TWI886007B - Circuit board and manufacturing method thereof - Google Patents

Abstract

A circuit board includes a wiring base, a temperature control element, multiple flexible parts, multiple conductive pillars and an electronic component disposed on the temperature control element. The wiring base includes multiple pads. The temperature control element is disposed on the wiring base, forms a gap with the wiring base, and includes a first memory metal layer, a second memory metal layer fixed on the first memory metal layer, multiple first magnetic attraction parts disposed in the first memory metal layer, and multiple second magnetic attraction parts disposed in the second memory metal layer and respectively corresponding to the first magnetic attraction parts. The flexible parts are disposed in the gaps and respectively correspond to the first magnetic attraction parts, and are electrically connected to the pads respectively. The conductive pillars are disposed between the electronic component and the temperature control element, penetrate the second magnetic attraction parts respectively, and are electrically connected to the electronic component.

Description

Circuit board and manufacturing method thereof

The present invention relates to a circuit board and a manufacturing method thereof.

When the voltage, current and working time of the electronic components installed on the circuit board increase, the heat generated will also increase, and the heat dissipation path is mainly from the surface of the electronic components to the surrounding environment. However, as electronic products have entered the era of high-density and thinner assembly, it is not enough to rely solely on electronic components with a very small surface area to dissipate heat. In addition, the heat generated by electronic components may also be transferred to the circuit board in large quantities, causing the failure of the circuit board or the failure of the electronic components located at the heat accumulation position, thereby reducing reliability and shortening the product life.

At least one embodiment of the present invention provides a circuit board that can implement an overheat protection function through a temperature control element, thereby reducing the damage to the product caused by high temperature, thereby helping to improve reliability and increase product life.

At least another embodiment of the present invention provides a method for manufacturing the above-mentioned circuit board to help the above-mentioned circuit board realize an overheat protection function through a temperature control element, thereby reducing damage to the product caused by high temperature, thereby helping to improve reliability and extend product life.

A circuit board proposed in at least one embodiment of the present invention includes a circuit substrate, a temperature control element, a plurality of retractable parts, an electronic component and a plurality of conductive posts. The circuit substrate includes a plurality of pads. The temperature control element is arranged on the circuit substrate and forms a gap with the circuit substrate, and includes a first memory metal layer, a second memory metal layer, a plurality of first magnetic attraction parts and a plurality of second magnetic attraction parts. The second memory metal layer is fixed on the first memory metal layer, and the first memory metal layer is located between the second memory metal layer and the circuit substrate. A plurality of first magnetic attraction parts are arranged in the first memory metal layer, and a plurality of second magnetic attraction parts are arranged in the second memory metal layer and correspond to the plurality of first magnetic attraction parts respectively. A plurality of retractable members are arranged in the gap and correspond to the plurality of first magnetic attraction parts respectively, and are electrically connected to the plurality of pads respectively. An electronic component is arranged on the temperature control element. A plurality of conductive posts are arranged between the electronic component and the temperature control element and penetrate the plurality of second magnetic attraction parts respectively, and are electrically connected to the electronic component.

In at least one embodiment of the present invention, the deformation temperature of the first memory metal layer is the same as the deformation temperature of the second memory metal layer, and the bending direction of the first memory metal layer is opposite to the bending direction of the second memory metal layer.

In at least one embodiment of the present invention, the temperature control element further includes a third magnetic attraction portion and a fourth magnetic attraction portion. The third magnetic attraction portion is disposed in the first memory metal layer and is located between two adjacent first magnetic attraction portions, and the width of the third magnetic attraction portion is greater than the width of each of the first magnetic attraction portions. The fourth magnetic attraction portion is disposed in the second memory metal layer and is located between two adjacent second magnetic attraction portions, and the width of the fourth magnetic attraction portion is greater than the width of each of the second magnetic attraction portions, and the third magnetic attraction portion and the fourth magnetic attraction portion attract and contact each other, so that the second memory metal layer is fixed on the first memory metal layer.

In at least one embodiment of the present invention, when the second memory metal layer is not bent relative to the first memory metal layer, the first memory metal layer and the second memory metal layer are adhered to each other so that the multiple first magnetic attraction parts and the multiple second magnetic attraction parts attract and contact each other, thereby making the multiple conductive posts contact the multiple retractable parts respectively.

In at least one embodiment of the present invention, when the second memory metal layer is bent relative to the first memory metal layer, the first memory metal layer is partially separated from the second memory metal layer, so that the multiple first magnetic attraction portions are separated from the multiple second magnetic attraction portions, thereby separating the multiple conductive pillars from the multiple retractable members.

In at least one embodiment of the present invention, the circuit substrate further includes an insulating layer, the plurality of pads are embedded in the insulating layer, and the upper surfaces of the plurality of pads are flush with the upper surface of the insulating layer.

In at least one embodiment of the present invention, each of the retractable members includes a conductive portion and an outer portion surrounding the conductive portion, and the plurality of conductive portions respectively penetrate the plurality of first magnetic portions and are respectively electrically connected to the plurality of pads.

In at least one embodiment of the present invention, the circuit board further includes a connection layer disposed between the temperature control element and the electronic component, and the plurality of conductive posts penetrate the connection layer.

In at least one embodiment of the present invention, the material of the first memory metal layer and the second memory metal layer includes nickel-titanium alloy, the material of the plurality of retractable members includes conductive fibers, and the material of the plurality of conductive pillars includes copper.

A method for manufacturing a circuit board proposed in at least one embodiment of the present invention includes the following steps. A first sacrificial layer and a conductive layer are provided, wherein the first sacrificial layer is located on the conductive layer. The first sacrificial layer is patterned to form a plurality of first trenches. A plurality of conductive portions are formed in the plurality of first trenches. After the plurality of conductive portions are formed, the conductive layer is patterned to form a plurality of pads. After the plurality of pads are formed, a build-up layer structure is attached to the plurality of pads, and the build-up layer structure is patterned to form a plurality of second trenches. A plurality of circuit structures are formed in the plurality of second trenches. After the plurality of circuit structures are formed, the first sacrificial layer is removed to expose the side walls of the plurality of conductive portions. After removing the first sacrificial layer, a plurality of peripheral portions are formed to surround the side walls of the plurality of conductive portions to form a plurality of retractable members. A second sacrificial layer is formed to surround the plurality of retractable members. A plurality of first magnetic attraction portions corresponding to the plurality of retractable members and a third magnetic attraction portion located on the second sacrificial layer are formed. A first memory metal layer is formed on the second sacrificial layer to surround the plurality of first magnetic attraction portions and the third magnetic attraction portion. After forming the first memory metal layer, the second sacrificial layer is removed to form a gap. An initial connection layer and a second initial memory metal layer are provided, and the initial connection layer is located on the second initial memory metal layer. The initial connection layer and the second initial memory metal layer are patterned to form a connection layer and a second memory metal layer, wherein the connection layer has a plurality of slots, and the second memory metal layer has a plurality of openings. A plurality of second magnetic attraction portions and a fourth magnetic attraction portion are formed in the plurality of openings. After the plurality of second magnetic attraction portions and the fourth magnetic attraction portions are formed, an electronic component is attached to the connection layer, wherein the electronic component includes a plurality of pins, and the plurality of pins are respectively disposed in the plurality of slots and respectively penetrate the plurality of second magnetic attraction portions. After the electronic component is attached to the connection layer, a second memory metal layer is disposed on the first memory metal layer, so that the plurality of first magnetic attraction portions and the plurality of second magnetic attraction portions attract and contact each other, and the third magnetic attraction portion and the fourth magnetic attraction portion attract and contact each other.

In the following text, in order to clearly present the technical features of the present invention, the dimensions (e.g., length, width, thickness, and depth) of the elements (e.g., layers, films, substrates, and regions, etc.) in the drawings will be enlarged in unequal proportions, and the number of some elements will be reduced. Therefore, the description and explanation of the embodiments below are not limited to the number of elements in the drawings and the dimensions and shapes presented by the elements, but should cover the dimensions, shapes, and deviations therefrom caused by actual processes and/or tolerances. For example, the flat surface shown in the drawings may have rough and/or nonlinear features, and the sharp corners shown in the drawings may be rounded. Therefore, the elements presented in the drawings of the present invention are mainly used for illustration, and are not intended to accurately depict the actual shape of the elements, nor are they used to limit the scope of the patent application of the present invention.

Secondly, the words "approximately", "approximately" or "substantially" used in the present invention not only cover the numerical values and numerical ranges clearly stated, but also cover the permissible deviation range that can be understood by a person of ordinary skill in the art to which the invention belongs, wherein the deviation range can be determined by the error generated during measurement, and the error is caused by the limitations of the measurement system or process conditions, for example. For example, two objects (such as the planes or traces of a substrate) are "substantially parallel" or "substantially perpendicular", wherein "substantially parallel" and "substantially perpendicular" respectively represent that the parallelism and perpendicularity between the two objects may include non-parallelism and non-perpendicularity caused by the permissible deviation range.

The spatially relative terms used in the present invention, such as "below", "under", "above", "on", etc., are for the purpose of facilitating the description of the relative relationship between one element or feature and another element or feature, as shown in the figure. The true meaning of these spatially relative terms includes other orientations. For example, when the figure is flipped 180 degrees up and down, the relationship between one element and another element may change from "below" or "under" to "above" or "on". In addition, the spatially relative descriptions used in the present invention should also be interpreted in the same way.

It should be understood that, although the present invention may use terms such as "first", "second", and "third" to describe various components or features, these components or features should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one feature from another feature. In addition, the term "or" used in the present invention may include any one or more combinations of the related listed items depending on the actual situation.

Although a series of operations or steps are used in the present invention to illustrate the manufacturing method, the order in which these operations or steps are shown should not be interpreted as a limitation of the present invention. For example, certain operations or steps can be performed in different orders and/or simultaneously with other steps. In addition, each operation or step described herein can include a plurality of sub-steps or actions.

In addition, the present invention may be implemented or applied through other different specific embodiments, and the details of the present invention may also be combined, modified and changed in various embodiments based on different viewpoints and applications without departing from the concept of the present invention.

1A and 1B are partial cross-sectional schematic diagrams of a circuit board 10 in at least one embodiment of the present invention in a bonded state and a separated state, respectively. Referring to FIG. 1A and FIG. 1B , the circuit board 10 includes a circuit substrate 100 , a temperature control element 200 , a plurality of retractable members 300 , an electronic component 400 , and a plurality of conductive posts 500 .

The circuit substrate 100 includes a plurality of pads 102. The temperature control element 200 is disposed on the circuit substrate 100 and forms a gap G with the circuit substrate 100, and includes a first memory metal layer 202, a second memory metal layer 204, a plurality of first magnetic attraction portions 206, and a plurality of second magnetic attraction portions 208. The second memory metal layer 204 is fixed on the first memory metal layer 202, and the first memory metal layer 202 is located between the second memory metal layer 204 and the circuit substrate 100.

A plurality of first magnetic portions 206 are disposed in the first memory metal layer 202, and a plurality of second magnetic portions 208 are disposed in the second memory metal layer 204 and correspond to the plurality of first magnetic portions 206, respectively. A plurality of retractable members 300 are disposed in the gap G and correspond to the plurality of first magnetic portions 206, respectively, and are electrically connected to the plurality of pads 102, respectively. An electronic component 400 is disposed on the temperature control element 200. A plurality of conductive posts 500 are disposed between the electronic component 400 and the temperature control element 200 and penetrate the plurality of second magnetic portions 208, respectively, and are electrically connected to the electronic component 400.

Since the temperature control element 200 can form a circuit between the electronic component 400 with an over-high temperature and the pad 102 of the circuit substrate 100, an overheat protection function is achieved, which reduces the damage to the product caused by high temperature, thereby helping to improve reliability and increase product life.

Continuing to refer to FIG. 1A and FIG. 1B , the temperature control element 200 further includes a third magnetic portion 210 and a fourth magnetic portion 212. The third magnetic portion 210 is disposed in the first memory metal layer 202 and is located between two adjacent first magnetic portions 206, and the width of the third magnetic portion 210 is greater than the width of each first magnetic portion 206. The fourth magnetic portion 212 is disposed in the second memory metal layer 204 and is located between two adjacent second magnetic portions 208, and the width of the fourth magnetic portion 212 is greater than the width of each second magnetic portion 208, and the third magnetic portion 210 and the fourth magnetic portion 212 attract and contact each other, so that the second memory metal layer 204 is fixed on the first memory metal layer 202.

In some embodiments, the third magnetic portion 210 corresponds to the fourth magnetic portion 212. Specifically, on the normal line of the circuit substrate 100, the third magnetic portion 210 overlaps with the fourth magnetic portion 212, the plurality of first magnetic portions 206 overlap with the plurality of second magnetic portions 208, and the area of the third magnetic portion 210 projected on the circuit substrate 100 is larger than the area of each first magnetic portion 206 projected on the circuit substrate 100, and the area of the fourth magnetic portion 212 projected on the circuit substrate 100 is larger than the area of each second magnetic portion 208 projected on the circuit substrate 100. In addition, the deformation temperature of the first memory metal layer 202 is substantially the same as the deformation temperature of the second memory metal layer 204 , and the bending direction of the first memory metal layer 202 is substantially opposite to the bending direction of the second memory metal layer 204 .

As shown in FIG. 1A , when the temperature of the circuit board 10 has not substantially reached the deformation temperature of the first memory metal layer 202 and the deformation temperature of the second memory metal layer 204, the second memory metal layer 204 does not bend relative to the first memory metal layer 202, and the first memory metal layer 202 and the second memory metal layer 204 adhere to each other, so that the plurality of first magnetic portions 206 and the plurality of second magnetic portions 208 attract and contact each other, thereby causing the plurality of conductive posts 500 to contact the plurality of retractable members 300 respectively.

Specifically, the first memory metal layer 202 and the second memory metal layer 204 have a first surface S1 and a second surface S2 facing each other, the first magnetic attraction portion 206 and the third magnetic attraction portion 210 are exposed on the first surface S1, and the second magnetic attraction portion 208 and the fourth magnetic attraction portion 212 are exposed on the second surface S2. When bent, the first surface S1 and the second surface S2 adhere to each other, so that the first magnetic portion 206 and the second magnetic portion 208 and the third magnetic portion 210 and the fourth magnetic portion 212 attract and contact each other, and the conductive column 500 and the retractable member 300 contact each other, thereby making the electronic component 400 electrically connected to the pad 102 of the circuit substrate 100, so that the electronic component 400 is in a normal working state.

As shown in FIG. 1B , when the temperature of the circuit board 10 substantially reaches or exceeds the deformation temperature of the first memory metal layer 202 and the deformation temperature of the second memory metal layer 204, the second memory metal layer 204 bends relative to the first memory metal layer 202, and the first memory metal layer 202 and the second memory metal layer 204 are partially separated, so that the plurality of first magnetic portions 206 are separated from the plurality of second magnetic portions 208, thereby separating the plurality of conductive posts 500 from the plurality of retractable members 300.

Specifically, when the second memory metal layer 204 is bent relative to the first memory metal layer 202, a gap S is formed between the first surface S1 and the second surface S2, so that the first magnetic portion 206 is separated from the second magnetic portion 208, and the conductive column 500 is separated from the retractable member 300, thereby disconnecting the electronic component 400 from the electrical connection of the pad 102 of the circuit substrate 100, so that the electronic component 400 is in a power-off state.

Since the separation force of the first memory metal layer 202 and the second memory metal layer 204 when bent is greater than the magnetic attraction between the first magnetic attraction portion 206 and the second magnetic attraction portion 208 , the first magnetic attraction portion 206 and the second magnetic attraction portion 208 can be separated. However, since the widths of the third magnetic portion 210 and the fourth magnetic portion 212 are respectively greater than the widths of the first magnetic portion 206 and the second magnetic portion 208, and the areas of the third magnetic portion 210 and the fourth magnetic portion 212 projected onto the circuit substrate 100 are respectively greater than the areas of the first magnetic portion 206 and the second magnetic portion 208 projected onto the circuit substrate 100, the magnetic attraction force between the third magnetic portion 210 and the fourth magnetic portion 212 is greater than the separation force of the bending of the first memory metal layer 202 and the second memory metal layer 204, and the second memory metal layer 204 can be fixed on the first memory metal layer 202 by the third magnetic portion 210 and the fourth magnetic portion 212 attracting and contacting each other.

Therefore, when the circuit board 10 is overheated, as shown in FIG. 1B , the first memory metal layer 202 and the second memory metal layer 204 are bent and partially separated, so that the first magnetic portion 206 is separated from the second magnetic portion 208 and the conductive column 500 is separated from the retractable member 300, thereby disconnecting the electrical connection between the electronic component 400 and the pad 102 of the circuit substrate 100 and being in a power-off state, thereby realizing the overheat protection function. When the circuit board 10 returns to normal temperature, As shown in FIG. 1A , the first memory metal layer 202 and the second memory metal layer 204 are not bent and are attached to each other, so that the first magnetic portion 206 and the second magnetic portion 208 attract and contact each other, and the conductive column 500 and the retractable member 300 contact each other, thereby making the electronic component 400 electrically connected to the pad 102 of the circuit substrate 100 in a normal working state, thereby reducing the damage to the product caused by high temperature, thereby helping to improve reliability and increase product life.

Please continue to refer to FIG. 1A and FIG. 1B , the circuit board 10 further includes a connection layer 600 disposed between the temperature control element 200 and the electronic component 400, and a plurality of conductive posts 500 penetrate the connection layer 600. The circuit substrate 100 further includes an insulating layer 104 and a plurality of circuit structures 106, a plurality of pads 102 and a plurality of circuit structures 106 are embedded in the insulating layer 104, and the upper surfaces of the plurality of pads 102 are flush with the upper surface of the insulating layer 104. In addition, each retractable member 300 includes a conductive portion 302 and an outer portion 304 surrounding the conductive portion 302. The plurality of conductive portions 302 respectively penetrate the plurality of first magnetic portions 206 and are respectively electrically connected to the plurality of pads 102.

In some embodiments, the material of the insulating layer 104 and the connecting layer 600 may include resin, such as prepreg, the material of the first memory metal layer 202 and the second memory metal layer 204 may include nickel-titanium alloy, the material of the retractable member 300 may include conductive fiber, the material of the pad 102 and the conductive column 500 may include metal, such as copper, and the electronic component 400 may be a chip.

In addition, the materials of the first magnetic attraction portion 206, the second magnetic attraction portion 208, the third magnetic attraction portion 210, and the fourth magnetic attraction portion 212 may include ferromagnetic materials or ferrimagnetic materials. In some embodiments, one of the first magnetic attraction portion 206 and the second magnetic attraction portion 208 is a magnet (e.g., a permanent magnet), the other of the first magnetic attraction portion 206 and the second magnetic attraction portion 208 is not a magnet, one of the third magnetic attraction portion 210 and the fourth magnetic attraction portion 212 is a magnet (e.g., a permanent magnet), and the other of the third magnetic attraction portion 210 and the fourth magnetic attraction portion 212 is not a magnet. In other embodiments, the materials of the first magnetic attraction portion 206 and the second magnetic attraction portion 208 are both magnets, and the materials of the third magnetic attraction portion 210 and the fourth magnetic attraction portion 212 are both magnets.

FIG. 2A to FIG. 2R are partial cross-sectional views of the circuit board 10 of FIG. 1A and FIG. 1B at different process stages. First, referring to FIG. 2A , a first sacrificial layer SL1 and a conductive layer ML are provided, and the first sacrificial layer SL1 is located on the conductive layer ML. Next, referring to FIG. 2B , the first sacrificial layer SL1 is patterned to form a plurality of first trenches T1. In some embodiments, patterning the first sacrificial layer SL1 can be implemented by a laser process.

Referring to FIG. 2C , a plurality of conductive portions 302 are formed in a plurality of first trenches T1. Referring to FIG. 2D , after forming a plurality of conductive portions 302, the conductive layer ML is patterned to form a plurality of pads 102. Next, referring to FIG. 2E and FIG. 2F , after forming a plurality of pads 102, a build-up structure BS is bonded on the plurality of pads 102, and the build-up structure BS is patterned to form a plurality of second trenches T2. In some embodiments, the build-up structure BS includes an insulating layer 104, the formation of the plurality of conductive portions 302 can be implemented by a printing process, the patterning of the conductive layer ML can be implemented by an etching process, and the patterning of the build-up structure BS can be implemented by a laser process.

Referring to FIG. 2G , a plurality of circuit structures 106 are formed in a plurality of second trenches T2. Referring to FIG. 2H , after forming a plurality of circuit structures 106, the first sacrificial layer SL1 is removed to expose the sidewalls of a plurality of conductive portions 302. In some embodiments, as shown in FIG. 2H , before removing the first sacrificial layer SL1, a protection structure PS may be formed on the circuit structure 106. In addition, forming a plurality of circuit structures 106 may be implemented by a plating process and an etching process.

2I , after removing the first sacrificial layer SL1, a plurality of peripheral portions 304 are formed to surround the sidewalls of the plurality of conductive portions 302 to form a plurality of retractable members 300. Next, referring to FIG. 2J , a second sacrificial layer SL2 is formed to surround the plurality of retractable members 300. In some embodiments, forming the plurality of peripheral portions 304 and forming the second sacrificial layer SL2 may be implemented by a printing process.

Referring to FIG. 2K , a plurality of first magnetic portions 206 corresponding to the plurality of retractable members 300 and a third magnetic portion 210 located on the second sacrificial layer SL2 are formed. Next, referring to FIG. 2L , a first memory metal layer 202 is formed on the second sacrificial layer SL2 to surround the plurality of first magnetic portions 206 and the third magnetic portion 210. In some embodiments, the formation of the first magnetic portion 206, the third magnetic portion 210 and the formation of the first memory metal layer 202 can be implemented by a printing process.

2M, after forming the first memory metal layer 202, the second sacrificial layer SL2 is removed to form a gap G. Next, referring to FIG2N and FIG2O, an initial connection layer 600I and a second initial memory metal layer 204I are provided, and the initial connection layer 600I is located on the second initial memory metal layer 204I. In some embodiments, the initial connection layer 600I is formed on the second initial memory metal layer 204I by a lamination process.

Referring to FIG. 2P , the initial connection layer 600I and the second initial memory metal layer 204I are patterned to form the connection layer 600 and the second memory metal layer 204, and the connection layer 600 has a plurality of slots O1, and the second memory metal layer 204 has a plurality of openings O2. Next, referring to FIG. 2Q , a plurality of second magnetic attraction portions 208 and a fourth magnetic attraction portion 212 are formed in the plurality of openings O2. In some embodiments, the patterning of the initial connection layer 600I and the second initial memory metal layer 204I can be implemented by a laser process, and the formation of the second magnetic attraction portion 208 and the fourth magnetic attraction portion 212 can be implemented by a printing process.

Please refer to FIG. 2R . After forming a plurality of second magnetic attraction portions 208 and a fourth magnetic attraction portion 212, the electronic component 400 is attached to the connection layer 600, and the electronic component 400 includes a plurality of pins PN, and the plurality of pins PN are respectively inserted into the plurality of slots O1 and respectively penetrate the plurality of second magnetic attraction portions 208. In some embodiments, the electronic component 400 may not include the pins PN, but after the second magnetic attraction portions 208 and the fourth magnetic attraction portions 212 are formed, a plurality of conductive posts 500 as shown in FIG. 1A and FIG. 1B are formed in the plurality of slots O1, and the plurality of conductive posts 500 respectively penetrate the plurality of second magnetic attraction portions 208, and then the electronic component 400 is attached to the connection layer 600, so that the electronic component 400 is electrically connected to the conductive posts 500.

After the electronic component 400 is attached to the connection layer 600, the second memory metal layer 204 is disposed on the first memory metal layer 202 so that the first magnetic portions 206 and the second magnetic portions 208 attract and contact each other, and the third magnetic portions 210 and the fourth magnetic portions 212 attract and contact each other, thereby forming the circuit board 10 as shown in FIG. 1A and FIG. 1B.

In summary, in the circuit board and its manufacturing method of at least one embodiment of the present invention, the temperature control element can form a circuit between the electronic component with too high temperature and the pad of the circuit substrate to achieve the overheating protection function, reduce the damage of high temperature to the product, and thus help to improve reliability and increase product life.

Although the present invention has been disclosed as above by way of embodiments, they are not intended to limit the present invention. A person having ordinary knowledge in the relevant technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the attached patent application.

10: Circuit board 100: Circuit substrate 102: Pad 104: Insulation layer 106: Circuit structure 200: Temperature control element 202: First memory metal layer 204: Second memory metal layer 204I: Second initial memory metal layer 206: First magnetic attraction part 208: Second magnetic attraction part 210: Third magnetic attraction part 212: Fourth magnetic attraction part 300: Retractable part 302: Conductive part 304: Peripheral part 400: Electronic component 500: Conductive column 600: Connection layer 600I: Initial connection layer BS: Add-on structure G: Gap ML: Conductive layer O1: slot O2: opening PN: pin PS: protection structure S: gap S1: first surface S2: second surface SL1: first sacrificial layer SL2: second sacrificial layer T1: first trench T2: second trench

Figures 1A and 1B are partial cross-sectional schematic diagrams of a circuit board in at least one embodiment of the present invention in a bonded state and a separated state, respectively. Figures 2A to 2R are partial cross-sectional diagrams of the circuit board of Figures 1A and 1B at different stages of the manufacturing process.

Domestic storage information (please note the order of storage institution, date, and number) None Overseas storage information (please note the order of storage country, institution, date, and number) None

10: Circuit board

100:Circuit substrate

102:Pad

104: Insulation layer

106: Line structure

200: Temperature control element

202: First memory metal layer

204: Second memory metal layer

206: First magnetic attraction part

208: Second magnetic attraction part

210: The third magnetic attraction part

212: Fourth magnetic attraction part

300: Telescopic parts

302: Conductive Department

304: Outer periphery

400: Electronic components

500:Conductive pillar

600: Connection layer

G: Gap

S1: First surface

S2: Second surface

Claims (10)

A circuit board, comprising: A circuit substrate, comprising a plurality of pads; A temperature control element, arranged on the circuit substrate and forming a gap with the circuit substrate, and comprising: A first memory metal layer; A second memory metal layer, fixed on the first memory metal layer, wherein the first memory metal layer is located between the second memory metal layer and the circuit substrate; A plurality of first magnetic attraction parts, arranged in the first memory metal layer; and A plurality of second magnetic attraction parts, arranged in the second memory metal layer and corresponding to the plurality of first magnetic attraction parts respectively; A plurality of retractable parts, arranged in the gap and corresponding to the plurality of first magnetic attraction parts respectively, and electrically connected to the plurality of pads respectively; An electronic component is disposed on the temperature control element; and a plurality of conductive posts are disposed between the electronic component and the temperature control element and penetrate the plurality of second magnetic attraction portions respectively and electrically connect the electronic component. A circuit board as described in claim 1, wherein the deformation temperature of the first memory metal layer is the same as the deformation temperature of the second memory metal layer, and the bending direction of the first memory metal layer is opposite to the bending direction of the second memory metal layer. The circuit board as described in claim 1, wherein the temperature control element further comprises: a third magnetic attraction portion, disposed in the first memory metal layer and between two adjacent first magnetic attraction portions, wherein the width of the third magnetic attraction portion is greater than the width of each first magnetic attraction portion; and a fourth magnetic attraction portion, disposed in the second memory metal layer and between two adjacent second magnetic attraction portions, wherein the width of the fourth magnetic attraction portion is greater than the width of each second magnetic attraction portion, and the third magnetic attraction portion and the fourth magnetic attraction portion attract and contact each other, so that the second memory metal layer is fixed on the first memory metal layer. A circuit board as described in claim 3, wherein when the second memory metal layer is not bent relative to the first memory metal layer, the first memory metal layer and the second memory metal layer adhere to each other so that the multiple first magnetic portions and the multiple second magnetic portions attract and contact each other, thereby causing the multiple conductive posts to contact the multiple retractable members respectively. A circuit board as described in claim 3, wherein when the second memory metal layer is bent relative to the first memory metal layer, the first memory metal layer is partially separated from the second memory metal layer, so that the multiple first magnetic portions are separated from the multiple second magnetic portions, thereby separating the multiple conductive posts from the multiple retractable members. A circuit board as described in claim 1, wherein the circuit substrate further includes an insulating layer, the plurality of pads are embedded in the insulating layer, and the upper surfaces of the plurality of pads are flush with the upper surface of the insulating layer. A circuit board as described in claim 1, wherein each of the retractable members includes a conductive portion and a peripheral portion surrounding the conductive portion, wherein the plurality of conductive portions respectively penetrate the plurality of first magnetic portions and are respectively electrically connected to the plurality of pads. The circuit board as described in claim 1 further includes a connecting layer disposed between the temperature control element and the electronic component, wherein the plurality of conductive posts penetrate the connecting layer. A circuit board as described in claim 1, wherein the material of the first memory metal layer and the second memory metal layer includes nickel-titanium alloy, the material of the multiple retractable parts includes conductive fibers, and the material of the multiple conductive pillars includes copper. A method for manufacturing a circuit board, comprising: Providing a first sacrificial layer and a conductive layer, wherein the first sacrificial layer is located on the conductive layer; Patterning the first sacrificial layer to form a plurality of first trenches; Forming a plurality of conductive parts in the plurality of first trenches; After forming the plurality of conductive parts, patterning the conductive layer to form a plurality of pads; After forming the plurality of pads, attaching a build-up layer structure on the plurality of pads, and patterning the build-up layer structure to form a plurality of second trenches; Forming a plurality of circuit structures in the plurality of second trenches; After forming the plurality of circuit structures, removing the first sacrificial layer to expose the side walls of the plurality of conductive parts; After removing the first sacrificial layer, forming a plurality of peripheral portions respectively surrounding the side walls of the plurality of conductive portions to form a plurality of retractable members; forming a second sacrificial layer to surround the plurality of retractable members; forming a plurality of first magnetic attraction portions respectively corresponding to the plurality of retractable members and a third magnetic attraction portion located on the second sacrificial layer; forming a first memory metal layer on the second sacrificial layer to surround the plurality of first magnetic attraction portions and the third magnetic attraction portion; after forming the first memory metal layer, removing the second sacrificial layer to form a gap; providing an initial connection layer and a second initial memory metal layer, wherein the initial connection layer is located on the second initial memory metal layer; Patterning the initial connection layer and the second initial memory metal layer to form a connection layer and a second memory metal layer, wherein the connection layer has a plurality of slots and the second memory metal layer has a plurality of openings; Forming a plurality of second magnetic attraction portions and a fourth magnetic attraction portion in the plurality of openings; After forming the plurality of second magnetic attraction portions and the fourth magnetic attraction portions, attaching an electronic component to the connection layer, wherein the electronic component includes a plurality of pins, the plurality of pins are respectively inserted into the plurality of slots and respectively penetrate the plurality of second magnetic attraction portions; and After the electronic component is attached to the connection layer, the second memory metal layer is disposed on the first memory metal layer so that the plurality of first magnetic attraction parts and the plurality of second magnetic attraction parts attract and contact each other, and the third magnetic attraction part and the fourth magnetic attraction part attract and contact each other.

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