TWI644600B - Rigid-flexible circuit board and method of manufacturing the same - Google Patents

Abstract

A soft and hard composite circuit board comprising a first hard board, a second hard board, a soft board, and a first conductive wiring layer. The first rigid plate has a first side wall. The second rigid plate has a second side wall. The soft board is disposed between the first hard board and the second hard board. The flexible board has opposite sides, and the opposite sides are respectively connected and aligned with the first side and the second side. The first conductive wiring layer is disposed on the first hard board and extends from the first hard board to the soft board and the second hard board.

Description

Soft and hard composite circuit board and manufacturing method thereof

The present invention relates to a structure and a manufacturing method for manufacturing a soft and hard composite circuit board, and more particularly to a soft and hard composite circuit board having a bent portion and a non-bent portion.

In recent years, with the development of the technology industry, electronic products such as notebook computers, tablet computers and smart phones have frequently appeared in daily life. The types and functions of electronic products are becoming more and more diverse, so the circuit boards used in electronic products have also become an important role in related technologies. In addition, in order to increase the application of the board, the board can also be designed as a multi-layer board according to requirements to increase the space used for wiring layout inside. Many different types of electronic components, such as connectors, wafers, or optoelectronic components, can be placed on a multi-layer circuit board as needed to increase their functionality. A printed circuit board made of a flexible substrate and a hard board, also known as a flexible printed circuit board, is light in weight, ultra-thin, soft, flexible, and has a large degree of freedom in shape. advantage.

Soft and hard composite printed circuit boards have been widely used in notebook type Brain, liquid crystal display, digital camera, mobile phone and many consumer electronics. As information electronic products become thinner and lighter, soft and hard composite printed circuit boards often need to be bent, so it is necessary to set a bending zone in the soft and hard composite circuit board. However, the substrate used in the bending zone will extend from the bending zone to the non-bending zone on both sides, that is, the substrate material of the bending zone is the same as that of the non-bending zone, resulting in a hard and soft composite printed circuit board. It is not easy to bend.

According to various embodiments of the present invention, there is provided a soft and hard composite circuit board comprising a first hard board, a second hard board, a soft board, and a first conductive wiring layer. The first rigid plate has a first side wall. The second rigid plate has a second side wall. The soft board is disposed between the first hard board and the second hard board. The flexible board has opposite sides, and the opposite sides are respectively connected and aligned with the first side and the second side. The first conductive wiring layer is disposed on the first hard board and extends from the first hard board to the soft board and the second hard board.

In some embodiments, the soft and hard composite circuit board further includes a first circuit layer, a second circuit layer, and an upper cover layer. The first circuit layer is disposed above the first hard board. The second circuit layer is disposed above the second hard board. The upper cover layer is disposed above the soft board.

In some embodiments, the soft and hard composite circuit board further includes a protective layer disposed on the lower surfaces of the first hard board, the second hard board, and the soft board.

In some embodiments, the soft and hard composite circuit board further includes a second conductive wiring layer, and the second conductive wiring layer is disposed on a lower surface of the first hard board, and Extending from the lower surface of the first rigid plate to the lower surface of the soft plate and the second hard plate.

In some embodiments, the flexible sheet comprises a first adhesive layer, a polymeric layer, and a second adhesive layer. The polymer layer is disposed on the first adhesive layer. The second adhesive layer is disposed on the polymer layer.

In some embodiments, the soft and hard composite circuit board further includes a third circuit layer, a fourth circuit layer, and a lower cover layer. The third circuit layer is disposed above the lower surface of the first hard board. The fourth circuit layer is disposed above the lower surface of the second hard board. The lower cover layer is disposed above the lower surface of the soft board.

In certain embodiments, the polymer layer comprises a polyimide layer.

In certain embodiments, the first hard plate or the second hard plate comprises an insulating prepreg layer.

Various embodiments of the present invention provide a method of manufacturing a soft and hard composite circuit board. Forming a first layer on the upper surface of the substrate, the first layer comprises a first layer and a first conductive wiring layer, the first conductive wiring layer is disposed on the first layer, and the first layer comprises the first layer of soft material And a first layer of rigid material, the first layer of soft material being sandwiched between the first rigid materials. Forming a second layer on the first layer, the second layer includes a second layer and a second conductive wiring layer, the second conductive wiring layer is disposed on the second layer, the first layer comprises the second soft material and the second layer A rigid material, the second soft material being sandwiched between the second rigid materials. A cover layer is formed on the second layer. A lower protective layer is formed on the lower surface of the substrate. Forming a first groove, the first groove penetrating the substrate and the lower protective layer, and the sidewall of the first groove is The edges of the first layer of soft material are aligned.

In some embodiments, the method of making a soft and hard composite circuit board further includes forming a wiring layer on the cover layer. An upper protective layer is formed on the wiring layer. A second groove is then formed. The second recess penetrates the circuit layer and the upper protective layer, and opposite sidewalls of the second recess are aligned with edges of the second layer of soft material.

With some of the above embodiments, since the composition of the substrate in the bending zone is different from the composition of the substrate in the non-bending zone, the soft and hard composite circuit board can not only improve the bending quality, but also maintain the strength of the substrate.

The above and other objects, features, and advantages of the present invention will become more apparent from the description of the appended claims.

100,200‧‧‧soft and hard composite circuit boards

110, 210, 410‧‧‧ substrates

112, 113, 212, 213‧‧‧ hard boards

114, 214‧‧‧ soft board

1141, 1143, 2141, 2143‧‧‧ adhesive layer

1142, 2142‧‧‧ polymer layer

120, 130, 220, 230‧‧‧ conductive wiring layer

140, 150, 240, 250, 270, 280‧‧‧ circuit layers

141, 143, 145, 151, 153, 155‧‧ dielectric layers

142, 144, 146, 152, 154, 156‧‧‧ conductive wiring layers

170‧‧‧Upper cover

172, 174‧‧ ‧ sub-coverage

1742‧‧‧Adhesive layer

1744‧‧‧ polymer layer

180‧‧‧Under cover

182, 184‧ ‧ sub-coverage

1842‧‧‧Adhesive layer

1844‧‧‧ polymer layer

240, 250, 270, 280‧‧‧ circuit layers

2411, 243, 245, 251, 253, 255‧‧ dielectric layers

242, 244, 246, 252, 254, 256‧‧‧ conductive wiring layers

260‧‧‧Upper cover

262, 264‧ ‧ sub-coverage

2642, 2942‧‧‧ adhesive layer

2644, 2944‧‧‧ polymer layer

271, 273, 275, 281, 283, 285‧‧ dielectric layers

272, 274, 276, 282, 284, 286‧‧‧ conductive wiring layers

290‧‧‧ under cover

292, 294‧‧ ‧ sub-coverage

30‧‧‧Method

S31, S32, S33, S34, S35‧‧ steps

402, 406‧‧‧ non-bending area

404‧‧‧Bending area

412‧‧‧ dielectric layer

414, 416‧‧‧ conductive wiring layer

420‧‧‧Soft material layer

422‧‧‧ polymer layer

424‧‧‧Adhesive layer

510‧‧‧ dielectric layer

520‧‧‧ Conductive wiring layer

610‧‧‧soft board

614, 616‧‧‧ adhesive layer

612‧‧‧ polymer layer

710‧‧‧hard board

720‧‧‧conductive wiring layer

810‧‧‧ Coverage

812‧‧‧Adhesive layer

814‧‧‧ polymer layer

910‧‧‧Line layer

912‧‧‧ dielectric layer

914‧‧‧ Conductive wiring layer

920, 930‧‧ ‧ protective layer

1010‧‧‧ dielectric layer

1020‧‧‧ Conductive wiring layer

1030, 1040, 1050‧‧‧ circuit layer

1032, 1042, 1052‧‧ dielectric layer

1034, 1044, 1054‧‧‧ conductive wiring layer

1060, 1070‧‧‧ protective layer

R ₁ , R ₂ , R ₃ ‧‧‧ grooves

1 is a schematic cross-sectional view of a soft and hard composite circuit board in accordance with some embodiments.

2 is a cross-sectional view of a soft and hard composite circuit board in accordance with some embodiments.

3 is a flow chart of a method of fabricating a soft and hard composite circuit board in accordance with some embodiments.

4-8, 9A-9B, and 10A-10B are schematic cross-sectional views of one of various stages for fabricating a soft and hard composite circuit board in accordance with certain embodiments.

The manufacture and use of the present embodiments will be discussed in detail below, however, it should be appreciated that the present invention provides an innovative concept of practice in which a wide variety of specific content can be presented. The embodiments or examples described below are illustrative only and are not intended to limit the scope of the invention.

The terms "first", "second", and the like may be used to describe various elements, regions, layers and/or portions in the present disclosure, but such terms are not limited to such elements, regions, layers and/or portions. These terms are only used to distinguish one element, region, layer and/or portion from another region, layer and/or portion. Thus, a first element, region, layer or portion described hereinafter may be referred to as a second element, region, layer or portion, without departing from the disclosure.

In addition, the terminology used herein is for the purpose of describing particular embodiments, and is not intended to limit the disclosure. As used in the specification, the singular forms ""

The present disclosure provides a soft and hard composite circuit board and a method of fabricating the same. The soft and hard composite circuit board has a bending zone and a non-bending zone. The soft and hard composite circuit board includes a soft board in the bending zone, and the non-bending area includes a hard board. Therefore, the soft and hard composite circuit board can not only improve the bending quality, but also maintain the strength of the substrate.

1 is a cross-sectional view of a soft and hard composite circuit board in accordance with certain embodiments of the present disclosure. In various embodiments, as shown in FIG. 1 , in some embodiments, the soft and hard composite circuit board 100 includes a substrate 110 and a conductive wiring layer 120 . The conductive wiring layer 120 is disposed on the upper surface of the substrate 110 On the face and in direct contact with the upper surface. The substrate 110 includes a hard board 112, a hard board 113, and a soft board 114. The hard board 112 and the hard board 113 are respectively disposed on both sides of the soft board 114. In certain embodiments, the hard plate 112 comprises an insulating prepreg layer. For example, the composition of the insulating prepreg layer comprises a glass fiber nonwoven material and an epoxy resin. In some embodiments, the flexible board 114 includes an adhesive layer 1141, a polymer layer 1142, and an adhesive layer 1143. The polymer layer 1142 is disposed on the adhesive layer 1141. The adhesive layer 1143 is disposed on the polymer layer 1142.

Since the substrate 110 includes the hard board 112, the hard board 113, and the soft board 114, the soft board 114 is disposed in the bending area. Therefore, the soft and hard composite circuit board 100 can not only improve the bending quality, but also does not sacrifice the strength of the substrate 110.

The soft and hard composite circuit board 100 further includes a conductive wiring layer 130, circuit layers 140 and 150, an upper cladding layer 170, and a lower cladding layer 180. The conductive wiring layer 130 is disposed on the lower surface of the substrate 110 and is in direct contact with the lower surface. The circuit layers 140 and 150 are respectively disposed on the conductive wiring layer 120 of the non-bending region. The wiring layer 140 includes a dielectric layer 141, a dielectric layer 143, a dielectric layer 145, a conductive wiring layer 142, a conductive wiring layer 144, and a conductive wiring layer 146. The wiring layer 150 includes a dielectric layer 151, a dielectric layer 153, a dielectric layer 155, a conductive wiring layer 152, a conductive wiring layer 154, and a conductive wiring layer 156. It should be understood by those of ordinary skill in the art that the circuit layers 140 and 150 are merely exemplary, and the dielectric layers and conductive wiring layers included in the circuit layers 140 and 150 may actually be increased or decreased according to design requirements. The upper cover layer 170 includes a sub-cover layer 172 and 174. The sub-cover layer 172 is disposed on the circuit layers 140 and 150. The sub-cladding layer 174 is disposed on the conductive wiring layer 120 over the flexible board 114. The sub-cladding layer 174 includes an adhesive layer 1742 and a polymer layer 1744, and the polymer layer 1744 is disposed on the adhesive layer 1742. The lower cover layer 180 is disposed on the conductive wiring layer 130. The lower cover layer 180 includes sub-cover layers 182 and 184. The sub-cover layer 182 is disposed on the conductive wiring layer 130 corresponding to the hard board 112 and the hard board 113, and the sub-cover layer 184 is disposed on the conductive wiring layer 130 above the lower surface of the corresponding soft board 114. Sub-cladding layer 184 includes an adhesive layer 1842 and a polymer layer 1844. The polymer layer 1844 is disposed on the adhesive layer 1842.

In some embodiments, the soft and hard composite circuit board 100 may not include the conductive wiring layer 130 formed on the lower surface of the substrate 110 to form a single-sided soft and hard composite circuit board.

2 is a cross-sectional view of a soft and hard composite circuit board according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 2, in some embodiments, the soft and hard composite circuit board 200 includes a substrate 210 and a conductive wiring layer 220. The conductive wiring layer 220 is disposed on the upper surface of the substrate 210 and is in direct contact with the upper surface. The substrate 210 includes a hard plate 212, a hard plate 213, and a soft plate 214. The hard plate 212 and the hard plate 213 are respectively disposed on both sides of the soft plate 214. In some embodiments, the hard plate 212, and the hard plate 213 comprise an insulating prepreg layer. For example, the composition of the insulating prepreg layer comprises a glass fiber nonwoven material and an epoxy resin. In some embodiments, the flexible sheet 214 includes an adhesive layer 2141, a polymer layer 2142, and an adhesive layer 2143. The polymer layer 2142 is disposed on the adhesive layer 2141. The adhesive layer 2143 is disposed on the polymer layer 2142.

The soft and hard composite circuit board 200 further includes a conductive wiring layer 230, a wiring layer 240, a wiring layer 250, a wiring layer 270, a wiring layer 280, an upper cladding layer 260, and a lower cladding layer 290. The conductive wiring layer 230 is disposed on the lower surface of the substrate 210 and is in direct contact with the lower surface. The circuit layers 240 and 250 are respectively disposed on the conductive wiring layer 220 corresponding to the hard board 212 and the hard board 213. The circuit layers 270 and 280 are respectively disposed on the conductive wiring layer 230 corresponding to the hard board 212 and the lower surface of the hard board 213. The wiring layer 240 includes a dielectric layer 241, a dielectric layer 243, a dielectric layer 245, a conductive wiring layer 242, a conductive wiring layer 244, and a conductive wiring layer 246. The wiring layer 250 includes a dielectric layer 251, a dielectric layer 253, a dielectric layer 255, a conductive wiring layer 252, a conductive wiring layer 254, and a conductive wiring layer 256. The wiring layer 270 includes a dielectric layer 271, a dielectric layer 273, a dielectric layer 275, a conductive wiring layer 272, a conductive wiring layer 274, and a conductive wiring layer 276. The wiring layer 280 includes a dielectric layer 281, a dielectric layer 283, a dielectric layer 285, a conductive wiring layer 282, a conductive wiring layer 284, and a conductive wiring layer 286. Those of ordinary skill in the art will appreciate that circuit layers 240, 250, 270, and 280 are merely exemplary, and that the dielectric layers included in circuit layers 240, 250, 270, and 280 may actually be increased or decreased as desired by the design. And a conductive wiring layer. The upper cover layer 260 includes sub-cover layers 262 and 264. The sub-cover layer 262 is disposed on the circuit layers 240 and 250. The sub-cover layer 264 is disposed on the conductive wiring layer 220 above the flexible board 214. The sub-cover layer 264 includes an adhesive layer 2642 and a polymer layer 2644, the polymer layer 2644 is disposed on the adhesive layer 2642. The lower cover layer 290 includes sub-cover layers 292 and 294. The sub-cover layer 292 is disposed on the circuit layers 270 and 280. The sub-cover layer 294 is disposed on the conductive wiring layer 230 above the lower surface of the flexible board 214. The sub-cover layer 294 includes an adhesive layer 2942 and a polymer layer 2944.

The structure of the soft and hard composite circuit board 200 is similar to that of the soft and hard composite circuit board 100, and the repeated material properties are not described again. The soft and hard composite circuit board 200 further includes circuit layers 270 and 280 as compared to the soft and hard composite circuit board 100. The circuit layers 270 and 280 are disposed between the conductive wiring layer 230 and the sub-cover layer 292 and correspond to the upper surfaces of the hard board 212 and the hard board 213, respectively.

3 is a flow chart of a method 30 of fabricating a soft and hard composite circuit board in accordance with some embodiments. As shown in FIG. 3, the method 30 includes steps S31, S32, S33, S34, and S35. It will be appreciated that additional steps may be provided before, during or after method 30, and that some of the steps described below may be substituted or deleted as an additional embodiment of the method of manufacture.

4-8, 9A-9B, and 10A-10B are schematic cross-sectional views showing various stages of manufacturing a soft and hard composite circuit board in accordance with some embodiments of the present invention. Referring to FIGS. 3 and 4-5, the method 30 begins in step S31 to form a first layer on the upper surface of the substrate. In some embodiments, as shown in FIG. 4 , the substrate 410 includes a dielectric layer 412 , a conductive wiring layer 414 , and a conductive wiring layer 416 . The conductive wiring layer 414 and the conductive wiring layer 416 are respectively disposed on the dielectric layer 412 . On the upper and lower surfaces. The substrate 410 is divided into presets The non-bending area 402, the bending area 404, and the non-bending area 406. The bend zone 404 is located between the non-bent zone 402 and the non-bend zone 406. A layer of soft material 420 is formed on the bend region 404 of the substrate 410. The soft material 420 includes a polymer layer 422 and an adhesive layer 424. In some embodiments, the dielectric layer 412 comprises a polyester (PET) layer, a polyamidamine (PI) layer, a cyanoate, a glass fiber resin, and a bismuthimide (Bismaleimide). A resin, BT resin (Bismaleimide Triazine Resin), or a mixed material layer of a mixed epoxy resin and glass fiber. In one embodiment, polymer layer 422 comprises a polyiminamide (PI) layer and adhesive layer 424 comprises an acrylic layer, or an epoxy layer. In another embodiment, a coverlay film (Coverlay) may be used as the soft material layer 420. In still another embodiment, the material forming the conductive wiring layers 414 and 416 comprises rolled copper, or electrolytic copper.

As shown in FIG. 5, a dielectric layer 510 and a conductive wiring layer 520 are provided. The location of the dielectric layer 510 corresponds to the non-bent regions 402 and 406 of the substrate 410. The conductive wiring layer 520 is disposed on the soft material layer 420 and the dielectric layer 510 and directly contacts the soft material layer 420 and the dielectric layer 510. Thereafter, the substrate 410, the soft material layer 420, the dielectric layer 510, and the conductive wiring layer 520 are subjected to a pressure bonding process. In an embodiment, the dielectric layer 510 comprises an insulating prepreg layer. For example, the composition of the insulating prepreg layer comprises a glass fiber nonwoven material and an epoxy resin.

The above is merely an illustrative description, and any steps of forming the soft material layer 420, the dielectric layer 510, and the conductive wiring layer 520 can be used as the disclosure. An alternative implementation of the content. In another embodiment, the dielectric layer 510 may be formed on the substrate 410 first, then the soft material layer 420 is formed, and finally the conductive wiring layer 520 is provided and subjected to a pressing process.

Referring to Figures 3 and 6-7, the method 30 proceeds to step S32 to form a second layer on the first layer. In some embodiments, as shown in FIG. 6, the flexible board 610 is formed on the conductive wiring layer 520 and corresponds to the upper side of the bent region 404 of the substrate 410. The flexible board 610 includes an adhesive layer 614, a polymer layer 612, and an adhesive layer 616. In one embodiment, the layer of polymer 612 comprises a layer of polyamine (PI), and the layers of adhesive 614 and 616 comprise an acrylic layer, or an epoxy layer. In another embodiment, a cover film (Coverlay) can be used in place of the polymer layer 612 and the adhesive layer 614. In yet another embodiment, a cover glue can be used in place of the polymer layer 612 and the adhesive layer 616.

As shown in FIG. 7, a hard board 710 and a conductive wiring layer 720 are provided. The position of the hard plate 710 corresponds to the non-bending regions 402 and 406 of the substrate 410. The conductive wiring layer 720 is disposed on the flexible board 610 and the hard board 710. Thereafter, the soft board 610, the hard board 710, and the conductive wiring layer 720 are subjected to a press-bonding process. In an embodiment, the hard plate 710 comprises an insulating prepreg layer. For example, the composition of the insulating prepreg layer comprises a glass fiber nonwoven material and an epoxy resin. In another embodiment, the material forming the conductive wiring layer 720 comprises rolled copper, or electrolytic copper.

Referring to FIGS. 3 and 8, the method 30 proceeds to step S33 to form a cover layer on the second layer. In some embodiments, such as the 8th As shown, a capping layer 810 is formed over the conductive routing layer 720 and corresponds to the overlying region 404 of the substrate 410. In an embodiment, the cover layer 810 includes an adhesive layer 812 and a polymer layer 814. For example, polymer layer 814 comprises a polybenzamine (PI) layer and adhesive layer 812 comprises an acrylic resin, or an epoxy resin. In another embodiment, the cover layer 810 is a cover film. In yet another embodiment, the cover layer 810 is a soft solder mask.

Referring to FIGS. 3 and 9A, the method 30 proceeds to step S34 to form a lower protective layer on the lower surface of the substrate. In some embodiments, as shown in FIG. 9A, a protective layer 920 is formed over the lower surface of the substrate 410. In an embodiment, the wiring layer 910 may be formed over the lower surface of the substrate 410 before the protective layer 920 is formed. The wiring layer 910 includes a dielectric layer 912 and a conductive wiring layer 914. After the wiring layer 910 is formed, the protective layer 920 is formed on the wiring layer 910. It should be understood by those of ordinary skill in the art that the circuit layer 910 is merely exemplary, and in fact, more layers of circuit layers can be configured according to design requirements. In another embodiment, the protective layer 920 directly contacts the lower surface of the substrate 410. In still another embodiment, the protective layer 930 may be further formed on the conductive wiring layer 720, and the position where the protective layer 930 is formed corresponds to the non-bending regions 402 and 406.

Referring to FIGS. 3 and 9B, the method 30 proceeds to step S35 to form a groove. In certain embodiments, the first as shown in FIG. 9B, R ₁ form a groove penetrating the protective layer 920, circuit layer 910 and the substrate 410. The position of the groove R ₁ corresponds to the lower side of the bent portion 404 of the substrate 410. In some embodiments, there is no other wiring layer between the protective layer 920 and the substrate 410, so the recess R ₁ only penetrates the protective layer 920 and the substrate 410.

Figures 10A-10B are continued from Figure 8, and Figures 10A-10B are alternative embodiments of Figures 9A-9B. Referring to FIGS. 3 and 10A, the method 30 proceeds to step S34 to form a lower protective layer on the lower surface of the substrate. In some embodiments, as shown in FIG. 10A, a protective layer 1060 is formed over the lower surface of the substrate 410. In an embodiment, the wiring layer 1040 may be formed over the lower surface of the substrate 410 before the protective layer 1060 is formed. The wiring layer 1040 includes a dielectric layer 1042 and a conductive wiring layer 1044. After the wiring layer 1040 is formed, the protective layer 1060 is formed on the wiring layer 1040. It should be understood by those of ordinary skill in the art that the circuit layer 1040 is merely exemplary, and in fact, more layers of circuit layers can be configured according to design requirements. In another embodiment, the protective layer 1060 directly contacts the lower surface of the substrate 410.

Compared with the embodiment shown in FIG. 9A , in the embodiment illustrated in FIG. 10A , a 1010 dielectric layer is further formed on the conductive wiring layer 720 , and the position of the 1010 dielectric layer corresponds to the non-bend of the substrate 410 . Above the fold zones 402 and 406. The conductive wiring layer 1020 is then formed on the 1010 dielectric layer and the cap layer 810. A suitable wiring layer can be selectively formed on the conductive wiring layer 1020, for example, the wiring layers 1030, and 1050 are formed on the conductive wiring layer 1020. The wiring layer 1030 includes a dielectric layer 1032 and a conductive wiring layer 1034. The wiring layer 1050 includes a dielectric layer 1052 and a conductive wiring layer 1054. It will be understood by those of ordinary skill in the art that the circuit layers 1030 and 1050 are merely illustrative, and in fact fewer or more layers of circuit layers may be configured as desired by the design. Forming a line After the via layer 1050, a protective layer 1070 is formed on the wiring layer 1050.

Referring to FIGS. 3 and 10B, the method 30 proceeds to step S35 to form a groove. In some embodiments, as shown in FIG. 10B, grooves R ₂ and R _{3 are formed} . The groove R ₂ penetrates through the protective layer 1070, the wiring layer 1050, the wiring layer 1030, and the conductive wiring layer 1020. The position of the groove R ₂ corresponds to above the bending region 404 of the substrate 410. The groove R _{3 is} formed to penetrate the protective layer 1060, the wiring layer 1040, and the substrate 410. The position of the groove R ₃ corresponds to the lower side of the bent portion 404 of the substrate 410.

In summary, certain embodiments provided by the present disclosure can improve the bending quality and maintain the strength of the substrate. It should be understood that not all of the advantages are discussed herein, that all embodiments or embodiments do not require particular advantages, and that other embodiments or embodiments may provide different advantages.

The features of the several embodiments are summarized above so that those skilled in the art can better understand the aspects of the invention. It will be appreciated by those skilled in the art that the present invention can be readily utilized as a basis for designing or modifying other processes and structures to achieve the same objectives and/or achieve the same advantages of the embodiments described herein. It will be appreciated by those skilled in the art that the present invention is not limited to the spirit and scope of the invention, and various changes, substitutions and alterations of the invention may be made without departing from the spirit and scope of the invention. .

Claims (10)

A soft and hard composite circuit board comprising: a first hard board having a first side wall; a second hard board having a second side wall; and a soft board disposed on the first hard board and the second hard board The first flexible conductive layer is disposed on the first hard board, and the first conductive layer is disposed on the first hard board, and the opposite side surfaces are respectively connected to the first side wall and the second side wall. Extending from the first hard board to the soft board and the second hard board, wherein the first lead wiring layer directly contacts the first hard board, the soft board and the second hard board. The soft and hard composite circuit board of claim 1, further comprising: a first circuit layer disposed above the first hard board; a second circuit layer disposed above the second hard board; and an upper layer The cover layer is disposed above the soft board. The soft and hard composite circuit board of claim 2, further comprising a protective layer disposed on the first hard board, the second hard board, and the lower surface of the soft board. The soft and hard composite circuit board of claim 2, further comprising a second conductive wiring layer disposed on the lower surface of the first hard board and extending from the lower surface of the first hard board to the soft board And on the lower surface of the second hard plate. The soft and hard composite circuit board of claim 3 or 4, wherein the soft board comprises: a first adhesive layer; a polymer layer disposed on the first adhesive layer; and a second adhesive layer disposed on On the polymer layer. The soft and hard composite circuit board of claim 4, further comprising: a third circuit layer disposed above the lower surface of the first hard board; and a fourth circuit layer disposed on the lower surface of the second hard board Upper; and a lower cover layer disposed above the lower surface of the flexible board. The soft and hard composite circuit board of claim 5, wherein the polymer layer comprises a polyimide layer. The soft and hard composite circuit board of claim 1, wherein the first hard board or the second hard board comprises an insulating prepreg layer. A method of manufacturing a soft and hard composite circuit board, comprising: forming a first layer on an upper surface of a substrate, the first layer comprising a first layer and a first conductive wiring layer, the first conductive wiring layer Disposed on the first layer, the first layer comprises a first layer of soft material and a layer of first rigid material, the first layer of soft material being sandwiched between the first rigid materials; forming a second layer On the first layer, the second layer includes a second layer and a second conductive wiring layer, the second conductive wiring layer is disposed on the second layer, and the second layer includes a second softness a material and a second rigid material, the second soft material is interposed between the second rigid materials; forming a cover layer on the second layer; forming a protective layer on a lower surface of the substrate; and forming a first a groove extending through the substrate and the lower protective layer, and a sidewall of the first groove is aligned with an edge of the first layer of soft material. The method of claim 9, further comprising: forming a circuit layer on the cover layer; Forming an upper protective layer on the circuit layer; and forming a second recess extending through the circuit layer and the upper protective layer, and sidewalls of the second recess and the second soft material layer The edges are aligned.