TW202114502A - Flexible and rigid composite circuit board - Google Patents

Abstract

A flexible and rigid composite circuit board includes a flexible circuit board, a plurality of rigid circuit board, and an insulating adhesive layer. The flexible circuit board has a bending area and two non-bending area located at two opposite sides of the bending area. The flexible circuit board includes a flexible substrate with a first surface and a second surface opposite to the first surface, a first build-up layer disposed on the first surface, and a second build-up layer disposed on the second surface. The first build-up layer includes a first flexible layer and a first circuit layer. The second build-up layer includes a second flexible layer and a second circuit layer. The rigid circuit board is disposed close to the first surface of the flexible substrate. An orthogonal projection of the rigid circuit board on the flexible circuit board overlaps with the two non-bending area. The insulating adhesive layer is disposed on the first build-up layer, and is located between the flexible circuit board and the rigid circuit board.

Description

Flexible and hard composite circuit board

The present invention relates to a circuit board, and particularly relates to a flexible and hard composite circuit board.

According to the flexibility of the insulating layer, circuit boards can be divided into rigid circuit boards and flexible circuit boards. When the electronic parts are soldered to the flexible circuit board, the flexible circuit board cannot provide sufficient structural strength. On the other hand, in the case of soldering electronic parts, although rigid circuit boards provide better structural strength, they have poor flexibility, which limits the application of rigid circuit boards.

The flexible and hard composite circuit board is a circuit board composed of a flexible circuit board and a rigid circuit board, which has the flexibility of a flexible circuit board and the structural strength of a rigid circuit board. The conventional flexible and hard composite circuit board is press-fitted by arranging the flexible circuit board between two rigid circuit boards. Therefore, it is necessary to remove waste through two-sided processing, which leads to a lengthy process and lowers the yield. In addition, the high-temperature and high-pressure bonding process conditions will cause the flexible circuit board located between the two rigid circuit boards to produce greater deformation and reduce the quality of the product.

The present invention provides a flexible and hard composite circuit board, the processing technology of which can be simplified to improve the yield, and the deformation can be reduced to improve the quality of the product.

The flexible and hard composite circuit board of the present invention includes a flexible circuit board, a plurality of rigid circuit boards and an insulating adhesive layer. The flexible circuit board has a bending area and two non-bending areas located on opposite sides of the bending area. The flexible circuit board includes a flexible substrate having a first surface and a second surface opposite to the first surface, the first build-up layer is arranged on the first surface, and the second build-up layer is arranged on the second surface. The first build-up layer includes a first soft board layer and a first circuit layer. The second build-up layer includes a second soft board and a second circuit layer. The rigid circuit board is arranged close to the first surface of the flexible substrate. The orthographic projection of the rigid circuit board on the flexible circuit board overlaps the two non-bending areas. The insulating adhesive layer is arranged on the first build-up layer and is located between the flexible circuit board and the rigid circuit board.

In an embodiment of the present invention, the above-mentioned first build-up layer is the first flexible board layer and the first circuit layer in order from bottom to top. The second build-up layer is the second soft board layer and the second circuit layer in order from bottom to top. The first circuit layer contacts the first surface, and the second soft board layer contacts the second surface.

In an embodiment of the present invention, the above-mentioned multiple rigid circuit boards include a first rigid circuit board and a second rigid circuit board. The first rigid circuit board has a first opening and is disposed on the first build-up layer. The second rigid circuit board has a second opening and is disposed on the first rigid circuit board. The orthographic projections of the first opening and the second opening on the flexible circuit board are aligned and overlap the bending area to form an opening structure.

In an embodiment of the present invention, the above-mentioned opening structure penetrates through the rigid circuit boards, and the opening structure overlaps the bending area. Part of the first build-up layer is exposed in the opening structure.

In an embodiment of the present invention, the above-mentioned flexible and rigid composite circuit board further includes a first dielectric layer disposed between the first rigid circuit board and the second rigid circuit board.

In an embodiment of the present invention, the above-mentioned first rigid circuit board includes a plurality of first patterned conductive layers and a plurality of first rigid board insulating layers, and the first patterned conductive layers are respectively disposed on the first rigid boards Opposite sides of the insulating layer. The second rigid circuit board includes a plurality of second patterned conductive layers and a plurality of second rigid board insulating layers, and the second patterned conductive layers are respectively disposed on opposite sides of the second rigid board insulating layers.

In an embodiment of the present invention, the above-mentioned flexible and rigid composite circuit board further includes a second dielectric layer and a third patterned conductive layer. The second dielectric layer is disposed on the second rigid circuit board. The second rigid circuit board is located between the second dielectric layer and the first dielectric layer. The third patterned conductive layer is disposed on the second dielectric layer. The second dielectric layer is located between the third patterned conductive layer and the second rigid circuit board.

In an embodiment of the present invention, the above-mentioned flexible and rigid composite circuit board further includes a first conductive through hole. The first conductive via penetrates the first build-up layer, the first rigid circuit board, the second rigid circuit board, the first dielectric layer, the second dielectric layer, and the third patterned conductive layer to electrically connect the first build-up layer , The first rigid circuit board, the second rigid circuit board and the third patterned conductive layer.

In an embodiment of the present invention, the above-mentioned flexible and rigid composite circuit board further includes a third dielectric layer and a fourth patterned conductive layer. The third dielectric layer is disposed on the second dielectric layer and covers the third patterned conductive layer and part of the second dielectric layer. The fourth patterned conductive layer is disposed on the third dielectric layer, wherein the third dielectric layer is located between the fourth patterned conductive layer and the second dielectric layer.

In an embodiment of the present invention, the above-mentioned flexible and hard composite circuit board further includes a first solder mask and a second solder mask. The first solder mask is arranged on the second build-up layer of the flexible circuit board. The second solder mask layer is disposed on the fourth patterned conductive layer.

Based on the above, in the flexible and hard composite circuit board of an embodiment of the present invention, since the rigid circuit board of the flexible and rigid composite circuit board only needs to be arranged on a single side of the flexible circuit board, the rigid circuit board can only be used on one side of the flexible circuit board. The circuit board is processed to remove waste. Under the above-mentioned setting, only one side is required to remove waste materials, which can save processing time, reduce costs, and improve production yield. In addition, the flexible and rigid composite circuit board presents an asymmetrical structure. Therefore, a glass fiber-containing film material is used through the flexible substrate to increase the supporting force of the flexible circuit board and reduce the deformation of the asymmetric structure. In addition, the flexible substrate can also pass through the first build-up layer and the second build-up layer, so that the flexible substrate obtains the effect of stable dimensional deformation and is not easy to be broken, and improves the bendability. Therefore, compared with the conventional flexible substrate, the flexible circuit board of the present invention can provide the flexible and rigid composite circuit board with excellent flexibility and toughness, and has good elasticity, and can reduce deformation and improve product quality.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Hereinafter, some embodiments are listed in conjunction with the accompanying drawings for detailed description, but the provided embodiments are not intended to limit the scope of the present invention. In addition, the drawings are for illustrative purposes only, and are not drawn in accordance with the original dimensions. To facilitate understanding, the same elements in the following description will be described with the same symbols.

In addition, the terms "first", "second"... etc. used in the text do not mean order or sequence, and it should be understood that they are used to distinguish elements or operations described in the same technical terms.

Secondly, the terms "include", "include", "have" and so on used in this article are all open terms; that is, include but are not limited to.

Furthermore, the terms "contact", "connecting", "joining", etc. used in this text, unless otherwise specified, can mean direct contact or indirect contact through other layers.

1A to 1G are schematic cross-sectional views of the manufacturing process of a flexible and rigid composite circuit board according to an embodiment of the present invention. Please refer to FIG. 1G first. In this embodiment, the flexible and hard composite circuit board 10 includes a flexible circuit board 100, a plurality of rigid circuit boards 200, and an insulating adhesive layer 140. The flexible circuit board 100 has a bending area 12 and two non-bending areas 14 located on opposite sides of the bending area 12. The flexible circuit board 100 includes a flexible substrate 120 having a first surface 121 and a second surface 122 opposite to the first surface 121, a first build-up layer 110 disposed on the first surface 121, and a first build-up layer 110 disposed on the second surface 122. The second build-up layer 130. The first build-up layer 110 includes a first flexible board layer 111 and a first circuit layer 112. The second build-up layer 130 includes a second flexible board layer 131 and a second circuit layer 132. A plurality of rigid circuit boards 200 are arranged close to the first surface 121 of the flexible substrate 120, wherein in the direction N perpendicular to the flexible circuit board 100, the orthographic projections of these rigid circuit boards 200 on the flexible circuit board 100 overlap the aforementioned two A non-bending area14. The insulating adhesive layer 140 is disposed on the first build-up layer 110, and the insulating adhesive layer 140 is located between the flexible circuit board 100 and the rigid circuit board 200. In addition, the flexible and rigid composite circuit board 10 further includes an opening structure OP1 that penetrates the rigid circuit boards 200 and overlaps the bending area 12, wherein a part of the first build-up layer 110 is exposed in the opening structure OP. In addition, the flexible and hard composite circuit board 10 further includes a first solder mask layer SR1 and a second solder mask layer SR2. Hereinafter, an embodiment will be used to briefly describe the manufacturing method of the flexible and hard composite circuit board 10.

Please refer to FIG. 1A, the manufacturing method of the flexible and hard composite circuit board 10 (marked in FIG. 1G) includes the following steps. First, a first build-up layer 110 is provided. The first build-up layer 110 includes a first flexible board layer 111 and a first circuit layer 112 disposed on the first flexible board layer 111. The material of the first flexible board layer 111 is, for example, polyimide (PI), and the material of the first circuit layer 112 is, for example, copper foil, but it is not limited thereto.

Next, a release layer 150 is provided on the surface of the first flexible board layer 111 opposite to the first circuit layer 112. In detail, the first build-up layer 110 may first define the bending area 12 and the non-bending area 14 located on opposite sides of the bending area 12. Then, the release layer 150 is disposed on the first build-up layer 110 and located in the bending area 12. From another perspective, in the direction N perpendicular to the first build-up layer 110, the orthographic projection of the release layer 150 on the first build-up layer 110 completely overlaps the bending area 12. In this embodiment, the release layer 150 may be a photo-curable release film or a thermal curable release film, but the invention is not limited thereto. The viscosity of the photo-curable release film will be reduced through a photo-curing process; and the viscosity of the thermally cured release film will be reduced through a thermal-curing process. In other embodiments, the release layer 150 may also be a laser debond release film.

Next, referring to FIG. 1A, a plurality of rigid circuit boards 200 are provided. In this embodiment, the plurality of rigid circuit boards 200 include a first rigid circuit board 210 and a second rigid circuit board 220, and the first rigid circuit board 210 and the second rigid circuit board 220 can be laminated to form a multi-layer The composite rigid circuit board 200. In detail, the first rigid circuit board 210 includes a first rigid board insulating layer 212 and a plurality of first patterned conductive layers 214 respectively disposed on two opposite upper and lower surfaces of the first rigid board insulating layer 212. In this embodiment, the first rigid circuit board 210 is formed by, for example, a first rigid board insulating layer 212 and two first patterned conductive layers 214 respectively disposed on the upper and lower surfaces of the first rigid circuit board 210, but the present invention is not based on this. limit. In some embodiments, the first rigid circuit board may also be formed by a plurality of first rigid board insulating layers and a plurality of first patterned conductive layers respectively disposed on the upper and lower surfaces of the first rigid board insulating layer. In this embodiment, the material of the first rigid board insulating layer 212 is, for example, a prepreg material (PrePreg) to provide the rigidity required by the first rigid circuit board 210. The material of the first patterned conductive layer 214 is a patterned copper foil, but it is not limited to this.

As shown in FIG. 1A, the first rigid board insulating layer 212 also has two cutting grooves 216 formed in the bending area 12. Specifically, the outer edges of the two cutting grooves 216 may be aligned with and/or overlap with the outer edges of the bending area 12 respectively. In addition, the outer edges of the two cutting grooves 216 can also be aligned with and/or overlap with the outer edges of the release layer 150, but the present invention is not limited thereto. As shown in FIG. 1A, the cutting groove 216 may not penetrate through the first rigid board insulating layer 212 and form an opening (not shown) on the upper surface of the first rigid board insulating layer 212, and have a bottom surface (not shown) near the second rigid circuit board 220 ( Not marked, but not limited to this. In this embodiment, the cutting groove 216 can be used as an alignment mark in the process of removing waste in the subsequent processing process.

In this embodiment, the second rigid circuit board 220 includes a second rigid board insulating layer 222 and a plurality of second patterned conductive layers 224 respectively disposed on two opposite upper and lower surfaces of the second rigid board insulating layer 222. As shown in FIG. 1A, the second rigid circuit board 220 is formed by, for example, a second rigid board insulating layer 222 and two second patterned conductive layers 224 respectively disposed on the upper and lower sides of the second rigid circuit board 220, but the present invention is not based on this. limit. In some embodiments, the second rigid circuit board may also be formed by a plurality of second rigid board insulating layers and a plurality of second patterned conductive layers respectively disposed on the upper and lower surfaces of the second rigid board insulating layer. In this embodiment, the material of the second rigid board insulating layer 222 is, for example, a prepreg material (PrePreg) to provide the rigidity required by the second rigid circuit board 220. The material of the second patterned conductive layer 224 is a patterned copper foil, but it is not limited to this.

In this embodiment, the first dielectric layer 231 is disposed between the first rigid circuit board 210 and the second rigid circuit board 220, so as to press the first rigid circuit board 210 to the second rigid circuit board 220 during the manufacturing process. , The first rigid circuit board 210 is joined to the second rigid circuit board 220. Under the above configuration, the first dielectric layer 231 may also be located between the first patterned conductive layer 214 and the second patterned conductive layer 224 to prevent the first patterned conductive layer 214 from contacting the second patterned conductive layer 224 This leads to an electrical short circuit. In this embodiment, the material of the first dielectric layer 231 includes glass fiber-containing film (Prepreg), but it is not limited to this.

In this embodiment, a second dielectric layer 232 may be provided on the surface of the second rigid circuit board 220 opposite to the first dielectric layer 231, and a third pattern may be formed on the second dielectric layer 232. The third conductive material layer 241' of the conductive layer 241 (shown in FIG. 1C). Under the above configuration, the second rigid circuit board 220 is located between the second dielectric layer 232 and the first dielectric layer 231, and the second dielectric layer 232 is located between the third conductive material layer 241' and the second rigid circuit board Between 220. In this embodiment, the material of the second dielectric layer 232 includes glass fiber-containing film (Prepreg), and the material of the third conductive material layer 241' is, for example, copper foil, but it is not limited thereto.

Next, an insulating adhesive layer 140 is provided on the surface of the first rigid circuit board 210 close to the first build-up layer 110, but it is not limited to this. In some embodiments, an insulating adhesive layer 140 may also be provided on the surface of the first build-up layer 110 close to the first rigid circuit board 210. Then, press the first build-up layer 110 to the first rigid circuit board 210 to bond the first build-up layer 110 to the rigid circuit board including the first rigid circuit board 210 and the second rigid circuit board 220 through the insulating adhesive layer 140 200. As shown in FIG. 1A, the insulating adhesive layer 140 may overlap the cutting groove 216, and the orthographic projection of the insulating adhesive layer 140 on the first build-up layer 110 overlaps the non-bending area 14, and may be arranged around the release layer 150. In this embodiment, the material of the insulating adhesive layer 140 is, for example, a pure glue material (Prepreg), but it is not limited to this.

Then, referring to FIG. 1B and FIG. 1C, a conduction process is performed to form the first conductive via V1. For example, from top to bottom, the first conductive via V1 penetrates the first build-up layer 110, the first rigid circuit board 210, the first dielectric layer 231, the second rigid circuit board 220, the second dielectric layer 232, and The third conductive material layer 241'.

Next, the third conductive material layer 241' is patterned to form a third patterned conductive layer 241, wherein the second dielectric layer 232 is located between the third patterned conductive layer 241 and the second rigid circuit board 220, and The first conductive via V1 penetrates the third patterned conductive layer 241. Thereby, the first conductive via V1 can electrically connect the first build-up layer 110, the first rigid circuit board 210, the first dielectric layer 231, the second rigid circuit board 220, the second dielectric layer 232, and the third pattern化conductive layer 241. In this embodiment, the first conductive via V1 includes a conductive wall 314 electrically connected to the first circuit layer 112, the first patterned conductive layer 214, the second patterned conductive layer 224, and the third patterned conductive layer 241, and The filler 312 surrounded by the conductive wall 314. The material of the conductive wall 314 includes metal or metal alloy, such as copper, aluminum, silver, gold, other suitable materials or alloys of the above materials, and the filler 312 can be a metal or non-metal material, but the present invention is not limited to this .

In this embodiment, the second conductive via V2 can be formed simultaneously in the same conduction process to penetrate the first build-up layer 110 and contact the first patterned conductive layer 214. In this way, the second conductive via V2 can conduct the first circuit layer 112 and the first patterned conductive layer 214. In addition, the third conductive via V3 can also be simultaneously formed in the same conduction process to penetrate the second dielectric layer 232 and contact the second patterned conductive layer 224. In this way, the third conductive via V3 can conduct the second patterned conductive layer 224 and the third patterned conductive layer 241. In this embodiment, the material of the second conductive via V2 and the third conductive via V3 includes metal or metal alloy, such as copper, aluminum, silver, gold, other suitable materials or alloys of the foregoing materials, but the present invention does not Limit this.

1C, after the third patterned conductive layer 241 is formed, a lamination process is then performed to form the flexible substrate 120 on the first build-up layer 110. In this embodiment, the first surface 121 of the flexible substrate 120 is close to the rigid circuit board 200, and the first surface 121 contacts the first circuit layer 112 of the first build-up layer 110.

Then, the second build-up layer 130 is disposed on the second surface 122 of the flexible substrate 120 opposite to the first surface 121. Specifically, the second build-up layer 130 includes a second flexible board layer 131 and a second circuit layer 132. In this embodiment, the second soft board layer 131 contacts the second surface 122. In this embodiment, the material of the second flexible board layer 131 is, for example, polyimide, and the material of the second circuit layer 132 is, for example, copper foil, but it is not limited thereto. In this way, the installation of the flexible circuit board 100 has been completed.

In this embodiment, from bottom to top, the structure of the flexible circuit board 100 includes a first build-up layer 110, a flexible substrate 120, and a second build-up layer 130 in sequence. The first build-up layer 110 is the first flexible board layer 111 and the first circuit layer 112 from bottom to top, and the second build-up layer 130 is the second flexible board layer 131 and the second circuit layer 132 from bottom to top. . The first circuit layer 112 contacts the first surface 121 of the flexible substrate 120, and the second soft board layer 131 contacts the second surface 122 of the flexible substrate 120. Under the above configuration, the configuration of the build-up layer can be simplified, and it can be ensured that the first circuit layer 112 and the second circuit layer 132 can be insulated, and the manufacturing yield and reliability of the flexible and hard composite circuit board 10 can be improved.

In addition, during the process of laminating the flexible substrate 120 and the second build-up layer 130, the third dielectric layer 233 and the fourth patterned conductive layer 242 (shown in the figure) can be laminated simultaneously or separately. 1D) The process of the fourth conductive material layer 242' to the rigid circuit board 200. In detail, the third dielectric layer 233 may be disposed on the second dielectric layer 232 and cover the third patterned conductive layer 241 and part of the second dielectric layer 232. Then, the fourth conductive material layer 242' may be disposed on the third dielectric layer 233.

It is worth noting that in this embodiment, the flexible substrate 120 and the third dielectric layer 233 can be formed on the first build-up layer 110 and the second dielectric layer 232 through the same manufacturing process, respectively. In this way, the manufacturing process can be simplified and costs can be reduced. In addition, the flexible substrate 120 and the third dielectric layer 233 may be made of the same material, including glass fiber-containing film (Prepreg). Since the first build-up layer 110 and the second build-up layer 130 are easily bendable materials, the material of the flexible substrate 120 is relatively harder, so that the flexible circuit board 100 can be supported by the flexible substrate 120. Strength, reduce the deformation of asymmetric stack structure. In addition, compared with the deformation amount of the first build-up layer 110 and the second build-up layer 130, the flexible substrate 120 has a smaller amount of deformation and is easier to break. Therefore, the two surfaces of the flexible substrate 120 can be The first build-up layer 110 and the second build-up layer 130 are covered, thereby enabling the flexible substrate 120 to obtain the effect of stable dimensional deformation and not easy to break, and to improve the bendability. Therefore, compared with the conventional flexible substrate, the flexible circuit board 100 of the present embodiment has excellent flexibility and toughness at the same time, and has better elasticity.

In this embodiment, the material of the fourth conductive material layer 242' is, for example, copper foil, but the invention is not limited to this.

Then, referring to FIG. 1D, a patterning process is performed on the fourth conductive material layer 242' to form a fourth patterned conductive layer 242. In this embodiment, the fourth patterned conductive layer 242 is disposed on the third dielectric layer 233, and the third dielectric layer 233 is located between the fourth patterned conductive layer 242 and the second dielectric layer 232.

Next, as shown in FIG. 1D, a through process is performed to connect the second circuit layer 132 to the first circuit layer 112 and the fourth patterned conductive layer 242 to the third patterned conductive layer 241. Specifically, the fourth conductive via V4 may be formed to penetrate the second build-up layer 130 and the flexible substrate 120 and contact the first circuit layer 112. In this way, the fourth conductive via V4 can conduct the first circuit layer 112 and the second circuit layer 132. In addition, a fifth conductive via V5 may be formed to penetrate the third dielectric layer 233 and contact the third patterned conductive layer 241. In this way, the fifth conductive via V5 can conduct the third patterned conductive layer 241 and the fourth patterned conductive layer 242. In this embodiment, the material of the fourth conductive via V4 and the fifth conductive via V5 includes metal or metal alloy, such as copper, aluminum, silver, gold, other suitable materials or alloys of the foregoing materials, but the present invention does not Limit this.

Under the above configuration, the electrical connection of the flexible circuit board 100 to the fourth patterned conductive layer 242 on the rigid circuit board 200 has been completed. Thereby, the second circuit layer 132 can pass through the fourth conductive via V4, the first circuit layer 112, the second conductive via V2, the first patterned conductive layer 214, the first conductive via V1, the second patterned conductive The layer 224, the third conductive via V3, and the third patterned conductive layer 241 are electrically connected to the fourth patterned conductive layer 242.

Next, referring to FIG. 1E, the first solder mask SR1 is disposed on the second build-up layer 130 of the flexible circuit board 100. For example, the first solder mask SR1 is disposed on the second circuit layer 132. In addition, the second solder resist layer SR2 is disposed on the fourth patterned conductive layer 242. In this embodiment, the second solder resist layer SR2 may cover a portion of the fourth patterned conductive layer 242 and a portion of the third dielectric layer 233, but it is not limited to this. As shown in FIG. 1E, the second solder mask layer SR2 only covers the fourth patterned conductive layer 242 in the overlapping non-bending area 14, and does not cover the fourth patterned conductive layer 242 in the overlapping bending area 12. In this embodiment, the materials of the first solder resist layer SR1 and the second solder resist layer SR2 include green paint, photosensitive dielectric material, ABF film, and polymer resin material, but the invention is not limited thereto.

Then, referring to FIG. 1E and FIG. 1F, the cutting process is performed at the position corresponding to the cutting groove 216. Specifically, in the direction N perpendicular to the flexible circuit board 100, the cutting groove 216 is used as an alignment mark, and the cutting groove 216 is cut at the orthographic projection of the flexible circuit board 100 to form the cutting channel 218. From bottom to top, the cutting line 218 can penetrate the third dielectric layer 233, the second dielectric layer 232, the second rigid circuit board 220 and the first dielectric layer 231, and partially remove the first rigid circuit board 210. Hard board insulation layer 212. In this embodiment, the cutting process includes laser cutting or knife cutting, but the present invention is not limited to this.

In this embodiment, the formation of the cutting channel 218 can overlap and remove the part of the first hard board insulating layer 212 that forms the cutting groove 216, so that the cutting groove 216 becomes part of the cutting channel 218, but the present invention is not limited to this. . In this embodiment, since the cutting groove 216 is located in the bending area 12, the orthographic projection of the cutting track 218 on the flexible circuit board 100 is also located in the bending area 12. For example, the outer edge of the cutting lane 218 may overlap the outer edge of the bending area 12. In addition, the outer edge of the cutting lane 218 may also overlap the outer edge of the release layer 150, but the present invention is not limited to this.

Next, referring to FIG. 1G, the process of removing waste is performed, and the release layer 150 in the bending area 12 and the rigid circuit board 200, the second dielectric layer 232, and the third patterned circuit located between the cutting lanes 218 The layer 241, the third dielectric layer 233, and the fourth patterned circuit layer 242 are removed. In detail, after removing the portion of the first rigid circuit board 210 that overlaps the bending area 12, the first opening O1 may be formed in the first rigid circuit board 210. After removing the portion of the second rigid circuit board 220 that overlaps the bending area 12, a second opening O2 can be formed in the second rigid circuit board 220. As shown in FIG. 1G, the first opening O1 and the second opening O2 are located in the bending area 12, and the orthographic projections of the first opening O1 and the second opening O2 on the flexible circuit board 100 are aligned and overlap the bending area 12. From another perspective, the outer edge of the first opening O1 is aligned with the outer edge of the second opening O2, and the first opening O1 and the second opening O2 completely overlap the bending area 12. In this embodiment, after removing waste materials from the release layer 150, the rigid circuit board 200, and the dielectric layer (including the first, second, and third dielectric layers 231, 232, 233), in the bending area 12 The first opening O1 and the second opening O2 inside may form an opening structure OP.

In this embodiment, after the waste is removed, the opening structure OP can expose the first flexible board 111 of the first build-up layer 110 of the flexible circuit board 100. In addition, the release layer 150 can also assist in removing the rigid circuit board 200 from the first flexible board 111. So far, the manufacture of the flexible and hard composite circuit board 10 is completed.

In short, since the rigid circuit board 200 of the flexible and rigid composite circuit board 10 can be arranged on one side of the flexible circuit board 100 (for example, the first surface 121), the rigid circuit board can only be arranged on one side of the flexible circuit board 100. A process of removing waste materials is performed on the board 200 to form an opening structure OP in the bending area 12. Under the above arrangement, the flexible and hard composite circuit board 10 has an asymmetric structure, and only needs to remove the waste on one side, which can save processing time, reduce costs, and improve the production yield. In addition, a rigid circuit board 200 with an opening structure OP is formed on a single surface of the flexible circuit board 100. Since the opening structure OP overlaps the bending area 12 of the flexible circuit board 100, the flexible and rigid composite circuit board 10 is more suitable for non-dynamic bending. And the application of rigid and flexible composite panels with large bending angles.

To sum up, in the flexible and hard composite circuit board of an embodiment of the present invention, since the rigid circuit board of the flexible and rigid composite circuit board only needs to be arranged on a single side of the flexible circuit board, it can only be installed on a single side of the flexible circuit board. The rigid circuit board is processed to remove waste materials so that the opening structure overlaps the bending area of the flexible circuit board. Under the above-mentioned setting, only one side is required to remove waste materials, which can save processing time, reduce costs, and improve production yield. In addition, since the opening structure in the rigid circuit board overlaps the bending area of the flexible circuit board, the flexible and rigid composite circuit board of this embodiment is more suitable for applications of non-dynamic bending and large bending angle flexible and rigid composite boards.

In addition, the flexible and hard composite circuit board of this embodiment has an asymmetric structure, and the flexible substrate can be made of glass fiber-containing film material. Thereby, the supporting force of the flexible circuit board can be improved, and the deformation of the asymmetric structure can be reduced. In addition, the two surfaces of the flexible substrate are respectively covered by the first build-up layer and the second build-up layer, thereby enabling the flexible substrate to obtain the effect of stable dimensional deformation and not easy to break, and improve the bending properties. Therefore, compared with the conventional flexible substrate, the flexible circuit board of this embodiment can provide the flexible and rigid composite circuit board with excellent flexibility and toughness, and has better elasticity. In this way, the processing technology of the flexible and hard composite circuit board of the present invention can not only be simplified to improve the yield, but also can reduce the deformation and improve the quality of the product.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

10: Soft and hard composite circuit board 12: bending area 14: Non-bending area 100: Flexible circuit board 110: first buildup 111: The first soft board layer 112: The first circuit layer 120: Flexible substrate 121: first surface 122: second surface 130: second buildup 131: The second soft board layer 132: second circuit layer 140: insulating adhesive layer 150: release layer 200: rigid circuit board 210: The first rigid circuit board 212: first hard board insulation layer 214: first patterned conductive layer 216: Cutting groove 218: Cutting Road 220: second rigid circuit board 222: second hard board insulation layer 224: second patterned conductive layer 231: first dielectric layer 232: second dielectric layer 233: third dielectric layer 241: third patterned conductive layer 241’: The third conductive material layer 242: fourth patterned conductive layer 242’: Fourth conductive material layer 312: Filler 314: Conductive Wall N: direction O1: first opening O2: second opening OP: Open structure SR1: The first solder mask SR2: The second solder mask V1: The first conductive via V2: second conductive via V3: Third conductive via V4: Fourth conductive via V5: Fifth conductive via

1A to 1G are schematic cross-sectional views of the manufacturing process of a flexible and rigid composite circuit board according to an embodiment of the present invention.

10: Soft and hard composite circuit board

12: bending area

14: Non-bending area

100: Flexible circuit board

110: first buildup

111: The first soft board layer

112: The first circuit layer

120: Flexible substrate

121: first surface

122: second surface

130: second buildup

131: The second soft board layer

132: second circuit layer

140: insulating adhesive layer

200: rigid circuit board

210: The first rigid circuit board

212: first hard board insulation layer

214: first patterned conductive layer

220: second rigid circuit board

222: second hard board insulation layer

224: second patterned conductive layer

231: first dielectric layer

232: second dielectric layer

233: third dielectric layer

241: third patterned conductive layer

242: fourth patterned conductive layer

312: Filler

314: Conductive Wall

N: direction

O1: first opening

O2: second opening

OP: Open structure

SR1: The first solder mask

SR2: The second solder mask

V1: The first conductive via

V2: second conductive via

V3: Third conductive via

V4: Fourth conductive via

V5: Fifth conductive via

Claims (10)

A flexible and hard composite circuit board, including: A flexible circuit board. Having a bending area and two non-bending areas located on opposite sides of the bending area, the flexible circuit board includes: A flexible substrate having a first surface and a second surface opposite to the first surface; A first build-up layer is disposed on the first surface, and the first build-up layer includes a first flexible board layer and a first circuit layer; and A second build-up layer is disposed on the second surface, and the second build-up layer includes a second soft board layer and a second circuit layer; A plurality of rigid circuit boards are arranged close to the first surface of the flexible substrate, wherein orthographic projections of the rigid circuit boards on the flexible circuit board overlap the two non-bending areas; and An insulating adhesive layer is disposed on the first build-up layer, wherein the insulating adhesive layer is located between the flexible circuit board and the rigid circuit boards. The flexible and rigid composite circuit board described in item 1 of the scope of patent application, wherein the first build-up layer is the first flexible board layer and the first circuit layer from bottom to top, and the second build-up layer is from bottom to top. The upper part is the second flexible board layer and the second circuit layer in sequence, wherein the first circuit layer contacts the first surface, and the second flexible board layer contacts the second surface. For the flexible and hard composite circuit board described in item 1 of the scope of patent application, the rigid circuit boards include: A first rigid circuit board with a first opening disposed on the first build-up layer; and A second rigid circuit board with a second opening, disposed on the first rigid circuit board, The orthographic projections of the first opening and the second opening on the flexible circuit board are aligned and overlap the bending area to form an opening structure. The flexible and rigid composite circuit board according to item 3 of the scope of patent application, wherein the opening structure penetrates the rigid circuit boards, and the opening structure overlaps the bending area, wherein a part of the first build-up layer is exposed to the opening structure in. The flexible and rigid composite circuit board described in item 3 of the scope of patent application further includes a first dielectric layer disposed between the first rigid circuit board and the second rigid circuit board. The flexible and rigid composite circuit board according to item 5 of the scope of patent application, wherein the first rigid circuit board includes a plurality of first patterned conductive layers and a plurality of first rigid board insulating layers, and the first patterned conductive layers The layers are respectively disposed on opposite sides of the first rigid board insulating layers, wherein the second rigid circuit board includes a plurality of second patterned conductive layers and a plurality of second rigid board insulating layers, and the second patterned The conductive layers are respectively arranged on the two opposite sides of the second hard board insulating layers. The flexible and hard composite circuit board as described in item 5 of the scope of patent application includes: A second dielectric layer is disposed on the second rigid circuit board, wherein the second rigid circuit board is located between the second dielectric layer and the first dielectric layer; and A third patterned conductive layer is disposed on the second dielectric layer, wherein the second dielectric layer is located between the third patterned conductive layer and the second rigid circuit board. The flexible and hard composite circuit board described in item 7 of the scope of patent application includes: A first conductive via, the first conductive via penetrates the first build-up layer, the first rigid circuit board, the second rigid circuit board, the first dielectric layer, the second dielectric layer and the first Three patterned conductive layers to electrically connect the first build-up layer, the first rigid circuit board, the second rigid circuit board, and the third patterned conductive layer. The flexible and hard composite circuit board described in item 7 of the scope of patent application includes: A third dielectric layer is disposed on the second dielectric layer, covering the third patterned conductive layer and part of the second dielectric layer; and A fourth patterned conductive layer is disposed on the third dielectric layer, wherein the third dielectric layer is located between the fourth patterned conductive layer and the second dielectric layer. The flexible and hard composite circuit boards described in item 9 of the scope of patent application include: A first solder mask layer disposed on the second build-up layer of the flexible circuit board; and A second solder mask layer is arranged on the fourth patterned conductive layer.

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