the contact rail used in the method according to the invention additionally offers the advantage that it can dissipate power loss heat of the electrical components over their surface.

All further connections of the components, for example signal or power connections, can be electrically connected to conductive tracks of the substrate, for example copper tracks, by conventional methods such as electrically conductive bonding, soldering or welding. The ends of respective contacts, which are typically located outside the module, can be formed in a variety of ways, for example by screwing, clamping, pressing, soldering or welding. Thus, for example, an electrical connection to a control electronics can be formed.

For the purposes of this application, the term "a number of elements" should be understood to mean that either such an element or several such elements are present. By a number of electrical components is thus understood, for example, either a component or a plurality of components. Typically, an assembly has three such electrical components to which the contact rail is applied.

The electrical components are preferably transistors, and in particular, power transistors. These are preferably made in silicon technology. Such power transistors enable a high power density. The contact rail may be electrically connected to transistors, for example, with respective source contacts.

The electrically conductive contact rail is typically a component that is not formed by the use of a patterning process carried out on the substrate or a metallization process typical in the field of semiconductor technology, for example dual damascene technology. Rather, the contact rail is manufactured independently of the substrate by means of suitable shaping methods such as, for example, machining or injection molding. Typically, it can still be easily recognized in the finished assembly that the contact rail is such an externally manufactured component.

The contact rail is preferably straight. This leads to a simple design and is particularly suitable when the electrical components to which the contact rail is to be applied, are also arranged along a straight line. Particularly preferably, three such components are arranged side by side.

Preferably, the method further comprises a step of applying an electrically conductive material, preferably a conductive polymer or sintered polymer, to the contact surface which is performed prior to the step of applying the contact rail. With the aid of such a conductive polymer or sintered polymer, it is possible to produce an advantageous electrically conductive and possibly also thermally conductive connection between the contact surface of the electrical component and the contact rail.

In particular, when using a sintered polymer, it is further preferred that the method comprises a step of sintering for forming a mechanically strong and electrically conductive connection between the contact surfaces and the contact rail via the electrically conductive material, which after the step of applying the contact rail on the electrical components is executed. In this case, after the step of applying the contact rail, the at least partially produced assembly can be heated in particular, so that the sintered polymer hardens. In support of this, a pressure on the contact rail in the direction of the components can be exercised.

The lead polymer and / or the sintered polymer are preferably applied by the method of screen printing. This allows accurate and efficient application of these materials.

Preferably, the contact rail is coated on surface sections, which produce an electrical contact with a contact surface in the applied state, with a noble metal. Thus, the electrical conductivity between the contact rail and the contact surface of an electrical component can be improved. Preferably, the noble metal is gold.

A process of coating the contact rail with such a noble metal is typically carried out before the provision of the contact rail for use in the context of the method according to the invention.

Preferably, the contact rail is integrated in a cover of the module. This allows a compact design and a simple production, wherein more preferably cover and contact rail can be applied together. The lid is typically made of plastic, in particular of a non-electrically conductive polymer.

Preferably, the contact rail has a number of press-fit contacts, which project in the applied state transversely to the substrate. Such press-fit contacts allow for advantageous attachment of the assembly to another component while reliably forming an electrical contact. To this end, the other component typically has complementary holes to the press-fit contacts into which the press-fit contacts can be inserted under pressure and slight deformation. The complementary holes are typically coated with an electrically conductive material and thus can produce a reliable electrical contact with the press-fit contacts, which preferably also consist of electrically conductive material.

A protrusion of the press-fit contacts transversely to the substrate is typically understood to extend with a respective longitudinal direction substantially or exactly transversely to the surface of the substrate on which the electrical components are applied.

A longitudinal end of the contact rail preferably protrudes transversely to the substrate in the applied state, wherein a section of the contact rail adjoining this longitudinal end is bent by approximately 90 °. In this way, a contact that protrudes in the assembled state via a housing of the module can be formed, which is formed by the longitudinal end projecting transversely to the substrate.

The contact rail is preferably made of copper or a copper alloy. These materials have the advantage of good electrical conductivity and also good thermal conductivity. It should be noted that most materials which are well electrically conductive are also very thermally conductive.

It should be understood that the mentioned advantageous properties of the contact rail are features of the contact rail, wherein the inventive method is then preferably carried out such that a contact rail is provided with corresponding features.

The electrical components preferably have at least one further electrical contact surface on the surface facing away from the substrate, wherein the method further comprises a step of applying an electrically insulating material to the further contact surfaces, which is performed before the step of applying the contact rail.

Such a further electrical contact surface may, for example, be a gate contact, in particular if the electrical component is a transistor. Such a gate contact is preferably not contacted by means of the contact rail, but by another electrical connection. Therefore, it is advantageous to apply the mentioned electrically insulating material to the gate contact in order to avoid a short circuit to the contact rail.

The electrically insulating material is preferably a non-electrically conductive polymer. The electrically insulating material is further preferably applied by means of a screen printing process. This allows a precise and cost-effective production.

The substrate is preferably electrically insulating. A surface of the substrate on which the electrical components are applied then more preferably has a number of electrically conductive coated sections, wherein a respective section is electrically insulated from all other sections, wherein each electrical component has a contact surface on a surface facing the substrate wherein each electrical component is associated with one of the sections, and wherein a respective electrically conductive coated portion, which is associated with an electrical component, is larger than the electrical component, so that the respective contact surface on the substrate facing surface of the electrical component with the associated portion is electrically contacted.

The sections are preferably coated with copper. This is a good electrically conductive material. In such an embodiment, for example, the substrate and its coating may be a Direct Copper Bonded (DCB) substrate, which may be used in a known manner for known bonding techniques.

By the described embodiment of an electrically insulating substrate with applied electrically conductive coated sections can be achieved that each electrical component can be contacted electrically on its side facing the substrate. As a result of the electrical insulation of the individual sections relative to one another, a respective contact surface can be formed on the surface of each individual component facing the substrate individually contacted electrically, provided that only one component is assigned to the section. This can be used, for example, for applying different potentials. However, a section can also be assigned several components.

In the case of the contact surfaces on the surfaces facing the substrate, in the case in which the electrical components are transistors, these are preferably respective drain contacts. This is particularly advantageous in connection with an embodiment in which respective source contacts of such transistors are electrically contacted with the contact rail and respective gate contacts are contacted separately.

Between the electrically conductive coated portions and the electrical components, a solder is preferably applied, before the application of the respective component to the substrate. This achieves a mechanically stable and electrically conductive connection.

The method preferably further comprises a step of applying further electrical components to the substrate, which is preferably performed prior to the step of applying the contact rail, wherein a respective electrical component to which the contact rail is applied, along a direction transverse to a longitudinal direction the contact rail two associated further electrical components are arranged so that the electrical component to which the contact rail is applied, is arranged in the middle of the two associated further electrical components.

With such an embodiment, an extension of the assembly is achieved by electrical components, which are not contacted by the contact rail. Rather, for these other connection techniques can be used. The functionality of the module to be produced can thus be significantly increased.

The further electrical components are preferably components of the same type as the respective component arranged between these two further electrical components, with the contact rail being applied to the latter. By way of example, all the components are transistors, in particular power transistors. It is particularly preferred if a total of nine electrical components are present, of which on three of these electrical components, the contact rail is applied and a total of six of the electrical components are arranged next to it. The electrical components are then preferably arranged in a 3 × 3 matrix. This is advantageous for typical functionalities, as further described below.

• – Aufbringen von elektrisch isolierendem Material, bevorzugt ein Polymer, seitlich an jedem der weiteren elektrischen Bauelemente, so dass ein Bereich von einem jeweiligen elektrisch leitfähig beschichteten Abschnitt, welchem ein von der Kontaktschiene zu kontaktierendes elektrisches Bauelement zugeordnet ist, zu einer Kontaktfläche eines jeweiligen zugeordneten weiteren elektrischen Bauelements überdeckt wird, und
• – Aufbringen eines elektrisch leitfähigen Materials, bevorzugt ein Leitpolymer, auf das elektrisch isolierende Material, so dass eine elektrische Verbindung zwischen dem elektrisch leitfähig beschichteten Abschnitt und der Kontaktfläche hergestellt wird.

Further preferably, each of the further electrical components has at least one electrical contact surface on a surface facing away from the substrate, wherein the method further comprises the following steps, which are carried out before the step of applying the contact rail:

• - Applying electrically insulating material, preferably a polymer, laterally on each of the further electrical components, so that a portion of a respective electrically conductive coated portion, which is assigned to be contacted by the contact rail electrical component, to a contact surface of a respective associated further electrical component is covered, and
• - Applying an electrically conductive material, preferably a conductive polymer, on the electrically insulating material, so that an electrical connection between the electrically conductive coated portion and the contact surface is produced.

Such an embodiment ensures that a respective contact surface, facing the substrate, of an electrical component, to which the contact rail is applied, is electrically connected to a contact surface on a surface of an associated further electrical component facing away from the substrate. By means of the initially applied electrically insulating material, a short circuit, for example with an electrically conductive coated section underneath the further electrical component, can be prevented. The electrical connection described is particularly advantageous for certain assemblies to be produced by the method according to the invention, for example for a B6 bridge with phase switch.

• – Aufbringen mindestens einer Flüssigkeitsschicht auf das Substrat und auf jeweilige elektrische Bauelemente, bevorzugt mittels Siebdruck,
• – Aushärten der mindestens einen Flüssigkeitsschicht zum Ausbilden einer elektrisch isolierenden Schicht, und
• – Aufbringen mindestens einer elektrischen Leitschicht zum elektrischen Verbinden einer elektrischen Kontaktfläche oder einer weiteren elektrischen Kontaktfläche des jeweiligen elektrischen Bauelements mit zumindest einer Leiterbahn des Substrats.

The method preferably further comprises the following steps, which are carried out before the step of applying the contact rail:

• Applying at least one liquid layer to the substrate and to respective electrical components, preferably by screen printing,
• Curing the at least one liquid layer to form an electrically insulating layer, and
• - Applying at least one electrical conductive layer for electrically connecting an electrical contact surface or a further electrical contact surface of the respective electrical component with at least one conductor track of the substrate.

By means of these method steps, contact surfaces of electrical components, which are not contacted by the contact rail, are electrically connected in an advantageous manner. Ideally, bonding can be completely dispensed with. The disadvantages described above are thus completely avoided. It should be understood that with the method step just described contact surfaces and other contact surfaces of all electrical components, including other electrical components, can be connected.

The liquid layer and / or the electrical conductive layer are preferably applied in a predetermined pattern on selected areas of the substrate, wherein other areas of the substrate are each recessed. The use of a screen printing process is particularly suitable for this because it is accurate and cost-effective to perform. The mentioned steps can also be repeated as often as desired in order to form more complex, even three-dimensional structures. This electrical lines can be superimposed in several levels.

After completion of the previously mentioned method steps or any subcombination of these steps, a cover layer can preferably be applied to the substrate with the applied electrical components, the contact rail, further components applied for electrical connection and other components. This cover layer can bring about advantageous passivation and protection of the assembly.

After carrying out the method steps described or any subcombination, the module can preferably be inserted into an injection-molded housing in a known manner. For this purpose, for example, an injection-moldable material can be sprayed around the assembly around and hardened. Connections, for example, the press-fit contacts mentioned above and / or the above-mentioned longitudinal end of the contact rail can protrude from the injection molded housing, so that an electrical contact is possible. Upon completion, use of such an injection molded housing may, for example, speak of a module containing the assembly. For such a module, among other things, various mounting options exist, for example by screws or clamps. The selection of a heat transfer medium to the heat sink is not limited, so that a variety of known heat transfer media can be used. In addition, it is possible to integrate all the potential connections in a plastic housing and then to connect the contacts on the substrate with known technologies.

To avoid stress cracks and thermal stress on parts to be joined, such as those made of silicon or copper, which may in some cases have different coefficients of expansion, ductile, elastic materials are preferably used for carrying out the process.

• – ein Substrat,
• – eine Anzahl von elektrischen Bauelementen auf dem Substrat, wobei jedes elektrische Bauelement auf einer dem Substrat abgewandten Oberfläche zumindest eine elektrische Kontaktfläche aufweist, und
• – eine elektrisch leitfähige Kontaktschiene, welche auf den elektrischen Bauelementen angeordnet ist und mit den jeweiligen elektrischen Kontaktflächen auf der dem Substrat abgewandten Oberfläche der elektrischen Bauelemente elektrisch verbunden ist.

The invention further relates to an assembly comprising:

• A substrate,
• A number of electrical components on the substrate, each electrical component having at least one electrical contact surface on a surface facing away from the substrate, and
• - An electrically conductive contact rail, which is arranged on the electrical components and is electrically connected to the respective electrical contact surfaces on the surface facing away from the substrate of the electrical components.

Such an assembly according to the invention has the particular advantage of a reduced space requirement compared to assemblies according to the prior art. This is primarily due to the contact rail, which leads to the fact that it is possible to dispense with at least one conductor track on the substrate, since the corresponding electrical potential is shifted into a third dimension, typically upwards. It can also be spoken of a stacked construction.

All described with reference to the inventive method advantageous embodiments, provided that they are applicable to the assembly according to the invention, also advantageous embodiments of the assembly according to the invention. This applies in particular to materials and arrangements described with reference to the method according to the invention. Illustrated benefits apply accordingly.

The assembly according to the invention is particularly preferably produced by means of a method according to the invention. In this case, all embodiments described with reference to the method according to the invention can be used. Illustrated benefits apply accordingly.

The assembly according to the invention is particularly preferably designed as a B6 bridge with phase switch. In such an assembly, the advantages of the invention come in a special way to advantage.

Further features and advantages will become apparent to those skilled in the art from the following with reference to the attached drawing described embodiments.

Showing:

1a to 1d the transition from an assembly according to the prior art to a surface-optimized assembly according to the invention,

2a to 2g : Components of an assembly and a module containing the assembly between several steps of a method according to the invention,

3 FIG. 2: a cross-sectional view through an assembly according to the invention, FIG.

4a to 4d : Components of an assembly between different steps of a method according to the invention.

The 1a to 1d illustrate what constitutes a basic principle of the invention and how to significantly reduce the space required for an assembly.

1a shows an assembly 10 according to the prior art. The assembly 10 has a substrate 100 with a surface 110 on which a total of nine electrical components in the form of a first transistor 210 , a second transistor 220 a third transistor 230 a fourth transistor 240 , a fifth transistor 250 , a sixth transistor 260 , a seventh transistor 270 , an eighth transistor 280 and a ninth transistor 290 are applied. At the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 these are power transistors.

On the surface 110 There are a total of seven electrically conductive coated sections, namely a first section 111 , a second section 112 , a third section 113 , a fourth section 114 , a fifth section 115 , a sixth section 116 and a seventh section 117 , being within each of the sections 111 . 112 . 113 . 114 . 115 . 116 . 117 a layer of copper on the surface 110 is applied. The electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 are each electrically isolated from all other sections. The substrate 100 is formed of a ceramic material which is electrically insulating. The described arrangement of an electrically insulating substrate with copper coating can also be referred to as a direct-copper-bonded (DCB) substrate.

The first to sixth transistors 210 . 220 . 230 . 240 . 250 . 260 is each one of the first to sixth sections 111 . 112 . 113 . 114 . 115 . 116 assigned. This means that the respective transistor 210 . 220 . 230 . 240 . 250 . 260 on each one of the copper-coated sections 111 . 112 . 113 . 114 . 115 . 116 is applied, wherein an electrically conductive connection between a bottom of the respective transistor 210 . 220 . 230 . 240 . 250 . 260 and the associated, copper-coated portion 111 . 112 . 113 . 114 . 115 . 116 consists. As shown, the respective sections are also shown 111 . 112 . 113 . 114 . 115 . 116 in the plane of the surface 110 seen larger than the respective transistor 210 . 220 . 230 . 240 . 250 . 260 to which the respective section 111 . 112 . 113 . 114 . 115 . 116 assigned. This allows the respective bottom of the transistors 210 . 220 . 230 . 240 . 250 . 260 by providing an electrical connection to the respective section 111 . 112 . 113 . 114 . 115 . 116 to contact electrically.

The seventh, eighth and ninth transistors 270 . 280 . 290 are together the seventh electrically conductive section 117 associated, in which case a respective bottom of the respective transistor 270 . 280 . 290 with the copper coated section 117 electrically contacted. Thus, all subpages of the seventh, eighth and ninth transistors are 270 . 280 . 290 interconnected to a common potential, which due to the also larger, so protruding extent of the section 117 can be electrically connected.

At the respective undersides of the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 There is in each case an electrical contact surface in the form of a drain contact. These are however in the representation of 1a not visible.

On a respective the substrate 100 opposite surface facing each of the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 each an electrical contact surface in the form of a respective source contact 212 . 222 . 232 . 242 . 252 . 262 . 272 . 282 . 292 and a respective further electrical contact surface in the form of a respective gate contact 214 . 224 . 234 . 244 . 254 . 264 . 274 . 284 . 294 on. The respective source contacts 212 . 222 . 232 . 242 . 252 . 262 . 272 . 282 . 292 are each made larger in area than the respective gate contacts 214 . 224 . 234 . 244 . 254 . 264 . 274 . 284 . 294 ,

Between the electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 is a wide track 120 on the surface 110 of the substrate 100 arranged. The conductor track 120 also consists of a copper coating, similar to the electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 , Your Expansion on the surface 110 is so large that it can meet requirements regarding the amount of current to be absorbed.

The wide track 120 sets in several places on the surface 110 of the substrate 100 available potential. The conductor track 120 is by means of three electrical connectors 145 with the respective source contacts 212 . 222 . 232 the first, second and third transistors 210 . 220 . 230 connected. It thus serves as a common source terminal of the first, second and third transistors 210 . 220 . 230 ,

Other electrical connectors 145 are between the first electrically conductive coated section 111 to which the first transistor 210 is assigned, and the respective source contacts 242 . 272 the fourth and seventh transistors 240 . 270 between the second electrically conductive coated portion 112 to which the second transistor 220 is assigned, and the respective source contacts 252 . 282 the fifth and eighth transistors 250 . 280 and between the third electrically conductive coated portion 113 to which the third transistor 230 is assigned, and the respective source contacts 262 . 292 the sixth and ninth transistors 260 . 290 intended.

As in 1a can be seen, are the total of nine transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 arranged in three rows of three transistors each. In the middle row are the first, second and third transistors 210 . 220 . 230 , Each of these transistors of the middle row is assigned a transistor of the upper row and a transistor of the lower row. About the electrical connector just described 145 is a respective transistor 210 . 220 . 230 connected to its respective two associated transistors such that the drain contact of the respective transistor of the middle row is connected to the respective source contacts of the transistors of the upper and lower row.

The electrical connectors 145 are simplified in the present case shown as wider connections. They are realized by a plurality of parallel-running bonding wires in order to achieve a higher current-carrying capacity required at the corresponding connections.

On the surface 110 of the substrate 100 is further a plurality of electrical connections 130 intended. These can be used to connect individual contact surfaces or contacts on the substrate 100 arranged electrical components or other conductive components are used. The electrical connections 130 are present as well as the electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 as well as the broad track 120 formed by a copper coating.

In the execution according to 1a are the respective electrical connections 130 by means of respective bonding wires 140 each having a source or gate contact of the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 connected. In this way, the respective contacts which are formed as electrical contact surfaces can be electrically connected to external units such as a power supply or a motor. The bonding wires 140 bring the disadvantages already mentioned at the beginning of this description. In particular, they must be secured against mechanical damage and vibration and require an increased space requirement for installation. Furthermore, in 1a to see that two of the bonding wires 140 namely, those bonding wires leading to the gate contacts 244 . 264 the fourth and sixth transistors 240 . 260 lead, are kinked in the middle, which is under the respective kink a small, in 1a not shown post for supporting the respective bonding wire 140 located. This requires additional installation effort and space requirements.

1b shows a modification of the assembly 10 from 1a in which already a feature according to the invention is realized. It is instead of the wide trace 120 an electrically conductive contact rail 300 for contacting the respective source contacts 212 . 222 . 232 the first, second and third transistors 210 . 220 . 230 intended. Thus, the supply of the corresponding potential for these source contacts 212 . 222 . 232 starting from the flat surface 110 into the third dimension, ie shifted upwards.

By this measure, the original for the broad trace 120 intended area on the surface 110 no longer needed. Therefore, the assembly can 10 Overall, for example, be made more compact, that the distance between the upper and the middle row of transistors is reduced. This is in 1c shown.

A further areal optimization can be achieved by the arrangement also in the longitudinal direction of the contact rail 300 smaller is executed. For this purpose, in particular the dimensions of the electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 significantly reduced. A corresponding design shows 1d , It was not only the space required significantly reduced, but it was now also - in contrast to the statements according to the 1a to 1c - the bonding wires 140 through tracks 150 replaced. The tracks 150 are applied by means of a screen printing process and do not bring the disadvantages of the bonding wires 140 with him, which were described in the beginning. In particular, they can not sag, cause short circuits or other unwanted contacts and do not require support structures.

The 2a to 2g show components of an assembly 10 and a module 20 which the assembly 10 contains, between respective process steps of a method according to the invention for producing an assembly according to the invention. On the basis of these figures, an embodiment of a method according to the invention will be explained below. It should be mentioned that the illustration of some components has been omitted for reasons of clarity.

2a shows a substrate 100 with a surface 110 on which other components of the assembly 10 should be applied. The substrate 100 is made of electrically non-conductive ceramic and coated with copper. This results in a total of seven, namely first to seventh electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 on the surface 110 and a plurality of electrical connections 130 educated. These are each electrically isolated from each other, as well as with respect to 1a has been described.

On the surface 110 are further a first, second, third, fourth, fifth, sixth, seventh, eighth and a ninth transistor 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 arranged, in three rows of three transistors, as already with reference to the 1a to 1d has been described. Each transistor of the middle row, so the first, second and third transistors 210 . 220 . 230 are each a transistor 240 . 250 . 260 the upper row and one transistor each 270 . 280 . 290 assigned to the lower row. The respective transistor of the middle row is located between its two associated transistors of the other two rows.

Each of the first, second, third, fourth, fifth and sixth transistors 210 . 220 . 230 . 240 . 250 . 260 is in each case one of the first to sixth electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 assigned. The seventh, eighth and ninth transistors 270 . 280 . 290 is a single, namely the seventh electrically conductive coated section 117 assigned. The respective electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 are each larger than the transistors arranged thereon 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 , The transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 each have their on the substrate facing, in 2a invisible underside an electrical contact surface in the form of a drain contact, which by means of a non-visible solder on the respectively associated electrically conductive coated portion 111 . 112 . 113 . 114 . 115 . 116 . 117 is applied. Thus, the respective drain contact by means of the respectively associated electrically conductive coated portion 111 . 112 . 113 . 114 . 115 . 116 . 117 be electrically connected.

On the respective surface of the transistors facing away from the substrate 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 there is one source contact each 212 . 222 . 232 . 242 . 252 . 262 . 272 . 282 . 292 of the respective transistor. Although there are also gate contacts on this surface, these are, for reasons of simplicity, in the US Pat 2a to 2g not shown.

2 B shows a state after a process step in which respective strips 241 . 251 . 261 . 271 . 281 . 291 of electrically insulating material, namely an electrically nonconductive polymer were applied. The respective stripes 241 . 251 . 261 . 271 . 281 . 291 in each case run from one of the first to third electrically conductive coated sections 111 . 112 . 113 to which transistors of the middle row of transistors are assigned to the respective source contacts 242 . 252 . 262 . 272 . 282 . 292 the respective associated transistors of the upper and lower rows.

2c shows a state after a further process step, in which respective strips 243 . 253 . 263 . 273 . 283 . 293 made of electrically conductive material, namely a conductive polymer, on the respective strips 241 . 251 . 261 . 271 . 281 . 291 made of electrically insulating material. The Stripes 243 . 253 . 263 . 273 . 283 . 293 made of electrically conductive material in each case extend from an electrically conductive coated section 111 . 112 . 113 , which is associated with a transistor of the middle row of transistors, to respective source contacts 242 . 252 . 262 . 272 . 282 . 292 the respective associated transistors from the upper and lower row. Thus, an electrical connection is made between the respective electrically conductive coated portion and the respective source contact.

2d shows a state after another process step. It was on each of the three transistors 210 . 220 . 230 the middle row a respective layer 215 . 225 . 235 made of an electrically conductive material, namely a conductive polymer applied. This allows a contacting of the respective drain contact 212 . 222 . 232 of the respective transistor 210 . 220 . 230 from above.

2e shows a state after another process step. It was on the respective layers 215 . 225 . 235 from Leitpolymer an electrically conductive contact rail 300 applied. The contact rail 300 In this case consists of copper and extends with a longitudinal direction corresponding to the middle row of transistors. Due to the direct contact of the contact rail 300 on the respective layers 215 . 225 . 235 lead polymer becomes a respective electrical connection from the contact rail 300 to the respective source contacts 212 . 222 . 232 the underlying first, second and third transistors 210 . 220 . 230 produced. In other words, the contact rail 300 a common potential for these source contacts 212 . 222 . 232 ready.

The contact rail 300 also has three press-fit contacts 310 which can be compressed in a known manner when introduced into corresponding holes with a slightly smaller diameter, whereby both a mechanical fixation as well as the formation of an electrical contact in a known manner is possible. The contact rail 300 furthermore has a longitudinal end 320 on which in the 2e shown applied state across the substrate 100 ie to the surface 110 of the substrate 100 , stands out. In other words, stands the longitudinal end 320 or to the longitudinal end 320 adjacent section of the contact rail 300 perpendicular to the surface 110 of the substrate 100 , Between this transversely projecting longitudinal end 320 and the rest of the contact rail 300 there is a curved section 325 , which ensures a bend of 90 °. That across the substrate 100 protruding longitudinal end 320 For example, it can be used as a power connection, as will be explained further below.

By applying the contact rail 300 may have a common potential for the source contacts 212 . 222 . 232 the underlying first, second and third transistors 210 . 220 . 230 be provided. There is no additional surface on the surface for this 110 necessary, as this is a place above the surface 110 is used. In other words, this corresponds to a stacked construction. The on the substrate 100 required area can thus be significantly reduced.

Since now all necessary for a complete assembly components are present, they can in the state which in 2e is shown, now also as an assembly 10 be designated. It is an embodiment of an assembly according to the invention.

2f shows a state after a further process step, with which the assembly 10 is processed to a module. For this purpose, a contact block 160 on the electrical connections 130 applied. From the contact block 160 stand Press-Fit contacts 165 which, in each case with one of the plurality of electrical connections 130 are connected. These press-fit contacts are signal contacts in the present case.

It should be mentioned again that at the 2a to 2g some components have not been displayed for clarity and clarity. In this case, in particular electrical interconnects between the electrical connections 130 and transistors or electrically conductive coated portions of the assembly 10 omitted. It should be understood that such interconnects or other electrical connections are present in real assemblies and thus by the signal contacts respective source, drain or gate contacts of the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 are electrically accessible. For example, these can be via the signal contacts 165 be electrically connected.

Furthermore, the transition to the in 2f state shown a total of four high-current contacts, namely a lower high-current contact 170 and three upper high current contacts, namely a first high current contact 171 , a second high current contact 172 and a third high current contact 173 applied. The lower high-current contact 170 , is electrically conductive with the seventh electrically conductive coated section 117 connected to which the seventh, eighth and ninth transistors 270 . 280 . 290 assigned. The upper high current contacts 171 . 172 . 173 are each with one of the fourth to sixth electrically conductive coated sections 114 . 115 . 116 electrically connected, which in each case one of the fourth, fifth and sixth transistors 240 . 250 . 260 assigned. The respective high current contacts 170 . 171 . 172 . 173 are glued to a respective electrically conductive portion, with electrically conductive adhesive material. This allows a simple and reliable electrical connection.

2g shows a state after another step, and in particular shows a complete module 20 which is the electrical assembly 10 contains. For this purpose, a housing 180 made of injection-molded material, by means of an injection molding process. The housing 180 has a total of four protruding eyelets 181 . 182 . 183 . 184 on which for fixing the module 20 can serve. The signal contacts 165 , the press-fit contacts 310 the contact rail 300 , the curved longitudinal end 320 the contact rail 300 as well as the four high current contacts 170 . 171 . 172 . 173 stand over the housing 180 and can thus be electrically connected or contacted. This allows a connection of the individual Components of the assembly 10 each with a suitable design for the respectively required current density.

As at the top of 2g can be seen, is a small part of the substrate 100 with respective small parts of the electrically conductive coated sections 114 . 115 . 116 over the housing 180 out. This is advantageous for certain installation situations.

3 shows a cross section through an assembly 10 according to an embodiment, which is in principle similar to that which the assembly of the 2e to 2g underlying, but is slightly modified in particular in terms of proportions.

It can be seen that below the substrate 100 another coated with copper and thus conductive layer 105 is arranged. This can also be used for suitable power supply.

On the substrate are two electrically conductive coated sections 111 and 114 , The sectional view of 3 is thus taken approximately along a line which is in 2g from the first transistor 210 extends upward, past the fourth transistor 240 ,

3 shows the first transistor 210 , which on its underside an electrical contact surface in the form of a drain contact 211 having. Between the drain contact 211 and the electrically conductive coated portion 111 which is the first transistor 210 is assigned, there is a lot 216 , which is a mechanically stable and electrically conductive connection between the first transistor 210 and the substrate 100 over the electrically conductive coated section 111 generated. On top of the first transistor 210 are the source contact 212 and the gate contact 214 , Above the source contact 212 there is a layer 215 of lead polymer, whereas above the gate contact 214 a layer 217 made of electrically insulating material.

Furthermore, located above the first transistor 210 the contact rail 300 , with a press-fit contact 310 and its curved longitudinal end 320 , The contact rail 300 lies both on the layer 215 from Leitpolymer as well as on the electrically insulating layer 217 on, leaving an electrically conductive connection between the contact rail 300 and the source contact 212 but not to the gate contact 214 will be produced. This can be the source contact 212 be electrically connected in the manner already described above.

On the other of the two electrically conductive coated sections, namely on the electrically conductive coated section 114 , is the first high current contact 171 applied, with reference being made to the above description for further details.

All above the substrate 100 located components, with the exception of protruding contacts, are located within the housing 180 made of injection-molded material. Thus, these are advantageously protected against damage or unwanted electrical contacts. It should be mentioned that in the embodiment according to 3 - in contrast to the execution according to 2g - the case 180 not so short is that part of the substrate 100 over the housing 180 also available. Rather, in the embodiment according to 3 The housing is designed so that it has all the electrically conductive coated sections on the surface 110 as well as the surface 110 of the substrate 100 completely encloses.

The 4a to 4d show components of an assembly 10 between respective process steps, wherein the components and the arrangements are very similar to those already described with reference to the 2a to 2g have been described. Essentially, only proportions are slightly changed and, in addition, are of the respective transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 also respective further electrical contact surfaces in the form of respective gate contacts 214 . 224 . 234 . 244 . 254 . 264 . 274 . 284 . 294 shown. The representations of the 4a to 4d In each case refer to states between two respective process steps, in addition to those already in the 2a to 2g shown components are shown further components which in the 2a to 2g have been omitted for clarity.

Regarding the already from the 2a to 3 known components, in particular with respect to the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 , the source contacts 212 . 222 . 232 . 242 . 252 . 262 . 272 . 282 . 292 , the stripe 241 . 251 . 261 . 271 . 281 . 291 made of electrically insulating material, the strip 243 . 253 . 263 . 273 . 283 . 293 made of electrically conductive material, the electrically conductive coated sections 111 . 112 . 113 . 114 . 115 . 116 . 117 , the substrate 100 with its surface 110 , as well as the electrical connections 130 can be fully based on the description of the 2a to 3 to get expelled. A repetition should be omitted for reasons of simplification.

4a shows a state which, for example, between the in the 2c and 2d shown states can occur. Were already all in 2c shown applied components, in addition, however, are now also electrical conductive layers 150 and surrounding insulating layers 155 shown. These are in the 2a to 2g basically not shown for reasons of simplification.

Respective conductive layers 150 each provide an electrical connection between each one of the electrical connections 130 and a source or gate contact of each one of the transistors 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 ago. Thus they fulfill practically the same function as in 1a shown bonding wires 140 but are much more robust.

4b shows a state which after the in 4a shown state and before the application of the contact rail 300 can occur. Thereby the gate contacts became 214 . 224 the first and second transistors 210 . 220 with a layer 217 covered by electrically insulating material.

Likewise, the gate contact became 234 of the third transistor 230 with a layer 237 covered by electrically insulating material. This can be prevented that in the subsequent application of the contact rail 300 an unwanted electrical contact between the contact rail 300 and one of the gate contacts 214 . 224 . 234 will be produced.

4c shows a state, which in particular after the in 4b illustrated state, but even before the application of the contact rail 300 can occur. Compared to the state of 4b In addition, respective layers were added 215 . 225 . 235 of conductive polymer on the first, second and third transistors 210 . 220 . 230 applied. Regarding the details and advantages of these respective layers may refer to the description 2d to get expelled.

4d shows a state in which compared to the state of 4c the contact rail 300 was applied and an electrical connection between the contact rail 300 and the respective source contacts 212 . 222 . 232 the first, second and third transistors 210 . 220 . 230 was trained. With regard to the details, reference is made to the above description. This will cause the assembly 10 completed as such. Furthermore, in the state of 4d compared to that of 3c also the four high current contacts 170 . 171 . 172 . 173 applied. For further details, please refer to the description of 2f directed.

The assembly 10 , which in particular in the 2e and 4d is particularly suitable as a B6 bridge with phase switch. With such a use, the effect of area reduction described several times in the text is particularly advantageous, since more B6 switches of this type can be applied to a given area.

The typical wiring of a B6 bridge with phase switch is known in the art and is also from the 2e and 4d as well as the corresponding description.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011083627 A1 [0005]

Claims (15)

Method for producing an assembly ( 10 ), comprising the following steps: - providing a substrate ( 100 ), - applying a number of electrical components ( 210 . 220 . 230 ) on the substrate ( 100 ), wherein each electrical component ( 210 . 220 . 230 ) on a substrate ( 100 ) facing away from the surface at least one electrical contact surface ( 212 . 222 . 232 ), - providing an electrically conductive contact rail ( 300 ), - applying the contact rail ( 300 ) on the electrical components ( 210 . 220 . 230 ), and - forming an electrical contact between the contact surfaces ( 212 . 222 . 232 ) of the electrical components ( 210 . 220 . 230 ) and the contact rail ( 300 ). The method of claim 1, further comprising a step of applying an electrically conductive material ( 215 . 225 . 235 ), preferably a conductive polymer or sintered polymer, on the contact surfaces ( 212 . 222 . 232 ), which before the step of applying the contact rail ( 300 ) is performed. Method according to one of the preceding claims, wherein the contact rail ( 300 ) on surface portions which in the applied state make electrical contact with a contact surface ( 212 . 222 . 232 ), coated with a noble metal, preferably gold. Method according to one of the preceding claims, wherein the contact rail ( 300 ) in a cover of the assembly ( 10 ), which preferably consists of plastic, is integrated. Method according to one of the preceding claims, wherein the contact rail ( 300 ) a number of press-fit contacts ( 310 ), which in the applied state transversely to the substrate ( 100 ) stand out. Method according to one of the preceding claims, wherein a longitudinal end ( 320 ) of the contact rail ( 300 ) in the applied state transversely to the substrate ( 100 ) and one at this longitudinal end ( 320 ) adjacent portion of the contact rail ( 300 ) is bent by about 90 °. Method according to one of the preceding claims, wherein the contact rail ( 300 ) consists of copper or a copper alloy. Method according to one of the preceding claims, wherein the electrical components ( 210 . 220 . 230 ) on the substrate ( 100 ) facing away from the surface at least one further electrical contact surface ( 214 . 224 . 234 ), and wherein the method further comprises a step of applying an electrically insulating material ( 217 . 237 ), preferably a non-electrically conductive polymer, on the further contact surfaces ( 214 . 224 . 234 ), which before the step of applying the contact rail ( 300 ) is performed. Method according to one of the preceding claims, wherein the substrate ( 100 ) is electrically insulating and further on a surface ( 110 ) on which the electrical components ( 210 . 220 . 230 ), a number of electrically conductive coated sections ( 111 . 112 . 113 . 114 . 115 . 116 . 117 ), wherein a respective section ( 111 . 112 . 113 . 114 . 115 . 116 . 117 ) compared to all other sections ( 111 . 112 . 113 . 114 . 115 . 116 . 117 ) is electrically isolated, each electrical component ( 210 . 220 . 230 ) on a substrate ( 100 ) facing surface a contact surface ( 211 ), each electrical component ( 210 . 220 . 230 ) one of the sections ( 111 . 112 . 113 ), and wherein a respective electrically conductive coated section ( 111 . 112 . 113 ), to which an electrical component ( 210 . 220 . 230 ) is greater than the electrical component ( 210 . 220 . 230 ), so that the respective contact surface ( 211 ) on the substrate ( 100 ) facing surface of the electrical component ( 210 . 220 . 230 ) with the assigned section ( 111 . 112 . 113 ) is electrically contacted. The method of claim 9, further comprising a step of applying further electrical components ( 240 . 250 . 260 . 270 . 280 . 290 ) on the substrate ( 100 ), which before the step of applying the contact rail ( 300 ) is carried out, wherein in addition to a respective electrical component ( 210 . 220 . 230 ) to which the contact rail ( 300 ) is applied, along a direction transverse to a longitudinal direction of the contact rail ( 300 ) two associated further electrical components ( 240 . 250 . 260 . 270 . 280 . 290 ) are arranged so that the electrical component ( 210 . 220 . 230 ) to which the contact rail ( 300 ) is applied, in the middle of the two associated further electrical components ( 240 . 250 . 260 . 270 . 280 . 290 ) is arranged. Method according to claim 10, wherein each of the further electrical components ( 240 . 250 . 260 . 270 . 280 . 290 ) on a substrate ( 100 ) facing away from the surface at least one electrical contact surface ( 242 . 252 . 262 . 272 . 282 . 292 and the method further comprises the steps of prior to the step of applying the contact rail (10); 300 ): - applying electrically insulating material ( 241 . 251 . 261 . 271 . 281 . 291 ), preferably a polymer, laterally on each of the further electrical components ( 240 . 250 . 260 . 270 . 280 . 290 ) so that a region of a respective electrically conductive coated portion ( 111 . 112 . 113 ), which one of the contact rail ( 300 ) to be contacted electrical component ( 210 . 220 . 230 ) is assigned to a contact surface ( 242 . 252 . 262 . 272 . 282 . 292 ) of a respective associated further electrical component ( 240 . 250 . 260 . 270 . 280 . 290 ), and - applying an electrically conductive material ( 243 . 253 . 263 . 273 . 283 . 293 ), preferably a conductive polymer, onto the electrically insulating material ( 241 . 251 . 261 . 271 . 281 . 291 ), so that an electrical connection between the electrically conductive coated portion ( 111 . 112 . 113 ) and the contact surface ( 242 . 252 . 262 . 272 . 282 . 292 ) will be produced. The method of claim 11, further comprising the steps of prior to the step of applying the contact rail (10). 300 ): - applying at least one liquid layer to the substrate ( 100 ) and to respective electrical components ( 210 . 220 . 230 . 240 . 250 . 260 . 270 . 280 . 290 ), preferably by means of screen printing, - curing the at least one liquid layer to form an electrically insulating layer ( 155 ), and - applying at least one electrical conductive layer ( 150 ) for electrically connecting an electrical contact surface ( 242 . 252 . 262 . 272 . 282 . 292 ) or another electrical contact surface 214 . 224 . 234 . 244 . 254 . 264 . 274 . 284 . 294 ) of the respective electrical component with at least one conductor track of the substrate ( 100 ). Assembly ( 10 ), comprising: - a substrate ( 100 ), - a number of electrical components ( 210 . 220 . 230 ) on the substrate ( 100 ), wherein each electrical component on a substrate ( 100 ) facing away from surface at least one electrical Kotaktfläche ( 212 . 222 . 232 ), and - an electrically conductive contact rail ( 300 ), which on the electrical components ( 210 . 220 . 230 ) is arranged and with the respective electrical contact surfaces ( 212 . 222 . 232 ) on the substrate ( 100 ) facing away from the surface of the electrical components ( 210 . 220 . 230 ) is electrically connected. Assembly ( 10 ) according to claim 13, which is produced by a method according to any one of claims 1 to 12. Assembly ( 10 ) according to one of claims 13 or 14, which is designed as a B6 bridge with phase switch.

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