EP2634864B1 - Circuit board device and a related electrical assembly - Google Patents

Description

State of the art

In direct plug-in technology, direct plug-in connectors or connectors are contacted directly on the printed circuit board without additional pin headers. The plugs are usually attached to the edge-mounted contact pads on the circuit boards. The contact pads can be integrated on the PCB top side as well as on the underside of the PCB in the PCB layout. The contact pads are usually formed from the mechanically firmly connected to an electrically insulating substrate of the circuit board interconnects. The plug consist essentially of a plug housing and a contact element, wherein in the attached state, the contact element is pressed by a spring force against the contact pad. The contact element is in this case usually resilient, so that the contact element for applying the spring force to the conductor track, respectively on the contact pad on which made of an insulating material, usually made of plastic, plug housing of the plug is supported.

However, it has been found that, under the influence of the spring force acting essentially perpendicularly on the contact pads, the plug housing made of plastic relaxes, thus becoming plastically deformed. Thus, over the life of a printed circuit board-plug combination, the spring force decrease such that a secure electrically conductive connection between the contact pad and the contact element is not guaranteed.

From the EP 0 036 933 A2 a connector is known. This connector is formed by a female connector and a circuit board to be contacted with this. The female connector carries two rows of weakly elastic contact elements whose contact surfaces point inwards. The contact elements are touched externally by strand-shaped elastic elements. These are stored captive in slot openings in the longitudinal walls of the female connector and protrude laterally beyond the longitudinal sides. The printed circuit board can be inserted with its contact strips, which end on a projection in the opening of the female connector. The circuit board is rigidly supported on both sides with its associated clip elements. These have L-shaped cross section, and their insides are wedge-shaped beveled. The circuit board and the clip elements beak force-free at the beginning of the plug-in process. Upon further insertion of the elastic elements are elastically deformed by the clip elements and pressed into the interior of the female connector, where they press the contact elements against the contact strips of the circuit board. At the end of the plug-in procedure, a secure plug-in seat results, since the deformed elastic elements result in no force which, contrary to the plug-in direction, could cause the separate separation of the socket strip and the printed circuit board.

Summary of the invention

There may therefore be a need to ensure an electrical conductive connection of the plug-and-board combination over their calculated life.

The need can be satisfied by the subject matters of the independent claims. Advantageous embodiments will become apparent from the subject matters of the dependent claims.

A printed circuit board device comprising a printed circuit board with an electrically insulating substrate and at least one electrically conductive printed conductor can be provided. The conductor track is firmly connected to the substrate. The conductor extends along a longitudinal direction of the substrate. A plug having a plug housing and an electrical contact element arranged in the plug housing can be electrically conductively connected to the printed circuit board. With the circuit board, a spring element is firmly connected. When the plug is connected to the printed circuit board, the spring element exerts a force on the plug housing substantially perpendicular to the printed circuit board in order to press the electrical contact element onto the printed conductor.

In such an embodiment, the contact element may be resilient or designed only as a rigid plate. In particular, when the contact element is resilient, the relaxation of the plug housing and thus decreasing the conductor track pressure force is compensated for by the fact that the spring element presses the plug housing and thus the contact element to the circuit board. By this spring element is thus ensured that the contact element is secured to the conductor over the calculated lifetime of the PCB-connector connection. In this case, the printed circuit board can be made of resin-impregnated glass fiber fabric in a quality of FR4 or higher. Also, the electrically non-conductive substrate may be made of ceramic. The conductor can also be formed as a stamped grid. The force acting perpendicular to the circuit board of the spring element does not necessarily have to be introduced into the circuit board. For example, the force introduced into the spring element can be supported on a carrier element, wherein the circuit board may be connected to the carrier element without supporting the carrier element. Thus, no forces are introduced into the circuit board, which are required to press the contact elements to the conductor tracks. Of course, the spring element can also be connected to the printed circuit board in such a way that the force acting on the spring element is conducted into the printed circuit board.

The connector housing may have a groove. When the plug is connected to the circuit board, a portion of the circuit board is covered by the groove.

Especially in this embodiment, the electrical contact element can be supported on the connector housing to be resiliently pressed against the conductor track. The spring element may be arranged with respect to the circuit board such that the contact elements are already connected to the conductor track before the spring element is in engagement with the connector housing. This can be avoided in an advantageous manner, damage to the surface of the contact elements and / or the conductor, which is often due to the high pressure force of the contact elements of the known direct connector, which already acts on the conductor track when pushing these contact elements. It may therefore, for example, the contact element be designed to be slightly resilient so as to perform a pre-positioning of the plug housing when pushed onto the conductor track, while the contact pressure for reliable electrical contacting of the contact elements is effected by the spring element.

The spring element may have at least in a partial area essentially a Z-shape with a first leg element, a second leg element and a first leg element and the second leg element with each other inseparably connecting first web element. The first leg member is connected to the circuit board. When the plug is connected to the circuit board, the second leg member exerts the force on the plug.

Here, the circuit board may be designed such that the forces acting on the circuit board in the longitudinal direction of the circuit board or perpendicular to the Printed circuit board, are absorbed by the circuit board. However, the circuit board may also be designed such that only a force in the longitudinal direction of the circuit board is received. For example, the spring element can in this case be arranged on a first side of the printed circuit board, whereas the force acting through the plug on the spring element perpendicular to the longitudinal direction of the circuit board force can be introduced into a receiving element, wherein the receiving element on one of the first side of the circuit board opposite second side of Printed circuit board can be arranged. Here, the circuit board may be fixed to the receiving element such that no forces must be absorbed by the spring element through the circuit board. Thus, the circuit board can be free from the forces generated by the spring element.

The second leg element may be formed substantially S-shaped with a first bay and a second bay. The first bay is firmly connected to the web element. When the plug is connected to the circuit board, the second bay exerts the force on the plug.

By the S-shaped configuration of the second leg member, the force is applied linearly to the connector housing. Characterized in that the second leg member is connected by means of a first bay to the web element, the force is entered by the second leg member in the web element arcuate. As a result, high stresses are avoided within the material, as they could otherwise occur if the transition of the rod element in the second leg member would be sharp-edged.

The second leg element may have at least one notch, so that the second leg element has at least two independent resilient spring lamellae.

By a division of the second leg member in at least two resilient spring blades manufacturing tolerances of both the spring element and the connector housing can be compensated and thus an uneven force distribution over the connector housing can be avoided. According to one embodiment of the invention, the circuit board device further comprises a second spring element. The first spring element and the second spring element are firmly connected to one another such that when the plug is connected to the printed circuit board, the second spring element exerts a second force on the plug substantially perpendicular to the printed circuit board. The second spring element is configured such that the first force and the second force are substantially equal.

In this proposed embodiment, neither the first force nor the second force are conducted into the circuit board. By the first and the second spring element, the plug housing is encompassed and pressed the contact elements to the respective conductor tracks. In this case, the plug housing can be made reversibly elastically deformable, so that the plug housing is deformed by the two counteracting forces such that the electrical contact element are pressed by the two Federlemente to the conductor. In particular, when the conductor tracks are arranged both on a first side of the electrically insulating substrate and a second side of the substrate opposite the first side, it is achieved by such an arrangement that both the first side facing contact elements and those facing the second side Contact elements of the connector are pressed against the conductor tracks. Here, the first spring element and the second spring element may be connected to one another by soldering, screwing, riveting, welding or clinching.

According to a further embodiment of the invention, the first spring element and the second spring element are substantially equal to each other when the plug housing is configured with respect to a mirror formed in the plug housing mirror image. The first spring element and the second spring element are rigidly connected to one another with respect to the printed circuit board.

Thus, the first spring element and the second spring element can be manufactured in a tool. For a very inexpensive production of the spring elements is possible. Through the groove, when the plug is connected to the circuit board is connected, comprising a portion of the circuit board. Due to the rigid connection, both spring elements can exert a force on the plug housing.

According to a further embodiment of the invention, the second spring element is formed substantially L-shaped with a third leg member and a non-detachably connected to the third leg member second web member. The second web element and the first web element are non-releasably rigidly connected to each other.

The first force is introduced via the second leg element into the first web element and the second force via the third leg element into the second web element. In particular, the two web elements are rigidly connected to each other in such a way that the forces introduced into the web elements over the entire service life of the printed circuit board / plug combination can not damage this connection.

According to a further embodiment of the invention, the first spring element and the second spring element made of metal or a metal alloy.

In particular, metals or metal alloys which have resilient properties, such as, for example, cold-rolled, as a rule, stainless steel sheets, are suitable for this purpose. Furthermore, metal or its alloys has no relaxation behavior, as is known from plastics. Thus, the spring made of metal spring elements can ensure over the entire life of the PCB-plug combination that the contact elements are pressed electrically conductive to the tracks.

According to a further embodiment of the invention, the first spring element or the second spring element or a combination of the first spring element and the second spring element is in one piece.

The one-piece design eliminates further steps for the preparation of the individual spring elements. Thus, it is possible that only with the use of a tool first spring elements or second Spring elements or a combination of the first spring element and the second spring element can be manufactured.

According to a further embodiment of the invention, an electrical arrangement is provided with a printed circuit board device and a plug as described above. The plug is electrically conductively connected to the circuit board. At least one component of the group of first spring element and second spring element exerts a force on the plug.

It is noted that thoughts on the invention are described herein in the context of both a printed circuit board device and an electrical device. It will be clear to a person skilled in the art that the individual features described can be combined with one another in various ways so as to arrive at other embodiments of the invention.

Brief description of the drawings

Figur 1

zeigt eine Leiterplattenvorrichtung mit einer Leiterplatte und einem ersten Federelement und einem zweiten Federelement sowie einem Stecker bereit zum Aufschieben auf die Leiterplatte in einem Längsschnitt;

Figur 2

zeigt die aus Figur 1 bekannte Leiterplattenvorrichtung mit aufgeschobenem Stecker in einem Längsschnitt;

Figur 3

zeigt die aus Figur 1 bekannte Leiterplattenvorrichtung ohne Stecker in einer 3D-Explosionszeichnung;

Figur 4

zeigt die aus Figur 3 bekannte Leiterplattenvorrichtung in montiertem Zustand in einer 3D-Ansicht;

Figur 5

zeigt eine weitere Leiterplattenvorrichtung mit einer einstückig ausgebildeten Kombination aus erstem Federelement und zweitem Federelement in einer 3D-Explosionszeichnung; und

Figur 6

zeigt die aus Figur 5 bekannte Leiterplattenvorrichtung in montiertem Zustand in einer 3D-Ansicht.

Embodiments of the invention will be described below with reference to the appended drawings FIGS. 5 and 6 described. The figures are only schematic and not to scale.

FIG. 1

shows a printed circuit board device with a circuit board and a first spring element and a second spring element and a plug ready for sliding onto the circuit board in a longitudinal section;

FIG. 2

shows the off FIG. 1 known printed circuit board device with a pushed plug in a longitudinal section;

FIG. 3

shows the off FIG. 1 known circuit board device without plug in a 3D exploded view;

FIG. 4

shows the off FIG. 3 known printed circuit board device in the assembled state in a 3D view;

FIG. 5

shows a further printed circuit board device with an integrally formed combination of the first spring element and the second spring element in a 3D exploded view; and

FIG. 6

shows the off FIG. 5 known printed circuit board device in the assembled state in a 3D view.

Detailed description of exemplary embodiments

FIG. 1 shows a printed circuit board device 2 with a printed circuit board 4, which consists of an electrically insulating substrate 6 and a conductor 8 mechanically connected to the substrate 6. Here, the conductor 8 extends along a longitudinal extension direction L of the substrate 6 FIG. 1 a plug 10 with a connector housing 12 and two facing contact elements 14 can be seen. The two contact elements 14 project partially into a groove 16 formed in the plug housing 12. The groove 16 is designed to receive a partial area 24 of the printed circuit board 4 when the plug 10 is connected to the printed circuit board 4. In the partial region 24 of the printed circuit board 4, the printed conductors 8 can be electrically conductively contacted by means of the contact elements 14. Furthermore, a first spring element 18 and a second spring element 20 with respect to the circuit board 4 is arranged in mirror image on the circuit board 4. In the direction of an arrow 22, the plug 10 can be pushed onto the printed circuit board 4 in the longitudinal direction L of the substrate 6, or the printed circuit board 4.

FIG. 2 shows the off FIG. 1 known printed circuit board device 2 with a pushed plug 10. Here, the first spring element 18 practice a first force F1 and the second spring element 20, a second force F2 on the plug 10, respectively, the plug housing 12, from. By these two forces F1, F2, the contact elements 14 are pressed against the conductor tracks 8. Here, the contact elements 14 are in turn designed to be resilient, so that is increased by the two forces F1, F2, the contact force of the contact elements 14 to the conductor tracks 8. In particular, when the spring force of the contact elements 14 decreases due to relaxation of the plastic housing made of plug housing 12, the forces exerted by the two spring elements 18, 20 on the connector housing 12 forces F1, F2, that the

Contact elements 14 over the entire life of the circuit board 4 - plug 10 - combination remain electrically conductively connected to the tracks 8. Furthermore, it can be seen that the portion 24 of the circuit board 4 is surrounded by the groove 16 of the plug housing 12.

FIG. 3 shows the off FIG. 1 known circuit board assembly without the plug in a 3D exploded view. Clearly visible are arranged in the portion 24 of the circuit board 2 printed conductors 8, which may be formed as contact pads. These interconnects 8 are usually connected electrically conductive with electrical components not shown here. Both the first spring element 18 and the second spring element 20 each have a Z-shape 26 with a first leg member 28 facing the printed circuit board 4 and a second leg member 30 spaced from the printed circuit board 4, wherein the first leg member 28 and the second leg member 30 by means of a first stake element 32 are permanently connected to each other. The second leg member 30 is adapted to engage the plug 10 as in FIG FIG. 1 shown to exert a force F1, F2. The second leg member 30 has an S-shape 34 with a first bay 36 and a second bay 38. Here, the second bay 38 is designed to be on the not shown here, but from FIG. 1 to press known connector housing 12. By means of the second bay 38, the second leg member 30 is non-detachably connected to the first web member 32. Both the first spring element 18 and the second spring element 20 are each made in one piece from a cold-rolled sheet of stainless steel. Through the first bay 36, the force F1, F2 is arcuately introduced into the first web element 32, so that no high stresses arise within the material at the transition of the first web element 32 to the second leg element 30. Furthermore, the second leg member 30 has cuts 40, which extend up to the first bay 36.

Through these cuts 40, the better in FIG. 4 can be seen, the second leg member 30 is divided into resilient spring blades 42. By this resilient spring blades 42 a uniform force distribution of the forces F1, F2 is ensured over the entire length of the plug housing 10. By the resilient spring blades 42 manufacturing tolerances, in particular of the plug 10 can be compensated. The first leg member 28 of the first Spring element 18 and the first leg member 28 of the second spring element 20 are here by means of clinching, also called toxins, inextricably rigidly connected, wherein the circuit board 4 extends between the two first leg members 28 in the longitudinal direction L of the circuit board 4. When the plug 10 is pushed onto the printed circuit board 4, the forces F1, F2 are based on the two first web elements 32 via the two first leg elements 28. Characterized in that the two first leg members 28 are rigidly connected to each other, the forces acting perpendicular to the circuit board 4 forces F1, F2 are not passed into the circuit board 4. Thus, the circuit board 4 takes only forces that occur along the longitudinal direction L. These are usually the forces needed to push the plug 10 into its predetermined position on the printed circuit board 4. Incidentally, the first spring element 18 and the second spring element 20 are the same, so that they can be manufactured in a common tool. Also, the first spring element 18 and the second spring element 20 with respect to the circuit board 4 are arranged mirror images of each other.

FIG. 5 shows a further embodiment of the printed circuit board assembly 2. Here, the first leg member 28 of the first spring element 18 with respect to the representations in the FIGS. 3 and 4 The second spring element 20 is configured essentially in an L-shape 44 with a third leg element 46 and a second web element which is non-detachably connected to the third leg element 46 48. The first web element 32 of the first spring element 18 and the second web element 48 of the second spring element 20 are non-releasably rigidly connected to each other. The two web elements 32, 48 have centrally a common slot 52, which is present at a first end 56 and at a first end 56 opposite the second end 58 in each case by a web 54.

How better in FIG. 6 it can be seen, the slot 52 is designed such that the portion 24 of the circuit board 4 can be threaded through the slot 52. This is done along the arrow 62. Furthermore, the circuit board 4 has adjacent to the portion 24 each have a recess 60 into which the two webs 54 can be inserted.

If now the off FIG. 1 known connector 10 is pushed onto the circuit board 4, the forces acting on the plug 10 forces F1, F2 are introduced exclusively into the web elements 32, 48, so that none of the forces F1, F2 is passed into the circuit board 4.

By the proposed printed circuit board device 2, the forces acting perpendicular to the longitudinal direction L of the circuit board 4 in connection with the plug 10 forces F1, F2 are received within the interconnected spring elements 18, 20, so that dispenses with an additional component for receiving the forces F1, F2 can be. Since the joining force increases along the longitudinal extension direction L of the printed circuit board 4 upon contact of the spring elements 18, 20 with the plug 10, a powerless insertion of the plug 10 on the printed circuit board 4 can take place. Of course, the spring elements 18, 20 may be configured continuously instead of the comb-like configuration.

Claims (9)

1. Printed circuit board apparatus having a printed circuit board (4) comprising an electrically insulating substrate (6) and at least one electrically conductive conductor track (8),
   wherein the conductor track (8) is fixedly connected to the substrate (6),
   wherein the conductor track (8) extends along a direction (L) of longitudinal extent of the substrate (6),
   wherein a plug (10) comprising a plug housing (12) and an electrical contact element (14) which is arranged in the plug housing (12) can be electrically conductively connected to the printed circuit board (4),
   wherein a spring element (18, 20) is fixedly connected to the printed circuit board (4),
   wherein, when the plug (10) is connected to the printed circuit board (4), the spring element (18, 20) exerts a force (F1, F2) onto the plug housing (12) substantially perpendicularly in relation to the printed circuit board (4) in order to push the electrical contact element (14) onto the conductor track (8),
   wherein the printed circuit board apparatus (2) further has a second spring element (20),
   characterized in that
   the first spring element (18) and the second spring element (20) are fixedly connected to one another in such a way that, when the plug (10) is connected to the printed circuit board (4), the second spring element (20) exerts a second force (F2) onto the plug (10) substantially perpendicularly in relation to the printed circuit board (4),
   wherein the second spring element (20) is configured in such a way that the first force (F1) and the second force (F2) are substantially identical,
   wherein neither the first force (F1) nor the second force (F2) are conducted into the printed circuit board (4).
2. Printed circuit board apparatus according to Claim 1,
   characterized in that
   the spring element (18, 20) substantially has, at least in a subregion, a Z shape (26) comprising a first limb element (28), a second limb element (30) and a first web element (32) which connects the first limb element (28) and the second limb element (30) to one another in a non-releasable manner,
   wherein the first limb element (28) is connected to the printed circuit board (4),
   wherein, when the plug (10) is connected to the printed circuit board (4), the second limb element (30) exerts the force (F1, F2) onto the plug (10).
3. Printed circuit board apparatus according to Claim 1 or 2,
   characterized in that
   the second limb element (30) is of substantially S-shaped design with a first recess (36) and a second recess (38),
   wherein the first recess (36) is fixedly connected to the web element (32, 48),
   wherein, when the plug (10) is connected to the printed circuit board (4), the second recess (38) exerts the force (F1, F2) onto the plug (10).
4. Printed circuit board apparatus according to one of the preceding claims,
   characterized in that
   the second limb element (30) has at least one notch (40), so that the second limb element (30) has at least two spring lamellae (42) which are resilient independently of one another.
5. Printed circuit board apparatus according to Claim 4,
   characterized in that,
   when the plug housing (12) is of mirror-image symmetrical configuration with respect to a groove (16) which is formed in the plug housing (12), the first spring element (18) and the second spring element (20) are substantially identical to one another,
   wherein the first spring element (18) and the second spring element (20) are connected to one another in a flexurally rigid manner with mirror-image symmetry with respect to the printed circuit board (4).
6. Printed circuit board apparatus according to Claim 4 or 5,
   characterized in that
   the second spring element (20) is of substantially L-shaped design with the second limb element (30) and a second web element (48) which is connected to the second limb element (30) in a non-releasable manner, wherein the second web element (48) and the first web element (32) are connected to one another in a non-releasable and flexurally rigid manner.
7. Printed circuit board apparatus according to one of the preceding claims,
   characterized in that
   the first spring element (18) and the second spring element (20) are produced from metal or a metal alloy.
8. Printed circuit board apparatus according to one of the preceding claims,
   characterized in that
   the first spring element (18) or the second spring element (20) or a combination of the first spring element (18) and the second spring element (20) is integral.
9. Electrical arrangement comprising a printed circuit board apparatus (2) according to one of Claims 1 to 8 and a plug,
   characterized in that
   the plug (10) is electrically conductively connected to the printed circuit board (4),
   wherein at least one component from the group comprising the first spring element (18) and the second spring element (20) exerts a force (F1, F2) onto the plug (10).

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