Adhesive composite structure of printed circuit board and further component

Abstract

The invention relates to an arrangement of a printed circuit board (1) and a further component (2), the printed circuit board (1) having at least one electrically insulating first layer (3) on which at least one electrically conductive second layer (4) is arranged, which forms a plurality of conductor paths, characterized in that an adhesive (6) connects the printed circuit board (1) to the further component (2) at a connection point (5), the adhesive (6) is in contact, on the one hand, with a section of the further component (2) and, on the other hand, with a section of the second layer (4) or with an intermediate element (10) in contact with the second layer (4).

Description

Technical Field

[0001] The invention relates to a composite structure of a printed circuit board and another component. Background Art

[0002] A printed circuit board is a carrier for electronic components. The printed circuit board is used to mechanically fix and electrically connect these components in a printed circuit board unit. The printed circuit board consists of at least one electrically insulating layer and a printed conductor (Leiterbahn) attached thereto. The printed conductor is present in the form of at least one second layer. Here, the printed conductor is usually formed by etching a thin copper layer. The components are usually connected to the printed conductor in an electrically conductive manner by welding. In many printed circuit boards, the electrically insulating layer is the supporting structure of the printed circuit board. In this case, this layer is usually made of fiber-reinforced plastic or also of hard paper and is designed to have a relatively large layer thickness.

[0003] It is usually necessary to mechanically integrate the printed circuit board into an electrical unit such as an inverter sufficiently firmly. The fixing of the printed circuit board to another component of the electrical unit should be able to be performed as simply and cheaply as possible. At the same time, the connection must have sufficient load capacity. This is particularly applicable to units that are part of a mobile device, such as inverters of motor vehicles. In this case, a sufficiently vibration-resistant connection is required. In addition, if necessary, the connection of the printed circuit board to the ground should be achieved through this connection, so the connection must be designed to be conductive. It is known to screw the printed circuit board to another component with screws, thereby achieving a mechanically sufficient load capacity and conductive connection. However, screwing leads to great expenditure and therefore relatively high costs.

[0004] Patent document US2014 / 0293558 A1 discloses electrically connecting a lens housing to a printed circuit board via a conductive adhesive.

[0005] Patent document US 2009 / 0153772 A1 describes an LCD module having a backlight unit, a printed circuit board and a frame, wherein the printed circuit board is arranged without a gap between the backlight unit and the frame with an elastomeric element arranged in between.

[0006] Patent document CN 203243598 U discloses a flexible printed circuit board having a conductive adhesive layer. Summary of the invention

[0007] The object of the present invention is to provide an advantageous possibility for connecting a printed circuit board to other components.

[0008] This technical problem is solved by the arrangement according to the invention. Advantageous embodiments of the arrangement are apparent from the following description of the invention.

[0009] According to the invention, an arrangement of a printed circuit board and a further component is provided, wherein the printed circuit board has at least one (preferably flat) electrically insulating first layer, on which at least one (preferably flat) electrically conductive second layer is arranged, wherein the second layer forms a plurality of conductor tracks. The printed circuit board and the further component are connected to one another at at least one connection point by means of an adhesive, wherein the adhesive is in contact with a section of the further component on the one hand and with a section of the second layer (the adhesive is directly connected to the second layer) or with an intermediate element that contacts the second layer (the adhesive is indirectly connected to the second layer) on the other hand. The further component is preferably a supporting structure of the arrangement, i.e. the printed circuit board is supported on the further component.

[0010] The bonding of the printed circuit board to the further components allows a simple and inexpensive connection of these components, while at the same time ensuring sufficient load-bearing capacity. It may also be advantageous for the load-bearing capacity if the adhesive interacts with the second layer of the printed circuit board or with an intermediate element which consists or can consist of an electrically conductive, in particular metallic material, preferably copper. Such a material allows a good adhesion of the adhesive and / or has a good mechanical load-bearing capacity.

[0011] Preferably, it can be provided that the second layer has a layer thickness between 0.015 mm and 0.3 mm, preferably between 0.015 mm and 0.035 mm. The electrically insulating first layer can, for example, include epoxy resin, especially epoxy resin compounded with reinforcing fibers (such as FR-4). In addition, the first layer can have a layer thickness between 0.01 mm and 1 mm, preferably between 0.14 mm and 0.6 mm. It can be provided that the electrically insulating first layer is thinner than the conductive second layer. In particular, when the two layer types of the printed circuit board are designed to have a given (relatively small) layer thickness, it may be advantageous that the printed circuit board according to the present invention includes a plurality of first layers and / or a plurality of second layers in a layered structure or stacked structure, so that sufficient thickness and therefore mechanical stability of the printed circuit board can be achieved as a whole. In addition, at least a plurality of second layers can achieve a relatively complex electrical interconnection of printed conductors or electronic components connected to these printed conductors, such as capacitors, ohmic resistors, etc., wherein, due to the plurality of second layers, the corresponding printed circuit board unit can also include a relatively large number of electronic components. The plurality of second layers can be connected to one another at defined connection locations, as can also be provided in conventional printed circuit boards by so-called vias (Durchkontaktierung or metallized holes, “vertical electrical connections” (VIA)).

[0012] A further advantage of bonding the printed circuit board to other components can be that such a connection or adhesive can have a vibration-damping effect, which can have a positive effect on the vibration load of the printed circuit board and the electronic components fastened thereto. Thus, the arrangement according to the invention can also advantageously be part of a component that is relatively highly subjected to vibration loads, such as a component of a motor vehicle (e.g. an inverter).

[0013] In addition, the direct or indirect connection of the adhesive on the second layer can realize the electrical connection between the second layer of the printed circuit board and other components in an advantageous manner. For this reason, the adhesive and / or the intermediate element are preferably designed to be conductive. In order to achieve conductivity, the adhesive can, for example, include particles composed of conductive materials, such as metals or carbon, which are contained in a matrix that exerts an adhesive effect. And the intermediate element can preferably be composed of conductive materials, especially metals, and particularly preferably copper. The conductive material of the intermediate element can also preferably be consistent with the material that also constitutes at least one second layer. Due to the conductive connection between the second layer of the printed circuit board and other components through the adhesive and / or the intermediate element, the other components can advantageously act as an electrical grounding device for the second layer of the printed circuit board or be arranged for this purpose. In particular, it can also be provided that the second layer is electrically grounded through the adhesive and / or the intermediate element and other components. Therefore, the second layer of the printed circuit board and the earth and / or a separate conductive connection for grounding can be omitted.

[0014] According to a preferred embodiment of the arrangement according to the invention, it can be provided that the intermediate element (if present) contacts the further component. This allows a particularly mechanically load-bearing connection and / or a well-conducting connection to be achieved between the second layer of the printed circuit board and the further component.

[0015] Furthermore, it can preferably be provided that a through-hole of the printed circuit board is arranged in the region of the connection location, wherein the adhesive is (also) arranged in the through-hole. In this case, the adhesive can at least partially, preferably completely, fill the through-hole. This also makes it possible to achieve a connection with particularly high mechanical load capacity and / or a connection with good electrical conductivity.

[0016] It can also be preferably provided that the intermediate element is arranged in at least one section in the through-hole, which can also have a favorable effect on achieving a connection with particularly high mechanical load capacity and / or a connection with good electrical conductivity. It can be particularly preferably provided that the intermediate element or at least the section of the intermediate element arranged inside the through-hole of the printed circuit board is designed as a tube, wherein the outer side of the tube sleeve is in contact with the circumferential boundary of the through-hole. The inner side of the tube sleeve can advantageously be in contact with the adhesive.

[0017] According to a preferred embodiment of the arrangement according to the invention, in which an adhesive is arranged in the through-hole, it can be provided that the adhesive acts on the printed circuit board from behind on the side of the printed circuit board facing away from the further component. Thus, a positive connection between the printed circuit board and the further component can also be achieved by the adhesive, which can have a correspondingly favorable effect on the mechanical load-bearing capacity of the connection.

[0018] For the same purpose, as is preferably provided, the further component forms an undercut relative to the connection axis, wherein the adhesive is also arranged in the region of this undercut. An "undercut" is understood here to be a recess extending transversely and preferably perpendicularly to the connection axis, which forms an adhesive that secures the connection in a form-fitting manner. The connection axis is oriented here so as to extend along the shortest distance between the printed circuit board and the further component in the center of the connection location.

[0019] According to an embodiment of the arrangement structure according to the present invention, it can be provided that the printed circuit board and the other components are spaced apart from each other at the connection position, wherein the adhesive bridges the distance. It is thus possible to achieve relative mobility between the printed circuit board and the other components, which is based on the flexibility and especially elasticity of the adhesive, which can have a favorable effect, especially in terms of weakening the transmission of vibration movement from the other components to the printed circuit board. In addition, in this case, it is also possible to achieve electromagnetic shielding (or shielding) effects in an advantageous manner by the adhesive. For this purpose, it can be particularly provided that the adhesive between the printed circuit board and the other components is designed as a wall. Such a shape of the adhesive is understood as "wall-shaped" here, and in the case of this shape, the longitudinal extension is at least twice, preferably at least five times or ten times, the two extensions extending perpendicularly thereto, namely the width and height extensions. The wall-shaped direction of the adhesive along the direction of the longitudinal extension can be designed geometrically arbitrarily, for example, it is designed as a straight line, (single or multiple) bends or (single or multiple) bends and each has an open end or is closed and surrounded. By means of such a wall-shaped design of the adhesive between the printed circuit board and the other components, electronic components adjacent thereto can advantageously be at least partially, preferably completely, covered when viewed from the electromagnetic radiation source, thereby shielding them from electromagnetic radiation.

[0020] According to a preferred embodiment of the arrangement according to the invention, it can be provided that the adhesive is designed to be thermally conductive in a targeted manner. This allows heat transfer between the printed circuit board and the other components, in particular to cool the printed circuit board and / or the electronic components fastened thereto. To achieve a targeted thermally conductive design of the adhesive, it can be provided, for example, that the adhesive comprises particles of a material that is (as far as possible) thermally conductive, for example a metal, which are contained in a matrix that exerts an adhesive effect.

[0021] The invention also relates to a method for forming an arrangement according to the invention, wherein the method comprises at least positioning a printed circuit board and a further component relative to one another in a defined arrangement and positioning an adhesive at the connection location. The method may also comprise removing a first layer of electrically insulating material at the connection location before positioning the adhesive and, if necessary, also before positioning the printed circuit board and the further component relative to one another in a defined arrangement. As an alternative to this, it may also be provided that the printed circuit board is manufactured in such a way that it does not (never) contain electrically insulating material at the connection location.

[0022] The terms “electrically insulating”, “electrically conductive” and “thermally conductive” are to be understood in a functional sense, so that a targeted design of the corresponding components is provided to achieve this function. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described in detail below based on the embodiments shown in the accompanying drawings. In the accompanying drawings, respectively:

[0024] Figure 1 A first embodiment of an arrangement according to the invention is shown;

[0025] Figure 2 A second embodiment of the arrangement according to the invention is shown;

[0026] Figure 3 A third embodiment of the arrangement according to the invention is shown;

[0027] Figure 4 A fourth embodiment of the arrangement according to the invention is shown;

[0028] Figure 5 A fifth embodiment of the arrangement according to the invention is shown;

[0029] Figure 6 shows a sixth embodiment of an arrangement according to the invention; and

[0030] Figure 7 A seventh specific embodiment of the arrangement according to the invention is shown. DETAILED DESCRIPTION

[0031] Figure 1 An arrangement of a printed circuit board 1 and further components 2 according to the invention is shown in accordance with one specific embodiment.

[0032] The printed circuit board 1 comprises two first layers 3 of an electrically insulating material, such as so-called solder resist, and a second layer 4 of an electrically conductive material, such as copper, which is arranged between the two first layers 3. The second layer 4, which is shown in a simplified manner, is formed by a plurality of conductor tracks 11 lying in a plane. A plurality of electronic components (not shown), such as capacitors and ohmic resistors, can be connected to these conductor tracks 11 in a mechanically fixed and electrically conductive manner in order to combine these electronic components in a printed circuit board unit and to electrically connect these electronic components to one another.

[0033] The printed circuit board 1 is connected to a further component 2, which can be, for example, a carrier element of an inverter, via an adhesive 6 at at least one connection point 5. It is provided that the adhesive 6 contacts a section of the further component 2 on the one hand and a section of the second layer 4 of the printed circuit board on the other hand, so that in accordance with Figure 1 In the arrangement of , a connection which is merely materially bonded is produced by the adhesive action of the adhesive 6 on the second layer 4 of the printed circuit board 1 and the corresponding contact sections of the further component 2. The printed circuit board 1 and the further component 2 are arranged at a distance from each other at least at the connection point 5, wherein the adhesive 6 bridges this distance 7.

[0034] The adhesive 6 can be designed to be electrically conductive, so that, through the contact of the adhesive 6 with the second layer 4 of the printed circuit board 1, there is an electrically conductive connection from the second layer via the adhesive 6 to the further component 2. Thus, the further component 2, which is itself designed to be electrically conductive, can act as an electrical grounding device for the second layer, or the grounding of the second layer 4 of the printed circuit board 1 can be achieved through the further component 2.

[0035] exist Figure 2 The arrangement shown in Figure 1 The arrangement of the circuit board 1 and the further component 2 differs only in that the further component 2 forms an undercut 8 in the region of the connection point 5, which is filled with the adhesive 6. The adhesive 6 thus cooperates with the further component 2 not only in a materially bonded manner but also in a form-fitting manner, which can have a favorable effect on the mechanical load-bearing capacity of the connection between the printed circuit board 1 and the further component 2.

[0036] Figure 3 and Figure 4 The arrangement shown is based on Figure 1 and Figure 2 The arrangement of PCB 1 differs in that a through-hole 9 of printed circuit board 1 is arranged in the region of connection location 5 , wherein adhesive 6 is also arranged in through-hole 9 .

[0037] In accordance with Figure 3 In the arrangement structure, the role of the adhesive 6 is only material bonding, and according to Figure 4 In the arrangement of , the adhesive 6 additionally cooperates with the further component 2 in a form-fitting manner. For this purpose, the further component 2 forms an undercut 8.

[0038] In addition, according to Figure 3 In the arrangement of the embodiment of the present invention, a tubular intermediate element 10 is provided, which consists of an electrically conductive material, for example copper, and which is arranged in the through hole 9 and in this case with its outer side of the tube sleeve is in contact with the circumferential boundary or wall of the through hole 9 and thus also with the corresponding section of the second layer 4 of the printed circuit board 1. At the same time, the adhesive 6 is in contact with the inner side of the tube sleeve of the intermediate element 10, so that an indirect connection of the adhesive 6 with the second layer 4 of the printed circuit board 1 is produced. The intermediate element 10 forms a circumferential flange 10a at each of the two longitudinal axial ends, which is bent outward at an angle of approximately 90° relative to the main section 10b of the intermediate element located in the through hole 9. The intermediate element 10 is fixed in a form-fitting manner in the through hole 9 of the printed circuit board 1 (in the longitudinal direction of the through hole 9) by these flanges 10a. The production of these flanges 10a can be achieved by forming (flanging) the corresponding end sections of the substantially tubular intermediate element 10.

[0039] In accordance with Figure 3 In the arrangement of , it is also provided that the further component 2 is in contact with the intermediate element 10 or one of the flanges 10a of the intermediate element. Thus, the conductive connection between the second layer 4 of the printed circuit board 1 and the further component 2 is produced both directly via the intermediate element 10 and via the intermediate element 10 and the adhesive 6.

[0040] On the contrary, according to Figure 4 In the arrangement structure, the printed circuit board 1 and the further component 2 are arranged at a distance from each other at least at the connection point 5, wherein the adhesive 6 bridges the distance. Figure 4 In the arrangement of FIG. 1 , no intermediate element 10 is provided, so that the adhesive 6 is in contact with the second layer 4 of the printed circuit board 1 .

[0041] according to Figure 5 The layout structure and basis Figure 3 The arrangement differs only in that the adhesive 6 is not only arranged in the through-hole 9 or in the inner volume of the tubular intermediate element 10, but also acts on the printed circuit board 1 from behind on the side facing away from the further component 2, so that a positive fit effect of the adhesive 6 is also achieved on the printed circuit board 1. Figure 6 The layout structure and basis Figure 4 The arrangement of the structures differs in this same feature.

[0042] Figure 7 It is described how an electrically conductive adhesive 6 can also be used to shield electronic components 12, the function of which could be disrupted by electromagnetic radiation 16, from being influenced by such radiation 16. The magnetic radiation 16 is generated by a corresponding radiation source 13. To this end, in an arrangement design in which the printed circuit board 1 is arranged at a distance from the further component 2 at least at the connection point 5, it can be provided that the adhesive 6 is arranged in the area between the printed circuit board 1 and the further component 2 with such a large dimension transversely to the connection axis 14 that the electronic component 12 is covered with respect to the direct distance relative to the radiation source 13. In particular, it can be provided that the adhesive 6 between the printed circuit board 1 and the further component 2 is designed in the form of a wall and, for example, surrounds an edge area of ​​the printed circuit board 1 in a closed manner. The electromagnetic radiation 16 emitted from the radiation source 13 in the direction of the electronic component 12 is directed away via the electrically conductive adhesive 6 and the electrically conductive further component 2. In addition to this, Figure 7 It is also shown that a plate-shaped electrically conductive protective element 15 is arranged between printed circuit board 1 and radiation source 13 , which protective element is likewise in contact with adhesive 6 , so that printed circuit board 1 is also shielded from electromagnetic radiation 16 .

[0043] In accordance with Figure 7 In the arrangement structure, the connection method of the printed circuit board 1 and the other component 2 is the same as that according to Figure 3 The connection method is basically consistent with that of the embodiment of the present invention, wherein the difference is that the printed circuit board 1 and the other component 2 are arranged at a distance from each other so as to enable the adhesive 6 to shield the electromagnetic radiation 16. Figure 7 In the arrangement of , an intermediate element 10 is also arranged in the through-hole 9 of the printed circuit board 1, wherein the intermediate element 10 is in contact with the second layer 4 of the printed circuit board 1 on the outside and with the adhesive 6 on the inside. In principle, the adhesive 6 between the printed circuit board 1 and the further component 2 can also be present in the through-hole(s) 9 of the printed circuit board 1 at multiple sections of the wall-shaped course of the adhesive and, if necessary, in the inner volume of the intermediate element(s) 10 arranged in these through-holes 9.

[0044] In principle, the printed circuit board 1 and the other components 2 are arranged as in Figures 1 to 7 The features of the different connection methods shown in can be combined with each other as desired. Figure 1 In the arrangement structure, it can also be provided that the printed circuit board 1 is in contact with another component 2, and in accordance with Figure 2 Alternatively, this may not be the case in an arrangement according to Figure 3In the arrangement structure of the present invention, a distance can also be set between the printed circuit board 1 and the other component 2 and / or the adhesive 6 can be formed to fit the other component 2 by the undercut 8 of the other component 2. Figure 4 In the arrangement structure, the contact between the printed circuit board 1 and the other component 2 can be provided and / or the undercut 8 of the other component 2 can be omitted. Figure 3 and Figure 4 These variants of the arrangement structure can also be implemented according to Figure 5 and Figure 6 For the arrangement structure according to Figure 7 The arrangement of can provide all the described connection types of printed circuit board 1 and further component 2 in which printed circuit board 1 and further component 2 are arranged at a distance from one another.

[0045] Reference numerals list

[0046] 1. Printed Circuit Board

[0047] 2 Additional components

[0048] 3The first layer of the printed circuit board

[0049] 4 The second layer of the printed circuit board

[0050] 5 Connection Location

[0051] 6. Adhesives

[0052] 7. Distance between printed circuit board and other components

[0053] 8 side concave part

[0054] 9 Through Holes

[0055] 10Intermediate components

[0056] 10a Flange of intermediate element

[0057] 10b Main section of the intermediate element

[0058] 11 Printed conductors

[0059] 12 Electronic components

[0060] 13 Radiation Sources

[0061] 14Connection axis

[0062] 15 Protection elements

[0063] 16 Electromagnetic Radiation

Claims

1. An arrangement of a printed circuit board (1) and a further component (2), wherein: The printed circuit board (1) comprises at least one electrically insulating first layer (3), on which at least one electrically conductive second layer (4) is arranged, the second layer forming a plurality of conductor tracks, characterized in that an adhesive (6) connects the printed circuit board (1) to a further component (2) at a connection point (5), wherein the adhesive (6) is in contact with a section of the further component (2) on the one hand and with a section of the second layer (4) or with an intermediate element (10) contacting the second layer (4) on the other hand.

2. The arrangement according to claim 1, characterized in that The adhesive (6) and / or the intermediate element (10) are designed to be electrically conductive.

3. The arrangement according to claim 2, characterized in that The further component (2) is provided as an electrical grounding device for the second layer (4) of the printed circuit board (1).

4. Arrangement according to any one of the preceding claims, characterized in that The intermediate element (10) is in contact with the further component (2).

5. Arrangement according to any one of the preceding claims, characterized in that A through-hole (9) of the printed circuit board (1) is arranged in the region of the connection location (5), wherein the adhesive (6) is arranged in the through-hole (9).

6. The arrangement according to claim 5, characterized in that The adhesive (6) acts on the printed circuit board (1) from behind on the side of the printed circuit board facing away from the further component (2).

7. Arrangement according to any one of the preceding claims, characterized in that The further component (2) forms an undercut (8) relative to the connection axis (14), wherein the adhesive (6) is also arranged in the region of the undercut (8).

8. Arrangement according to any one of the preceding claims, characterized in that The printed circuit board (1) and the further component (2) are spaced apart from one another at a connection point (5), wherein an adhesive (6) bridges the distance (7).

9. The arrangement according to claim 8, characterized in that The adhesive (6) between the printed circuit board (1) and the further component (2) is designed in the form of a wall.

10. An arrangement according to any one of the preceding claims, characterized in that The adhesive (6) is designed to be thermally conductive.

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