The present invention relates to a circuit module consisting of a plurality of components interconnected in an electrically conductive and a method for producing a circuit module of this kind.
Problems can arise when conventional semiconductor components such as integrated semiconductor circuits are to be mounted on flexible line carriers, for example, on films, since both wire bond connections and soldered connections having relatively stiff wire lines which are led out of a plastic housing of the semiconductor component are usually mechanically overloaded, particularly when the flexible line carrier is severely deformed in an installation situation or is subject to further movements after its installation. Different solutions have already been made in order to solve these problems.
For example, DE 41 29 964 A1 discloses a method for producing an electrically conductive fastening of an integrated circuit with contact pieces on a flexible printed circuit. An elastic plastic film has conductor tracks on its surface, which are provided with hump-like thickenings, with which the electrical contact to the contact pieces of the electrical circuit can be made. The arrangement formed in this way can be fastened to a printed circuit designed as a flat plate having conductor tracks and connected thereto in an electrically conductive manner.
JP 2000 77 835 A discloses an electronic component having a plurality of terminals which are led out of a housing and which are mounted on a circuit board by means of webs or connecting sections. The webs or connecting sections can here be formed by film sections.
The primary aim of the present invention can be seen in providing a universally usable mounting option, a method for its implementation and a corresponding arrangement that make it possible to mount circuit components and/or semiconductor components on flexible line carriers without the contact connections between the circuit component or semiconductor component and the flexible line carrier equipped with conductor tracks being mechanically overstressed, particularly when the flexible line carrier is deformed.
The above aim of the invention is achieved by the subject matter of the independent claims. Further advantageous embodiments are described by the respective dependent claims.
To achieve the stated aim, the invention proposes a circuit module consisting of a plurality of components interconnected in an electrically conductive manner which comprises at least one integrated semiconductor circuit which is enclosed or encapsulated in an isolating housing and has a plurality of electrical terminal contacts which are led out of the isolating housing. In addition, the module comprises a planar intermediate carrier having contact surfaces which are connected in an electrically conductive manner to the electrical terminal contacts which are led out of the isolating housing of the integrated semiconductor circuit, wherein the integrated semiconductor circuit together with its housing lies on or against a first side of the planar intermediate carrier. Furthermore, the planar intermediate carrier has edge-side outer contacts on a second side opposite the first side having the housing of the integrated semiconductor circuit lying on or against it, which outer contacts are connected in an electrically conductive manner to corresponding terminal contacts of a film-like line carrier. In addition, it is provided that the planar intermediate carrier has connection lines between the contact surfaces and the outer contacts.
The use of a relatively rigid intermediate carrier according to the invention, on which the integrated semiconductor circuit is mounted, advantageously allows conventional semiconductor circuits with their typically relatively stiff wire contacts which are led out of a housing to be mounted on pliable, film-like line carriers by means of an intermediate carrier of this kind. These film-like line carriers are usually relatively thin and very flexible, whereby they can be used in an extremely varied manner and in a wide variety of mounting situations. Due to their flexibility, however, they are poorly suited for the direct mounting of integrated semiconductor components such as semiconductor circuits, since their relatively stiff wire legs and contacts require an installation situation with a stable carrier, otherwise there is always the risk of loss of contact due to damage to the wire legs or contacts and/or electrical contacts. Particularly, the soldered and/or glued connections usually used to make electrical contact with the terminal contacts of the electrical semiconductor circuit, which are inflexible due to its housing, require largely stable installation and use situations, since otherwise the soldered and/or glued connections are hardly capable of permanently guaranteeing the electrical contacts when there are frequent bending stresses or load changes.
In the circuit module according to the invention, the connection lines arranged on, at and/or in the planar intermediate carrier can be arranged thereon and/or run on the surface. Optionally, the connection lines can run at least along one of the two surfaces of the planar intermediate carrier. However, it is also possible for the connection lines to run on both sides along each of the two surfaces of the planar intermediate carrier. In addition, it can be advantageous when the connection lines are integrated in the planar intermediate carrier and penetrate the intermediate carrier in their course from one surface to the other. In a more complex embodiment variant of this kind, the planar intermediate carrier preferably has a thickness that enables the connection lines to run transversely and/or diagonally from one surface to the other and thus through the material of the intermediate carrier.
The relatively rigid intermediate carrier can, for example, be made from a suitable plastic, optionally from a multilayer isolating material or the like, which carries the necessary terminal contacts and connection lines on the surface and, if necessary, embedded in the material. Particularly advantageously, the connection lines running in the material of the intermediate carrier of the more complex circuit module according to the invention and embedded there can have at least one crossing point in their course from one surface to the other, but preferably also a plurality of or numerous crossing points.
Optionally, the terminal contacts of the semiconductor circuit can be connected to the contact surfaces of the intermediate carrier via wire bond connections. It is also possible to use semiconductor circuits, the terminal contacts of which are connected to the contact surfaces of the intermediate carrier via rigid wire legs and soldered connections. In both variants, the relatively stiff intermediate carrier offers the advantage of a mechanically stable connection of all electrical terminal contacts, which makes it possible to mount semiconductor circuits of this kind on relatively pliable, film-like line carriers without the electrical terminal contacts being exposed to excessive mechanical loads and thereby endangering their stability.
A further advantage of the intermediate layer of the planar intermediate carrier used in the circuit module according to the invention can be seen in the fact that in this way, crossings of lines that would be difficult to implement in the film are not only possible, but also the contacting of comparatively coarse conductor track structures, which can be combined with the significantly finer IC contacts of the semiconductor circuit, for example, in the case of films or film-like line carriers having large conductor track widths and/or large conductor track spacings (that is, a wide pitch in the mm range).
The planar intermediate carrier of the circuit module according to the invention can preferably be formed by a rigid material such as laminate or the like; however, it is also conceivable for the planar intermediate carrier to be formed by a flexible material consisting of a plurality of conductor film layers joined to one another. In such a case, the planar intermediate carrier cannot be formed by a printed circuit or a circuit board or the like, but by a multilayer film composite or by a plurality of conductor film layers, wherein these layers can be formed by associated film conductor sections or also by individual blanks. Optionally, a relatively flexible additional potting compound to be described further below can be configured as a stiffening sheath for the entire film composite having the plurality of conductor film layers including part of the housing and the semiconductor circuit encased therein. Smaller-volume sheaths of partial regions, particularly a transition region between the planar intermediate carrier and the film-like line carrier, would also be conceivable.
In this variant, the necessary through-contacts of the terminal contacts and/or the contacts between the conductor film layers can be implemented using so-called vias (for example, as rivets), but optionally also by gluing, soldering or welding, possibly also in connection with bending and/or twisting of the film, so that its contact surface can turn from bottom to top or vice versa. The through-contacts can also optionally be produced by removing the isolation layer in places (for example, by so-called “kiss-cut”).
A further advantageous variant of the circuit module according to the invention can provide that at least transition regions between the planar intermediate carrier and the film-like line carrier are at least partially embedded in a potting compound or encased thereby. It is preferably provided here that the potting compound has a flexibility which is greater than that of the planar intermediate carrier and which is equal to or less than the flexibility of the film-like line carrier.
Transition regions between the intermediate carrier and the line carrier can prove to be critical in practical use of the modules, particularly in the immediate vicinity of an edge of the relatively rigid intermediate carrier, since a configuration of this kind can damage the conductor tracks (not depicted) of the film-like line carrier when bending loads occur. Particularly, it cannot be ruled out that the conductor tracks of the film-like line carrier kink or break, or that their isolation can be damaged. In order to avoid or at least reduce a risk of this kind, the edges on the longitudinal sides of the planar intermediate carrier can be modified as a sensible measure. The circumferential edges on the second side of the intermediate carrier facing the film-like line carrier can thus be beveled, rounded or otherwise blunted, which contributes to reducing the notch effect in this transition region and can significantly reduce the risk of breakage or damage mentioned. A beveled edge of this kind can, for example, resemble a 45° bevel. This beveled edge can optionally be provided on all longitudinal sides or only in defined sections. The beveled edge can be produced by suitable shaping in the production of the intermediate carrier or also by subsequent processing, that is, by removing material or by applying material. Further measures can also be taken in order to reduce the above-mentioned risks of damage to the conductor track of the film-like line carrier. For example, an additional potting compound can be used, which can be formed, for example, by a suitable laminate or by an adhesive material. The potting compound can optionally be applied on both sides in the vicinity of the contact surfaces of the intermediate carrier. However, it may also be sufficient to apply the potting compound only to one side of the intermediate carrier and the line carrier, optionally on the first side or on the second side. The flexibility of this additional potting compound is preferably between that of the intermediate carrier and the flexibility of the line carrier, whereby an effective protection of the contact regions or contact surfaces between the two elements and thus an effective protection against undesired breakage phenomena can be created. That is, the potting compound should be more flexible than the relatively rigid intermediate carrier, but somewhat more rigid than the flexible and pliable line carrier.
Optionally, when using a potting compound of this kind, the long sides can also be designed and/or beveled or rounded in the manner described above, with which the alternative protection options can be combined. However, it is also possible to use the application of the additional potting compound as an alternative variant of protection against breakage.
The possible uses of the potting compound can be further refined or graded in a further variant of the circuit module according to the invention. A somewhat more flexible layer of a flexible potting compound can also be applied in this way, which in turn can be formed, for example, by an adhesive material, a suitable laminate or by another suitable material. The potting compound can optionally be applied to both sides in the vicinity of the contact surfaces of the intermediate carrier in this variant too. Here, too, it can alternatively suffice to apply the potting compound only to one side of the intermediate carrier and the line carrier, optionally to the first side or to the second side. The flexibility of the additional potting compound applied in the region of the contact surfaces is preferably between that of the intermediate carrier and the flexibility of the line carrier, while the flexible potting compound extending to an outer region of the line carrier is closer to the flexibility of the line carrier in terms of its flexibility.
Thus, in a variant of this kind of the circuit module, the potting compound can be used with graded flexibility or rigidity, wherein the rigidity should decrease or the flexibility or flexural slackness should increase with increasing distance from the intermediate carrier. These desired properties can be achieved in the manner described by using differently flexible materials, different material thicknesses (decreasing means more flexible), recesses in the material distribution or locally different curing or cross-linking (for example, UV exposure time).
In a further advantageous embodiment variant of the circuit module according to the invention, the terminal contacts of the semiconductor circuit can be flattened and/or widened at their connection surfaces (SMD design, surface mounted device) and thus, while avoiding the intermediate carrier, can be applied directly to corresponding terminal contact surfaces of the film-like line carrier. It should be expressly made clear at this point that the intermediate carrier can optionally be dispensed with in this embodiment variant because the special shape of the terminal contacts of the electrical semiconductor circuit allows permanent and reliable mounting directly on a film-like line carrier. The terminal contacts of the electrical semiconductor circuit can be applied here in an electrically conductive manner to the terminal contact surfaces of the film-like line carrier.
The terminal contacts can optionally be soldered to the terminal contact surfaces of the film-like line carrier. In addition, it can be advantageous when stiffening strips are placed on the upper side of the flat areas of the terminal contacts of the semiconductor circuit. These stiffening strips can be laminated, for example, on the terminal contacts or on the terminal contacts of the semiconductor circuit.
A further function of the aforementioned stiffening strip can be that the terminal contacts otherwise often cannot be plugged into their counterparts. It is only through the stiffening that sufficient force can be applied during the production of the contacts without the contacts yielding or bending on their carrier substances. Alternatively, a complex plug-in tool is often required, which can be omitted due to the design according to the invention.
In a modified embodiment variant of a circuit module of this kind, a plurality of film conductors or film conductor sections or the film-like line carriers can be combined such that multiple-row plug contacts are created and multiple-row plugs (terminals, housings, . . . ) can be fitted or connected. The stiffening is preferably located between the planes formed by the adjacent line carriers.
In addition, it should be pointed out that in the case of stiffening, measures to reduce the risk of breakage in the region of the contact surfaces in the form of beveled edges, additional potting compounds or a combination of these measures can also be provided as an alternative or in addition.
To achieve the above-mentioned aim, the invention further proposes a method for producing a circuit module, particularly a circuit module as has already been explained and defined above in different embodiment variants. This circuit module according to the invention is formed from a plurality of components interconnected in an electrically conductive manner, namely from at least one integrated semiconductor circuit which is enclosed or encapsulated in an isolating housing and has a plurality of electrical terminal contacts which are led out of the isolating housing and which are connected in an electrically conductive manner to contact surfaces of a planar intermediate carrier, from a planar intermediate carrier and from a film-like line carrier. The method provides that the integrated semiconductor circuit together with its housing is placed on or against a first side of the planar intermediate carrier, which planar intermediate carrier has edge-side outer contacts on a second side opposite the first side having the housing of the integrated semiconductor circuit lying on or against it and has connection lines between the contact surfaces and the outer contacts, which outer contacts of the intermediate carrier in turn are connected in an electrically conductive manner to corresponding terminal contacts of a film-like line carrier.
The use of the relatively rigid intermediate carrier, which carries the integrated semiconductor circuit and stabilizes all of its electrical terminals, makes it possible to mount conventional semiconductor circuits on pliable, film-like line carriers without breaking or damaging the electrical terminal wires and terminal contacts. Since the film-like line carriers that are typically used are generally relatively thin and very flexible, they can be used in a variety of ways and in a wide variety of mounting situations. Due to their flexibility, however, they are poorly suited for the direct mounting of integrated semiconductor components such as semiconductor circuits, since their relatively stiff wire legs and contacts require an installation situation with a stable carrier, otherwise there is always the risk of loss of contact due to damage to the wire legs or contacts and/or electrical contacts. Particularly, the soldered and/or glued connections usually used to make electrical contact with the terminal contacts of the electrical semiconductor circuit, which are inflexible due to its housing, require largely stable installation and use situations, since otherwise the soldered and/or glued connections are hardly able to permanently guarantee the electrical contacts when there are frequent bending stresses or load changes. The method according to the invention provides a practical solution for this.
An alternative embodiment of the method according to the invention provides that the terminal contacts of the semiconductor circuit are flattened and/or widened at their connection surfaces (SMD design—surface mounted device) and thus, while avoiding the intermediate carrier, can be applied directly to corresponding terminal contact surfaces of the film-like line carrier. The intermediate carrier can optionally be dispensed with in this embodiment variant because the special shape of the terminal contacts of the electrical semiconductor circuit allows permanent and reliable mounting directly on a film-like line carrier. The terminal contacts of the electrical semiconductor circuit can be applied here in an electrically conductive manner to the terminal contact surfaces of the film-like line carrier. The terminal contacts can optionally be soldered to the terminal contact surfaces of the film-like line carrier. In addition, it can be advantageous when stiffening strips are placed on the upper side of the flat areas of the terminal contacts of the semiconductor circuit. These stiffening strips can be laminated, for example, on the terminal contacts or on the terminal contacts of the semiconductor circuit.
In addition, it should be pointed out at this point that all aspects, variants and specifics that were mentioned and described in connection with the various design variants of the circuit module according to the invention can also be seen in connection with the method according to the invention for producing a circuit module of this kind. The same also applies vice versa, so that those aspects that were mentioned in connection with the method described above can also be in connection with the circuit module. This also stipulates that the disclosure of the invention through the above description is to be viewed as an overall disclosure without a mandatory and mutually exclusive assignment to the circuit module according to the invention in its various embodiment variants or to the method according to the invention for producing the circuit module being given or defined.
In the following, exemplary embodiments are intended to explain the invention and its advantages in more detail with reference to the accompanying figures. The proportions of the individual elements to one another in the figures do not always correspond to the real proportions, since some forms are simplified and other forms are depicted enlarged in relation to other elements for better illustration.
Identical reference symbols are used for identical or identically acting elements of the invention. Furthermore, for the sake of clarity, only reference symbols which are necessary for the description of the respective figure are depicted in the individual figures. The depicted embodiments merely represent examples of how the device according to the invention or the method according to the invention can be designed and do not constitute a final limitation.
The circuit module 10 shown in such a way in
The circuit module 10 furthermore comprises a planar intermediate carrier 18 having contact surfaces 20 which are connected in an electrically conductive manner to the electrical terminal contacts 16 which are led out of the isolating housing 14 of the integrated semiconductor circuit 12. In addition,
The intermediate carrier 18 shown in the plan view of
The connection lines 32 arranged on, at and/or in the planar intermediate carrier 18 are arranged at least at the surface thereon and/or run there. Optionally, the connection lines 32 can run at least along one of the two surfaces, that is, the first side 22 and/or the second side 26 of the planar intermediate carrier 18 (see the view of the first side 22 in
The relatively rigid intermediate carrier 18 can, for example, be made from a suitable plastic, optionally from a multilayer isolating material or the like, which carries the necessary terminal contacts 20, 24 and connection lines 32 on the surface and, if necessary, embedded in the material. Particularly advantageously, the connection lines 32 running in the material of the intermediate carrier 18 of the more complex circuit module 10 according to the invention and embedded there can have at least one crossing point in their course from one surface to the other or from one side 22 to the other side 26, but preferably also a plurality of or numerous crossing points, which are isolated from one another if necessary or make a contact in an electrically conductive manner.
A further advantage of the intermediate layer of the planar intermediate carrier 18 used can be seen in the fact that in this way, crossings of lines that would be difficult to implement in the film are not only possible, but also the contacting of comparatively coarse conductor track structures, which can be combined with the significantly finer IC contacts of the semiconductor circuit 14, for example, in the case of films or film-like line carriers 30 having large conductor track widths and/or large conductor track spacings (that is, a wide pitch in the mm range).
In the first embodiment variant of the circuit module 10 according to the invention shown in
However, in practical use of the modules 10, this transition point between the intermediate carrier 18 and the line carrier 30 can prove to be critical, particularly in the immediate vicinity of the edge 44, since a configuration of this kind can damage the conductor tracks (not depicted) of the film-like line carrier 30 when bending loads occur. Particularly, the conductor tracks of the film-like line carrier 30 can kink or break, or their isolation can be damaged.
In order to avoid or at least reduce this risk, the edges 46 on the longitudinal sides 42 of the planar intermediate carrier 18 can be modified as a sensible measure, as is shown in the illustration in
In the illustration of
In order to reduce the above-mentioned risks of damage to the conductor track of the film-like line carrier 30, further measures can also be taken, as the schematic representation of
Optionally, the longitudinal sides 42 according to
The rest of the construction of the third variant of the circuit module 10 shown in
As the schematic representation of
Thus, in the fourth variant of the circuit module 10 shown in
The rest of the construction of the fourth variant of the circuit module 10 shown in
The necessary through-contacts of the terminal contacts 16 and/or between the conductor film layers 52, which the latter are not depicted in the drawing here, can be implemented, for example, as so-called vias (for example, as rivets), but optionally also by gluing, soldering or welding, optionally also in connection with bending and/or twisting the film, so that its contact surface can turn from bottom to top or vice versa. The through-contacts can also optionally be produced by removing the isolation layer in places (for example, by so-called “kiss-cut”).
The rest of the structure of the fifth variant shown in
The schematic detailed view of
In the further embodiment variants of the circuit module 10 according to the invention shown in various details and views in
As illustrated in
A further function of the stiffening strip 40 in
In addition, it should be pointed out that the measures to reduce the risk of breakage in the region of the contact surfaces 20 corresponding to
The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or changes can be made to the invention without departing from the scope of protection of the following claims.
Number | Date | Country | Kind |
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10 2018 006 625.9 | Aug 2018 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/DE2019/000144 | 5/21/2019 | WO | 00 |