WO2005053366A1

WO2005053366A1 - Electric circuit arrangement

Info

Publication number: WO2005053366A1
Application number: PCT/EP2004/012607
Authority: WO
Inventors: Stephan Schauz
Original assignee: Festo Ag & Co
Priority date: 2003-11-29
Filing date: 2004-11-08
Publication date: 2005-06-09
Also published as: DE10355921B4; TW200537655A; DE10355921A1; EP1688022A1; CN1887036A

Abstract

The invention relates to an electric circuit arrangement (1) comprising an interconnect device (2) that is equipped with a chip (3). Said interconnect device (2) contains a substrate (4), in which a receiving recess (5) is configured that is closed on all sides. First contact pads that are connected to printed conductors (6) are provided on the base. Said pads are electrically connected to second contact pads (17) of the chip (3) that is positioned above the first pads by the interposition of a contact element (24) that is an anisotropic electric conductor and simultaneously elastically deformable. A force exertion structure that is fixed to the substrate (4) exerts a force on the upper face of the chip (3) to produce the contact pressure required for the establishment of electrical contact.

Description

Electrical circuitry

description

The invention relates to an electrical circuit arrangement which has a circuit carrier equipped with an electronic chip, which has a carrier substrate on which conductor tracks are provided which lead to first contact pads arranged on a first contact area, the chip being connected to one of the first contact areas che facing second contact surface has second contact pads, which are electrically contacted with the interposition of anisotropically electrically conductive contact means with the first contact pads.

In a circuit arrangement of this type known from DE 102 17 698 AI, an electronic chip is arranged on an injection-molded circuit carrier designed as a three-dimensional MID part (MID = Molded Interconnect Device). The circuit carrier has a carrier substrate with a plurality of protruding contact bumps, the contact bumps carrying first contact pads connected to conductor tracks, which are contacted with assigned second contact pads of the chip set up in flip-chip technology with the interposition of an anisotropically electrically conductive adhesive. The adhesive connection also ensures the mechanical attachment of the chip to the circuit carrier. In addition to the contacting function, the adhesive also takes on the function of an underfiller, which fills the space between the chip and the circuit carrier. Circuit arrangements of a similar type are also apparent from DE 10163799 AI, US 6,555,759 and EP 0782765 B1.

The known type of flip-chip technology enables the electrical connection of components with a small footprint. However, this technology has disadvantages with regard to the complex handling of the required assembly and connection technology and with regard to the operational influences on the electronic interconnection. Above all, the different thermal expansion coefficients of circuit carriers and chips, which are usually made of silicon, are complex and make the technology risky and expensive. Especially with MID technology, the difference in the expansion coefficients is extremely large, so that the operating temperatures for the electrical circuit arrangement are severely restricted. The underfiller provided between the components is also unable to buffer the resulting mechanical stresses.

It is the object of the present invention to provide an electrical circuit arrangement which is simpler

Manufacturing is less susceptible to temperature fluctuations and at the same time also ensures good mechanical protection of the electronic chip.

To solve this problem,

that the first contacting puddle is located at the bottom of a receiving recess of the carrier substrate which is closed laterally all round, in which the contact means and the chip are completely received,

- That the contact means from at least one placed between the two contact surfaces, elastically deformable in the direction of the vertical axis of the recess Contacting element exist, which has a rubber-elastic base body with mutually opposite, the two contact surfaces facing first and second counter-contact surfaces as well as a large number of elastically deformable guide bodies which pull through the base body with mutual insulation and end on the counter-contact surfaces with guide surfaces,

- And that there is an application structure fixed to the carrier substrate, which acts on the chip on the upper side opposite the base of the receiving recess, so that the contacting element is clamped between the carrier substrate and the chip and the first and second contact pads are attached to the respective opposite surfaces of the Contacting element are pressed.

In the case of this circuit arrangement, a mechanically fixed connection between the contacting areas assigned to one another is no longer required for the electrical contacting of the chip and circuit carrier. The desired reliable electrical contact between the contact surfaces on both sides results solely from the pressing of the elastically deformable contact element. The elasticity of the contacting element results in a flexible connection that is able to automatically compensate for different expansion coefficients of the chip and the carrier substrate, so that even with large temperature fluctuations and with widely differing expansion coefficients, as in MID technology, it is always secure electrical connection is guaranteed. At the same time, the chip is also always fixed mechanically, with the contacting element at least in the height direction of the receiving recess creating a type of floating mounting that allows relative movements between the components mentioned. Since the chip is sunk in the recess, this avoids an exposed location, which protects the chip from mechanical damage.

The advantages result from both inaccurate and thawed chips. The term “chip” is therefore understood to mean both designs without a housing surrounding the chip and designs in which the chip is located in a housing, the second contact pads being able to be provided on the chip itself or on the housing.

Another advantage of the electrical circuit arrangement is that it does not require an underfiller. There is also no need to apply liquid adhesive in the joining area between the chip and the circuit board. Compared to the flip-chip technology based on soldering, there is also no need to attach the solder pads required for contacting the contact pads.

WO 96/15551 AI already describes the assembly of electronic components on a printed circuit board, a large number of flexible contact means being used between a semiconductor package and a carrier substrate. However, these contact means are arranged individually free-standing and firmly anchored at one end to the carrier substrate.

Elastically deformable contacting elements that are suitable for use in the electrical circuit arrangement are already known as such. No. 5,617,898 discloses a contacting element which is composed of stacked layers of conductive and non-conductive elastic material. Furthermore, the company Shin-Etsu Polymer Europe BV, 5928 NS Venlo, the Netherlands, sells a connector under the type designation "GX4", in which a matrix of gold-coated metal wires are embedded in a silicone rubber layer. A similarly constructed contacting element is also described in US Pat. No. 4,209,481. The protected placement of a chip together with an elastic However, there is no provision for table-formable contacting element in a receptacle recess of a carrier substrate, which is closed laterally all around, as is the fixing according to the invention by means of loading means acting between the carrier substrate and the chip for generating the desired bias in the area of the contacted surfaces.

Advantageous developments of the invention emerge from the subclaims.

It is particularly expedient to use an elastically deformable contacting element in which the individual guide surfaces each have a smaller surface area than the contact pads on the chip and circuit carrier, the guide surfaces on the countercontacting surfaces being combined in a fine, matrix-like distribution to form one or more guide surface groups are. For example, the two mating contact surfaces can each be occupied over the entire surface by a guide surface group, so that no attention has to be paid to the position of the contact pads during manufacture, because in the assembled state those guide bodies automatically ensure the electrical connection, the guide surfaces of which are acted upon by the contact pads. However, there is definitely the possibility of providing one or more guide surface groups, the extent of which is considerably less than that of the assigned counter-contact surface. In this way it is possible, for example, to implement a plurality of groups of guiding surfaces in the form of points or strips.

The loading structure for the chip expediently has a cover which overlaps the chip and is fixed to the carrier substrate. Optimal protection for the chip is obtained if the lid has no openings and the opening of the receiving recess is completely closed by it. The connection between the cover and the support structure is preferably made of a material conclusive connection realized, in particular by an adhesive connection, the use of an adhesive curing by UV radiation is recommended. No heating is necessary here and the time required to mechanically fix the chip until the adhesive bond cures is extremely short.

In principle, the cover can lie completely outside the receiving recess or can also only partially protrude into the receiving recess. However, an embodiment is particularly expedient in which the cover sits completely inside the receiving recess.

If necessary, the cover can act as a carrier for at least one further electronic component. It is also possible to use another electronic component directly as a cover, for example a so-called SMD component (SMD = Surf ce Mounted Device).

WO 01/95486 A1 describes a method for producing individual microelectronic devices, a multiplicity of spaced-apart recesses being formed in a non-conductive material, in each of which a component based on piezoelectric principles is seated, the recesses being closed at the top by tightly inserted lids are. Contacting the component by means of elastic contact means is not provided, however.

As an alternative to an inseparable fixation of the chip, a detachable fixation can also be achieved by means of an appropriately designed impact structure. For example, the loading structure can be equipped with latching hooks arranged on the support structure, which either overlap the chip directly or over a cover located above the chip and press in the direction of the base of the receiving recess. If the chip is defective, it can be deformed the locking hook is removed from the recess and replaced with a new chip.

If cooling of the chip is required, the cover can be provided with cooling fins immediately, so that no special cooling element is required.

The invention is explained in more detail below with reference to the accompanying drawing. In this show:

FIG. 1 shows, in a greatly enlarged and schematic illustration, a preferred first embodiment of the electrical circuit arrangement according to the invention in a perspective exploded illustration,

FIG. 2 shows a longitudinal section through the arrangement from FIG. 1 according to section line II-II in the assembled state, the contacting element being cut transversely according to section line Ila-IIa of FIG. 5,

FIG. 3 shows an individual illustration of the circuit carrier from FIGS. 1 and 2 in a plan view of the side having the receiving recess,

FIG. 4 shows an individual illustration of the chip used in the arrangement according to FIGS. 1 and 2 in a bottom view,

5 shows an individual illustration of the contacting element used in the arrangement according to FIGS. 1 and 2 in a perspective illustration, FIG.

FIG. 6 shows the contacting element from FIG. 5 in longitudinal section according to section line VT-VT, FIG. 7 shows an alternative design of a contacting element in a perspective view,

FIG. 8 shows a side view of the contacting element from FIG. 7, the guide bodies passing through the base body being indicated by dash-dotted lines,

FIG. 9 again shows a further alternative design of the contacting element in a perspective view,

FIG. 10 shows a side view of the contacting element from FIG. 9, the guide bodies again being indicated by dash-dotted lines,

FIG. 11 shows a modified design of the electrical circuit arrangement in perspective, with a different design of the cover compared to FIG. 1,

FIG. 12 shows the cover used in the circuit arrangement from FIG. 1 in a perspective individual illustration,

FIG. 13 shows a modified design of the circuit arrangement with rib-like heat sinks arranged on the cover,

FIG. 14 shows a modified design of the circuit arrangement in which the cover is equipped with further electronic components,

FIG. 15 shows a further embodiment of the electrical circuit arrangement, in which latching means are provided for releasably fixing the chip,

FIG. 16 shows a design of the circuit arrangement realized in connection with a multilayer printed circuit board, with one closing the exception recess Lid is only indicated by dash-dotted lines, and

FIG. 17 shows a side view of the circuit arrangement from FIG. 16, the circled area being shown in longitudinal section along section line XVII.

The drawing shows several exemplary embodiments of an electrical circuit arrangement, generally designated by reference number 1, which has a circuit carrier 2 which is equipped with at least one electronic chip 3. A possible embodiment of such a chip 3 is shown schematically in FIG. 4 in a perspective bottom view.

In the designs of FIGS. 1 to 3, 11 and 13 to 15, the circuit carrier 2 is designed as a three-dimensional MID part. It contains a carrier substrate 4 made of injection-moldable, preferably thermoplastic, plastic material, which is provided on one or more sides with conductor tracks 6, which are used for the transmission of electrical signals between the appropriate placed connection points and the chip 3 and any other existing electronic components 49. The exemplary embodiments show arrangements in which a plurality of conductor tracks 6 are electrically contacted at the same time with a chip 3 placed in a receiving recess 5 of the carrier substrate 4.

The aforementioned statements apply correspondingly to the design of FIGS. 16 and 17, but with the difference that there the circuit carrier 2 is designed as a multilayer printed circuit board, the carrier substrate of which is composed of a plurality of sandwich-like printed circuit boards 7 which are glued to one another.

The receiving recess 5, which is recessed like a pit from the carrier substrate 4, has a vertical axis 8 which, in the exemplary embodiment, is at right angles to the main plane of expansion of the extends, for example, plate-shaped circuit carrier 2. The receiving recess 5 has a bottom 12 at the bottom and an opening 1 opening at the top to the outer surface 13 of the carrier substrate 4. Laterally, the receiving recess 5 between the base 12 and the opening 14 is closed all around and is delimited by an all-round side wall surface 15, which is defined by the carrier substrate 4.

The conductor tracks 6 extend from the outer surface 13 into the receiving recess 5 until they merge into first contact pads 16, which are arranged on a first contacting surface 18 of the carrier substrate 4 defined by the base 12 of the receiving recess. The distribution pattern of the first contact pads 16 corresponds to the specific technical requirements, with two groups of four first contact pads 16 lying next to each other in a row being provided in the exemplary embodiment.

The first contacting surface 18 is expediently flat, so that all the first contact pads 16 also lie in a common plane, wherein they face the opening 14 in the direction of the vertical axis 8.

In the exemplary embodiments in FIGS. 1 to 3, 11 and 13 to 15, the conductor tracks 6 run at the transition between the outer surface 13 and the base 12 along the side wall surface 15 of the receiving recess 5. The corresponding wall region 22 expediently has an oblique shape

Course, so that the cross section of the receiving recess 5 widens starting from the base 12 towards the opening 14. The conductor tracks 6 are here preferably produced using MID technology, for example using the so-called laser direct structuring method. The starting point here is, for example, a PBT plastic (polybutylene terephthalate) optimized for MID applications, the plastic material being provided with embedded metal particles or metal nuclei. After the injection molding of the carrier substrate 4 is through local activation of the substrate surface using a laser beam generates the desired circuit layout. In this case, a laser beam is guided over the surface of the carrier substrate 4, with local material activation taking place in the irradiated surface areas. On the one hand, metal nuclei are split off from special, non-conductive active substances. At the same time, other fillers of the plastic material create a pronounced roughness on the irradiated surface. In a subsequent galvanic metallization process, a local copper metallization follows the laser trace in the area of the cleaved and partially exposed metal nuclei, the roughness ensuring very good adhesion for the metal layer formed in the electroplating bath. In this way, the conductor tracks 6 result exclusively and precisely in those surface regions of the carrier substrate 4 which have previously been exposed to the laser beam activation described. The first contact pads, which are expediently formed by end sections of the conductor tracks having a somewhat larger area, are realized in the same way.

The receiving recess 5 is formed in the MID production during the injection molding of the carrier substrate 4.

In the exemplary embodiment in FIGS. 15 and 16, the receiving recess 5 results from cutouts in some of the circuit board layers formed by the circuit boards 7. The recessed boards 7 define the side wall surface 15, while the base 12 is defined by a board 7 which has not been left open. In order to lead the conductor tracks 6 to the base 12 of the recess 5, so-called vias 23 are used which penetrate different ones of the circuit boards 7 to provide an electrically conductive transition between the conductor track sections running on the outer surface 13 and the base 12 to obtain. In all embodiments, the chip 3 is completely accommodated in the receiving recess 5 together with an elastically deformable contacting element 24 which serves to make electrical contact with it. The contacting element 24 lies in the direction of the vertical axis 8 between the chip 3 and the base 12 of the receiving recess 5.

The bottom side of the chip 3 facing the base 12 forms a second contact area 19 on which a plurality of second contact pads 17 are provided, which are connected to the circuit integrated in the chip 3. These second contact pads 17 are distributed such that they are each opposite one of the first contact pads 16 provided on the carrier substrate 4 in the direction of the vertical axis 8 (FIG. 4). The interposed contacting element 24 electrically connects the first and second contact pads 16, 17, which are assigned to one another in pairs in this way.

The chip 3 can be a housed or an unhoused chip. If the chip 3 has a housing, the second contact pads 17 cooperating with the contacting element 24 are generally located on the chip housing.

The contacting element 24 has an anisotropic electrical conductivity, the direction of conductivity coinciding with the course of the vertical axis 8. FIGS. 5 and 6 each show the contacting element 24 used in the design according to FIGS. 1 to 3 in an individual representation.

The contacting element 24 is elastically deformable overall in the direction of the vertical axis 8. It has a rubber-elastic base body 25, in particular made of silicone rubber, which has a first or second mating contact surface 20, 21 on opposite sides. The base body 25 is preferably of plate-like design and placed in the receiving recess 5 such that the Plate plane is perpendicular to the vertical axis 8. The mating contact surfaces 20, 21 are then formed by the two larger outer surfaces of the base body 25, which face the base 12 and the opening 14.

The base body 25 is traversed in the direction of the vertical axis 8 by a plurality of guide bodies 26 embedded in the base body material with mutual insulation. These guide bodies 26 each end on both mating contact surfaces 20, 21 with first or second guide surfaces 27, 28 accessible from the outside. They are elastically deformable in such a way that they permit a change in the distance between their respectively assigned first and second guide surfaces 27, 28.

If the contacting element 24 is clamped between two components in the area of its countercontacting surfaces 20, 21, the base body 25 can be compressed in the direction of the vertical axis 8, the acted upon first and second guide surfaces 27, 28 of the individual guide bodies 26 simultaneously approaching one another. When the two guide surfaces 27, 28 of a guide body 26 approach each other, the latter can, for example, buckle or bend sideways, as is indicated by a dot-dash line at 32 in FIG.

A design has proven to be particularly expedient in which the guide bodies 26 consist of elastically bendable metal wires, the end faces of which directly form the first and second guide surfaces 27, 28. The guiding surfaces

27, 28 transverse to the vertical axis 8 each have a substantially smaller surface area than the contact pads 16, 17 to be contacted. They extend through the base body 25 in an alignment parallel to one another and preferably in a matrix-like distribution closely adjacent to one another.

From case to case, the base body 25 can be completely or only partially penetrated by the guide bodies 26. In this way, the guide surfaces 27, 28 on the mating contacts tion surfaces 20, 21 combined in a fine matrix-like distribution to form one or more guide surface groups 33.

In the exemplary embodiment in FIGS. 5 and 6, the guide bodies 26 are placed in such a way that a number of guide surface groups 33 corresponding to the number of contact pads 16 and 17 to be contacted is obtained on each mating contact surface 20, 21, which groups are arranged such that they are each opposite a first and second contact pad 16, 17 to be contacted. In this way, a punctiform design or distribution of the guide surface groups 33 is achieved.

By means of a loading structure 34 fixed to the carrier substrate 4, the chip 3 is loaded on the upper side opposite the base 12 of the receiving recess 5, so that it is biased against the contacting element 24, which in turn is pressed onto the first contacting surface 18. The contacting element 24 is thus clamped in the direction of the vertical axis 8 between the carrier substrate 4 and the chip 3. In this case, the first and second contact pads 16, 17 are pressed onto the respective facing Lei surfaces 27, 28. In this way, there is an electrical connection between the opposing first and second contact pads 16, 17 via the number of guide bodies 26 arranged between them, which are simultaneously acted upon by these contact pads 16, 17. Due to its elasticity, the contacting element 24 builds up a counterpressure which ensures a secure electrical connection between a respective contact pad and the guide bodies 26 resting thereon solely by the contact pressure, so that further connecting measures, for example soldering or gluing by means of conductive adhesive, are in the offing Can be dispensed with in favor of simplified assembly.

The contacting element 24 of FIGS. 5 and 6 is specific to the distribution of the contact pads 16, 17 with regard to the configuration and distribution of the guide surface groups 33 customized. However, a design that enables use independent of the contact pad distribution is significantly more advantageous. Such an embodiment is shown in FIGS. 9 and 10, in which case only one guide surface group 33 is provided on each of the two mating contact surfaces 20, 21, but which in each case extends over the entire surface of the mating contact surfaces 20, 21 in question. In this way, an electrical connection between contact pads lying on opposite sides of the contacting element 24 is possible irrespective of the point at which the

Base of the contacting element 24 they are opposite each other and are pressed against the contacting element 24.

Another possible alternative design of the contacting element 24 is shown in FIGS. 7 and 8. The guide bodies 26 are arranged there in such a way that they form a plurality of strip-like guide surface groups 33 on the two mating contact surfaces 20, 21.

Due to the elastic resilience of the contacting element 24, different coefficients of thermal expansion of the carrier substrate 4 and the chip 3 are automatically compensated for, while at the same time maintaining a reliable electrical connection.

Apart from the exemplary embodiment in FIG. 15, the loading structure 34 in all exemplary embodiments includes a cover 35 which overlaps the chip 3 on the upper side opposite the base 12 of the receiving recess 5. This cover is expediently inserted into the receiving recess 5 in the region of the opening 14 in such a way that it is complete comes to rest in the interior of the recess 5. An arrangement is expedient in which the outer surface 36 of the cover 35 which points away from the base 12 in the direction of the vertical axis 8 runs flush with the edge region of the outer surface 13 of the carrier substrate 4 which surrounds the opening 14. In all exemplary embodiments, the cover 35 is integrally connected to the carrier substrate. In particular, an adhesive connection is used, a suitable adhesive being indicated at 37. A UV-curing adhesive 37 is expediently used, which achieves its strength even without the introduction of heat, which means protection for the chip.

When assembling the circuit arrangement 1, the cover 35 is pressed onto the chip 3 by means of a suitable tool until the adhesive 37 has hardened. In this way it is achieved that the combination of chip 3 and contacting element 34 is clamped non-positively between cover 35 and base 12 of receiving recess 5 with the desired pretension.

The adhesive 37 is expediently applied in the liquid state due to capillary action in a narrow gap 38 which extends around the cover 35 between the latter and the carrier substrate 4. This gap 38 is connected to one or more pot-like recesses 42, which are formed in the outer surface 13 of the carrier substrate 4. In the exemplary embodiment, the opening 14 has a rectangular outline, one of the mentioned pot-like recesses 42 being placed in each of the four corner regions. To glue the lid 35 on, the adhesive is fed into the pot-like recesses 42, from where it is drawn into the gap 38 due to the capillary action until the entire gap 38 is finally filled with adhesive 37.

In the modified embodiment shown in FIGS. 11 and 12, there is a pot-like recess 42, in particular at a central point, in the outer surface 36 of the cover 35. In the rectangular plan view of the cover 35 shown, Four such groove-like depressions 43 are provided, each of which lead to an edge center of the cover 35.

Here, during the assembly of the circuit arrangement 1, the adhesive 37 is fed into the pot-like recess 42 of the cover 35, from where it reaches the gap 38 via the groove-like depressions 43, in order to spread there again by capillary action.

In order to achieve a dirt and moisture-tight encapsulation of the chip 3 and the electrical connection measures within the receiving recess 5, it is provided that the cover 35 completely closes the opening 14 of the receiving recess 5. Adhesive 37 ensures the sealing of the joint area.

If a special seal is not required, a cover can also be used which, in contrast to the design described, is not continuously closed, but has one or more openings. The cover can then also be designed, for example, in such a way that it spans only part of the opening 14 of the receiving recess 5, for example in a web-like configuration.

As can be seen from FIG. 14, the cover 35 can be provided on its outer surface 36 with an electrical conductor structure 44, which enables the electrical contacting of one or more electronic components 49. By way of example, FIG. 14 shows two SMD components, some of which are seated on the cover 35 and which are in contact with the electrical conductor structure 44 of the cover 35 and with another electrical conductor structure 45 arranged on the outer surface 13 of the carrier substrate 4.

In particular if the cover 35 is flush with the outer surface 13 of the carrier substrate 4 in the receiving recess 5 is used, the outer surface 36 of the cover 35, like the outer surface 13 of the carrier substrate 4, can thus be used as a mounting surface for further electronic components. This enables extremely space-saving installation of electrical circuits.

FIG. 13 shows the possibility of using the cover 35 as a carrier for the heat sink 46 if the chip 3 requires cooling in the intended use. The heat sinks 46 are in particular rib-shaped and can be integrally formed on the cover 35.

In the circuit arrangement 1 shown in FIG. 15, the loading structure 34 is designed in such a way that it enables the chip 3 to be fixed releasably. For this purpose, it preferably has latching means, which are expediently made in one piece with the carrier substrate 4.

In the exemplary embodiment shown, the latching means consist of latching hooks 48 which can be elastically bent transversely to the vertical axis 8 according to double arrows 47 and which protrude slightly beyond the opening 14. When the chip 3 is inserted, the latching hooks 48 are temporarily spread apart in order to spring back in the direction of its starting position after the chip 3 has been passed through, so that on the one hand it overlaps the chip 3 on its upper side and on the other hand it exerts a compressive force acting in the direction of the base 12 exert the top of the chip 3 so that it is pressed against the contacting element 24. In the event of a chip 3 being defective, the latching hooks 48 can be spread apart manually or by means of a suitable tool, so that the chip 3 which is only in contact with the contacting element 24 and is not firmly connected to this contacting element 24 can be removed without problems.

While the latching means or latching hooks 48 interact directly with the chip 3 in the exemplary embodiment in FIG. 15, a design would also be possible in which the chip 3 is covered by a cover or another force transmission element, the latching means acting on this cover or the force transmission element.

In order to enable a compact layering of several circuit arrangements 1 in the direction of the vertical axis 8, it is advantageous in all exemplary embodiments if the loading structure 34 does not protrude beyond the outer surface of the carrier substrate 4, to which the opening 14 opens. In the exemplary embodiments in FIGS. 1 to 3, 11 and 13 to 15, this is achieved by a recessed arrangement of the cover 35. In the case of FIG. 15, the latching means or latching hooks 48 are located completely within the recess 5 for this purpose. In order to guarantee the transverse mobility of the latching hooks 48, the lateral wall surface 15 can in each case have a cross section of the recessed area 5 have enlarging recess 52.

Instead of using only one contacting element 24 as contact means for the electrical connection of chip 3 and circuit carrier 2, a plurality of contacting elements 24 arranged next to one another could also be provided. For stabilization, the contacting element or elements 24 can be held or stabilized by a separate holding structure.

The inner contour of the receiving recess 5 can be designed such that the at least one contacting element 24 placed in place is positively fixed transversely to the vertical axis 8 by the wall of the receiving recess 5. Such a design is particularly useful when the guide surface groups 33 have a distribution pattern that is specially adapted to the distribution of the contact pads 16, 17.

Instead of the contacting element 24 used in the exemplary embodiments, a contacting element could also be used 24 can be used with a different structure that has the required rubber elasticity and at the same time is exclusively anisotropically conductive in the direction of the vertical axis 8.

Depending on the design chosen, the circuit arrangement according to the invention can have one or more of the following advantages. When assembling, there is only little heat-related stress for the chip and the assembly process is very simple overall. The expansion coefficient problem encountered with conventional flip-chip technologies is alleviated. Additional installation space for further circuit arrangements and / or electronic components can be provided via the circuit arrangement 1. A chip exchange can be implemented by appropriately designing the loading structure. Without limitation, chips 2 can be used for the circuit arrangement that are also used in conventional flip-chip technologies and are designed, for example, for contacting by bonding. Efficient chip cooling is possible. Several chips can be installed one above the other.

Claims

Expectations

1. Electrical circuit arrangement which has a circuit carrier (2) which is equipped with an electronic chip (3) and which has a carrier substrate (4) on which conductor tracks (6) are provided which are connected to a first contact area (18). lead arranged first contact pads (16), the chip (3) on a second contact surface (18) facing the second contact surface (19) has second contact pads (17) which, with the interposition of anisotropically electrically conductive contact means, with the first contact pads ( 16) are electrically contacted, characterized in that the first contacting surface (18) is located at the bottom of a receiving recess (5) of the carrier substrate (4) which is closed on all sides and in which the contact means and the chip (3) are completely accommodated, that the contact means of at least one placed between the two contacting surfaces (18, 19) in the direction of the vertical axis (8) of the receiving vertical efung (5) elastically deformable contacting element (24), which have a rubber-elastic base body (25) with mutually opposite, the two contacting surfaces (18, 19) facing first and second counter-contacting surfaces (20, 21) and a variety of the basic body (25) with mutually insulating, elastically deformable guide bodies (26) ending at the mating contact surfaces (20, 21) with guide surfaces (27, 28), and - that there is an action structure (34) fixed to the carrier substrate (4) that supports the chip (3) on the upper side opposite the base (12) of the receptacle recess (5), so that the contacting element (24) is clamped between the carrier substrate (4) and the chip (3) and the first and second contact pads (16, 17) are pressed against the guide surfaces (27, 28) of the contacting element (24) opposite each other.

2. Circuit arrangement according to claim 1, characterized in that the base body (25) is plate-shaped, the two larger outer surfaces forming the mating contact surfaces (20, 21).

3. Circuit arrangement according to claim 1 or 2, characterized in that the rubber-elastic base body (25) consists of silicone rubber.

4. Circuit arrangement according to one of claims 1 to 3, characterized in that the guide bodies (26) consist of elastically bendable metal wires, the end faces of which form the guide surfaces (27, 28).

5. Circuit arrangement according to one of claims 1 to 4, characterized in that the individual guide surfaces (27, 28) each have a smaller surface area than the contact pads (16, 17) and on the mating contact surfaces

(20, 21) are combined in a fine matrix-like distribution to form one or more guide surface groups (33).

6. Circuit arrangement according to claim 5, characterized in that the two mating contact surfaces (20, 21) are each occupied over the entire area by a guide surface group (33).

7. Circuit arrangement according to claim 5, characterized by point and / or stripe-shaped guide surface groups (33) which each occupy only a partial surface of the mating contact surfaces (20, 21).

8. Circuit arrangement according to one of claims 1 to 7, characterized in that the contact pads (16, 17) and guide surfaces (27, 28) are contacted with each other solely by the contact pressure applied by the loading structure (34).

9. Circuit arrangement according to one of claims 1 to 8, characterized in that the loading structure (34) has a cover (35) overlapping the chip (3) and fixed on the carrier substrate (4).

10. Circuit arrangement according to claim 9, characterized in that the cover (35) with the carrier substrate (4) is integrally connected, in particular by means of an adhesive connection.

11. Circuit arrangement according to claim 9 or 10, characterized in that the cover (35) is also completely received in the receiving recess (5), wherein it expediently flush with the edge area surrounding the opening (14) of the receiving recess (5) the outer surface (13) of the carrier substrate (4) can complete.

12. Circuit arrangement according to one of claims 9 to 11, characterized in that the cover (35) completely closes the opening (14) of the receiving recess (5).

13. Circuit arrangement according to one of claims 9 to 12, characterized in that the cover (35) on the outside of the chip (3) opposite is designed as a carrier for at least one further electronic component (49).

14. Circuit arrangement according to one of claims 9 to 13, characterized in that the cover (35) on the opposite side of the chip (3) is provided with preferably rib-shaped heat sinks (46).

15. Circuit arrangement according to one of claims 1 to 14, characterized in that the loading structure (34) is designed for releasable fixing of the chip (3).

16. Circuit arrangement according to one of claims 1 to 15, characterized in that the loading structure (35) on the carrier substrate (4) arranged, in particular as a latching hook (48) designed latching means for releasably fixing the chip (3).

17. Circuit arrangement according to claim 16, characterized in that the latching means are arranged within the receiving recess (5).

18. Circuit arrangement according to one of claims 1 to 17, characterized in that the circuit carrier (2) as

MID part (MID = Molded Interconnect Device) is formed, the conductor tracks (6) along the side wall surface (15) of the receiving recess (5) from the outside to the second contact pads (17) on the base (12) of the receiving recess (5 ) are guided.

19. Circuit arrangement according to one of claims 1 to 17, characterized in that the circuit carrier (2) is designed as a multilayer printed circuit board, the receiving recess (5) being formed by cutouts in one or more printed circuit board layers and the conductor tracks (6) are guided through vias (23) to the level of the base (12) of the receiving recess (5).