PRINTED CIRCUIT BOARD, TRANSMISSION CONTROLLER WITH A PRINTED CIRCUIT BOARD, AND METHOD FOR PRODUCING A PRINTED CIRCUIT BOARD

Abstract

The disclosure relates to a printed circuit board with a printed circuit board core which has an upper face. A metallization layer is formed on at least some sections of the upper face. The metallization layer includes at least one first region and a second region which differs from the first region. An electric module is arranged on the first region and is connected to same in an electrically conductive manner, the second region is arranged and/or formed at a distance to the first region, and the second region surrounds and/or borders the first region. The electric module is encapsulated with a sealing material, where the encapsulation is delimited by the second region.

Claims

1. A printed circuit board comprising: a printed circuit board core having an upper face; a metallization layer being formed on at least some sections of the upper face, the metallization layer comprising at least one first region and a second region which differs from the first region; and an electric module arranged on the first region and is connected to same in an electrically conductive manner; wherein the second region is arranged and/or formed at a distance to the first region, and the second region surrounds and/or borders the first region, and wherein the electric module is encapsulated with a sealing material, wherein the encapsulation is delimited by the second region.

2. The printed circuit board of claim 1, wherein a material thickness of the first region of the metallization layer in a direction perpendicular to the plane of the printed circuit board core corresponds to a material thickness of the second region of the metallization layer in the direction perpendicular to the plane of the printed circuit board core.

3. The printed circuit board of claim 2, further comprising: a solder resist coating arranged on the upper face of the printed circuit board core, the solder resist coating is led as far as an outer border of the second region, the outer border is formed on a side of the second region facing away from the first region, and wherein a material thickness of the solder resist coating in a direction perpendicular to the plane of the printed circuit board core is greater than the material thickness of the second region.

4. The printed circuit board of claim 1, wherein the solder resist coating is led as far as an inner border of the second region facing the first region, and the solder resist coating covers the second region.

5. The printed circuit board of claim 1, wherein the second region is spiral-shaped and/or helical.

6. The printed circuit board of claim 1, wherein the second region comprises a plurality of spaced-apart second regions.

7. The printed circuit board of claim 1, wherein the printed circuit board core has a lower face which is arranged at a distance from the upper face and, correspondingly to the upper face, has a metallization layer with a first region and a second region, wherein an electric module is arranged on the first region, and the electric module is encapsulated with a sealing material, wherein the encapsulation is bounded by the second region.

8. The printed circuit board of claim 1, wherein the printed circuit board core is multi-layered.

9. A transmission controller for a motor vehicle comprising a printed circuit board of claim 1.

10. A method for producing a printed circuit board, the method comprising: providing a circuit board core, wherein the printed circuit board core has an upper face; providing a metallization layer arranged on the upper face; structuring the metallization layer so that a first region and a second region of the metallization layer, which is different from the first region and galvanically isolated therefrom, are formed on the upper face, and the first region surrounds and/or borders the second region; arranging and electrically contacting an electric module on the first region; arranging the printed circuit board core into an overmolding tool and closing the overmolding tool, wherein the overmolding tool seals with the second region; encapsulating and/or overmolding the electric module with a sealing material and/or sealant; opening the overmolding tool; and removing the printed circuit board.

Description

DESCRIPTION OF DRAWINGS

[0027] FIG. 1 shows a cross-section through an exemplary printed circuit board,

[0028] FIG. 2 shows a plan view of the exemplary printed circuit board,

[0029] FIG. 3 shows a cross-section through an overmolding tool with the printed circuit arranged therein,

[0030] FIG. 4 shows a cross-section through the exemplary printed circuit board with an encapsulation in at least some sections,

[0031] FIG. 5 shows a cross section through an exemplary printed circuit board,

[0032] FIG. 6 shows a cross-section through the exemplary printed circuit board with an encapsulation in at least some sections,

[0033] FIG. 7 shows a cross section through an exemplary printed circuit board,

[0034] FIG. 8 shows a plan view of the exemplary printed circuit board.

[0035] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0036] FIG. 1 shows a cross-section through a printed circuit board 10, for example, for a transmission controller of a motor vehicle. The printed circuit board 10 has a multi-layer circuit board core 12 with an upper face 14 and a lower face 16 arranged at a distance from the upper face 14. Both the upper face 14 and the lower face 16 are oriented and/or formed in a direction parallel to the plane of the printed circuit board core 12. Between the upper face 14 and the lower face 16, the printed circuit board core 12 has a plurality of spaced-apart conductive tracks (not shown) that may be electrically conductively connected to each other by way of vias and/or through-platings. Usually, the printed circuit board core 12 is formed from a prepreg.

[0037] On the upper face 14 and on the lower face 16, the printed circuit board core 12 has, at least in some sections, a metallization layer 18 which is electrically conductive. The metallization layer 18 may include and/or be formed from aluminum, copper and/or silver, at least in part. In this example, the metallization layer 18 is formed from copper.

[0038] The metallization layer 18 has a first region 20 and a second region 22 different from the first region 20. The first region 20 and the second region 22 of the upper face 14 and lower face 16 are galvanically isolated from each other. In other words, the first region 20 and the second region 22 are arranged electrically non-conductively with respect to each other on the respective upper face 14 or lower face 16. An electric module 24 is arranged on the first region 20 and is electrically conductively connected thereto. The electrical connection to the first region 20 of the metallization layer 18 and the electric module 24 can be, for example, an integrally bonded connection, such as an adhesive connection, a bonded connection, a sintered connection and/or a soldered connection. The electric module 24 may be a MOSFET, an IGBT, an ASIC and/or a sensor, such as a sensor dome.

[0039] The second region 22 is arranged and/or formed in a spaced manner relative to the first region 20, where the second region 22 surrounds and/or borders the first region 20. Presently, a plurality of first regions 20 are arranged on the upper face 14, which is surrounded by the second region 22.

[0040] Further, it is apparent that a material thickness of the first region 20 of the metallization layer 18 in a direction perpendicular to the plane of the printed circuit board core 12 corresponds to a material thickness of the second region 22 of the metallization layer 18 in the direction perpendicular to the plane of the printed circuit board core 12. In other words, the first region 20 and the second region 22 have an equal material thickness. The first region 20 and the second region 22 are preferably formed by the metallization layers 18 formed on the upper face 14 and the lower face 16 of the printed circuit board core 12 by a material-removing process, such as a chemical removal process such as an etching process. Thus, the first region 20 and the second region 22 can be cost-effectively fabricated in a simple manner and have the same material thickness.

[0041] FIG. 2 shows a plan view of the printed circuit board 10. The circuit board core 12 has the plurality of first regions 20 surrounded by the second region 22 on the upper face 14. Accordingly, the second region 22 is formed circumferentially.

[0042] FIG. 3 shows a cross-section through an overmolding tool 26 with the printed circuit board 10 arranged therein. The overmolding tool 26 can also be referred to as an encapsulation tool. It has at least one upper tool half 28 and a lower tool half 30. The printed circuit board 10 is arranged between the two tool halves 28, 30. For encapsulation of the printed circuit board 10, the tool halves 28, 30 have corresponding recesses 32 and/or returns on a side facing the printed circuit board 10.

[0043] The upper tool half 28 sits on the lower tool half 30 and on the upper face 14 of the printed circuit board core 12. In this regard, a first surface 34 surrounding the recess 32 of the upper tool half 28 seals with the second region 22 of the metallization layer 18. The cavity formed between the upper face 14 and the recess 32 of the upper tool half 28 is potted and/or overmolded with a sealing material 36, for example a plastic, such as an epoxy-based thermoset.

[0044] Correspondingly to the upper face 14, the lower tool half 30 sits on the upper tool half 28 and on the lower face 16 of the printed circuit board core 12, where a second surface 38 surrounding the recess 32 of the lower tool half 30 seals against the second region 22 of the lower face 16. The cavity formed between the lower face 16 and the recess 32 is potted or overmolded with the sealing material 36.

[0045] The first surface 34 of the upper tool half 28 surrounding the recess 32 and the second surface 38 of the lower tool half 30 are formed without protrusions. In other words, the upper tool half 28 and the lower tool half 30 do not have any protrusion on their side facing the printed circuit board 10 for sealing with the printed circuit board 10 for an encapsulation process and/or overmolding process. In this way, an encapsulation of the printed circuit board 10 that is material-friendly can be made possible. Likewise, damage to the printed circuit board 10 as a result of the encapsulation and/or overmolding process can be reduced.

[0046] FIG. 4 shows a cross-section through the printed circuit board 10 shown in FIG. 3 after the printed circuit board 10 has been at least partially encapsulated. The sealing material 36 is led as far as and/or is delimited by the second region 22, since the overmolding tool 26 shown in FIG. 3 seals against the second region 22. Accordingly, the printed circuit board 10 has a barrier formed on the upper face 14 and on the lower face 16 in the form of a metallization layer 18, which is generally arranged on both the upper face 14 and the lower face 16 of the printed circuit board core 12 anyway. Accordingly, no additional structure in the form of a dam structure built onto the upper face 14 or lower face 16 of the printed circuit board 10 is required to provide a seal for encapsulating the electric modules 24. Thus, by having the second region 22 of the metallization layer 18 formed on the upper face 14 or lower face 16 of the printed circuit board core 12 and surrounding the first region 20 in a spaced-apart manner, a sealing structure for the overmolding process can be provided cost-effectively. The costs of the printed circuit board 10 can thus be reduced, since only the metallization layer 18 arranged on the upper face 14 and lower face 16 of the printed circuit board core 12 is structured in such a way that it forms a sealing contour. By at least partially encapsulating the printed circuit board 10, a printed circuit board 10 protected against external, corrosive media, such as oil and/or water, can be provided.

[0047] FIG. 5 shows a cross-section through the printed circuit board 10 in another example. In contrast to the first example, in the second example a solder resist coating 40 or a solder resist layer formed of an electrically insulating material is arranged on the second region 22. In other words, the solder resist coating 40 is led as far as and surrounds an inner border of the second region 22. The inner border faces the first region 20. The second region 22 is covered by the solder resist coating 40. The solder resist coating 40 has an at least partially yielding and/or elastic property. Thus, as the encapsulation tool and/or overmolding tool 26 drives onto and seals against the second region 22, a slight deformation of the solder resist coating 40 may occur between the metallization layer 18 and the overmolding tool 26, such that an increased seal may be enabled between the metallization layer 18 of the second region 22 and the overmolding tool 26. Thus, an increased seal can be achieved during the overmolding process.

[0048] FIG. 6 shows a cross-section through the printed circuit board 10 shown in FIG. 5 after the printed circuit board 10 has been at least partially overmolded. The sealing material 36 is led as far as and/or is delimited by the solder resist coating 40 arranged on the second region 22.

[0049] FIG. 7 shows a cross-section through the printed circuit board 10 in a third example. Here, it is provided that the second region 22 of the upper face 14 is formed differently from the second region 22 of the lower face 16. The second region 22 of the lower face 16 has a plurality of spaced-apart second regions 22, which are galvanically isolated from each other and are formed circumferentially. The plurality of adjacently arranged second regions 22 can increase the deformability of the metallization layer 18 when the encapsulation tool or overmolding tool 26 is driven onto the printed circuit board 10, and may also increase a path between the overmolding tool 26 and the printed circuit board 10 in the mounting region to further extend the path for escaping material. The sealing effect of the printed circuit board 10 to the overmolding tool 26 can thus be increased.

[0050] FIG. 8 shows a plan view of the lower face 16 of the printed circuit board 10 with the second regions 22 arranged adjacently and formed circumferentially. The first regions 20 are not shown in the plan view.

[0051] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.