JP5254274B2 - Circuit board - Google Patents

Description

  The present invention generally relates to a circuit board and a manufacturing method thereof, and more particularly to a circuit board having a cavity and a manufacturing method thereof.

  Today's market demands that electrical products be designed to be small, thin, lightweight, and portable. Therefore, in such an electrical product, the thickness of the assembly of the electronic component and the circuit board must also be thin.

  Conventionally, the thickness of an electronic component (for example, a chip package product) and a circuit board assembly has been reduced by forming a cavity in the circuit board and placing the electronic component in the cavity. FIG. 1 is a cross-sectional view of a conventional circuit board. Referring to FIG. 1, a circuit board 100 has a core layer 110 and circuit structures 120 and 130 disposed above and below the core layer 110, respectively. The core layer 110 has a core dielectric layer 112 and two circuit layers 114 and 116 disposed above and below the core dielectric layer 112, respectively. The cavity R1 penetrates the circuit structure 120 and the core dielectric layer 112 and exposes the circuit layer 116.

  In the conventional manufacturing process of the circuit board 100, additional layers are stacked on both sides of the core layer 110 to form the circuit structure 120 and the circuit structure 130, and a part of the circuit structure 120 and a part of the core dielectric layer 112 are formed. The circuit layer 116 is exposed. In this way, the circuit layer 116 is embedded in the dielectric layer 132 of the circuit structure 130.

  Accordingly, the present invention is directed to a circuit board having two stacked core layers.

  The present invention is further directed to a method of manufacturing a circuit board having two stacked core layers.

  The present invention provides a circuit board having a cavity. The circuit board includes a first core layer, a second core layer, and a central dielectric layer. The first core layer includes a core dielectric layer and a core circuit layer, and the core circuit layer is disposed on the core dielectric layer. The second core layer is disposed on the first core layer. The central dielectric layer is disposed between the first core layer and the second core layer. The cavity penetrates the second core layer and the central dielectric layer and exposes a portion of the core circuit layer.

  According to an embodiment of the present invention, the core circuit layer protrudes from the surface of the core dielectric layer.

  According to an embodiment of the present invention, the circuit board further includes a first circuit structure and a second circuit structure. The first circuit structure is disposed on the opposite side of the first core layer from the central dielectric layer, and the second circuit structure is disposed on the opposite side of the second core layer from the central dielectric layer, and the cavity Penetrates the second circuit structure.

  According to an embodiment of the present invention, the first circuit structure includes a first dielectric layer and a first circuit layer, the first dielectric layer being disposed on the first core layer, The circuit layer is disposed on the first dielectric layer.

  According to an embodiment of the present invention, the second circuit structure includes a second dielectric layer and a second circuit layer, the second dielectric layer being disposed on the second core layer, The circuit layer is disposed on the second dielectric layer.

  According to an embodiment of the present invention, the core circuit layer has a laser resist pattern, and the laser resist pattern is located around a portion of the core dielectric layer exposed by the cavity.

  According to an embodiment of the present invention, the central dielectric layer covers part of the laser resist pattern and the cavity exposes other parts of the laser resist pattern.

  According to an embodiment of the present invention, a gap exists between the central dielectric layer and the core dielectric layer, and the gap is located around a part of the core dielectric layer exposed by the cavity.

The present invention provides a circuit board manufacturing method. Initially, a first core layer, a second core material layer, and a central dielectric material layer are provided. The first core layer includes a core dielectric layer and a core circuit layer. The core circuit layer is disposed on the core dielectric layer, and the core circuit layer is a non-embedded circuit layer. The second core material layer is disposed on the first core layer, and the central dielectric material layer is disposed between the first core layer and the second core material layer.
Next, the first core layer, the second core material layer, and the central dielectric material layer are pressed to form a composite circuit structure. The composite circuit structure has a pre-removed region, and at least a part of the core circuit layer is located in the pre-removed region. Subsequently, a portion of the central dielectric material layer located around the pre-removed region and a portion of the second core material layer located around the pre-removed region are removed. Thereafter, a portion of the central dielectric material layer located within the pre-removed region and a portion of the second core material layer located within the pre-removed region are removed to form the central dielectric layer and the second core layer To do.

  According to an embodiment of the present invention, the step of pressing the first core layer, the second core material layer, and the central dielectric material layer further includes the following steps. Initially, a first dielectric material layer and a first conductive layer are pressed over the first core layer, wherein the first dielectric material layer is the first core layer and the first conductive layer. Located between. The second dielectric material layer and the second conductive layer are pressed onto the second core layer, wherein the second dielectric material layer is interposed between the second core layer and the second conductive layer. To position. Next, the first conductive layer and the second conductive layer are patterned to form a first circuit layer and a second circuit layer.

  According to an embodiment of the present invention, the manufacturing method removes a portion of the central dielectric material layer and the second core material layer located around the pre-removed region, while the second material located around the pre-removed region. Removing a portion of the dielectric material layer of the first dielectric material layer, and removing the central dielectric material layer and a portion of the second core material layer located in the pre-removed region, while removing the second dielectric material layer in the pre-removed region. Removing a portion of the second dielectric material layer to form a second dielectric layer;

  According to an embodiment of the present invention, the technique of removing a portion of the central dielectric material layer located around the pre-removed region and a portion of the second core material layer located around the pre-removed region is laser etching. Including technology.

  According to an embodiment of the present invention, the core circuit layer has a laser resist pattern, and the laser resist pattern is located around the pre-removed area.

  According to an embodiment of the present invention, the manufacturing method further includes performing an etching process or a mechanical process to remove the laser resist pattern.

  According to an embodiment of the present invention, a technique for removing a portion of the central dielectric material layer located in the pre-removed region and a portion of the second core material layer located in the pre-removed region includes a lift-off technique. Is included.

  According to an embodiment of the present invention, the first core layer further includes a protective layer, which covers the portion of the core circuit layer located within the pre-removal layer.

According to an embodiment of the present invention, the manufacturing method includes after removing the portion of the central dielectric material layer located in the pre-removed region and the portion of the second core material layer located in the pre-removed region. The method further includes removing the protective layer.

  The present invention provides a circuit board having a cavity. The circuit board includes a multilayer core structure. The multilayer core structure includes a plurality of core layers and a plurality of central dielectric layers that are alternately stacked together. The cavity extends through a portion of the core layer and at least a portion of the central dielectric layer of the multilayer core structure. One of the core layers is located at the bottom of the cavity, and the cavity exposes the core circuit layer of the core layer located at the bottom of the cavity.

  According to an embodiment of the present invention, the circuit board further includes a first circuit structure and a second circuit structure. The first circuit structure is disposed on the first surface of the multilayer core structure. The second circuit structure is disposed on the second surface of the multilayer core structure. The first side is the opposite side of the second side and the cavity penetrates the second circuit structure.

  According to an embodiment of the present invention, the first circuit structure includes a first dielectric layer and a first circuit layer. The first dielectric layer is disposed on the first surface of the multilayer core structure. The first circuit layer is disposed on the first dielectric layer.

  According to an embodiment of the present invention, the second circuit structure includes a second dielectric layer and a second circuit layer. The second dielectric layer is disposed on the second surface of the multilayer core structure. The second circuit layer is disposed on the second dielectric layer.

  As described above, the circuit board provided in the present invention has a plurality of core layers and a plurality of central dielectric layers that are alternately stacked together. Thus, when the cavity penetrates more than half of the dielectric layer, the cavity penetrates several core layers and at least some central dielectric layers, and the core of the core layer located at the bottom of the cavity Expose the circuit layer.

  The accompanying drawings are included to provide a further understanding of the invention, and are included in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the nature of the invention.

It is sectional drawing of the conventional circuit board. It is sectional drawing of the circuit board based on one Example of this invention. It is a modification of the circuit board of FIG. 2A. It is sectional drawing which shows the manufacturing process of the circuit board based on one Example of this invention. It is sectional drawing which shows the manufacturing process of the circuit board based on one Example of this invention. It is sectional drawing which shows the manufacturing process of the circuit board based on one Example of this invention. It is sectional drawing which shows the manufacturing process of the circuit board based on one Example of this invention. It is sectional drawing which shows the manufacturing process of the circuit board based on one Example of this invention. It is a modification of the circuit board of FIG. 3E. It is a modification of the circuit board of FIG. 3E.

  Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

  FIG. 2A is a cross-sectional view of a circuit board in one embodiment of the present invention. FIG. 2B shows another embodiment of the circuit board of FIG. 2A. Referring to FIG. 2A, the circuit board 200 of this embodiment has a cavity R. The circuit board 200 includes a first core layer 210, a second core layer 220, a central dielectric layer 230, a first circuit structure 240, and a second circuit structure 250.

  The first core layer 210 includes a core dielectric layer 212 and two core circuit layers 214 and 216. The core circuit layers 214 and 216 are disposed on the upper surface 212a and the lower surface 212b of the core dielectric layer 212, respectively, and are electrically connected to each other. Core circuit layers 214 and 216 protrude from surfaces 212a and 212b of core dielectric layer 212, respectively.

  The second core layer 220 is disposed on the first core layer 210. The second core layer 220 includes a core dielectric layer 222 and two core circuit layers 224 and 226. The core circuit layers 224 and 226 are disposed on the upper surface 222a and the lower surface 222b of the core dielectric layer 222, respectively, and are electrically connected to each other. The central dielectric layer 230 is disposed between the first core layer 210 and the second core layer 220.

  The first circuit structure 240 is disposed on the surface 218 of the first core layer 210 opposite the central dielectric layer 230. In this example, the first circuit structure 240 includes two dielectric layers 242 and 246 and two circuit layers 244 and 248 stacked together. The dielectric layer 242 is disposed on the first core layer 210, the circuit layer 244 is disposed on the dielectric layer 242 between the dielectric layers 242 and 246, and the circuit layer 248 is a circuit layer of the dielectric layer 246. It is disposed on the surface opposite to 244. However, in this embodiment, the number of circuit layers and dielectric layers of the first circuit structure 240 is not limited. That is, there can be one or more circuit layers and dielectric layers.

  The second circuit structure 250 is disposed on the surface 228 of the second core layer 220 opposite to the central dielectric layer 230. In this example, the second circuit structure 250 includes two dielectric layers 252 and 256 and two circuit layers 254 and 258 stacked together. The dielectric layer 252 is disposed on the second core layer 220, the circuit layer 254 is disposed on the dielectric layer 252 between the dielectric layers 252 and 256, and the circuit layer 258 is a circuit layer of the dielectric layer 256. It is disposed on the surface opposite to 254. However, in this embodiment, the number of circuit layers and dielectric layers of the second circuit structure 250 is not limited. That is, there can be one or more circuit layers and dielectric layers.

  The cavity R of the circuit board 200 penetrates the second core layer 220, the central dielectric layer 230, and the second circuit structure 250 and exposes a part of the core circuit layer 214. In this embodiment, the number of dielectric layers that the cavity R penetrates (including the central dielectric layer 230, the core dielectric layer 222, and the dielectric layers 242 and 246) is the dielectric that the cavity R does not penetrate. Note that there are more body layers (including core dielectric layer 212 and dielectric layers 242 and 246). That is, the cavity R penetrates more than half of the dielectric layer (of the circuit board 200). However, in other embodiments, the cavity R may penetrate less than half of the dielectric layer. In this embodiment, the circuit board 200 has the first core layer 210 and the second core layer 220 stacked together, so that the cavity R passes through the second dielectric layer when more than half of the dielectric layer is passed through. The core circuit layer 214 of the first core layer 210 is exposed through the core layer 220.

It should be noted that in this embodiment, the number of core layers is not limited. That is, there may be three or more core layers. The cavity penetrates a part of the core layer and at least a part of the central dielectric layer, and one core layer is located at the bottom of the cavity, and the cavity is formed of the core layer located at the bottom of the cavity. The circuit layer may be exposed. For example, as shown in FIG. 2B, the circuit board 200a of the present embodiment includes a multilayer core structure M.
The multi-layer core structure M includes a first core layer 210, a second core layer 220, a third core layer 270, and a central dielectric layer disposed between the first core layer 210 and the second core layer 220. 230 and a central dielectric layer 280 disposed between the second core layer 220 and the third core layer 270. The cavity R penetrates the second core layer 220, the third core layer 270, the central dielectric layer 230, and the central dielectric layer 280, and the first core layer 210 is located at the bottom of the cavity R. The core circuit layer 214 is exposed. In this embodiment, it should be noted that the number of core layers through which the cavity R in the multilayer core structure M penetrates and the number of core layers that do not penetrate are not limited. That is, the cavity R may penetrate only the third core layer 270.

  Referring again to FIG. 2A, in this example, the core circuit layer 214 has a laser resist pattern 214a located around the core dielectric layer 212 exposed by the cavity R. The central dielectric layer 230 covers a part of the laser resist pattern 214a, and the cavity R exposes the other part of the laser resist pattern 214a. Further, in this embodiment, the solder resist layer 260 is formed for each of the first circuit structure 240, the second circuit structure 250, and the first core layer 210, and the circuit layer 248, the circuit layer 258, and the core are formed. A part of the circuit layer 214 is covered and protected.

  Below, the manufacturing method of the circuit board 200 in a present Example is described in detail.

  3A to 3E are cross-sectional views illustrating a circuit board manufacturing process according to an embodiment of the present invention. FIG. 3F is another example of the circuit board shown in FIG. 3E. FIG. 3G is another example of the circuit board shown in FIG. 3E.

  First, referring to FIG. 3A, a first core layer 210, a second core material layer 220a, a central dielectric material layer 230a, a dielectric layer 242, a conductive layer 244a, a dielectric material layer 252a, and a conductive layer 254a. Is provided.

  The first core layer 210 has the same structure as the first core layer 210 of FIG. 2A. The second core material layer 220 a is disposed on the first core layer 210. The central dielectric material layer 230a is disposed between the first core layer 210 and the second core material layer 220a. The dielectric layer 242 is disposed on the surface of the first core layer 210 opposite to the central dielectric material layer 230a, and is disposed between the first core layer 210 and the conductive layer 244a. The dielectric material layer 252a is disposed on the surface of the second core material layer 220a opposite to the central dielectric material layer 230a, and is disposed between the conductive layer 254a and the second core material layer 220a.

Next, referring to FIG. 3B, the first core layer 210, the second core material layer 220a, the central dielectric material layer 230a, the dielectric layer 242, the conductive layer 244a, the dielectric material layer 252a, and the conductive layer 254a. Are pressed together to form a composite circuit structure C. The synthetic circuit structure C has a pre-removal region P, and a part of the core circuit layer 214 is located in the pre-removal region P.
Subsequently, the conductive layer 244 and the conductive layer 254a are respectively patterned to form the circuit layer 244 and the circuit layer 254. The plurality of conductive channels V1 and V2 are the first core and the circuit layer 244 and the circuit layer 254 are respectively the first core. It is formed so as to be electrically connected to the layer 210 and the second core material layer 220a.

  Thereafter, referring to FIG. 3C, the dielectric layer 246a and the circuit layer 248 are formed by the same technique as that for forming the dielectric layer 242, the circuit layer 244, the dielectric material layer 252a, and the circuit layer 254. A dielectric material layer 256a and a circuit layer 258 are formed over the dielectric material layer 252a.

Subsequently, referring to FIG. 3D, the central dielectric material layer 230a, the second core material layer 220a, and the dielectric material layers 252a and 256a, which are located around the pre-removed region P, are formed of the material layer 230a described above. , 220a, 252a, and 256 to form a gap G that is removed by a laser etching process. In this embodiment, in order to protect the core dielectric layer 212 from being damaged by the laser etching process, the core circuit layer 214 may have a laser resist pattern 214a located on the surface of the pre-removed region P.
Further, the first core layer 210 may have a protective layer A. In order to protect the core circuit layer 214 in the subsequent removal step, the protective layer A covers a part of the core circuit layer 214 located in the pre-removed region P. Further, the protective layer A can be a release layer so that the central dielectric material layer 230a located in the pre-removed region P can be easily removed.

Subsequently, referring to FIG. 3E, the central dielectric layer 230, the second core layer 220, and the dielectric layers 252 and 256 and the cavity R are located in the pre-removed region P. The central dielectric material layer 230a, the second core material layer 220a, and the dielectric material layers 252a and 256a are removed by a lift-off technique. Dielectric layers 252 and 256, and circuit layers 254 and 258 form second circuit structure 250, and cavity R includes second circuit structure 250, second core layer 220, and middle-dielectric. It penetrates layer 230. Subsequently, the protective layer A is removed.
In another embodiment, the protective layer A, the central dielectric material layer 230a, the second core material layer 220a, and the dielectric material layers 252a and 256a, which are located in the pre-removed region P, are all removed together. be able to. Next, in this embodiment, in order to cover and protect the circuit layers 248 and 258 and a part of the core circuit layer 214, the solder resist layer 260 is provided with the first circuit structure 240 and the second circuit structure 250, respectively. , And on the first core layer 210.

  In another embodiment, referring to FIG. 3F, before forming the solder resist layer 260, a part of the laser resist pattern 214a exposed by the cavity R is removed by a mechanical process.

  In yet another embodiment, referring to FIG. 3G, before forming the solder resist layer 260, the laser resist pattern 214a is removed by an etching process. In this regard, the gap G exists between the central dielectric layer 230 and the core dielectric layer 212, and the gap G is located around the portion of the core dielectric layer 212 exposed by the cavity R. To do.

  In summary, the circuit board provided by the present invention has a plurality of core layers and a plurality of central dielectric layers that are alternately stacked together. Thus, when the cavity penetrates more than half of the dielectric layer, the cavity penetrates part of the core layer and at least part of the central dielectric layer, and the core of the core layer located at the bottom of the cavity. Expose the circuit layer.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the above, the present invention is intended to cover improvements and modifications of the invention which fall within the scope of the following claims and their equivalents.

Claims (6)

A circuit board having a cavity,
A first core layer comprising a core dielectric layer and a core circuit layer, wherein the core circuit layer is disposed on the core dielectric layer;
A second core layer disposed on the first core layer;
A central dielectric layer disposed between the first core layer and the second core layer;
A first circuit structure disposed on the first core layer opposite to the central dielectric layer;
A second circuit structure disposed on the second core layer opposite to the central dielectric layer;
With
The cavity penetrates through the second circuit structure, the second core layer and the central dielectric layer, exposing a portion of the core circuit layer;
The first circuit structure is:
A first dielectric layer disposed on the first core layer;
A first circuit layer disposed on the first dielectric layer,
The core circuit layer has a laser resist pattern;
The laser resist pattern is located around a portion of the core dielectric layer exposed by the cavity to expose a portion of the core circuit layer;
A circuit board characterized by that. The second circuit structure is:
A second dielectric layer disposed on the second core layer;
A second circuit layer disposed on the second dielectric layer;
The circuit board according to claim 1, comprising: The central dielectric layer covers a portion of the laser resist pattern;
The cavity exposes other portions of the laser resist pattern;
The circuit board according to claim 1. A circuit board having a cavity,
A first core layer comprising a core dielectric layer and a core circuit layer, wherein the core circuit layer is disposed on the core dielectric layer;
A second core layer disposed on the first core layer;
A central dielectric layer disposed between the first core layer and the second core layer;
A first circuit structure disposed on the first core layer opposite to the central dielectric layer;
A second circuit structure disposed on the second core layer opposite to the central dielectric layer;
With
The cavity penetrates through the second circuit structure, the second core layer and the central dielectric layer, exposing a portion of the core circuit layer;
The first circuit structure is:
A first dielectric layer disposed on the first core layer;
A first circuit layer disposed on the first dielectric layer,
There is a gap between the central dielectric layer and the core dielectric layer;
The gap is located around a portion of the core dielectric layer exposed by the cavity;
A circuit board characterized by that. A circuit board having a cavity,
A multilayer core structure comprising a plurality of core layers and a plurality of central dielectric layers stacked together;
A first circuit structure disposed on a first surface of the multilayer core structure;
A second circuit structure disposed on a second surface opposite to the first surface of the multilayer core structure;
With
The cavity penetrates through the second circuit structure, a portion of the core layer and at least a portion of the central dielectric layer of the multilayer core structure;
One of the core layers is located at the bottom of the cavity;
The cavity exposes a core circuit layer of the core layer located at a bottom of the cavity;
The first circuit structure comprises a first dielectric layer disposed on the first surface of the multilayer core structure and a first circuit layer disposed on the first dielectric layer;
The core circuit layer has a laser resist pattern;
The laser resist pattern is positioned around a portion of the dielectric layer of the core layer that is exposed by the cavity, exposing a portion of the core circuit layer;
A circuit board characterized by that. The second circuit structure comprises a second dielectric layer disposed on the second surface of the multilayer core structure and a second circuit layer disposed on the second dielectric layer;
The circuit board according to claim 5 .

Images