TWI749672B - Embedded circuit board and manufacturing method thereof - Google Patents

Abstract

The invention provides an embedded circuit board. The embedded circuit board includes a first circuit layer, a second circuit layer and an embedded component. The first circuit layer includes a first substrate and a first conductive circuit. The first substrate includes a first surface. The first conductive circuit is disposed on the first surface. The second circuit layer includes a second substrate. The first substrate and the second substrate have different light absorption rates. An embedded groove penetrating the second substrate is formed on the second substrate. The embedded groove exposes the first surface. The embedded component is arranged in the embedded groove. The first conductive circuit includes a heat dissipation unit. At least part of the heat dissipation unit extends to the embedded groove and contacts the embedded component. The invention also provides a manufacturing method of the embedded circuit board.

Description

Embedded circuit board and manufacturing method thereof

The invention relates to the technical field of embedded circuit boards, in particular to an embedded circuit board and a manufacturing method thereof.

In recent years, electronic products have been widely used in daily work and life, and light, thin, and small electronic products have become more and more popular. As the main component of electronic products, circuit boards occupies a large space of electronic products. Therefore, the volume of circuit boards affects the volume of electronic products to a large extent. Large-volume circuit boards are bound to be difficult to meet the requirements of light, thin and light electronic products. The trend of short and small. Among them, the embedded circuit board mainly embeds the electronic components inside the circuit board, so that the circuit board module can be miniaturized, the connection path between the components can be shortened, and the transmission loss can be reduced. The embedded circuit board can be realized. A technical approach for portable electronic devices to be smaller, more portable, multi-functional and high-performance.

In order to open the buried groove for accommodating the embedded components, the industry usually isolates the substrate layer from the copper layer by using peelable glue, then removes the substrate by etching, and then removes the peelable glue by opening the lid. ; However, in this method, there will be residual glue remaining on the surface of the copper layer after the peelable glue is peeled off, which makes the electrical connection between the copper layer and the embedded components ineffective or reduces the thermal conductivity, and the circuit board is easily scratched during the opening process Furthermore, the process of this method is complicated. The industry can also use the method of forming the fishing trough to open the buried tank. This method has a simple process and lower cost, but the accuracy is low. The depth of the formed buried tank is not easy to control, and it is easy to damage the substrate or Conductive lines.

Those skilled in the art need to consider how to solve the above-mentioned problems.

In view of this, the present invention provides an embedded circuit board, including: a first circuit layer, the first circuit layer includes a first substrate and a first conductive circuit, the first substrate includes a first surface, so The first conductive circuit is disposed on the first surface; a second circuit layer, the second circuit layer includes a second substrate, and the first substrate and the second substrate have different light absorption rates, An embedded groove penetrating the second substrate is formed on the second substrate, the embedded groove exposing the first surface; an embedded element, the embedded element is arranged in the embedded groove; And the first conductive circuit includes a heat dissipation unit, and at least a part of the heat dissipation unit extends to the buried groove and is in contact with the buried element.

In one embodiment, the material of the second substrate includes glass fiber.

In one embodiment, the second substrate includes a second surface, the second surface is disposed on a side of the second substrate away from the first substrate, and the embedded groove penetrates the second substrate. On the surface, the second circuit layer further includes a second conductive circuit, and the second conductive circuit is disposed on the second surface.

In one embodiment, the embedded circuit board further includes a third circuit layer, the third circuit layer includes a third substrate and a third conductive circuit, and the third conductive circuit is disposed on the third substrate. On the surface of the material, the first substrate covers at least part of the third conductive circuit.

The present application also provides a method for manufacturing an embedded circuit board, including the following steps: providing a first double-sided board, the first double-sided board including a third substrate and a third conductive layer formed on the surface of the third substrate line; A first substrate and a first conductive material layer are formed on one surface of the first double-sided board by pressing, the first substrate includes a first surface, and the first surface is disposed on the first substrate On the side away from the third substrate, the first conductive material layer is disposed on the first surface; the first conductive material layer is etched to obtain a first conductive circuit, and the first conductive circuit includes a Heat dissipation unit; forming a second substrate by pressing on the side of the first conductive circuit away from the first substrate, the first conductive circuit and the first surface are not the first conductive circuit In the covered part, the first substrate and the second substrate have different light absorption rates; and a laser etching method is used to form an embedded groove on the second substrate, and the embedded groove penetrates For the second substrate, the buried groove exposes at least part of the first surface and the heat dissipation unit.

In one embodiment, the light used for laser etching is excited by a carbon dioxide laser emitter.

In one embodiment, the light excited by the carbon dioxide laser does not etch the first substrate, and the light excited by the carbon dioxide laser etches the second substrate.

In one embodiment, the material of the second substrate includes glass fiber.

In one embodiment, when a second substrate is formed on the side of the first conductive circuit away from the first substrate by pressing, on the side of the second substrate away from the first substrate A second conductive material layer is provided, and the second conductive material layer is etched to obtain a second conductive circuit.

In one embodiment, the method further includes the following steps: providing an embedded element, arranging the embedded element in the embedded groove, and connecting the embedded element with the first conductive circuit.

Compared with the prior art, the embedded circuit board of the present invention and the manufacturing method thereof are formed by arranging a first substrate and a second substrate with different absorption of light, and then forming it by laser etching. The buried groove can achieve precise etching of the buried groove without damaging the first conductive circuit provided on the surface of the first substrate, or leaving glue residue on the surface of the first conductive circuit.

1: Embedded circuit board

11: The first circuit layer

111: The first substrate

112: The first conductive line

115: cooling unit

119: First Surface

12: The second circuit layer

121: second substrate

122: second conductive line

129: Second Surface

13: The third circuit layer

131: The third substrate

132: The third conductive circuit

14: The fourth circuit layer

141: Fourth substrate

142: The fourth conductive circuit

15: Embedded components

16: Buried groove

19: Conductive column

20: The first double panel

21: The first conductive material layer

22: second conductive material layer

23: The third conductive material layer

24: Fourth conductive material layer

Fig. 1 is a schematic partial cross-sectional view of an embedded circuit board according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

4 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

FIG. 9 is a schematic diagram of a manufacturing process of an embedded circuit board according to an embodiment of the present invention.

The following description will refer to the accompanying drawings to more fully describe the content of this application. The drawings show exemplary embodiments of the application. However, this application can be implemented in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided to make this application thorough and complete, and to fully convey the scope of this application to those skilled in the art. Similar reference numerals indicate the same or similar components.

The terminology used herein is only used for the purpose of describing specific exemplary embodiments, and is not intended to limit the application. As used herein, unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" are intended to also include the plural forms. In addition, when used herein, "include" and/or "include" or "include" and/or "include" or "have" and/or "have", Numbers, steps, operations, elements and/or elements, but does not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, elements and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the field described in this application. In addition, unless clearly defined in the text, terms such as those defined in a general dictionary should be interpreted as having meanings consistent with their meanings in the related technology and the content of this application, and will not be interpreted as idealized or overly formal meanings.

The following content will describe exemplary embodiments with reference to the accompanying drawings. It should be noted that the elements depicted in the reference drawings are not necessarily shown to scale; and the same or similar components will be given the same or similar reference signs or similar technical terms.

The specific implementation of the present application will be described in further detail below with reference to the accompanying drawings.

As shown in FIG. 1, the present application provides an embedded circuit board 1, which includes a first circuit layer 11, a second circuit layer 12, a third circuit layer 13 and an embedded component 15. The first circuit layer 11 is arranged on the side of the third circuit layer 13, the second circuit layer 12 is arranged on the side of the first circuit layer 11 away from the third circuit layer 13, and the second circuit layer 12 is provided with a buried groove 16 inside. The buried groove 16 penetrates the second circuit layer 12 to expose at least a part of the surface of the first circuit layer 11, and the buried element 15 is disposed in the buried groove 16.

The third circuit layer 13 includes a third substrate 131 and a third conductive circuit 132, and the third conductive circuit 132 is disposed on the surface of the third substrate 131. In one embodiment, the third circuit layer 13 may be a double-sided board, and the third conductive circuit 132 includes two layers of conductive circuits, and the two layers of conductive circuits are respectively disposed on two opposite surfaces of the third substrate 131.

In an embodiment, the embedded circuit board 1 may further include a fourth circuit layer 14, and the fourth circuit layer 14 is disposed on the side of the third circuit layer 13 away from the first circuit layer 11. In this embodiment, the fourth circuit layer 14 is a single-layer circuit stack structure, that is, the fourth circuit layer 14 includes a fourth substrate 141 and a fourth substrate 141 disposed on the surface of the fourth substrate 141 away from the first circuit layer 11. Four conductive lines 142. In other embodiments, the fourth line The layer 14 may be a multilayer circuit stack structure, that is, the fourth circuit layer 14 includes a substrate and a conductive circuit arranged in a multilayer stack.

The first circuit layer 11 includes a first substrate 111 and a first conductive circuit 112, the first substrate 111 includes a first surface 119, and the first conductive circuit 112 is disposed on the first surface 119. The first circuit layer 11 is disposed on the side of the third circuit layer 13 and covers at least one surface of the third circuit layer 13, and the first substrate 111 covers at least part of the third conductive circuit 132, which can be specifically disposed on the third substrate 131 A third conductive circuit 132 on one surface.

The second circuit layer 12 includes a second substrate 121 and a second conductive circuit 122. The second substrate 121 includes a second surface 129. The second surface 129 is disposed on the side of the second substrate 121 away from the first substrate 111. The two conductive lines 122 are disposed on the second surface 129.

In one embodiment, the embedded circuit board 1 further includes a plurality of conductive pillars 19, and the plurality of conductive pillars 19 are respectively disposed on the first substrate 111, the second substrate 121, the third substrate 131, and the fourth substrate. In 141, the first conductive circuit 112, the second conductive circuit 122, the third conductive circuit 132, and the fourth conductive circuit 142 can be electrically connected by the conductive pillar 19. In an embodiment, the conductive pillar 19 may be a plated conductive hole or a through hole filled with conductive paste.

The second substrate 121 is formed with an embedded groove 16 passing through the second substrate 121, the embedded groove 16 penetrates the second surface 129, and the embedded groove 16 exposes at least part of the first surface 119.

The first substrate 111 and the second substrate 121 have different absorption rates of light. Specifically, the first substrate 111 and the second substrate 121 have different absorption rates of light excited by the carbon dioxide laser generator, and the second substrate 121 It can be etched by the light excited by the carbon dioxide laser generator, and the first substrate 111 cannot be etched by the light excited by the carbon dioxide laser generator. In an embodiment, the material of the second substrate 121 may include glass fiber.

In one embodiment, the first conductive circuit 112 includes a heat dissipation unit 115, at least a part of the heat dissipation unit 115 extends to the embedded groove 16, a part of the heat dissipation unit 115 is covered by the second substrate 121, and the other part The points are exposed by the buried groove 16. In other embodiments, the heat dissipation unit 115 may be replaced with a terminal for transmitting electrical signals.

The embedded element 15 is disposed in the embedded groove 16, the embedded element 15 is connected to the heat dissipation unit 115, and the embedded element 15 is connected to the first conductive circuit 112; in one embodiment, the embedded element 15 is physically connected to the heat dissipation unit 115 The contact realizes heat dissipation. When the heat dissipation unit 115 is replaced with a terminal for transmitting electrical signals, the embedded element 15 can be electrically connected to the structure. In an embodiment, the embedded element 15 may be an active element or a passive element such as a resistor, a capacitor, or an inductor.

In an embodiment, the embedded circuit board 1 may further include a solder resist layer or a protective layer disposed on the outermost side to protect the embedded circuit board 1.

As shown in Figs. 2-9, a method for manufacturing an embedded circuit board 1 provided in this application includes the following steps:

Step S1: Provide a first double-sided board 20. The first double-sided board 20 includes a third substrate 131 and a third conductive circuit 132 formed on the surface of the third substrate 131.

Step S11: As shown in FIG. 2, a first double-sided board 20, a third substrate 131 of the first double-sided board 20, and a third conductive material layer 23 disposed on opposite surfaces of the third substrate 131 are provided.

In one embodiment, the first double-sided board 20 may be a double-sided copper clad substrate.

Step S12: As shown in FIG. 3, the third conductive material layer 23 is etched to form a third conductive circuit 132, and a third circuit layer 13 is obtained.

In one embodiment, the third conductive material layer 23 can be etched by yellow light development and etching, and the third conductive material layer 23 disposed on both sides of the third substrate 131 can be etched in the same etching. Or it can be etched in different etching processes.

Step S2: As shown in FIG. 4, a first substrate 111 and a first conductive material layer 21 are formed on one surface of the first double-sided board 20 by pressing. The first substrate 111 includes a first surface 119. One surface 119 The first substrate 111 is disposed on a side away from the third substrate 131, and the first conductive material layer 21 is disposed on the first surface 119.

Step S3: As shown in FIG. 5, the first conductive material layer 21 is etched to obtain a first conductive circuit 112, and the first conductive circuit 112 includes a heat dissipation unit 115.

In one embodiment, a plurality of conductive pillars 19 are formed, and the first conductive line 112 is electrically connected to the third conductive line 132 through the conductive pillars 19, and the third conductive lines 132 distributed on different surfaces can also be electrically connected by the conductive pillars 19 Electrical connection.

In one embodiment, the plurality of conductive pillars 19 may be formed by punching and electroplating, or may be formed by punching and plugging conductive paste.

Step S4: As shown in FIG. 6, a second substrate 121 is formed on the side of the first conductive circuit 112 away from the first substrate 111 by pressing, and the second substrate 121 covers the first conductive circuit 112 and the first surface In the portion 119 that is not covered by the first conductive circuit 112, the first substrate 111 and the second substrate 121 have different light absorption rates.

In one embodiment, when a second substrate 121 is formed on the side of the first conductive circuit 112 away from the first substrate 111 by pressing, a second substrate 121 is provided on the side of the second substrate 121 away from the first substrate 111. The second conductive material layer 22 is etched to obtain a second conductive circuit 122.

In an embodiment, a fourth substrate 141 and a fourth conductive material layer 24 may be pressed on the side of the third substrate 131 away from the first substrate 111.

Step S5: As shown in FIG. 7, an embedded groove 16 is formed on the second substrate 121 by laser etching, the embedded groove 16 penetrates the second substrate 121, and the embedded groove 16 allows the first surface 119 and heat to be dissipated At least part of the unit 115 is exposed.

In one embodiment, the light used for laser etching is excited by a carbon dioxide laser emitter.

In one embodiment, the light excited by the carbon dioxide laser emitter does not etch the first substrate 111, and the light excited by the carbon dioxide laser emitter etches the second substrate 121.

In an embodiment, the material of the second substrate 121 includes glass fiber.

By arranging the first substrate 111 and the second substrate 121 with different absorption rates of light, the first substrate 111 is not etched by the light emitted by the laser emitter or the absorption rate of the first substrate 111 to the etching light is maintained at An extremely low level keeps the etching of the first substrate 111 caused by the etching light at an extremely low level. At the same time, the second substrate 121 has a higher absorption rate of the etching light, and the second substrate 121 is easier to be etched. . That is, when a laser emitter (such as a carbon dioxide laser emitter) is used for etching, the buried groove 16 can be formed on the second substrate 121 by precise control, but the etching process will not affect the first conductive circuit 112 and the first conductive circuit 112 and the second substrate 121. A substrate 111 causes damage.

Step S6: As shown in FIG. 8, a plurality of conductive pillars 19 are formed, so that the first conductive circuit 112 and the second conductive circuit 122 are electrically connected through the conductive pillars 19, so that the third conductive circuit 132 and the fourth conductive circuit 142 are connected to each other. It is electrically connected by the conductive pillar 19.

Step S7: As shown in FIG. 9, an embedded element 15 is provided, and the embedded element 15 is arranged in the embedded groove 16 so that the embedded element 15 is connected to the first conductive circuit 112.

In the foregoing, specific implementations of the present application have been described with reference to the drawings. However, those of ordinary skill in the art can understand that various changes and substitutions can be made to the specific embodiments of the present application without departing from the spirit and scope of the present application. These changes and replacements fall within the scope defined by this application.

1: Embedded circuit board

11: The first circuit layer

111: The first substrate

112: The first conductive line

115: cooling unit

119: First Surface

12: The second circuit layer

121: second substrate

122: second conductive line

129: Second Surface

13: The third circuit layer

131: The third substrate

132: The third conductive circuit

14: The fourth circuit layer

141: Fourth substrate

142: The fourth conductive circuit

15: Embedded components

16: Buried groove

19: Conductive column

Claims (10)

An embedded circuit board is improved in that it includes: a first circuit layer, the first circuit layer includes a first substrate and a first conductive circuit, the first substrate includes a first surface, the first The conductive circuit is disposed on the first surface; the second circuit layer, the second circuit layer includes a second substrate, the first substrate and the second substrate have different light absorption rates, the first An embedded groove penetrating the second substrate is formed on the two substrates, and the embedded groove exposes the first surface; an embedded element, and the embedded element is disposed in the embedded groove; and The first conductive circuit includes a heat dissipation unit, and at least a part of the heat dissipation unit extends to the buried groove and is in contact with the buried element. The embedded circuit board according to claim 1, wherein the material of the second base material includes glass fiber. The embedded circuit board according to claim 1, wherein the second substrate includes a second surface, and the second surface is disposed on a side of the second substrate away from the first substrate, so The buried groove penetrates the second surface, the second circuit layer further includes a second conductive circuit, and the second conductive circuit is disposed on the second surface. The buried circuit board according to claim 1, wherein the buried circuit board further includes a third circuit layer, the third circuit layer includes a third substrate and a third conductive circuit, the third The conductive circuit is arranged on the surface of the third substrate, and the first substrate covers at least part of the third conductive circuit. A method for manufacturing an embedded circuit board is improved in that it includes the following steps: providing a first double-sided board, the first double-sided board comprising a third substrate and a third conductive layer formed on the surface of the third substrate line; A first substrate and a first conductive material layer are formed on one surface of the first double-sided board by pressing, the first substrate includes a first surface, and the first surface is disposed on the first substrate On the side away from the third substrate, the first conductive material layer is disposed on the first surface; the first conductive material layer is etched to obtain a first conductive circuit, and the first conductive circuit includes a Heat dissipation unit; a second substrate is formed by pressing on the side of the first conductive circuit away from the first substrate, and the second substrate covers the first conductive circuit and the first surface In the part covered by the first conductive circuit, the first substrate and the second substrate have different light absorption rates; and a laser etching method is used to form an embedded groove on the second substrate The embedded groove penetrates the second substrate, and the embedded groove exposes at least part of the first surface and the heat dissipation unit. The method for manufacturing an embedded circuit board according to claim 5, wherein the light used for the laser body etching is excited by a carbon dioxide laser emitter. The method for manufacturing an embedded circuit board according to claim 6, wherein the light excited by the carbon dioxide laser emitter does not etch the first substrate, and the light excited by the carbon dioxide laser emitter etches the second substrate . The method for manufacturing an embedded circuit board according to claim 7, wherein the material of the second base material includes glass fiber. The method for manufacturing an embedded circuit board according to claim 5, wherein when a second substrate is formed on the side of the first conductive circuit away from the first substrate by pressing, the A second conductive material layer is provided on the side of the two substrates away from the first substrate, and the second conductive material layer is etched to obtain a second conductive circuit. The method for manufacturing an embedded circuit board as described in claim 5, which further includes the following steps: An embedded element is provided, the embedded element is arranged in the embedded groove, and the embedded element is connected with the first conductive circuit.

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