Heat dissipation circuit board and manufacturing method thereof

Abstract

The invention relates to the technical field of circuit boards, in particular to a heat dissipation circuit board and a manufacturing method thereof.The heat dissipation circuit board comprises an inner-layer circuit board and a plurality of layer-adding circuit boards, the layer-adding circuit boards are sequentially pressed on the outer side of the inner-layer circuit board, and at least one electronic element embedding area is arranged in the inner-layer circuit board; the electronic component embedding area is used for installing embedded electronic components, a plurality of blind holes are formed in the layer-adding circuit board, the blind holes are communicated to the inner-layer circuit board, the blind holes comprise conductive blind holes and heat dissipation blind holes, and the heat dissipation blind holes are square blind holes. According to the heat dissipation circuit board and the manufacturing method thereof, the problem that the efficiency of a power element or an embedded electronic element is reduced or even fails due to poor heat dissipation of the power element or the embedded electronic element can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of circuit boards, and in particular to a heat dissipation circuit board and a manufacturing method thereof. Background Art

[0002] Printed circuit board, also known as printed circuit board, printed circuit board, often uses the English abbreviation PCB (Printedcircuit board), is an important electronic component, a support for electronic components, and a provider of circuit connections for electronic components. Because it is made using electronic printing technology, it is called a "printed" circuit board.

[0003] In recent years, with the increasing demand for high-power devices such as high-speed rail, in order to improve the switching efficiency of power components and reduce the inductance effect, while reducing overall energy consumption, a design trend of embedding power components in circuit boards has developed. Embedded power components need to use heat dissipation blind holes to transfer heat energy to the outside. In order to improve the heat dissipation efficiency of heat dissipation blind holes, the problem of poor heat dissipation of power components or embedded electronic components, which causes the efficiency of power components or embedded electronic components to decrease or even fail, has been solved.

[0004] In the prior art, power components are encapsulated with copper wires, buried in circuit boards, and connected to the outer layer with blind holes. However, circular blind holes are used to connect the power components to the outer layer. The cross-sectional area of ​​the circular blind hole for heat transfer and the bottom area of ​​the circular blind hole are smaller than those of a square blind hole with the same side length and diameter, so the thermal conductivity efficiency is also limited. Summary of the invention

[0005] The object of the present invention is to provide a heat dissipation circuit board and a manufacturing method thereof, which can solve the problem that power components or embedded electronic components have poor heat dissipation, resulting in reduced efficiency or even failure of power components or embedded electronic components.

[0006] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a heat dissipation circuit board, comprising an inner layer circuit board and a plurality of build-up layer circuit boards, wherein the plurality of build-up layer circuit boards are sequentially pressed onto the outer side of the inner layer circuit board, wherein at least one electronic component embedding area is provided in the inner layer circuit board, wherein the electronic component embedding area is used for installing embedded electronic components, wherein a plurality of blind holes are provided on the build-up layer circuit board, wherein the plurality of blind holes are connected to the inner layer circuit board, wherein the blind holes comprise conductive blind holes and heat dissipation blind holes, and the heat dissipation blind holes are square blind holes.

[0007] In combination with the first aspect, further, the embedded components include resistors, capacitors, inductors and power components.

[0008] In combination with the first aspect, further, the heat dissipation blind holes are filled with a thermal conductive medium, and the conductive blind holes are filled with a conductive medium.

[0009] In a second aspect, the present invention provides a method for manufacturing a heat dissipation circuit board, comprising the following steps: forming an inner circuit board with embedded electronic components by a lamination operation; Arranging a build-up circuit board outside the inner circuit board; Pressing the build-up circuit board and the inner circuit board together; A blind hole is opened on the build-up circuit board, and the embedded electronic component is connected to the outer side of the build-up circuit board through the blind hole; The blind holes include thermal conductive blind holes and electrical conductive blind holes, and the thermal conductive blind holes are square.

[0010] In combination with the second aspect, further, opening a blind hole on the build-up circuit board includes: opening a blind hole on the build-up circuit board by laser drilling, and the laser drilling method includes carbon dioxide laser and UV laser.

[0011] In combination with the second aspect, further, opening a blind hole on the build-up circuit board also includes: opening the blind hole on the build-up circuit board by mechanical drilling.

[0012] In combination with the second aspect, further, the blind hole is filled by electroplating, and the electroplating filling includes electroplating half-filling and electroplating filling.

[0013] In combination with the second aspect, further, forming an inner circuit board with embedded electronic components by a pressing operation includes: Laminating at least one embedded electronic component, a core layer, two upper and lower PP insulation layers, and copper foil together to form an inner layer circuit board; Wherein, an electronic component embedding area is arranged in the Core layer, and the embedded electronic components are installed in the electronic component embedding area.

[0014] In combination with the second aspect, further, forming the inner circuit board with embedded electronic components by lamination operation also includes: Laminating at least one embedded electronic component, a through-hole board, two upper and lower PP insulation layers, and copper foil together to form an inner-layer circuit board; Wherein, an electronic component embedding area is provided in the through-hole plate, and the embedded electronic component is installed in the electronic component embedding area.

[0015] In combination with the second aspect, further, the conductive blind via is also opened in a square shape.

[0016] Compared with the prior art, the present invention has the following beneficial effects: it can solve the problem that the power components or embedded electronic components have poor heat dissipation, which causes the power components or embedded electronic components to have reduced efficiency or even fail; The heat dissipation circuit board and the manufacturing method thereof provided by the present invention are used to install embedded electronic components by arranging an electronic component embedding area on the inner circuit board, and by opening a plurality of blind holes on the build-up circuit board so that the blind holes are connected to the inner circuit board, and the inner circuit board and the build-up circuit board are connected through the conductive blind holes, and the heat of the inner circuit board is transferred to the outer build-up circuit board and to the outside of the build-up circuit board through the heat dissipation blind holes, so as to solve the heat dissipation problem of the embedded electronic components, thereby ensuring the normal operation of the embedded electronic components; By installing resistors, capacitors, inductors and power components in the electronic component embedding area, the resistors, capacitors, inductors and power components are cooled, thereby improving the operating efficiency of embedded electronic components installed in the electronic component embedding area; By filling the heat-conducting medium in the heat-dissipating blind hole, the heat-conducting efficiency of the heat-dissipating blind hole is improved, and by filling the conductive medium in the conductive blind hole, the conductive performance of the conductive blind hole is improved; By setting the thermal blind hole to a square shape, the heat dissipation surface is increased and the heat dissipation effect is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a top view and a schematic diagram of a cross-sectional view of a blind hole of a heat dissipation circuit board provided by an embodiment of the present invention; Figure 2 A schematic diagram showing a size comparison between a circular blind hole and a square blind hole of a heat dissipation circuit board provided in an embodiment of the present invention; Figure 3 A flow chart of a method for manufacturing a heat dissipation circuit board provided in Embodiment 2 of the present invention; Figure 4 This is a flow chart of a method for manufacturing a heat dissipation circuit board provided in Example 3 of the present invention.

[0018] The markings in the attached figure are: 1. Conductive blind hole; 2. Heat dissipation blind hole; 3. Core layer; 4. PP insulation layer; 5. Copper foil; 6. Electronic component embedding area; 7. Through-hole board. DETAILED DESCRIPTION

[0019] The technical solution of the present application is further described in detail below in conjunction with specific implementation methods.

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limitations on the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0021] Embodiment 1: The present embodiment provides a heat dissipation circuit board and a manufacturing method thereof, including an inner layer circuit board and a plurality of build-up layer circuit boards, the build-up layer circuit boards including a plurality of upper build-up layer circuit boards arranged above the inner layer circuit board and a plurality of lower build-up layer circuit boards arranged below the inner layer circuit board, the plurality of build-up layer circuit boards are sequentially pressed onto the outer side of the inner layer circuit board, the plurality of upper build-up layer circuit boards, the inner layer circuit board and the plurality of lower build-up layer circuit boards are sequentially pressed together to form a heat dissipation circuit board, at least one electronic component embedding area 6 is arranged in the inner layer circuit board, the electronic component embedding area 6 is used to install embedded electronic components, a plurality of blind holes are opened on the build-up layer circuit board, the plurality of blind holes are connected to the inner layer circuit board, the blind holes include conductive blind holes 1 and heat dissipation blind holes 2, the heat dissipation blind holes 2 are square blind holes, and some conductive blind holes 1 can also be designed as square blind holes, by setting the heat conductive blind holes to be square, the cross-sectional dimensions of the square blind holes are designed to meet the dimensions of the circumscribed square of the circular blind holes, such as Figure 2 As shown, it is obvious that under the same wiring area and density, the overall cross-sectional area of ​​the square blind hole is about 62.1% of the overall cross-sectional area of ​​the circular blind hole, and the upper / lower aperture area of ​​the square blind hole is about 27.3% of the upper / lower aperture area of ​​the circular blind hole, which significantly increases the heat dissipation area and improves the heat dissipation effect. At the same time, the blind hole is opened in a square shape, which increases the contact area of ​​the bottom of the blind hole and improves the reliability of the connection at the bottom of the blind hole. The heat dissipation circuit board provided in this embodiment can solve the problem that the efficiency of power components or embedded electronic components is reduced or even fails due to poor heat dissipation. An electronic component embedding area 6 is provided on the inner circuit board for installing embedded electronic components, and a plurality of blind holes are opened on the build-up circuit board so that the blind holes are connected to the inner circuit board, the inner circuit board and the build-up circuit board are connected through the conductive blind hole 1, and the heat dissipation surface of the electronic component is connected to the heat dissipation blind hole 2. The heat of the inner circuit board is transferred to the outer build-up circuit board and to the outside of the build-up circuit board through the heat dissipation blind hole 2, thereby solving the heat dissipation problem of the embedded electronic components and ensuring the normal operation of the embedded electronic components.

[0022] In this embodiment, the embedded components include resistors, capacitors, inductors and power components. By installing the resistors, capacitors, inductors and power components into the electronic component embedded area 6, the resistors, capacitors, inductors and power components are cooled, thereby improving the operating efficiency of the embedded electronic components installed in the electronic component embedded area 6.

[0023] In this embodiment, the heat dissipation blind hole 2 is filled with a heat-conducting medium, and the conductive medium includes thermal grease. The conductive blind hole 1 is filled with a conductive medium, and the conductive medium includes copper. By filling the heat dissipation blind hole 2 with thermal grease as the heat-conducting medium, the thermal conductivity efficiency of the heat dissipation blind hole 2 is improved, and by filling the conductive blind hole 1 with copper as the conductive medium, the conductive performance of the conductive blind hole 1 is improved.

[0024] Embodiment 2: The embodiment of the present invention provides a method for manufacturing a heat dissipation circuit board. The heat dissipation circuit board of embodiment 1 can be manufactured by the method.

[0025] This embodiment provides a method for manufacturing a heat dissipation circuit board, such as Figure 3 As shown, the following steps are included: Step 1: forming an inner circuit board with embedded electronic components through a lamination operation; At least one embedded electronic component, a Core layer 3, two upper and lower PP insulation layers 4 and a copper foil 5 are pressed together to form an inner layer circuit board, and a window can be opened on the copper foil 5 above the blind hole by etching or laser; wherein an electronic component embedding area 6 is provided in the Core layer 3, and the embedded electronic component is installed in the electronic component embedding area 6.

[0026] Step 2: Arrange a build-up circuit board outside the inner circuit board; the build-up circuit board can be arranged on the upper and lower sides of the inner circuit board, and the build-up circuit board includes a PP insulation layer 4 close to the inner circuit board and a copper foil 5 outside the PP insulation layer 4; Step 3: Press the build-up circuit board and the inner circuit board together, and press a number of build-up circuit boards on the upper and lower sides of the inner circuit board; Step 4: Open blind holes on the build-up circuit board, and connect the embedded electronic components to the outside of the build-up circuit board through the blind holes; wherein the blind holes include heat-conducting blind holes and conductive blind holes 1, the heat-conducting blind holes are square, and part of the conductive blind holes 1 can also be opened as square blind holes, and the heat-dissipating blind holes 2 are connected to the heat-dissipating surface of the embedded electronic components in the electronic component embedding area 6; The blind hole can be made by laser drilling, which includes carbon dioxide laser and UV laser. The blind hole can also be made by mechanical drilling. By laser drilling or mechanical drilling, a blind hole penetrating the PP insulating layer 4 of the build-up circuit board is obtained, so that the PP insulating layer 4 is connected from top to bottom through the blind hole. A window can be opened on the copper foil 5 above the blind hole by chemical etching or laser, and the blind hole is filled by electroplating. The electroplating filling method includes electroplating half-filling and electroplating filling.

[0027] Embodiment 3: The embodiment of the present invention provides a method for manufacturing a heat dissipation circuit board. The heat dissipation circuit board of embodiment 1 can be manufactured by the method.

[0028] This embodiment provides a method for manufacturing a heat dissipation circuit board, such as Figure 4 As shown, the following steps are included: Step 1: forming an inner circuit board with embedded electronic components through a lamination operation; At least one embedded electronic component, a through-hole board 7, two upper and lower PP insulation layers 4 and a copper foil 5 are pressed together to form an inner layer circuit board. The through-hole board 7 can be made by a POFV process. An electronic component embedding area 6 is provided in the through-hole board 7, and the embedded electronic component is installed in the electronic component embedding area 6.

[0029] Step 2: Arrange a build-up circuit board outside the inner circuit board; the build-up circuit board can be arranged on the upper and lower sides of the inner circuit board, and the build-up circuit board includes a PP insulation layer 4 close to the inner circuit board and a copper foil 5 outside the PP insulation layer 4; Step 3: Press the build-up circuit board and the inner circuit board together, and press a number of build-up circuit boards on the upper and lower sides of the inner circuit board; Step 4: Open blind holes on the build-up circuit board, and connect the embedded electronic components to the outside of the build-up circuit board through the blind holes; wherein the blind holes include heat-conducting blind holes and conductive blind holes 1, the heat-conducting blind holes are square, and part of the conductive blind holes 1 can also be opened as square blind holes, and the heat-dissipating blind holes 2 are connected to the heat-dissipating surface of the embedded electronic components in the electronic component embedding area 6; The blind hole can be made by laser drilling, which includes carbon dioxide laser and UV laser. The blind hole can also be made by mechanical drilling. By laser drilling or mechanical drilling, a blind hole penetrating the PP insulating layer 4 of the build-up circuit board is obtained, so that the PP insulating layer 4 is connected from top to bottom through the blind hole. A window can be opened on the copper foil 5 above the blind hole by chemical etching or laser, and the blind hole is filled by electroplating. The electroplating filling method includes electroplating half-filling and electroplating filling.

[0030] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A heat dissipation circuit board, characterized in that: include: An inner layer circuit board and a plurality of build-up layer circuit boards, wherein the plurality of build-up layer circuit boards are sequentially pressed onto the outer side of the inner layer circuit board, wherein at least one electronic component embedding area (6) is provided in the inner layer circuit board, wherein the electronic component embedding area (6) is used to install embedded electronic components, wherein a plurality of blind holes are provided on the build-up layer circuit board, wherein the plurality of blind holes are connected to the inner layer circuit board, wherein the blind holes include conductive blind holes (1) and heat dissipation blind holes (2), wherein the heat dissipation blind holes (2) are square blind holes.

2. The heat dissipation circuit board according to claim 1, characterized in that: The embedded components include resistors, capacitors, inductors and power components.

3. The heat dissipation circuit board according to claim 1, characterized in that: The heat dissipation blind hole (2) is filled with a heat-conducting medium, and the conductive blind hole (1) is filled with a conductive medium.

4. A method for manufacturing a heat dissipation circuit board according to any one of claims 1 to 3, characterized in that: The steps include: forming an inner circuit board with embedded electronic components by a lamination operation; Arrange a build-up circuit board outside the inner circuit board; Pressing the build-up circuit board and the inner circuit board together; Opening a blind hole on the build-up circuit board, and connecting the embedded electronic component to the outside of the build-up circuit board through the blind hole; The blind holes include heat-conducting blind holes and electrical blind holes (1), and the heat-conducting blind holes are square.

5. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: Opening a blind hole on the build-up circuit board includes: A blind hole is opened on the build-up circuit board by laser drilling, and the laser drilling method includes carbon dioxide laser and UV laser.

6. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: The step of opening a blind hole on the build-up circuit board further comprises: A blind hole is opened on the build-up circuit board by mechanical drilling.

7. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: The blind hole is filled by electroplating, and the electroplating filling includes half-filling and flat-filling.

8. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: The inner layer circuit boards with embedded electronic components formed by lamination operations include: Pressing together at least one embedded electronic component, a core layer (3), two upper and lower PP insulation layers (4), and a copper foil (5) to form the inner layer circuit board; Wherein, an electronic component embedding area (6) is provided in the Core layer (3), and the embedded electronic component is installed in the electronic component embedding area (6).

9. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: The inner layer circuit board with embedded electronic components formed by lamination operation also includes: Pressing together at least one embedded electronic component, a through-hole plate (7), two upper and lower PP insulation layers (4), and a copper foil (5) to form the inner layer circuit board; Wherein, an electronic component embedding area (6) is provided in the through-hole plate (7), and the embedded electronic component is installed in the electronic component embedding area (6).

10. The method for manufacturing a heat dissipation circuit board according to claim 4, characterized in that: The conductive blind hole (1) is also formed in a square shape.

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