Chip protection for printed circuit boards

Abstract

Chip protection (100) for printed circuit boards, comprehensive - a printed circuit board (1) which is slotted at one end such that it has printed circuit board webs (11), - a support (2) designed to at least partially accommodate the printed circuit board (1), and - a chip guard cover (3) which is designed to be connected to the carrier (2) and the printed circuit board (1) in such a way as to form a chamber system in which each printed circuit board web (11) is arranged within a chamber (4) formed by the connection between the carrier (2) and the chip guard cover (3), and - Carrier (2) has a strand guide (22) which is formed and aligned in such a way that strands (23) can be guided through the strand guide (22) from the outside into the chip guard (100) in order to be contacted with the associated printed circuit board webs (11).

Description

[0001] The present invention relates to a chip protection device for printed circuit boards according to claim 1.

[0002] In the automotive industry, the development of transmissions and their control systems is a top priority. Chip protection covers are used to protect the transmission control systems from unwanted external influences, such as the impact of particles, especially conductive particles. These chip protection covers should also be suitable for use in areas of the vehicle that place high demands on materials and functionality, such as the transmission oil sump. The chip protection cover serves to protect electrical contacts and other sensitive components from, for example, manufacturing-related machining residues and conductive particles that could damage the transmission control system.

[0003] US 2014 / 0 192 986 A1 discloses a device comprising an electrical connector coupled to the end of a flexible circuit. The connector includes internal ribs that engage slots in the flexible circuit, with the ribs and slots separating adjacent contact pads on the flexible circuit. The contact pads are exposed portions. Other portions of the conductive traces may be covered by a dielectric material, such as a non-conductive ink. The ribs provide a raised insulation path between the contact pads.

[0004] DE 10 2012 204 004 A1 discloses a covering device for a contacting section of a printed circuit board for a mechatronic module. The contacting section has at least one connection opening for connecting an electrical connection element to the printed circuit board. The covering device is characterized in that the covering device has a chip protection element and a sealing element for sealing the connection openings.

[0005] Known protective measures for transmission control systems, which are used particularly inside the transmission, are designed to provide a completely sealed connection between the circuit board of the transmission control system and the electrical conductors for contacting the outside. To achieve this tight connection, the interface is often potted using an adhesive. This process is expensive. On the other hand, potting carries the risk of it becoming detached from neighboring components, allowing surrounding transmission oil to penetrate the transmission control system and thus breaking the tight connection. The transmission oil can no longer drain out of the transmission control system, and any conductive deposits that may be present can be washed away. Such deposits can then create a short circuit and damage or destroy the transmission control system.

[0006] To solve this problem, protective elements have been developed that do not have to be completely sealed, i.e. that oil can penetrate in small quantities. In these designs, the oil cannot form conductive deposits from one contact to another. Such a protective element, for example, provides pre-fixing of the assembly. After pre-fixing, the chip protection cover is folded down and then a final fixing of the components, e.g. the sensors, takes place. The disadvantage here is that the chip protection cover has to be generously dimensioned, which makes it expensive. To overcome this disadvantage, it was proposed to provide a chip protection element that can still be moved together with the assembly after preliminary fixing. This allows a smaller installation space to be achieved.

[0007] A further disadvantage of all these designs is that they do not provide cost-effective and compact chip protection. Furthermore, the chip protection covers and systems available to date are not designed for printed circuit boards, but rather for sensors or other assemblies, for example.

[0008] Therefore, it is an object of this invention to provide a chip protection device for printed circuit boards that prevents conductive deposits that could cause a short circuit from forming between individual contact points on the printed circuit board when oil penetrates the board. This object is achieved according to the invention by the features of patent claim 1. Advantageous embodiments are the subject of the dependent claims.

[0009] According to the invention, a chip protection device for printed circuit boards is proposed, comprising a printed circuit board which is slotted at one end in such a way that it has printed circuit board webs, a carrier which is designed to at least partially receive the printed circuit board, and a chip protection cover which is designed to be connected to the carrier and the printed circuit board in such a way that a chamber system is formed in which each printed circuit board web is arranged within a chamber which is formed by the connection between the carrier and the chip protection cover.

[0010] The proposed geometry and arrangement of the parts that form the chip guard allows oil surrounding the chip guard or the transmission control unit, to which the chip guard is preferably attached, to penetrate into the chip guard housing but also flow out again. This eliminates the need for a completely sealed housing, and the circuit board can therefore only be partially contained within the chip guard. In addition, the chamber system created prevents particles, especially conductive particles, from causing a short circuit between the conductor track bridges. The simple geometry makes it possible to provide a compact housing to protect the circuit board that offers good protection against short circuits and allows flushing with oil, but also allows the oil to drain away, preventing deposits from forming.

[0011] The carrier can be attached to the circuit board using different methods such as caulking or ultrasonic welding or other known methods.

[0012] The chip protection cover can be attached in a variety of ways, depending on the specific application and installation method. For example, the chip protection cover can be attached to the support by inserting it into place with additional locking elements, by screwing, welding (preferably laser welding), gluing, snapping, or other fastening methods. The chip protection cover can also be hinged to the support on one or more sides, meaning it is not formed as a separate component but rather as part of the support.

[0013] In one embodiment, the chip protection cover has separating webs, and the carrier has slots, each of which is arranged such that after connecting the carrier to the chip protection cover, the separating webs are arranged in the slots and thereby form the chamber system.

[0014] The separating bars on the chip protection cover and the matching slots in the carrier simplify the installation of the chip protection cover on the carrier and also create the desired chamber system. No additional method is required to attach the separating bars to the carrier because the separating bars already form the chambers thanks to the slots. Furthermore, this geometry does not require an absolutely leak-proof housing because the penetrating oil can be used to flush the interior of the chamber, allowing any particles present to be flushed out of the chamber along with the draining oil. Because the individual circuit board bars are separated from one another by the separating bars, no conductive connection can be established between the electrical contacts on the circuit board bars, thus preventing short circuits.

[0015] In order to avoid short circuits between the partition walls and the electrical contacts, which could be caused by particles or deposits extending from the partition walls to the circuit board lands, the partition walls are preferably made of an electrically insulating material such as a plastic.

[0016] According to the invention, the carrier has a stranded wire guide which is formed and aligned in such a way that stranded wires can be guided through the stranded wire guide from the outside into the chip protection in order to be contacted with the associated printed circuit board webs.

[0017] The wire guide can have different geometries depending on the application. For example, the wire guide can be round or polygonal; it can also be a slot or another type of opening through which a wire can be inserted. The only thing to note here is that the opening has the right shape for the respective wire and is as small as possible, thus ensuring that there is little free space between the inserted wire and the support.

[0018] On the one hand, the wire guide facilitates positioning of the circuit board on the carrier, since each wire guide must preferably be positioned on or above a corresponding circuit board land to establish an electrically conductive contact. On the other hand, as part of the chip protection housing, the wire guide provides a certain degree of external sealing of the chamber to limit the ingress of particles.

[0019] The stranded wires can be attached to the PCB bridges using conventional methods, such as soldering, bar soldering, etc., or other methods. It is important that an electrical connection is established between the stranded wire and the PCB bridge.

[0020] In a further embodiment, the chip protection additionally comprises a base carrier to which the carrier with the circuit board is fastened. By providing a base carrier, the carrier with the circuit board can be additionally protected from its underside against particles and oil. The base carrier is fastened to the carrier. The fastening can be carried out using various methods known to those skilled in the art. In order to achieve the object of the invention, it is not necessarily necessary to provide a base carrier, since the combination of circuit board, carrier, and chip cover already provides a chamber system that prevents short circuits between adjacent circuit board webs caused by particles or deposits.

[0021] In a further embodiment, the printed circuit board has at least one positioning aid for positioning the printed circuit board on the carrier. The positioning aid can be a notch made in the printed circuit board, for example, by milling or another material-removing method. However, a hole or a snap-in element attached to the printed circuit board can also be used as a positioning aid. The only important thing is that the positioning aid is attached in such a way that the printed circuit board can be attached to the carrier in the intended position. In addition, the carrier can also have a counterpart to the positioning aid arranged on the printed circuit board or, alternatively, have a positioning aid instead of the printed circuit board. The printed circuit board can then have a corresponding counterpart.

[0022] In addition, according to the invention, a transmission control unit is provided with at least one chip protection device for printed circuit boards arranged thereon.

[0023] In all embodiments, the chip guard can have a different number of PCB lands, strands, and strand guides. The number depends on the specific application, with the principle of chamber formation applying to any number of PCB lands, strands, and strand guides.

[0024] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, which illustrate details of the invention, and from the claims. The individual features can be implemented individually or in combination in a variant of the invention.

[0025] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. They show: Fig. 1a to 1c show the structure of a chip guard according to an embodiment of the present invention. Fig. 2a to 2c show detailed sections of the chip guard according to an embodiment of the present invention.

[0026] In the following descriptions of the figures, the same elements or functions are provided with the same reference symbols.

[0027] Fig. Figure 1a shows a printed circuit board 1 according to the invention, which is slotted and thus has printed circuit board webs 11, via which electrical contact with stranded wires is made. It also shows Fig. 1a shows an exemplary positioning aid 12 in the form of a notch on both sides of the circuit board 1.

[0028] Fig. Figure 1b shows a partially assembled chip protection device 100. Here, the printed circuit board 1 is already mounted on the carrier 2. Through the wire guide 22, stranded wires 23 are already attached, which are electrically connected to the respective printed circuit board bridges 11 inside the almost finished housing. In addition, Fig. 1b shows a base support 5, which protects the chip guard from below against particles. Furthermore, a chip guard cover 3 with separating webs 31 is shown, which must be applied to the support 2 to form the chamber system according to the invention with one chamber 4 per combination of conductor track web 11 and separating web 31, which in Fig. 2a to 2c is shown in more detail.

[0029] Fig. Figure 1c shows the fully assembled chip protection for printed circuit boards according to the present invention. Here, the chip protection cover 3 is now attached to the carrier 2 and, together with the carrier 2 and the base carrier 5, forms a housing that prevents the penetration of disruptive particles. The open geometry allows oil to penetrate into the individual chambers and then flow out again, thereby preventing deposits and allowing particles that have penetrated into the chambers to be flushed out. The chambers prevent a conductive connection from forming between the individual circuit board lands, so that the open geometry, unlike other known housings, does not present a disadvantage but rather the advantage of flushing.

[0030] Fig. Figure 2a shows a top view of a chip protector 100 according to an embodiment of the invention. Here, the chip protector cover 3 is mounted, but the cover is drawn transparent to provide a view from above, showing how the mounting or positioning of the circuit board 1 on the carrier 2 takes place. Details are described in Fig. 2b and Fig. 2c, which shows the detail C as shown in Fig. 2a shown, enlarged.

[0031] Fig. 2b shows a detail C from Fig. 2a, which shows the chambers 4 formed by the slots 21 of the carrier 2 and the separating webs 31 of the chip protection cover 3 inserted into the slots 21. Each chamber 4 contains a printed circuit board web 21 and a stranded wire 23 arranged thereon and electrically connected thereto. The stranded wire 23 is positioned precisely on or above the printed circuit board web 21 via the stranded wire guide 22, so that no further adjustment is necessary.

[0032] Fig. 2c also shows a detail C from Fig. 2a, which shows the geometry of the carrier 2, especially the slots 21 provided on the carrier 2, for inserting the separating webs 31 of the chip protection cover 3. The slots 21 are arranged such that they separate the individual stranded wire guides 22 and printed circuit board webs 21 from each other, thus forming a chamber system in which no short circuits can occur between individual printed circuit board webs 21 due to deposits or particles.

[0033] The present invention provides a compact and cost-effective chip protection for printed circuit boards, in which short circuits between two adjacent printed circuit board lands can be prevented in a simple and effective manner. Reference symbol 100 chip protection 1 circuit board 11 PCB bridges 12 Positioning aid 2 carriers 21 slots 22 strand guide 23 strands 3 chip protection covers 31 dividers 4 chamber 5 base supports C Detail section

Claims

[1] Chip protection (100) for printed circuit boards, comprising - a printed circuit board (1) which is slotted at one end in such a way that it has printed circuit board webs (11), - a carrier (2) which is designed to at least partially receive the printed circuit board (1), and - a chip protection cover (3) which is designed to be connected to the carrier (2) and the printed circuit board (1) in such a way that a chamber system is formed in which each printed circuit board web (11) is arranged within a chamber (4) which is formed by the connection between the carrier (2) and the chip protection cover (3), and - carrier (2) has a stranded wire guide (22) which is formed and aligned in such a way that strands (23) can be guided through the stranded wire guide (22) from the outside into the chip protection (100) in order to be contacted with the associated printed circuit board webs (11). [2] Chip protection (100) for printed circuit boards according to claim 1, characterized bythat the chip protection cover (3) has separating webs (31) and the carrier (2) has slots (21), which are each arranged such that after connecting the carrier (2) to the chip protection cover (3) the separating webs (31) are arranged in the slots (21) and thereby form the chamber system. [3] Chip protection (100) for printed circuit boards according to claim 2, characterized by that the carrier (2) and the separating webs (31) consist of an electrically insulating material. [4] Chip protection (100) for printed circuit boards according to one of the preceding claims, characterized by that the chip protection (100) additionally has a base support (5) on which the support (2) with the circuit board (1) is fastened. [5] Chip protection (100) for printed circuit boards according to one of the preceding claims, characterized by that the printed circuit board (1) has at least one positioning aid (12) for positioning the printed circuit board (1) on the carrier (2). [6] Chip protection (100) for printed circuit boards according to one of claims 1 to 5, characterized by that the carrier (2) has at least one positioning aid (12) for positioning the printed circuit board (1) on the carrier (2). [7] Transmission control unit with at least one chip protection (100) for printed circuit boards arranged thereon according to one of the preceding claims.

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