Flexible circuit board structure and method of manufacturing the same

Abstract

The present invention provides a kind of bending-resistant circuit board structure and its manufacturing method.The bending-resistant circuit board structure includes lower bending part and upper bending part.The lower bending part includes lower insulating layer, neutral layer, multiple step-shaped memory metal traces and multiple pillars.The top surface of these pillars is step-shaped.Upper bending part is arranged on the lower bending part and includes upper insulating layer, circuit layer and cavity with step-shaped top surface.The upper insulating layer is arranged on the lower bending part and includes multiple through holes, wherein the pillars are aligned with the through holes.The height of the upper bending part is equal to the height of the lower bending part.When bending, the pillars are inserted into the through holes, which improves the support and reliability.The stress during bending is reduced by the step-shaped configuration, which further improves the bending ability.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a circuit board structure, and particularly to a bend-resistant circuit board structure and a manufacturing method thereof. BACKGROUND

[0002] Currently, electronic products with bendable screens are provided with air gaps at the bending positions to achieve the purpose of repeated bending. However, the air gap positions lack support, so the bendable screen in the air gap section is prone to be uneven after bending. The lack of support at the air gap position also affects the reliability. SUMMARY

[0003] Therefore, an object of the present disclosure is to provide a bend-resistant circuit board structure and a manufacturing method thereof, thereby providing support and improving reliability.

[0004] According to the above object of the present disclosure, a bend-resistant circuit board structure is provided. The bend-resistant circuit board structure includes a lower bending portion and an upper bending portion. The lower bending portion includes a lower insulating layer, a neutral layer, a plurality of stepped memory metal traces, and a plurality of pillars. The neutral layer is disposed on the top of the lower insulating layer. The plurality of stepped memory metal traces are disposed in the lower insulating layer and connected to the neutral layer. The pillars are disposed in the neutral layer in a stepped distribution, and the top surfaces of the pillars are stepped. The upper bending portion is disposed on the lower bending portion and includes an upper insulating layer, a circuit layer, and a cavity. The upper insulating layer is disposed on the lower bending portion and includes a plurality of through holes, wherein the pillars are respectively aligned with the through holes. The circuit layer is disposed on the top of the upper insulating layer and covers the plurality of through holes. The cavity is located between the upper insulating layer and the lower insulating layer, and the cavity includes a stepped top surface, wherein the through holes are located between the circuit layer and the stepped top surface. The height of the upper bending portion is equal to the height of the lower bending portion. When the bend-resistant circuit board structure is bent, the plurality of pillars are respectively inserted into the plurality of through holes.

[0005] In at least one embodiment of the present disclosure, the lower bending portion includes a protective layer disposed on the bottom surface of the lower insulating layer and covering a portion of the stepped memory metal traces exposed on the bottom surface of the lower insulating layer.

[0006] In at least one embodiment of the present disclosure, the bottom surface of the lower insulating layer and the bottom surface of the protective layer form a stepped bottom surface.

[0007] In at least one embodiment of the present disclosure, the outer side surface of each of the pillars is provided with an insulating coating.

[0008] In at least one embodiment of the present application, the pillars are divided into a center pillar and a plurality of side pillars. The center pillar is located at a middle section of the neutral layer. The plurality of side pillars surround the center pillar and are respectively connected to the stepped memory metal traces. The height of each of the side pillars is greater than the height of the center pillar, and the height of the side pillars is increased from the center pillar to the sidewall of the upper insulating layer.

[0009] In at least one embodiment of the present application, the circuit layer includes a plurality of protrusions. The plurality of protrusions are respectively located in the through holes, and the end surface of each of the protrusions faces a corresponding one of the pillars.

[0010] In at least one embodiment of the present application, the pillars abut and electrically connect the protrusions.

[0011] According to the above-mentioned object of the present application, a manufacturing method of a bending-resistant circuit board structure is provided, including providing a lower bending part and an upper bending part; and combining the upper bending part on the lower bending part, and forming a cavity between the upper bending part and the lower bending part, so that a plurality of pillars of the lower bending part are located in the cavity and aligned with a plurality of through holes of the upper bending part.

[0012] In at least one embodiment of the present application, the manufacturing method of the lower bending part includes providing a substrate and etching a memory metal layer of the substrate; forming a photosensitive insulating material layer on the etched memory metal layer; depositing a metal pattern layer on the memory metal layer to form a plurality of stepped memory metal traces in the photosensitive insulating material layer; adhering a protective layer on the photosensitive insulating material layer and covering the stepped memory metal traces and removing a release film of the substrate; partially removing the protective layer and the photosensitive insulating material layer to form a stepped bottom surface; forming a plurality of pillars on the etched memory metal layer, wherein the top surface of the pillars is distributed in a stepped manner; and forming a plurality of insulating coating layers on the outer side surface of the pillars.

[0013] In at least one embodiment of the present application, the manufacturing method of the upper bending part includes providing a substrate; forming a plurality of protrusions on a metal layer of the substrate; forming a surface treatment layer on each of the protrusions; adhering an insulating material on the metal layer, the protrusions, and the surface treatment layer, and removing a release film of the substrate; etching the metal layer to form a circuit layer; and forming a cavity and a plurality of through holes in the insulating material, wherein the surface treatment layer is respectively located in the through holes.

[0014] Based on the above, the bending-resistant circuit board structure of the present application can reduce bending stress and improve bending ability by using the step-shaped memory metal trace, the step-shaped top surface of the post, and the cavity with a step-shaped top surface. When bending, the post is inserted into the through hole, and the bending part of the circuit board is supported to avoid unevenness, thereby improving supportability, reliability, and the overall structural strength after bending. BRIEF DESCRIPTION OF DRAWINGS

[0015] To make the above and other objects, features, advantages and embodiments of the present disclosure more comprehensible, the following will describe the drawings in brief as follows:

[0016] Figure 1 Fig. 1 shows a cross-sectional view of a bending-resistant circuit board structure according to at least one embodiment of the present application;

[0017] Figure 2 Fig. 2 shows a cross-sectional view of a bending-resistant circuit board structure according to at least one embodiment of the present application; Figure 1 Fig. 3 shows a cross-sectional view of a bending-resistant circuit board structure according to at least one embodiment of the present application;

[0018] Figure 3A Fig. 4 shows a cross-sectional view of a bending-resistant circuit board structure according to at least one embodiment of the present application; Figure 3B Fig. 5 shows a cross-sectional view of a bending-resistant circuit board structure according to at least one embodiment of the present application; Figure 1 Fig. 6 shows a cross-sectional view of a bending-resistant circuit board structure manufacturing method according to at least one embodiment of the present application;

[0019] Figures 4A to 4F Fig. 7 shows a cross-sectional view of a lower bending part manufacturing method according to at least one embodiment of the present application; and

[0020] Figures 5A to 5F Fig. 8 shows a cross-sectional view of an upper bending part manufacturing method according to at least one embodiment of the present application. DETAILED DESCRIPTION

[0021] The embodiments of the present application are discussed in detail below. It should be understood, however, that the embodiments provide many applicable concepts that can be implemented in a wide variety of specific contexts. The embodiments discussed and disclosed are merely for illustration and are not intended to limit the scope of the present application. For example, the statement "a first feature is formed on a second feature" includes embodiments in which a first feature is in direct contact with a second feature, and also includes embodiments in which other features are formed between the first feature and the second feature, such that the first feature is not in direct contact with the second feature.

[0022] In addition, spatially relative terms, such as "under", "below", "lower", "above", "upper", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the devices in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0023] Referring to Figure 1The diagram illustrates a cross-sectional view of a bend-resistant circuit board structure 100 combined with a component 200 according to at least one embodiment of the present invention. The bend-resistant circuit board structure 100 includes a lower bend portion 110 and an upper bend portion 120. The height H1 of the upper bend portion 120 is equal to the height H2 of the lower bend portion 110. A fixed region is formed in the middle of the bend-resistant circuit board structure 100, thereby improving the positioning accuracy during bending. Specifically, the neutral layer 112 is located in the middle of the bend-resistant circuit board structure 100, which is achieved by setting the thickness of the stacked material so that the thickness (height) of the upper and lower structural parts is equal, so that the neutral layer 112 is located in the fixed region. The neutral layer 112 is a key structure that supports the guide post 114, and the neutral layer 112 also has the most network configuration, in order to reduce the impact of bending on the network signal and the guide post 114. Therefore, the setting of the position of the neutral layer 112 can further ensure the bending reliability and electrical quality of the entire stack of the bend-resistant circuit board structure 100.

[0024] like Figure 1 The component 200 shown can be disposed on the upper bending portion 120 and electrically connected to the upper bending portion 120. When the bend-resistant circuit board structure 100 is flattened, the component 200 is not electrically connected to the lower bending portion 110.

[0025] See next Figure 2 Its illustration Figure 1 A schematic diagram of the bending state of the bend-resistant circuit board structure 100. When the bend-resistant circuit board structure 100 is bent, the guide post 114 of the lower bending part 110 is inserted into the through hole 121h of the upper bending part 120, allowing the component 200 to be electrically connected to the lower bending part 110. Therefore, the function of the component 200 can be triggered when bending.

[0026] Continue reading Figure 1 The lower bend 110 includes a lower insulating layer 111, a neutral layer 112, multiple stepped shape memory metal traces 113, multiple guide posts 114, and a protective layer 115. The neutral layer 112 is disposed on top of the lower insulating layer 111. The neutral layer 112 is made of a metallic material, and may further be made of a shape memory metal material.

[0027] Continue reading Figure 1 The stepped shape memory metal traces 113 are disposed in the lower insulating layer 111, arranged at intervals and connected to the neutral layer 112. The stepped shape memory metal traces 113 are made of shape memory metal materials, including but not limited to gold-cadmium (Au-Cd) alloys, silver-cadmium (Ag-Cd) alloys, copper-zinc (Cu-Zn) alloys, and titanium-nickel (TiNi) alloys. Through the shape memory properties and ductility of the shape memory metal, stress during bending can be reduced.

[0028] In one embodiment, the stepped memory metal traces 113 include at least one step. Further, the bottom surfaces 113s of the stepped memory metal traces 113 also form a stepped profile. Specifically, the distance D from the bottom surface 113s of the stepped memory metal traces 113 to the top surface 112s of the neutral layer 112 gradually increases from the center outward. Referring back to Figure 1 The stepped memory metal traces 113 can be symmetrically arranged with respect to the bending reference axis L of the flexible circuit board structure 100. That is, the stepped memory metal traces 113 on both sides of the bending reference axis L are mirror-symmetric with respect to the bending reference axis L. Specifically, the distance D from the bottom surface 113s of the stepped memory metal traces 113 to the top surface 112s of the neutral layer 112 is smaller for the stepped memory metal traces 113 closer to the bending reference axis L than for the stepped memory metal traces 113 farther away from the bending reference axis L.

[0029] Referring back to Figure 1 The posts 114 are spaced apart on the neutral layer 112, where the top surfaces 114s of the posts 114 form a stepped profile. In one embodiment, the posts 114 are divided into a center post 114a and a plurality of side posts 114b. The center post 114a is located at the center of the neutral layer 112. That is, the center post 114a is located on the bending reference axis L. The side posts 114b surround the center post 114a and are connected to the stepped memory metal traces 113, respectively. The height H3 of each side post 114b is greater than the height H3’ of the center post 114a, and the height H3 of the side posts 114b increases from the center post 114a toward the sidewalls 121w of the upper insulating layer 121. That is, the height H3’ of the center post 114a is the smallest, and the height H3 of the side posts 114b farther away from the center post 114a is greater.

[0030] In one embodiment, the outer surfaces of the posts 114 are coated with an insulating coating 116. The insulating coating 116 does not cover the top surfaces 114s of the posts 114 facing the through-holes 121h. During bending, the insulating coating 116 is located between the posts 114 and the inner walls of the aligned through-holes 121h. The material of the insulating coating 116 can be polytetrafluoroethylene (PTFE). The insulating coating 116 reduces the coefficient of friction and the effects of static electricity.

[0031] Referring back to Figure 1 The protective layer 115 is disposed on the bottom surface of the lower insulating layer 111 and covers a portion of the stepped memory metal traces 113 exposed on the bottom surface of the lower insulating layer 111. The bottom surface of the lower insulating layer 111 and the bottom surface of the protective layer 115 form a stepped bottom surface BS.

[0032] Referring back to Figure 1The upper bending portion 120 is disposed on the lower bending portion 110. The upper bending portion 120 includes an upper insulating layer 121, a circuit layer 122, and a cavity 123. The upper insulating layer 121 is disposed on the lower bending portion 110. In one example, the upper insulating layer 121 is a monolithic structure with a better structural strength, thus not causing delamination and fracture when bending. The upper insulating layer 121 includes a plurality of through holes 121h. The posts 114 of the lower bending portion 110 are aligned with the through holes 121h, respectively. Specifically, the height H3' of the center post 114a is equal to the height H4' of the aligned through hole 121h, and the height H3 of the side post 114b is equal to the height H4 of the aligned through hole 121h. Since the height H3' of the center post 114a is the smallest, the height H3 of the side post 114b farther away from the center post 114a is greater, thus the height H4 and H4' of the through hole 121h varies with the height H3 and H3' of the post 114. As shown in Figure 2 when bending, the side post 114b farthest away from the center post 114a is deflected and inserted into the aligned through hole 121h first, followed by the side post 114b between the center post 114a and the side post 114b farthest away from the center post 114a, and finally the center post 114a. Since the center post 114a is located at the middle section of the neutral layer 112, there is no deformation at this location. Furthermore, when bending, the post 114 is inserted into the through hole 121h, the post 114 can provide support and improve the structural strength.

[0033] Continuing to refer to Figure 1 , the circuit layer 122 includes a plurality of protrusions 124 and a plurality of surface treatment layers 125. The protrusions 124 are located at the through holes 121h, respectively. The end surface of each protrusion 124 faces the corresponding post 114. That is, the protrusion 124 and the through hole 121h are in a one-to-one correspondence, and the protrusion 124 and the post 114 are also in a one-to-one correspondence. The surface treatment layer 125 is disposed on the end surface of the protrusion 124. That is, the surface treatment layer 125 is located between the protrusion 124 and the post 114.

[0034] Referring to Figure 1 and Figure 2 , when the bending-resistant circuit board structure 100 is bent, the post 114 abuts against the surface treatment layer 125 and electrically connects the protrusion 124. The surface treatment layer 125 has the effect of reducing resistance and avoiding oxidation.

[0035] As shown in Figure 1 , the cavity 123 is located between the upper insulating layer 121 and the lower insulating layer 111. The cavity 123 includes a stepped top surface TS, wherein the through hole 121h is located between the circuit layer 122 and the stepped top surface TS. As shown in Figure 2As shown, when the bendable circuit board structure 100 is bent, the upper bendable portion 120 and the lower bendable portion 110 are deformed, the through hole 121h is filled by the post 114, and the cavity 123 is gradually filled by the lower bendable portion 110. The space provided by the through hole 121h and the cavity 123 can be used as a stress release area to reduce stress during bending deformation. Furthermore, the cavity 123 is filled, reducing the air gap AG between the upper bendable portion 120 and the lower bendable portion 110, increasing the contact area of the upper bendable portion 120 and the lower bendable portion 110, and the upper bendable portion 120 and the lower bendable portion 110 are generally integrated, thereby improving the overall structural strength after bending.

[0036] Referring to Figure 3A and Figure 3B , a cross-sectional view of a manufacturing method of the bendable circuit board structure 100 in FIG. 1 is shown. As shown in Figure 1 , first, the lower bendable portion 110 and the upper bendable portion 120 are provided. As shown in Figure 3A , the upper bendable portion 120 is then combined with the lower bendable portion 110, and a cavity 123 is formed between the upper bendable portion 120 and the lower bendable portion 110, so that the post 114 of the lower bendable portion 110 is located in the cavity 123 and aligned with the through hole 121h of the upper bendable portion 120. The upper bendable portion 120 and the lower bendable portion 110 are combined by adhesive A. Figure 3B

[0037] Referring to Figures 4A to 4F , a cross-sectional view of a manufacturing method of the lower bendable portion 110 in FIG. 3 is shown. As shown in Figure 4A , first, the substrate 300 is provided and the memory metal layer 310 of the substrate 300 is etched to form the neutral layer 112. Then, as shown in Figure 4B , a photosensitive insulating material layer 400 is formed on the etched memory metal layer 310, and the photosensitive insulating material layer 400 is patterned. Then, as shown in Figure 4C , a metal pattern layer 500 is deposited on the memory metal layer 310, and one layer of metal pattern layer 500 is deposited according to the requirements to form a stepped memory metal trace 113.

[0038] Since the stepped memory metal trace 113 formed by stacking deposition is made of the same material, stress is reduced and bending ability is improved, and cracks are less likely to occur during bending. Then, as shown in Figure 4D , the protective layer 115 is attached to the photosensitive insulating material layer 400 and covers the stepped memory metal trace 113, and the release film 320 of the substrate 300 is removed (as shown in Figure 4C ). Then, as shown in Figure 4E , part of the protective layer 115 and the photosensitive insulating material layer 400 are removed to form a stepped bottom surface BS. Then, as shown in Figure 4F ​Guide pillars 114 are formed on the etched memory metal layer 310 by printing or electroplating, wherein the top surfaces 114s of the guide pillars 114 are distributed in a stepped manner. Then, an insulating coating 116 is formed on the outer surface of the guide pillars 114.

[0039] Please see Figures 5A to 5F A cross-sectional schematic diagram of the manufacturing method of the upper bent portion 120 in Figure 3 is shown. (See Figure 3 for example.) Figure 5A First, a substrate 600 is provided. Then, as follows... Figure 5B The protrusions 124 are formed on the metal layer 610 of the substrate 600 by electroplating or printing. Then, as... Figure 5C A surface treatment layer 125 is formed on the protrusion 124. Then, as follows... Figure 5D The insulating material 700 is bonded to the metal layer 610, the protrusion 124, and the surface treatment layer 125, meaning the insulating material 700 covers the bottom surface of the metal layer 610, the outer surface of the protrusion 124, and the bottom surface of the surface treatment layer 125. Then, the release film 620 of the substrate 600 is removed (e.g., ...). Figure 5C (As shown). Then as... Figure 5E The metal layer 610 is etched to form the circuit layer 122. Then, as... Figure 5F A cavity 123 and a through hole 121h are formed in an insulating material 700, wherein a surface treatment layer 125 is located in the through hole 121h.

[0040] As can be seen from the above embodiments, one advantage of the present invention is that, due to the stepped shape memory metal traces, the stepped distribution of guide pillar top surfaces, and the cavity with stepped top surfaces, the bending-resistant circuit board structure of the present invention can reduce bending stress and thus improve bending capacity during bending. During bending, the guide pillars insert into the through holes, and the bent portion of the circuit board is supported to avoid unevenness, thereby improving support, reliability, and the overall structural strength after bending. Furthermore, after the circuit board is bent, the guide pillars insert into the through holes, further electrically connecting the circuit layers, thereby enabling the electrical functions of the components connected to the circuit layers and improving practicality.

[0041] Although this disclosure has been illustrated above with reference to embodiments, it is not intended to limit this disclosure. Any person skilled in the art may make various modifications and refinements without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the appended claims.

[0042] [Symbol Explanation]

[0043] 100: Bending-resistant circuit board structure

[0044] 110: Lower bend

[0045] 111: Lower insulation layer

[0046] 112: Neutral layer

[0047] 112s: top surface

[0048] 113: stepped memory metal trace

[0049] 113s: bottom surface

[0050] 114: post

[0051] 114a: center post

[0052] 114b: side post

[0053] 114s: top surface

[0054] 115: protective layer

[0055] 116: insulating coating

[0056] 120: upper bend

[0057] 121: upper insulating layer

[0058] 121h: via hole

[0059] 121w: sidewall

[0060] 122: circuit layer

[0061] 123: cavity

[0062] 124: protrusion

[0063] 125: surface treatment layer

[0064] 200: part

[0065] 300: substrate

[0066] 310: memory metal layer

[0067] 320: release film

[0068] 400: photosensitive insulating material layer

[0069] 500: metal pattern layer

[0070] 600: substrate

[0071] 610: metal layer

[0072] 620: release film

[0073] 700: insulating material

[0074] A: adhesive

[0075] AG: air gap

[0076] BS: stepped bottom surface

[0077] H1 : height

[0078] H2: height

[0079] H3: height

[0080] H3’: height

[0081] H4: height

[0082] H4’: height

[0083] L: bending reference axis

[0084] TS: stepped top surface.

Claims

1. A bend-resistant circuit board structure, characterized in that, The bend-resistant circuit board structure includes: The lower bend portion includes; Lower insulation layer; A neutral layer is disposed on top of the lower insulating layer; Multiple stepped shape memory metal traces are disposed in the lower insulating layer and connected to the neutral layer; and Multiple guide pillars are spaced apart in the neutral layer, wherein the top surfaces of the multiple guide pillars are arranged in a stepped pattern; and The upper bend portion is disposed on the lower bend portion and includes: An upper insulating layer is disposed on the lower bent portion and includes a plurality of through holes, wherein the guide posts are respectively aligned with the through holes; A circuit layer, disposed on top of the upper insulating layer, and covering the plurality of through-holes; and A cavity is located between the upper insulating layer and the lower insulating layer, the cavity including a stepped top surface, wherein the through-hole is located between the circuit layer and the stepped top surface; The height of the upper bend is equal to the height of the lower bend; When the bend-resistant circuit board structure is bent, the plurality of guide posts are respectively inserted into the plurality of through holes.

2. The bend-resistant circuit board structure according to claim 1, characterized in that, The lower bend includes a protective layer disposed on the bottom surface of the lower insulating layer and covering a portion of the stepped shape memory metal traces exposed on the bottom surface of the lower insulating layer.

3. The bend-resistant circuit board structure according to claim 2, characterized in that, The bottom surface of the lower insulating layer and the bottom surface of the protective layer form a stepped bottom surface.

4. The bend-resistant circuit board structure according to claim 1, characterized in that, Each of the guide pillars has an insulating coating on its outer surface.

5. The bend-resistant circuit board structure according to claim 1, characterized in that, The guide post area is divided into: The central guide post is located in the middle section of the neutral layer; and Multiple side guide pillars surround the central guide pillar and are respectively connected to the stepped shape memory metal traces; The height of each of the side guide posts is greater than the height of the central guide post, and the height of the side guide posts increases from the central guide post toward the sidewall of the upper insulating layer.

6. The bend-resistant circuit board structure according to claim 1, characterized in that, The line layer includes: Multiple protrusions are located in the through hole, and the end face of each of the protrusions faces the corresponding one of the guide posts.

7. The bend-resistant circuit board structure according to claim 6, characterized in that, The guide post abuts against and is electrically connected to the protrusion.

8. A method for manufacturing the bend-resistant circuit board structure of claim 1, characterized in that, The manufacturing method of the bending-resistant circuit board structure includes: Provides a lower bend and an upper bend; and The upper bend is joined to the lower bend, and a cavity is formed between the upper bend and the lower bend, so that the multiple guide posts of the lower bend are located in the cavity and aligned with the multiple through holes of the upper bend; The lower bend includes; Lower insulation layer; A neutral layer is disposed on top of the lower insulating layer; Multiple stepped shape memory metal traces are disposed in the lower insulating layer and connected to the neutral layer; as well as Multiple guide posts are spaced apart in the neutral layer, wherein the top surfaces of the multiple guide posts are stepped; wherein the upper bending portion includes: An upper insulating layer is disposed on the lower bent portion and includes a plurality of through holes, wherein the guide posts are respectively aligned with the through holes; A circuit layer, disposed on top of the upper insulating layer, and covering the plurality of through-holes; and A cavity, located between the upper insulating layer and the lower insulating layer, the cavity comprising a stepped top surface, wherein the via is located between the circuit layer and the stepped top surface.

9. The method for manufacturing the bend-resistant circuit board structure according to claim 8, characterized in that, The method for manufacturing the lower bend includes: Provide a substrate and etch a memory metal layer onto the substrate; A photosensitive insulating material layer is formed on the etched memory metal layer; A metal pattern layer is deposited on the memory metal layer to form the plurality of stepped memory metal traces in the photosensitive insulating material layer; The protective layer is bonded onto the photosensitive insulating material layer and covers the stepped memory metal traces, and the release film of the substrate is removed; Partially remove the protective layer and the photosensitive insulating material layer to form a stepped bottom surface; Multiple guide pillars are formed on the etched memory metal layer, wherein the top surfaces of the guide pillars are distributed in a stepped pattern; and Multiple insulating coatings are formed on the outer surface of the guide post.

10. The method for manufacturing the bend-resistant circuit board structure according to claim 8, characterized in that, The method for manufacturing the upper bent portion includes: Provide substrate; Multiple protrusions are formed on the metal layer of the substrate; A surface treatment layer is formed on each of the protrusions; The insulating material is bonded to the metal layer, the protrusion and the surface treatment layer, and the release film of the substrate is removed; The metal layer is etched to form the circuit layer; as well as The cavity and the plurality of through holes are formed in the insulating material, wherein the surface treatment layer is located in the through holes respectively.

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