Printed circuit board with a housing part

Abstract

The present invention provides a printed circuit board (100) comprising a substrate (110) having a first side (TOP) and a second side (BOT), at least one metal sheet (120) attached to the second side (BOT) of the substrate (110) by a narrow side and protruding from the second side (BOT) such that a flat side of the metal sheet (120) is exposed relative to the second side (BOT), and a housing part (160) at least partially surrounding the metal sheet (120) and coupled to the metal sheet (120) in a heat-transferable manner.

Description

Field of the Invention

[0001] The present invention relates to a printed circuit board with a housing part. Furthermore, the present invention also relates to a method for manufacturing a printed circuit board with a housing part. Background Art

[0002] Printed circuit boards can be used in various industries, such as industrial electronics, automotive technology, aerospace, etc., and can be used for various technical applications, such as power electronics, signal processing, etc. For example, in the field of power electronics, there are some applications that require components of a printed circuit board (e.g., power semiconductors) to have high current-carrying capacity and / or fast heat dissipation performance. Due to power dissipation, high stacking density of components on the printed circuit board, high clock frequencies, etc., these components will generate heat, so heat dissipation should be carried out frequently.

[0003] For technical applications that require high current-carrying capacity, so-called high-current printed circuit boards can be used, which have conductor tracks with relatively large conductor cross-sections, and the conductor tracks are produced, for example, by means of thick copper technology. Heat can be dissipated through large-sized printed conductors. In addition, there are also heat-conducting pads that can be arranged on the printed circuit board to make contact with the components to be cooled and / or with a metal heat sink. However, high-current printed circuit boards and heat-conducting pads are very costly, so there may be a desire for a printed circuit board with improved thermal management. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a printed circuit board with improved thermal management by means that are as simple as possible in structure.

[0005] This technical problem is solved by the subject matter of the independent claims. Advantageous further embodiments of the present invention are indicated in the dependent claims, the description, and the drawings.

[0006] The first aspect of the present invention relates to a printed circuit board. The printed circuit board comprises:

[0007] a substrate having a flat first side and a flat second side opposite thereto,

[0008] at least one metal sheet attached to the second side of the substrate by its narrow side and protruding from the soldering surface, such that the flat side of the metal sheet is exposed relative to the soldering surface, and

[0009] a housing part at least partially surrounding the metal sheet and connected to the metal sheet in a heat-transferable manner.

[0010] The first side can also be understood, for example, as the flat side, the upper side, or, if necessary, the assembly side. The term second side can also be understood, for example, as the bottom side or the soldering side. In this case, these names can be understood in a broad sense and can in principle be used to distinguish between the first flat side and the second flat side of the printed circuit board. The printed circuit board can also be assembled on both sides. If necessary, the printed circuit board can also be formed from multiple substrates in multiple layers.

[0011] The metal sheet can be made of a thermally conductive and / or electrically conductive material, such as copper material, copper alloy, aluminum material, aluminum alloy, or other suitable metal materials. For example, its thickness or specification can range from about 0.2 mm to about 2.5 mm, preferably from about 0.5 mm to about 2 mm, and more preferably from about 1 mm. In addition, the metal sheet can protrude from the printed circuit board, especially from its soldering surface, in the manner of a heat sink, and expose the flat side as a kind of contact surface to the environment. Furthermore, depending on the intended use or technical application, the size of the metal sheet protruding from the printed circuit board can vary, for example, from about 10 mm to about 120 mm, preferably from about 20 mm to about 100 mm, and particularly preferably from about 40 mm to about 50 mm.

[0012] The housing part can be made of a base material different from that of the metal sheet, that is, made of a material different from the metal material. In addition, the housing part can be the only part of the housing of the printed circuit board, especially the surrounding housing (Umgehaeuse). However, the housing part can also be one of the multiple housing parts that together form the housing of the printed circuit board, especially the surrounding housing.

[0013] The heat transfer coupling can use one or more heat transfer modes, such as heat conduction, convection, and radiation. Preferably, at least most of the heat can be transferred through heat conduction, that is, by mechanically coupling the metal sheet and the housing part.

[0014] The printed circuit board according to the present invention allows for improved thermal management. The size of the metal sheet can be changed to provide a larger surface area for heat conduction. In addition, the metal sheet can also simultaneously serve as a printed wire or electrical conductor. Therefore, different from the large-current printed circuit board using thick copper technology, it can provide a particularly large cross-section for both heat conduction and current conduction. In addition, due to its simple design and simple manufacturing, the printed circuit board can be provided at a particularly low cost.

[0015] According to an improvement, the housing part can be made of plastic. Preferably, the plastic is thermally conductive. The plastic is suitable for manufacturing by injection molding and can be freely formed if necessary. In some embodiments, the plastic can be a composite material or compound that has, for example, PA, PBT, PP, PPS, PEEK, etc. as the base polymer and is thermally conductive through appropriate fillers. Thus, the printed circuit board can be easily equipped with a plastic housing that also has a heat dissipation effect.

[0016] In an improvement, the housing part can have at least one outer contact surface for heat transfer to the environment, and the outer contact surface can be substantially parallel to the flat side of the metal sheet. Here, heat transfer can occur from the flat side of the metal sheet to the environment through thermal coupling and the housing part.

[0017] According to an improvement, the housing part can have ribbed protrusions for receiving the metal sheet. The interior of the protrusion can have a cavity, and at least a part of the metal sheet protruding from the printed circuit board is received in the cavity and coupled to the housing part. Thus, a large surface area can be provided for heat dissipation. For example, the cavity can have a fit between its inner wall and the metal sheet to couple the two together, or the cavity is at least partially filled or is to be filled with a thermally conductive material.

[0018] In an improvement, the housing part can have a plurality of heat sinks on its outer surface. The heat sinks can be designed to be integral with the material of the housing part, or are made of the same or similar or compatible materials separately from each other, or are made of metal materials, ceramics or similar materials separately from each other. Thereby, the surface area for heat dissipation can be further increased.

[0019] According to an improvement, the heat sinks can be oriented transversely to and / or perpendicular to the flat side of the metal sheet.

[0020] In an improvement, the housing part can have a fastening flange that is filled or has been filled with resin. The resin is preferably thermally conductive. It can also be fluid. This enables the device composed of the housing part and the printed circuit board to be sealed to prevent external influences such as liquid or gas media. In some embodiments, the resin can also provide adhesion. In other embodiments, additional fastening means such as screw connections, rivet connections or similar means can be provided.

[0021] According to an improvement, the metal sheet and the housing part can be connected together by a thermally conductive resin. For example, the internal space of the housing part around the metal sheet can be at least partially filled with resin, and the resin at least partially fills the air gap between the inner wall and the metal sheet. Thereby, the manufacturing work is particularly simple.

[0022] In an improved embodiment, the resin can at least partially fill the internal space between the surface of the metal sheet and the inner side of the housing part.

[0023] According to an improved embodiment, the resin can be a curable or cured casting material. The resin can be flowable, viscous, etc. before curing. This makes the manufacturing particularly simple.

[0024] In an improved embodiment, the metal sheet can form an electrical connection between the first component and the second component to which the printed circuit board is assembled. In other words, the metal sheet can be configured to conduct current or be configured to be current-conductive. This function can be similar to or the same as that of a printed wire. In this way, a large current can also be conducted, and in addition, the heat generated during this process can also be directly dissipated.

[0025] According to an improved embodiment, the metal sheet can be electrically connected to at least one first electrical contact, at least one power transistor, and at least one second electrical contact of the printed circuit board. The first contact can be designed, for example, for feeding in current. For example, the second contact can be designed for drawing out current. The power transistor can be designed for switching current. In this way, a large current can be conducted, and in addition, the generated heat can also be directly conducted out.

[0026] The second aspect of the present invention relates to a method for manufacturing a printed circuit board. The method includes the following steps:

[0027] Arranging at least one metal sheet on a substrate having a first side (e.g., the upper side or the assembly side) and a second side (e.g., the bottom side or the soldering side), such that the metal sheet preferably protrudes from the second side and at least one flat side of the metal sheet is exposed relative to the second side, and

[0028] Coupling the metal sheet to a housing part that at least partially surrounds the metal sheet in a heat-transferable manner.

[0029] In this way, the above-mentioned printed circuit board can be particularly manufactured.

[0030] According to an improved embodiment, when the metal sheet is coupled to the housing part, the metal sheet can be in contact with a curable resin, and then the resin can be cured. This makes the manufacturing of the printed circuit board particularly simple.

[0031] Further features, advantages, and possible applications of the present invention will become apparent from the following description of advantageous embodiments and the accompanying drawings. Description of the Drawings

[0032] An advantageous embodiment of the present invention will be explained below with reference to the accompanying drawings. In the drawings:

[0033] Figure 1Schematic bottom view of a printed circuit board according to an embodiment,

[0034] Figure 2 Schematic top view of a printed circuit board according to an embodiment,

[0035] Figure 3 Schematic side view of a printed circuit board according to an embodiment,

[0036] Figure 4 Schematic side view of a printed circuit board according to an embodiment,

[0037] Figure 5 Schematic cross-sectional view of the housing part of a printed circuit board according to an embodiment,

[0038] Figure 6 Schematic side view of a printed circuit board with a housing part according to an embodiment,

[0039] Figure 7 Schematic cross-sectional view of the housing part of a printed circuit board according to an embodiment,

[0040] Figure 8 Schematic sectional view of the housing part of a printed circuit board according to an embodiment, and

[0041] Figure 9 Schematic cross-sectional view of a printed circuit board with two housing parts according to an embodiment.

[0042] These figures are only schematic representations and are only used to explain the present invention. Elements with the same or similar functions have the same reference numerals throughout. Detailed description of the embodiments

[0043] Figure 1 Schematic bottom view of a printed circuit board 100 according to an embodiment. The printed circuit board can be used in various aspects, such as for switching current, measuring current, etc. An exemplary application can be in the on-vehicle electrical network of a motor vehicle, for example in a distributor or a similar device.

[0044] The printed circuit board 100 includes a substrate 110, which can be single-layered or, if necessary, multi-layered. The substrate 110 (if necessary, on each layer) has a first side TOP, which is usually the upper side of the printed circuit board and is the flat side of the printed circuit board 100. However, for example, in the case of a single-layer printed circuit board 100, the first side TOP can also be referred to as the assembly side, where two-sided assembly is not necessarily excluded, but the assembly position of the printed circuit board 100 can be specified. In addition, the substrate 110 has a second side BOT, which is opposite to the first side TOP and is the flat side of the printed circuit board 100. For example, in the case of a single-layer printed circuit board 100, the second side BOT can also be referred to as the soldering side, where two-sided assembly is not necessarily excluded, but the second side BOT can also be assembled. Figure 1 Shows the second side BOT.

[0045] At least one metal sheet 120 is attached to the second side BOT, that is Figure 1 the side of the printed circuit board 100 or the substrate 110 shown in. In Figure 1 three metal sheets 120 are exemplarily attached to the second side BOT, where the arrangement can vary according to the assembly and / or function of the printed circuit board 100. Each metal sheet 120 is connected to the second side BOT of the substrate 110 by its narrow side and is connected thereto, for example, by material bonding. The bonding of the metal sheet 120 to the second side BOT or to the substrate 110 can be carried out by, for example, fusion welding, brazing, etc. By attaching the metal sheet 120 through its narrow side, the metal sheet 120 protrudes from the second side BOT, and one or two flat sides are bare or exposed to the environment of the printed circuit board 100. In the exemplary embodiment according to Figure 1 one or more flat sides of one or more metal sheets 120 are arranged to be substantially perpendicular to the second side BOT. For example, the corresponding metal sheet is made of a thermally conductive and / or electrically conductive material, such as copper material, copper alloy, aluminum material, aluminum alloy or other suitable metal materials. For example, its thickness or specification ranges from about 0.2 mm to about 2.5 mm, preferably from about 0.5 mm to about 2 mm, more preferably from about 1 mm. In addition, according to the application purpose or technical application, the size of the metal sheet protruding from the printed circuit board can vary, for example, from about 10 mm to about 120 mm, preferably from about 20 mm to about 100 mm, particularly preferably from about 40 mm to about 50 mm.

[0046] In addition, the printed circuit board 100 exemplarily has a plurality of electrical components 130, 140, 150, which merely exemplarily have a first electrical contact 130 for feeding in current, a plurality of power transistors 140 for switching the current, and a second contact 150 for leading out the current. These components 130, 140, 150 are electrically connected to each other by metal sheets 120, which correspondingly conduct the switched current. For example, the electrical connection can be made by printed conductors, pads or the like. It should be noted that the type, arrangement and number of the components 130, 140, 150 can vary according to the intended use of the printed circuit board 100. In Figure 1 FIG. [0000111], the components 130, 140, 150 are shown as dashed lines to indicate that they are at least substantially arranged on the first side TOP.

[0047] Figure 2 FIG. [0000115] shows a schematic top view of the first side TOP of the printed circuit board 100 or the substrate 110. In Figure 2 FIG. [0000116], the metal sheet 120 is drawn as a dashed line, indicating that it is arranged on the second side BOT.

[0048] Figure 3 FIG. [0000119] is a schematic side view of the printed circuit board 100. It can be seen that the metal sheet 120 protrudes from the second side BOT of the printed circuit board 100 or the substrate 110 and is exposed with its flat side (i.e., the majority of the available surface). This allows heat to dissipate.

[0049] Figure 4 FIG. [0000120] is a schematic side view of the printed circuit board 100 rotated with respect to the Figure 3 side view shown in FIG. [0000119]. It can be seen that the metal sheet 120 protrudes from the second side BOT of the printed circuit board 100 or the substrate 110 and is exposed with its flat side (i.e., the majority of the available surface). This allows heat to dissipate.

[0050] Figure 5Shows a schematic cross-sectional view of the first housing part 160. The housing part 160 is here the lower housing part and is configured to at least partially surround the printed circuit board 100 from the second side BOT. In other words, the housing part 160 in its mounted position faces the second side BOT of the printed circuit board 100 or the substrate 110. The housing part 160 is made of a plastic material, preferably a plastic material that is thermally conductive. In addition, the housing part 160 has a plurality of ribbed protrusions 161, and each metal sheet 120 can be received or surrounded by the protrusions and can thus be coupled in a heat-transferable manner. In addition, the housing part 160 includes a plurality of outer contact surfaces 162 for transferring heat to the environment, where one or more of the outer contact surfaces 162 are, for example, part of the protrusions 161 and are substantially parallel to the flat sides of the corresponding metal sheets 120. In addition, the housing part 160 includes a flange or fastening flange 163, which is configured to couple the first housing part 160 to the substrate 110 or another housing part. For example, the fastening flange 163 can be formed by one or more grooves or the like.

[0051] In Figure 6 a first housing part 160 in another embodiment is shown, where it is shown in a schematic cross-sectional view. Here, the first housing part 160 has a plurality of heat sinks 164 on the outside. For example, these heat sinks can be arranged in a comb-like manner, in particular having a plurality of individual heat sinks 164. According to Figure 6 , the heat sinks 164 in this embodiment extend from the outer contact surfaces 162 of the first housing part 160.

[0052] Figure 7 Shows a schematic cross-sectional view of the first housing part 160, which in principle can be one of the embodiments according to Figure 5 or Figure 6 . Here, the fastening flange 163 designed as a groove has a sealant 170, where the sealant is a resin. For this purpose, the fastening flange 163 is at least partially filled with the resin 170. The protrusions 161 of the first housing part 160 are also partially filled with the sealant 170, where the sealant can also be a resin. The resin 170 is liquid or viscous and is suitable for curing after a certain time or by treatment such as ultraviolet light, heating, etc. For example, the resin 170 can be provided as a curable casting material.

[0053] Figure 8is a schematic (partial) cross-sectional view of a printed circuit board 100. Here, the printed circuit board 100 has a second housing part 180. The second housing part 180 is here the upper housing part, which is designed to at least partially surround the printed circuit board 100 from the first side TOP. In other words, the housing part 180 is facing the first side TOP of the printed circuit board 100 or the substrate 110 in its mounted position. The second housing part 180 is made of plastic, which does not necessarily have to be thermally conductive and does not necessarily have to be the same plastic as the first housing part 160, since at least a large part of the heat to be dissipated can be dissipated through the metal sheet 120 and / or the first housing part 160. Therefore, the second housing part 180 can also be made of a simpler and cheaper plastic. The second housing part 180 is connected or fixed to the substrate 110, for example, where clips (Verklipsung) can be provided for this purpose. However, the second housing part 180 can also alternatively or additionally be connected to the first housing part 160. Furthermore, according to Figure 8 , a plurality of components 150 are led to the outside through the second housing part 180 as electrical contacts (e.g., plug-in contacts, etc.). It should be noted that the components 150 do not necessarily have to be led to the outside from the first side TOP of the substrate 110, but the components 150 can also be led to the outside through the first housing part 160 from the second side BOT.

[0054] Figure 9 shows a schematic (partial) cross-sectional view of the circuit board 100, in which the housing parts 160 and 180 are coupled to each other by a sealing material or resin 170. The metal sheet 1200 is also coupled to the corresponding inner side of the housing part 160 by the sealing material or resin 170.

[0055] The above-described embodiment of the printed circuit board 100 can be manufactured, for example, as described below.

[0056] First, at least one metal sheet 120 is connected to a substrate 110 having a first side TOP and a second side BOT, and the metal sheet 120 projects from the second side BOT, and at least one flat side of the metal sheet 120 is exposed relative to the second side BOT. Then, the metal sheet 120 forms a heat transfer coupling with a housing part 160 that at least partially surrounds the metal sheet 120.

[0057] List of reference numerals

[0058] 100 Printed circuit board

[0059] 110 Substrate

[0060] 120 Metal sheet

[0061] 130 Component

[0062] 140 Component

[0063] 150 components

[0064] 160 First housing part

[0065] 161 Protrusion

[0066] 162 Contact surface

[0067] 163 Fastening flange

[0068] 164 Heat sink

[0069] 170 Sealing compound (e.g., resin)

[0070] 180 Second housing part

Claims

1. A printed circuit board (100), comprising a substrate (110) having a first side (TOP) and a second side (BOT), at least one metal sheet (120) attached to the second side (BOT) of the substrate (110) by its narrow side and protruding from the second side (BOT) such that a flat side of the metal sheet (120) is exposed relative to the second side (BOT), and a housing part (160) that at least partially surrounds the printed circuit board (100) from the second side (BOT) and at least partially surrounds the metal sheet (120) and is thermally connected to the metal sheet (120) in a heat - transferable manner, Among them, the housing part (160) having at least one outer contact surface (162) for heat transfer to the environment, and the outer contact surface (162) being substantially parallel to the flat side of the metal sheet (120).

2. The printed circuit board (100) according to claim 1, wherein, The housing part (160) is made of plastic.

3. The printed circuit board (100) according to claim 1 or 2, wherein, The housing part (160) has ribbed protrusions (161) for receiving the metal sheet (120).

4. The printed circuit board (100) according to claim 1 or 2, wherein, The housing part (160) has a plurality of heat sinks (164) on the outside.

5. The printed circuit board (100) according to claim 4, wherein, The heat sinks (164) are oriented transversely to the flat side of the metal sheet (120).

6. The printed circuit board (100) according to claim 1 or 2, wherein, The housing part (160) includes fastening flanges (163) that can be filled with resin (170).

7. The printed circuit board (100) according to claim 1 or 2, wherein, The metal sheet (120) and the housing part (160) are coupled to each other by a thermally conductive resin (170).

8. The printed circuit board (100) according to claim 7, wherein, The resin (170) at least partially fills the internal space between the surface of the metal sheet (120) and the inner side of the housing part (160).

9. The printed circuit board (100) according to claim 7, wherein, The resin (170) is a curable casting material.

10. The printed circuit board (100) according to claim 1 or 2, wherein, The metal sheet (120) forms an electrical connection between a first component and a second component to which the printed circuit board (100) is assembled.

11. A method of manufacturing a printed circuit board (100), the method comprising the steps of: arranging at least one metal sheet (120) on a substrate (110) having a first side (TOP) and a second side (BOT) such that the metal sheet (120) protrudes from the second side (BOT) and at least one flat side of the metal sheet (120) is exposed relative to the second side (BOT), and thermally coupling the metal sheet (120) to a housing part (160) that at least partially surrounds the printed circuit board (100) from the second side (BOT) and at least partially surrounds the metal sheet (120), wherein the housing part (160) has at least one outer contact surface (162) for heat transfer to the environment, and the outer contact surface (162) is substantially parallel to the flat side of the metal sheet (120).

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