DE102018204356A1 - Seals directly on the circuit board - Google Patents

Abstract

Manufacturing method for an electronic module for vehicles, comprising at least one circuit carrier (6) and at least one electronic component (2), - wherein the at least one circuit carrier (6) and the at least one electronic component (2) partially or completely in a housing (1 ), wherein at least one electrical conductor (4, 5) through a housing wall of the housing (1) from the interior of the housing (1) is guided on an outer side of the housing, wherein the at least one guided through the housing wall electrical conductor ( 4, 5) at least at one contact point (20) with the circuit carrier (6) is contacted directly and / or indirectly electrically, wherein the circuit carrier (6) at least a first circumferential structure (8, 9, 10, 11, 17, 18, 21, 22, 23) around the contact point (20) for sealing.

Description

The present invention relates to a manufacturing method for an electronic module according to the preamble of claim 1 and an electronic module according to the preamble of claim 12.

According to the prior art, it is known to surround electrical conductors for protection against mechanical damage as well as against environmental influences with a housing. It is also known that the interior of the housing, in which the electrical conductor is arranged, partially or completely filled with a potting, to make the protection even further. It is also known to enclose the electrical conductor with a protective layer, so that the electrical conductor is even better shielded from environmental influences. This protective layer is used for the oxidation or corrosion of the conductor surface and is also required to prevent other, known in the art in this context, negative effects.

The publication WO 2015/124 647 discloses an electronic module in which a protective layer of a conductor is at least partially removed by means of a laser. By removing the protective layer, a better bond between the potting and the conductor is made.

The object of the invention is to provide an electronic module which meets the high requirements in terms of tightness and / or robustness and / or is inexpensive to produce.

This object is achieved by the method according to claim 1 and the electronic module according to claim 12.

It is preferred that the contact point is not formed on a shunt, in particular not on a shunt of a battery sensor or current sensor.

It is preferred that the at least first circumferential structure is generated on the circuit carrier around the contact point for sealing.

The electronic module is preferably designed as a battery sensor and / or as a current sensor, in particular for determining a parameter of a vehicle battery and / or a current or load current flowing in and / or out of a vehicle battery.

Preferably, the electrical conductor is contacted at or with the contact point indirectly by means of a pin and / or an electrically conductive connecting element.

It is expedient that the electronic module in the interior of the housing has an interior, which is in particular partially or completely filled or encapsulated by the housing and / or a sealing compound.

It is preferred to seal critical paths for leaks. Uncritical paths are, in particular, those paths which have no direct connection, particularly preferably no direct metal and / or plastic connection, to the outside or through the housing. Critical paths are in particular all parts, particularly preferably all overmolded parts, which lead from the circuit carrier, directly and / or indirectly, to the outside or through the housing. For example, critical paths are designed as busbars or device plug.

Expediently, one or more peripherally closed structures are applied to the circuit carrier and / or incorporated into the circuit carrier.

The at least one circumferential structure is preferably formed as a rib or as a trench or as a roughened area. In particular, rib is to be understood as a dam.

It is preferred that the material properties are uniform within a circumferentially closed structure.

It is preferred that the material properties of different circumferentially closed structures, in particular around a contact point, differ from one another. This has the particular advantage that a layout of circumferentially closed structures can be used universally, for example for different overmolding materials.

For example, the circumferentially closed structure may have the material properties of solder resist, copper, tinned copper or solder with solder resist.

Preferably, one or more of the peripherally closed structures are formed by laser treatment, in particular uniformly, or modified or modified with respect to their surface.

The advantage of using a laser is, in particular, that a laser is already used in the production of circuit carriers and / or in the assembly, for example for the inscription of components. Thus, no new production equipment in a production plant is necessary.

It is preferred for at least one encapsulation and / or encapsulation to take place in a region around the contact point for sealing, wherein the encapsulation or the encapsulation is in particular part of the housing.

Preferably, the seal consists at least of a circumferentially closed structure around the contact point and at least one encapsulation and / or at least one encapsulation in a region around the contact point, wherein the encapsulation or encapsulation are in particular part of the housing. For this purpose, in particular, an encapsulation material and / or a potting material or a sealing compound are sprayed and / or cast onto a region on the circuit carrier. The region extends in particular on the surface of the circuit carrier, which is defined by the at least one circumferentially closed structure. In the case of several circumferentially closed structures, the area is particularly preferably defined by the outer peripherally closed structure.

It is particularly preferred to apply only one encapsulation or only one encapsulation to a region on the circuit carrier, wherein the region is then preferably defined by the outer circumferentially closed structure.

Alternatively, particularly preferably, a first encapsulation or a first encapsulation is applied to an area which is defined by the inner encircling closed structure. A second encapsulation or a second encapsulation is applied to a second area, which is defined by the second inner encircling closed structure. This is repeated iteratively until a last encapsulation or a final encapsulation is applied to a last region, which is defined by the outer encircling closed structure. It is waited in particular between the individual encapsulation or encapsulation until the previous encapsulation or the previous encapsulation is dried. Alternatively, a number of encapsulation and / or encapsulation, which deviates from the number of encircling closed structures and one, would also be conceivable. This would have the particular advantage that several peripherally closed structures and / or several encapsulation and / or encapsulation realize higher density and robustness.

It is preferred that at least one of the electrical conductors routed through the housing wall is designed as a measuring resistor, in particular as a measuring resistor or shunt of a current sensor, and in particular the measuring resistor is contacted to the circuit carrier indirectly by means of at least one electrical connecting element, wherein the electronic module is formed so that by means of a measuring device, a measuring voltage across the measuring resistor can be detected.

It is preferred that the at least one encircling closed structure has no edges and / or no corners and / or rounded corners and / or is formed circular and / or oval-shaped, in particular with respect to the circuit substrate level.

Preference is given to symmetrical as well as asymmetrical peripherally closed structures.

It is preferred that a sealing takes place by applying and / or incorporating a plurality of peripherally closed structures around the contact point onto or into the circuit carrier. In this case, the application and / or incorporation is carried out such that the structures have at least partially different material properties, in particular with respect to an adhesive strength.

It is preferred that at least one circumferentially closed structure is produced by a laser treatment, in particular by roughening and / or cleaning the surface of the circuit substrate around the contact point and / or removing material.

It is preferred that the housing is formed or a sealing compound is introduced into the housing such that the housing or the sealing compound engages in a form-fittingly sealing manner in the at least one peripheral structure or in one or more of the peripheral structures.

Preferably, the circuit carrier is a printed circuit board, in particular a printed circuit board.

The circuit carrier is preferably an injection-molded circuit carrier.

The circuit carrier is preferably a ceramic circuit carrier.

It is preferred that the circuit carrier has a plurality of layers and thus is a multilayer circuit carrier.

It is preferred that the at least one electronic component is a surface-mounted electronic component.

It is preferred that the at least one electronic component is a wired electronic component.

It is preferred that the contacting of the electrical conductor with the circuit carrier takes place by means of a printed circuit board hole or in the form of a plated-through hole. Advantageously, the wiring on the circuit carrier in one of continued inner layers in order not to disturb in particular the circumferentially closed structures by a wiring line.

It is expedient that the contacting of the electrical conductor with the circuit carrier by means of a pad. Advantageously, the pad or a location in the immediate vicinity of a via, which continues the wiring in one of the inner layers. This plated-through hole lies in particular within the first circumferentially closed structure. The via may also be within the pad as long as it does not adversely affect the bonding process.

It is expedient that the housing is realized by an encapsulation of the at least one circuit carrier and the at least one electronic component with a thermoset and / or a thermoplastic.

By thermoplastic is meant in particular a plastic which can be deformed in certain temperature ranges.

Preferably, a Erstumspritzung with a thermoset, wherein in the Erstumspritzung in particular an existing measuring resistor is encapsulated. In a Zweitumspritzung the entire electronic module can be encapsulated with a thermoplastic.

Alternatively, it is preferred that the housing is realized by an encapsulation of the at least one circuit carrier and the at least one electronic component with a hotmelt.

Hotmelt should be understood as meaning, in particular, solvent-free products which are essentially solid at room temperature and which are applied to the adhesive surface when hot and which produce a firm connection upon cooling.

It is preferred that encapsulation occurs at least around the at least one electrical conductor.

It is preferred that the at least one electrical conductor is encapsulated, in particular an overmolded busbar or an overmolded device plug. Preferably, the circuit board is encapsulated in a Erstumspritzung with a thermoset. Subsequently, the entire electronic module with a Zweitumspitzung, in particular of a thermoplastic, overmolded, wherein de Zweitumspritzung encapsulates the Erstumspritzung and an optionally existing measuring resistor.

The electronic module is preferably designed as a sensor or as part of a sensor.

The electronic module is particularly preferably designed as a battery sensor or as part of a battery sensor, in particular for motor vehicles. For this battery sensor expediently comprises a battery terminal for connection and for attachment to the pole of a vehicle battery.

Advantageous embodiments can be taken, for example, the dependent claims. The content of the claims is made by express reference to the content of the description.

Further preferred embodiments will become apparent from the following description of exemplary embodiments with reference to figures.

• 1 Seitenansicht eines Ausführungsbeispiels der erfindungsgemäßen Abdichtung der elektrischen Leiter an dem Schaltungsträger,
• 2 Draufsicht des Ausführungsbeispiels der erfindungsgemäßen Abdichtung der elektrischen Leiter an dem Schaltungsträger,
• 3 Detailansicht zweier beispielhafter Abdichtungen, jeweils aufweisend zwei umlaufend geschlossene Strukturen, und
• 4 Detailansicht einer beispielhaften Abdichtung, aufweisend mehrere Strukturen, welche unterschiedliche Materialeigenschaften aufweisen.

In a schematic representation show:

• 1 Side view of an embodiment of the inventive sealing of the electrical conductors on the circuit board,
• 2 Top view of the embodiment of the inventive sealing of the electrical conductors to the circuit board,
• 3 Detail view of two exemplary seals, each having two circumferentially closed structures, and
• 4 Detailed view of an exemplary seal comprising a plurality of structures having different material properties.

1 shows an electronic module. The electronic module has three electronic components 2 on which on a circuit carrier 6 are arranged. The electronic components 2 and the circuit carrier 6 be from a housing 1 includes. In addition, the electronic module has a busbar 4 on that over pins 3 at contact points 20 on the circuit carrier 6 is contacted. Furthermore, there are two external connections 5 at contact points 20 on the circuit carrier 6 contacted. The two external connections 5 and the busbar 4 , including the pins 3 , each represent an electrical conductor passing through a housing wall of the housing 1 from the interior of the housing 1 on an outside of the case 1 to be led. Directly at or around the contact points 20 at which the electrical conductor and the circuit carrier 6 electrically contacted with each other, there is a seal.

2 shows a plan view of the in from 1 shown in side view embodiment. The cutout 7 from 2 is in 3 shown in detail and shows the two external connections 5 ,

The first external connection 5 is at the contact point 20 with the circuit carrier 6 electrically by means of a via 12 implemented in the circuit carrier, which is also known as push-through mounting. The wiring will be on the circuit carrier 6 , which is multi-layered, continued in an inner layer around the circumferentially closed structures 8th . 9 on the circuit carrier, for example, not to be disturbed by a copper line. The contact point 20 becomes circumferential around the feedthrough 12 of a first and a second closed structure 8th . 9 includes. The first circulating closed structure 8th lies within the second circumferentially closed structure 9 , Both structures have a rectangular shape whose corners are rounded.

The second external connection 5 is at the contact point 20 with the circuit carrier 6 electrically by means of a pad 13 implemented in the circuit carrier, which is also known as surface mounting. Inside the pad 13 there is a via which connects the line to one of the inner layers of the circuit carrier 6 sets. As a result, the circumferentially closed structures 10 . 11 on the circuit carrier 6 For example, not disturbed by a copper line. The contact point 20 is circulating around the pad 13 of a first and a second closed structure 10 . 11 includes. The first circulating closed structure 10 lies within the second circumferentially closed structure 11 , Both structures 10 . 11 have a circular shape.

4 shows a seal of a pad connection 14 comprising several circumferentially closed structures 17 . 18 . 21 . 22 . 23 , The pad connection 14 is from a first circumferentially closed structure 17 surrounded by solder mask. An electrical conductor 15 connects the pad 14 electrically with a via 16 that are outside the first circumscribed closed structure 17 lies. The electrical conductor 15 is at an outermost layer of the circuit substrate 6 below the first circumferentially closed structure 17 guided. The via 16 leads the electrical trace 15 in one of the inner layers of the circuit substrate 6 , The pad 14 , the electrical conductor, the first structure 17 and the via 16 be from a second circumscribed closed structure 18 consisting of solder mask comprises. The second structure 18 is from a third circumscribed closed structure 21 consisting of copper with tin plating, or alternatively, for example, consisting of pure copper, surrounded. A fourth circumferentially closed structure 22 made of copper and solder mask-free area, which has been specially treated, for example, was roughened by means of a laser, enclosing the third structure 21 , The fourth structure 22 is from a fifth circumferentially closed structure 23 surrounded by copper and solder mask. Between the individual structures 17 . 18 . 21 . 22 . 23 the surface of the circuit substrate has an area 19 on, which is free of solder mask and free of copper. A surface around the contact 20 including the circumferentially closed structures 17 . 18 . 21 . 22 . 23 is preferably with a material, such as plastic, molded and / or encapsulated. At least one of the structures 17 . 18 . 21 . 22 . 23 should be designed so that a permanently tight connection between injection and / or encapsulation is ensured with the circuit carrier.

If, in the course of the procedure, it turns out that a feature or a group of features is not absolutely necessary, it is already desired on the applicant side to formulate at least one independent claim which no longer has the feature or the group of features. This may, for example, be a subcombination of a claim present at the filing date or a subcombination of a claim limited by further features of a claim present at the filing date. Such newly formulated claims or feature combinations are to be understood as covered by the disclosure of this application.

It should also be noted that embodiments, features and variants of the invention, which are described in the various embodiments or embodiments and / or shown in the figures, can be combined with each other as desired. Single or multiple features are arbitrarily interchangeable. Resulting combinations of features are to be understood as covered by the disclosure of this application.

Recoveries in dependent claims are not to be understood as a waiver of obtaining independent, objective protection for the features of the dependent claims. These features can also be combined as desired with other features.

Features that are disclosed only in the specification or features that are disclosed in the specification or in a claim only in conjunction with other features may, in principle, be of independent significance to the invention. They can therefore also be included individually in claims to distinguish them from the prior art.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/124647 [0003]

Claims (12)

Manufacturing method for an electronic module for vehicles, comprising at least one circuit carrier (6) and at least one electronic component (2), - wherein the at least one circuit carrier (6) and the at least one electronic component (2) partially or completely in a housing (1 ), wherein at least one electrical conductor (4, 5) through a housing wall of the housing (1) from the interior of the housing (1) is guided on an outer side of the housing, wherein the at least one guided through the housing wall electrical conductor ( 4, 5) is contacted electrically and / or indirectly electrically at least at one contact point (20) with the circuit carrier (6), characterized in that the circuit carrier (6) has at least one first circumferential structure (8, 9, 10, 11, 17 , 18, 21, 22, 23) around the contact point (20) for sealing. Production method according to Claim 1 , characterized in that for sealing at least one, in particular a plurality of peripherally closed structure (8, 9, 10, 11, 17, 18, 21, 22, 23) around the contact point (20) applied to the circuit carrier (6) and / or incorporated in the circuit carrier (6). Manufacturing method according to at least one of the preceding claims, characterized in that the at least one circumferential structure (8, 9, 10, 11, 17, 18, 21, 22, 23) is formed as a rib or as a trench or as a roughened area. Manufacturing method according to at least one of the preceding claims, characterized in that for sealing at least one encapsulation and / or at least one encapsulation in a region around the contact point (20), wherein the encapsulation or encapsulation is in particular part of the housing. Manufacturing method according to at least one of the preceding claims, characterized in that at least one of the housing wall guided by the electrical conductor (4) is designed as a measuring resistor, in particular as a measuring resistor of a current sensor is formed, and in particular the measuring resistor (4) with the circuit carrier (6). is contacted indirectly by means of at least one electrical connection element, wherein the electronic module is formed so that by means of a measuring device, a measuring voltage across the measuring resistor (4) can be detected. Manufacturing method according to at least one of the preceding claims, characterized in that the at least one circumferentially closed structure (8, 9, 10, 11, 17, 18, 21, 22, 23) has no edges and / or no corners and / or rounded corners and / or circular and / or oval-shaped, in particular with respect to the circuit substrate level. Manufacturing method according to at least one of the preceding claims, characterized in that a seal is achieved by application and / or incorporation of a plurality of circumferentially closed structures (8, 9, 10, 11, 17, 18, 21, 22, 23) around the contact point (20). on and / or in the circuit carrier (6), wherein the application and / or incorporation is performed such that the structures (8, 9, 10, 11, 17, 18, 21, 22, 23) at least partially different material properties, especially with respect to an adhesive strength. Manufacturing method according to at least one of Claims 2 to 7 , characterized in that at least one circumferentially closed structure (8, 9, 10, 11, 17, 18, 21, 22, 23) is generated by a laser treatment, in particular by the surface of the circuit substrate roughened around the contact point and / or cleaned and / or removed material. Manufacturing method according to at least one of the preceding claims, characterized in that the housing is formed or a sealing compound is introduced into the housing so that the housing or the sealing compound engages positively locking the at least one circumferential structure or in one or more of the circumferential structures , Manufacturing method according to at least one of the preceding claims, characterized in that the circuit carrier (6) is a printed circuit board, in particular a printed circuit board. Manufacturing method according to at least one of the preceding claims, characterized in that the at least one electronic component (2) is a surface-mounted electronic component and / or a wired electronic component. Electronic module for vehicles, comprising at least one circuit carrier (6) and at least one electronic component (2), wherein the at least one circuit carrier (6) and the at least one electronic component (2) are partially or completely surrounded by a housing (1), - wherein the at least one circuit carrier (6) and the at least one electronic component (2), in particular at least partially, in the interior or in an interior of the housing (1) are arranged, wherein at least one electrical conductor (3, 4, 5) through a housing wall of the housing (1) from the interior or the interior of the housing (1) on an outer side the housing (1) is guided, wherein the at least one guided through the housing wall electrical conductor (3, 4, 5) at least at one contact point (20) with the circuit carrier (6) directly and / or indirectly contacted, characterized in that the circuit carrier (6) has at least one first circumferential structure (8, 9, 10, 11, 17, 18, 21, 22, 23) around the contact point (20) for sealing.

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