Circuit board

Abstract

The utility model discloses a circuit board. The disclosed circuit board comprises a substrate and an embedded part arranged in the substrate; wherein the substrate comprises a copper-clad core plate, a bonding part and outer-layer copper foils, the outer-layer copper foils are arranged on the two opposite sides of the copper-clad core plate, the copper-clad core plate comprises an insulating layer and an inner-layer conductive circuit arranged on the surface of at least one side of the insulating layer, and the embedded part penetrates through the copper-clad core plate and is connected with the outer-layer copper foils; one part of the bonding part is arranged between the copper-clad core plate and the outer-layer copper foil so as to connect the outer-layer copper foil and the copper-clad core plate; and the other part of the bonding part wraps and is connected with the side wall of the embedded part so as to fix the embedded part to the substrate. According to the utility model, the single copper-clad core plate is matched with the bonding part to realize the fixation of the embedded part, so that the production cost can be reduced and the thinning of the multilayer circuit board can be realized.

Description

Technical Field

[0001] The utility model relates to the field of circuit boards; more specifically, to a circuit board with embedded parts inside. Background Art

[0002] In order to achieve the purpose of electrical conduction and / or thermal conduction, embedded parts such as ceramic blocks and copper blocks can be set in the circuit board. In the prior art, the fixing structure of the embedded parts in the circuit board requires multiple core boards, the embedded parts are set in the through holes of the core boards, and prepregs are set between the multiple core boards and pressed together. During the pressing process of the core boards, the prepregs flow and fill into the through holes of the core boards to simultaneously fix the embedded parts.

[0003] Since the embedded component fixing structure in the prior art requires at least two core boards, not only is the manufacturing cost of the circuit board high, but it is also not conducive to the thinning of the circuit board, and needs to be improved. Utility Model Content

[0004] In order to at least partially solve the problems of the prior art, the utility model provides a circuit board, comprising a substrate and an embedded component arranged in the substrate; wherein the substrate comprises a copper clad core board, a bonding portion and an outer copper foil, the outer copper foil is arranged on opposite sides of the copper clad core board, the copper clad core board comprises an insulating layer and an inner conductive circuit arranged on at least one side surface of the insulating layer, the embedded component penetrates the copper clad core board and is connected to the outer copper foil; a part of the bonding portion is arranged between the copper clad core board and the outer copper foil to fix the outer copper foil to the copper clad core board; another part of the bonding portion wraps around and connects to the side wall of the embedded component to fix the embedded component to the substrate.

[0005] According to a specific implementation of the utility model, the outer copper foil includes a laminated copper foil and a thickened copper foil, the laminated copper foil is arranged on the copper clad core board, and the thickened copper foil covers and connects the laminated copper foil and the embedded part.

[0006] Furthermore, the thickness of the laminated copper foil is 30 μm to 150 μm, and the thickness of the thickened copper foil is 10 μm to 30 μm.

[0007] Furthermore, the copper clad core board and the laminated copper foil are both provided with through holes for the embedded component to pass through; wherein, there is a gap of 0.1 mm to 0.15 mm between the hole wall of the through hole and the side wall of the embedded component, and the gap is filled by the bonding portion.

[0008] According to a specific implementation of the utility model, the embedded part is a copper block.

[0009] According to another specific embodiment of the utility model, the embedded part is a thermally conductive ceramic block, and a metal layer connected to the thickened copper foil is provided on the surface of the thermally conductive ceramic block.

[0010] Furthermore, the metal layer includes a copper layer connected to the thickened copper foil and a titanium layer arranged between the copper layer and the thermally conductive ceramic block.

[0011] According to a specific implementation of the utility model, the outer copper foils located on opposite sides of the copper clad core board are both provided with outer conductive circuits.

[0012] Furthermore, the outer conductive circuits and / or the outer conductive circuits and the inner conductive circuits are electrically connected through conductive vias.

[0013] According to a specific embodiment of the utility model, the inner conductive circuits are provided on both side surfaces of the insulating layer, and the inner conductive circuits are electrically connected through conductive vias penetrating the insulating layer, and the conductive vias are filled with the bonding portion or the plugging resin.

[0014] The technical solution of the utility model has the following beneficial effects:

[0015] The circuit board of the utility model uses only a single copper clad core board, the outer copper foil is connected to the copper clad core board by a bonding portion, and the bonding portion is used to fix the embedded parts, which not only reduces the production cost of the circuit board, but also helps to achieve the thinning of the multi-layer circuit board.

[0016] In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the overall structure of the circuit board in Example 1;

[0018] Figure 2 is a schematic diagram of the pressed structure of the circuit board in Example 1;

[0019] Figure 3 is a schematic diagram of the circuit board structure after the pressing step in Example 1;

[0020] Figure 4 It is a schematic diagram of the overall structure of the circuit board in Example 2. DETAILED DESCRIPTION

[0021] In the following description, the technical solution of the present invention is elaborated in detail in combination with specific embodiments, but the present invention can also be implemented in other variable ways based on this description, so the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0022] Example 1

[0023] like Figure 1 As shown, the circuit board of embodiment 1 includes a substrate 10 and an embedded part 20 disposed in the substrate 10, and the embedded part 20 is a metal block such as a copper block. The substrate 10 includes a copper clad core board 11, a bonding portion 12 and an outer copper foil 13, and the outer copper foil 13 is disposed on opposite sides of the copper clad core board 11. The embedded part 20 penetrates the copper clad core board 11 and is connected to the outer copper foil 13. The copper clad core board 11, the outer copper foil 13 and the embedded part 20 are bonded and fixed together by the bonding portion 12.

[0024] In the embodiment, the copper clad core board 11 is a double-sided copper clad core board, including an insulating layer 111 and inner conductive circuits 112 arranged on both sides of the insulating layer 111, and the inner conductive circuits 112 are electrically connected through conductive vias 113 that penetrate the insulating layer 111. The conductive vias 113 can be filled with a bonding portion 12 or a plugging resin (not shown). Exemplarily, a conductive via 113 with an inner diameter less than 0.3 mm can be filled with a bonding portion 12, and a conductive via 113 with an inner diameter greater than 0.3 mm is preferably filled with a plugging resin.

[0025] The copper clad core board 11 preferably adopts FR-4 copper clad board, but is not limited thereto. In the present application, the specific steps of making the inner conductive circuit 112 and the conductive via 113 on the copper clad core board 11 can refer to the known technology in the art, and will not be described in detail here. As a variation of the embodiment, the inner conductive circuit 112 can be made only on one side surface of the insulating layer 111, and the other side surface of the insulating layer 111 may not be provided with a copper foil layer or a copper foil layer may be provided but no inner conductive circuit is made.

[0026] The outer copper foil 13 includes a laminated copper foil 131 and a thickened copper foil 132. The laminated copper foil 131 is disposed on the copper clad core board 11, and the thickened copper foil 132 covers and connects the laminated copper foil 131 and the embedded part 20. The thickness of the laminated copper foil 131 is preferably greater than the thickness of the thickened copper foil 132; illustratively, the thickness of the laminated copper foil 131 may be 30 μm to 150 μm, and the thickness of the thickened copper foil 132 may be 10 μm to 30 μm.

[0027] The bonding portion 12 is obtained by laminating a prepreg 12a disposed between the laminating copper foil 131 and the copper clad core board 11. Specifically, as Figure 2As shown, the copper clad core board 11 is provided with a first through hole 110, the prepreg 12a is provided with a second through hole 12b, and the pressed copper foil 131 is provided with a third through hole 130; when pressed, the prepreg 12a and the pressed copper foil 131 are stacked in sequence on the upper and lower sides of the copper clad core board 11, and the embedded part 20 is arranged in the first through hole 110, the second through hole 12b and the third through hole 130.

[0028] There is a gap of 0.1 mm to 0.15 mm between the hole walls of the first through hole 110, the second through hole 12b and the third through hole 130 and the side wall of the embedded part 20, so as to facilitate the placement and positioning of the embedded part 20 and ensure that the prepreg 12a can fully flow and fill the gap during the pressing process. Specifically, there is a gap of 0.125 mm between the hole walls of the first through hole 110 and the third through hole 130 and the side wall of the embedded part 20, and there is a gap of 0.15 mm between the hole wall of the second through hole 12b and the side wall of the embedded part 20.

[0029] like Figure 3 As shown, after the lamination step, the semi-cured sheet 12a is cured to form a bonding portion 12, a portion of which is disposed between the copper clad core board 11 and the outer copper foil 13, forming a bonding sheet 121 connecting the outer copper foil 13 / pressed copper foil 131 and the copper clad core board 11; another portion of the bonding portion 12 fills the gap between the hole wall of the first through hole 110 and the third through hole 130 and the side wall of the embedded part 20, forming a connecting portion 122 that wraps and connects the side wall of the embedded part 20, so as to fix the embedded part 20 to the substrate 10. At the same time, the bonding portion 12 also forms a filling portion 123 that fills the conductive via 113.

[0030] After the lamination step, the entire circuit board is copper plated to obtain a thickened copper foil 132 . The thickened copper foil 132 can connect the embedded part 20 and the pressed copper foil 131 separated by the bonding portion 12 together to form an outer copper foil 13 .

[0031] In the embodiment, the outer copper foils 13 on opposite sides of the copper clad core board 11 are provided with outer conductive circuits, and the outer conductive circuits on the opposite sides are electrically connected through conductive vias 141 (see Figure 1 Specifically, after lamination, the substrate 10 may be drilled to obtain the through hole 140 (see Figure 3 ), the entire circuit board is copper plated to obtain a thickened copper foil 132 and copper is plated on the hole wall of the through hole 140 at the same time, that is, the conductive via 141 is obtained while the thickened copper foil 132 is produced, and finally the outer copper foil 13 is etched to obtain the outer conductive circuit.

[0032] As a variation of the embodiment, the outer conductive circuit can be made only in the outer copper foil 13 on one side of the copper clad core board 11. In addition, as required, the inner conductive circuit 112 and the outer conductive circuit / outer copper foil 13 can also be electrically connected through corresponding conductive vias, which will not be described in detail here.

[0033] Example 2

[0034] The main difference between the embodiment 2 and the embodiment 1 is that the embedded part 20 is different. Figure 4 As shown, the embedded part 20 in Embodiment 2 is a thermally conductive ceramic block, and a metal layer 21 connected to the outer copper foil 132 is provided on the surface of the thermally conductive ceramic block, that is, the thermally conductive ceramic block provided with the metal layer 21 on the surface is pressed and fixed in the substrate 10. Preferably, the metal layer 21 includes a copper layer connected to the thickened copper foil 132 and a titanium layer provided between the copper layer and the thermally conductive ceramic block, so as to increase the bonding force between the thermally conductive ceramic block and the copper layer through the titanium layer.

[0035] In Example 2, a heat-conducting ceramic block with insulating properties is used as the embedded part 20, which is beneficial to improving the voltage resistance performance of the circuit board. The heat-conducting ceramic block can be selected from aluminum nitride, silicon nitride, aluminum oxide, silicon carbide and other ceramic blocks, and the utility model does not limit this.

[0036] In summary, the utility model arranges an outer copper foil 13 on the copper clad core board 11, and the outer copper foil 13 is connected to the copper clad core board 11 through a bonding portion 12. At the same time, the bonding portion 12 is used to fix the embedded part 20. Since only a single copper clad core board 11 is needed, it not only reduces the production cost of the circuit board, but also helps to achieve the thinning of the multi-layer circuit board.

[0037] Although the present invention is disclosed as above with specific embodiments, these embodiments are not intended to limit the scope of implementation of the present invention. Any person skilled in the art may make some modifications or changes without departing from the scope of the invention of the present invention, that is, any equivalent changes made in accordance with the present invention shall be covered by the protection scope of the present invention.

Claims

1. A circuit board, comprising a substrate and an embedded component arranged in the substrate; characterized in that: The substrate comprises a copper clad core board, a bonding portion and an outer copper foil, wherein the outer copper foil is arranged on two opposite sides of the copper clad core board, the copper clad core board comprises an insulating layer and an inner conductive circuit arranged on at least one side surface of the insulating layer, and the embedded part penetrates the copper clad core board and is connected to the outer copper foil; A portion of the bonding portion is disposed between the copper clad core board and the outer copper foil to connect the outer copper foil and the copper clad core board; another portion of the bonding portion wraps around and connects the side wall of the embedded component to fix the embedded component to the substrate.

2. The circuit board according to claim 1, characterized in that: The outer copper foil comprises a laminated copper foil and a thickened copper foil. The laminated copper foil is arranged on the copper clad core board, and the thickened copper foil covers and connects the laminated copper foil and the embedded component.

3. The circuit board according to claim 2, characterized in that: The thickness of the laminated copper foil is 30 μm to 150 μm, and the thickness of the thickened copper foil is 10 μm to 30 μm.

4. The circuit board according to claim 2, characterized in that: The copper clad core board and the pressed copper foil are both provided with through holes for the embedded component to pass through, and a gap of 0.1 mm to 0.15 mm is provided between the hole wall of the through hole and the side wall of the embedded component, and the gap is filled by the bonding portion.

5. The circuit board according to claim 2, characterized in that: The embedded part is a copper block.

6. The circuit board according to claim 2, characterized in that: The embedded part is a heat-conducting ceramic block, and a metal layer connected to the thickened copper foil is provided on the surface of the heat-conducting ceramic block.

7. The circuit board according to claim 6, characterized in that: The metal layer includes a copper layer connected to the thickened copper foil and a titanium layer arranged between the copper layer and the thermally conductive ceramic block.

8. The circuit board according to claim 1, characterized in that: The outer copper foils located on opposite sides of the copper clad core board are both provided with outer conductive circuits.

9. The circuit board according to claim 8, characterized in that: The outer conductive circuits are electrically connected to each other and / or the outer conductive circuits are electrically connected to the inner conductive circuits through conductive vias.

10. The circuit board according to claim 1, characterized in that: The inner conductive circuits are disposed on both side surfaces of the insulating layer, and the inner conductive circuits are electrically connected through conductive vias penetrating the insulating layer, and the conductive vias are filled with the bonding portion or the plugging resin.

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