Circuit board and method for fabricating the same

Abstract

A circuit board and a method for fabricating the same are provided. The circuit board includes two wire boards. The wire boards are opposite to each other, and a spacing layer is located between the wire boards. Each wire board includes a circuit layer and a magnetic material layer disposed on the circuit layer. The magnetic material layer has a first magnetic pole and a second magnetic pole. The first magnetic pole is located between the circuit layer and the second magnetic pole, and the magnetic material layer of one of the wire boards faces to the magnetic material layer of the other one of the wire boards. A repulsive force is formed between the second magnetic poles of the magnetic material layers.

Description

[Technical Field]

[0001] This invention relates to a circuit board, and more particularly to a multilayer circuit board. [Previous Technology]

[0002] Currently, multilayer circuit boards typically have four or more layers, with each layer connected structurally and electrically via adhesive layers and conductive copper layers. However, due to these structural limitations, relative displacement between layers is impossible. In the trend towards multifunctional electronic products, this structure will significantly restrict the application of multilayer board functions. [Summary of the Invention]

[0003] Therefore, the present invention provides a circuit board for realizing relative displacement between two adjacent layers in the circuit board.

[0004] At least one embodiment of the present invention also provides a method for manufacturing the above-mentioned circuit board.

[0005] At least one embodiment of the present invention provides a circuit board comprising two circuit boards. The circuit boards are disposed opposite to each other, and a gap layer is provided between the circuit boards. Each circuit board includes a circuit layer and a magnetic material layer disposed on the circuit layer, and the magnetic material layer has a first magnetic pole and a second magnetic pole with opposite polarities. The first magnetic pole is located between the circuit layer and the second magnetic pole, and the magnetic material layer of one circuit board faces the magnetic material layer of the other circuit board, while a repulsive force is formed between the second magnetic pole of one magnetic material layer and the second magnetic pole of the other magnetic material layer.

[0006] The present invention also provides a method for manufacturing a circuit board, comprising providing an insulating substrate; forming a conductive layer on the insulating substrate; forming a first magnetic material layer on the conductive layer, wherein the first magnetic material layer has a first magnetic pole and a second magnetic pole with opposite polarities, the first magnetic pole being located between the conductive layer and the second magnetic pole; forming a removable material on the first magnetic material layer, wherein the first magnetic material layer is located between the conductive layer and the removable material; forming a second magnetic material layer on the removable material, wherein the removable material is located between the second magnetic material layer and the first magnetic material layer; forming a first circuit layer on the second magnetic material layer, wherein the second magnetic material layer is located between the first circuit layer and the removable material; and after forming the first circuit layer, forming a plurality of flexible conductive structures in the first magnetic material layer, the removable material, and the second magnetic material layer, wherein the flexible conductive structures are electrically connected to the conductive layer.

[0007] Based on the above, at least one embodiment of the present invention provides a repulsive force through opposite magnetic poles in the magnetic material layer, so that the two circuit boards do not directly contact each other, but are connected (including electrical connection) by a flexible connection structure. In this way, without affecting the electrical connection between the two circuit boards, the displacement or deformation of one circuit board due to external force will not drive the other circuit board, thereby providing the feasibility of relative displacement of internal components (e.g., circuit boards) of the circuit board.

Implementation Method

[0008] The present invention will be described in detail with reference to the following embodiments. It should be noted that the following description of the embodiments of the present invention is for illustrative purposes only and is not intended to disclose all embodiments exhaustively or to limit the specific embodiments of the present invention. For example, the phrase "a first feature is formed on a second feature" in the description includes various implementations, including situations where the first feature and the second feature are in direct contact, and situations where an additional feature is formed between the first feature and the second feature so that they are not in direct contact. Furthermore, the same element symbols used in the drawings and specification will, as far as possible, represent the same or similar elements.

[0009] Spatial relative terms, such as "lower," "below," "below," "above," and "above," are used here to simply describe the relationship between an element or feature as shown in the figure and another element or feature. These spatial relative terms cover not only the orientation depicted in the figure but also different orientations when using or operating the device. Furthermore, when the element is rotatable (rotating 90 degrees or other angles), the spatial relative descriptive terms used here can also be interpreted accordingly.

[0010] Furthermore, when a number or a range of numbers is described using terms such as "approximately" or "about," the term is intended to encompass numbers within a reasonable range and takes into account the natural differences that would be understood by those skilled in the art during the manufacturing process. A range of numbers encompasses a reasonable range including the described number; for example, within + / -10% of the described number is based on known manufacturing tolerances that relate to the characteristics of the manufacturing feature. For instance, a material layer with a thickness of "approximately 5 nanometers" can cover a size range from 4.25 nanometers to 5.75 nanometers, where a manufacturing tolerance of + / -15% for depositing the material layer is known to those skilled in the art. Furthermore, reference numerals and / or designations may be repeated in various examples. This repetition is for simplification and clarity and is not intended to indicate any relationship between the various embodiments and / or configurations discussed herein.

[0011] The present invention provides a circuit board 100. Referring to FIG1, the circuit board 100 includes a circuit substrate 110 and a circuit substrate 120, and a flexible connection structure 130. The circuit substrate 110 and the circuit substrate 120 are disposed opposite to each other, and a gap layer 150 is provided between the circuit substrate 110 and the circuit substrate 120. Each circuit substrate includes a circuit layer and a magnetic material layer. Specifically, the circuit substrate 110 includes a circuit layer 112 and a magnetic material layer 114, while the circuit substrate 120 includes a circuit layer 122 and a magnetic material layer 124.

[0012] A magnetic material layer 114 is disposed on the circuit layer 112, and the magnetic material layer 114 has a first magnetic pole 114S and a second magnetic pole 114N with opposite polarities. On the other hand, a magnetic material layer 124 is disposed on the circuit layer 122, and the magnetic material layer 124 also has a first magnetic pole 124S and a second magnetic pole 124N with opposite polarities. The first magnetic pole 114S is located between the circuit layer 112 and the second magnetic pole 114N, while the first magnetic pole 124S is located between the circuit layer 122 and the second magnetic pole 124N.

[0013] Notably, the magnetic material layer 114 of the circuit substrate 110 faces the magnetic material layer 124 of the circuit substrate 120. In other words, the magnetic material layers 114 and 124 are located between the circuit layers 112 and 122, and the second magnetic pole 114N of the magnetic material layer 114 faces the second magnetic pole 124N of the magnetic material layer 124. Since the magnetism of the first magnetic poles 114S and 124S is opposite to that of the second magnetic poles 114N and 124N, a repulsive force RF1 is formed between the second magnetic poles 114N and 124N.

[0014] Magnetic material layer 114 and magnetic material layer 124 may contain magnetic thin film material, which may be a strongly magnetic material with a thickness of less than 1µm. For example, it may contain ferromagnetic or ferrimagnetic materials such as ferrite thin film material, wherein the ferrite thin film material may be a thin film formed by iron, oxygen and other metallic elements (e.g., zinc, nickel, manganese, cobalt, etc.) through a specific process.

[0015] In addition, the circuit board 110 also includes a conductive layer 115, an insulating substrate 116, and a bonding layer 118. The conductive layer 115 is disposed between the magnetic material layer 114 and the circuit layer 112, the insulating substrate 116 is disposed between the circuit layer 112 and the conductive layer 115, and the bonding layer 118 is disposed between the insulating substrate 116 and the magnetic material layer 114. On the other hand, the circuit board 120 includes a bonding layer 128, which is disposed on the circuit layer 122, and the circuit layer 122 is located between the magnetic material layer 124 and the bonding layer 128.

[0016] In this embodiment, the conductive layer 115 of the circuit substrate 110 may contain copper or a similar metallic material. The insulating substrate 116 may contain, for example, polyimide (PI) or a similar insulating material. The bonding layer 118 and bonding layer 128 may contain, for example, epoxy resin or a similar insulating adhesive material.

[0017] A flexible connection structure 130 is disposed between the circuit board 110 and the circuit board 120, and connects the circuit board 110 and the circuit board 120. The circuit board 110 is electrically connected to the circuit board 120 through the flexible connection structure 130. In detail, the two ends of the flexible connection structure 130 are respectively connected to the circuit layer 112 of the circuit board 110 and the circuit layer 122 of the circuit board 120, so as to form an electrical connection between the circuit layer 112 and the circuit layer 122.

[0018] A flexible connection structure 130 is distributed in the gap layer 150, and the flexible connection structure 130 further includes a conductive material 135 and a bonding layer 138. The conductive material 135 connects the circuit board 110 and the circuit board 120, and the circuit layer 112 of the circuit board 110 is connected to the circuit layer 122 of the circuit board 120 through the conductive material 135. The bonding layer 138 covers the outer surface 135s of the conductive material 135 and completely covers this outer surface 135s to isolate the conductive material 135 from the gap layer 150. The conductive material 135 may contain copper or a similar metal material, while the bonding layer 138 may contain epoxy resin or a similar insulating adhesive material.

[0019] In this embodiment, the circuit board 100 further includes an electronic component 160 and a flexible conductive structure 170. The electronic component 160 is disposed on the circuit substrate 120, and the circuit substrate 120 is located between the electronic component 160 and the circuit substrate 110. More specifically, the electronic component 160 is disposed on the bonding layer 128 of the circuit substrate 120, wherein the bonding layer 128 is located between the electronic component 160 and the circuit layer 122.

[0020] A flexible conductive structure 170 is disposed between the circuit board 110 and the electronic component 160. As shown in FIG1, the flexible conductive structure 170 extends from the circuit board 120 through the gap layer 150 and to the conductive layer 115 in the circuit board 110, and the electronic component 160 is electrically connected to the circuit board 110 (and / or the circuit board 120) through the flexible conductive structure 170.

[0021] Notably, the circuit board 100 also includes a plurality of pads 102 and a plurality of soldering materials (not shown). These pads 102 are disposed between the bonding layer 128 of the circuit board 120 and the electronic component 160, while the soldering materials are disposed between the pads 102 and the electronic component 160. The electronic component 160 can be connected to the pads 102 via the soldering materials and, through the pads 102, to the flexible conductive structure 170. In other words, the electronic component 160 can be electrically connected to the flexible conductive structure 170 via the soldering materials and the pads 102.

[0022] Referring to FIG2, in another embodiment, the circuit board 100 may further include an electronic component 180. The electronic component 180 is disposed on and electrically connected to the circuit board 110. The circuit board 110 is located between the electronic component 160 and the electronic component 180. The electronic component 160 and the electronic component 180 may be active components such as transistors, or passive components such as capacitors and inductors. In addition, in other embodiments, the electronic component 160 may also be electrically connected to the circuit board 120 by, for example, wire bonding.

[0023] Referring back to Figure 1, the circuit substrates 110 and 120 also include multiple vias TH1 and TH2. These vias are distributed within the circuit layers and magnetic material layers, and connect opposite sides of the circuit substrates. Specifically, via TH1 is located within the circuit layer 112 and magnetic material layer 114, and connects opposite sides of the circuit substrate 110, while via TH2 is located within the circuit layer 122 and magnetic material layer 124, and connects opposite sides of the circuit substrate 120. Vias TH1 and TH2 can provide stress relief for the circuit substrates 110 and 120 during relative displacement, thereby reducing the possibility of damage to the circuit substrates 110 and 120.

[0024] As shown in FIG. 1, the circuit board 100 further includes a cover layer 190. This cover layer 190 is disposed on the circuit substrate 110. The circuit substrate 110 is located between the cover layer 190 and the circuit substrate 120, and the cover layer 190 covers the circuit layer 112 of the circuit substrate 110. The cover layer 190 may be a coverlay (CVL). In addition, the circuit board 100 also includes a protective layer 104, which is disposed on the cover layer 190, and the cover layer 190 is located between the protective layer 104 and the circuit substrate 110.

[0025] Please refer to Figures 3A and 3B together, which illustrate a schematic diagram of a circuit board of at least one embodiment of the present invention applied to an electronic module. As shown in Figure 3A, the electronic module 30 includes a circuit board 100, a first module element 301, and a second module element 302. The first module element 301 and the second module element 302 are respectively disposed on opposite sides of the circuit board 100. Specifically, the first module element 301 is disposed on a circuit board 110, and the second module element 302 is disposed on a circuit board 120. The circuit board 110 and the circuit board 120 are located between the first module element 301 and the second module element 302.

[0026] In this embodiment, the first module element 301 may include a camera lens, such as a complementary metal oxide semiconductor (CMOS) camera lens or a similar element, and is electrically connected to the circuit board 120. On the other hand, the second module element 302 may include a camera lens base plate and is electrically connected to the circuit board 110.

[0027] When the electronic module 30 is subjected to an external force F1, such as vibration or swaying, the first module element 301 will displace accordingly. Since the first module element 301 and the second module element 302 are connected to each other through the flexible connection structure 130, the flexible connection structure 130 will deform. Thus, the second module element 302 will not be affected by the first force and will not be displaced or deformed. In other words, although the flexible connection structure 130 provides a connection (electrical connection) between the first module element 301 and the second module element 302, it does not affect the independence of the displacement of the first module element 301 and the second module element 302.

[0028] At least one embodiment of the present invention provides a method for manufacturing a circuit board. Taking circuit board 100 as an example, this manufacturing method may include several steps as shown in Figures 4A to 4E. Referring to Figure 4A, firstly, an insulating substrate 116 is provided. Next, a conductive layer 115 is formed on the insulating substrate 116 by, for example, electroplating deposition, photolithography, and etching. After forming the conductive layer 115, a magnetic material layer 114 is formed on the conductive layer 115 by, for example, thermoforming. The magnetic material layer 114 has a first magnetic pole 114S and a second magnetic pole 114N with opposite polarities. As shown in Figure 4A, the first magnetic pole 114S is located between the conductive layer 115 and the second magnetic pole 114N.

[0029] Referring to FIG4B, a removable material 405 is formed on the magnetic material layer 114. The magnetic material layer 114 is located between the conductive layer 115 and the removable material 405. The removable material 405 may contain, for example, polyvinyl carbonate (e.g., QPAC) or similar materials, and can be removed by, for example, thermal decomposition.

[0030] Next, a magnetic material layer 124 can be formed on the removable material 405 by, for example, hot pressing. The removable material 405 is located between the magnetic material layer 124 and the magnetic material layer 114. Next, a circuit layer 122 can be formed on the magnetic material layer 124 by, for example, sputtering, photolithography, and etching. The magnetic material layer 124 is located between the circuit layer 122 and the removable material 405.

[0031] Referring to FIG4C, after forming the circuit layer 122, a plurality of flexible conductive structures 170 are formed in the magnetic material layer 114, the removable material 405, and the magnetic material layer 124, and these flexible conductive structures 170 are electrically connected to the conductive layer 115. In particular, the flexible conductive structures 170 are formed by first removing a portion of the magnetic material layer 114, the removable material 405, and the second magnetic material layer 124 by laser to form a plurality of openings (not shown).

[0032] Next, insulating material 407 is filled into the opening, and the insulating material 407 completely covers the inner wall of the opening. After filling the opening with insulating material 407, a portion of the insulating material 407 can be removed by means of, for example, laser drilling, to form a plurality of secondary openings (not shown) within the insulating material 407, and these secondary openings expose the conductive layer 115. After forming the secondary openings, a conductive material 409 can be filled into the secondary openings by means of, for example, electroplating deposition, and the conductive material 409 is electrically connected to the conductive layer 115.

[0033] Referring to FIG4D, after the flexible conductive structure 170 is formed, an electronic component 160 is disposed on the circuit layer 122. This electronic component 160 is electrically connected to the conductive layer 115 through the flexible conductive structure 170. Next, a metal layer 412' can be formed on the insulating substrate 116 by, for example, sputtering deposition.

[0034] Referring to FIG4E, after the metal layer 412' is formed, a plurality of flexible connection structures 130 are formed in the magnetic material layer 114, the removable material 405 (shown in FIG4D), the magnetic material layer 124, and the insulating substrate 116. These flexible connection structures 130 connect the circuit layer 122 and the metal layer 412' (shown in FIG4D). In addition, some of the flexible connection structures 130 connect the electronic component 160 and the circuit layer 112.

[0035] Notably, the flexible connection structure 130 is formed by first removing a portion of the magnetic material layer 114, the removable material 405, and the second magnetic material layer 124 using a laser to form a plurality of first openings (not shown), which expose the circuit layer 122. Next, a bonding material is filled into the first openings to form a bonding layer 138, which completely covers the inner wall of the first openings. After forming the bonding layer 138, a portion of the bonding layer 138 can be removed, for example, by laser drilling, to form a plurality of second openings (not shown) within the bonding layer 138, which expose the circuit layer 122. After forming the second openings, a conductive material 135 can be filled into the second openings, for example, by electroplating deposition, and the conductive material 135 is electrically connected to the circuit layer 122.

[0036] After forming the flexible connection structure 130, the metal layer 412' can be patterned by, for example, photolithography and etching to form the circuit layer 112. The circuit layer 122 is electrically connected to the circuit layer 112 through the flexible connection structure 130. After forming the circuit layer 112, the removable material 405 is removed to form a gap layer 150 between the magnetic material layer 114 and the magnetic material layer 124. At this point, the circuit board 100 shown in FIG1 has been substantially formed.

[0037] In summary, at least one embodiment of the present invention provides a repulsive force through opposite magnetic poles in a magnetic material layer, so that two circuit boards do not directly contact each other, but are connected (including electrical connection) by a flexible connection structure. In this way, without affecting the electrical connection between the two circuit boards, displacement or deformation of one circuit board due to external force will not affect the other circuit board, thereby providing the feasibility of relative displacement of internal components (e.g., circuit boards) of the circuit board.

[0038] Although the embodiments of the present invention have been disclosed above, they are not intended to limit the embodiments of the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0039] The nature of the present invention can be understood from the following detailed description and accompanying drawings. It should be noted that many features are not drawn to industry-standard scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion. Figure 1 illustrates a cross-sectional view of a circuit board according to at least one embodiment of the present invention. Figure 2 illustrates a cross-sectional view of a circuit board according to another embodiment of the present invention. Figure 3A illustrates a schematic cross-sectional view of a circuit board according to at least one embodiment of the present invention applied to an electronic module. Figure 3B illustrates a schematic cross-sectional view of a circuit board according to at least one embodiment of the present invention applied to an electronic module. Figures 4A to 4E illustrate cross-sectional views of a method for manufacturing a circuit board according to at least one embodiment of the present invention.

Claims

1. A circuit board comprising: two circuit substrates disposed opposite to each other, wherein a gap layer is provided between the circuit substrates, wherein each of the circuit substrates comprises: a circuit layer; and a magnetic material layer disposed on the circuit layer, wherein the magnetic material layer has a first magnetic pole and a second magnetic pole of opposite polarity, wherein the first magnetic pole is located between the circuit layer and the second magnetic pole, and the magnetic material layer of one of the circuit substrates faces the magnetic material layer of the other circuit substrate, and a repulsive force is formed between the second magnetic pole of one of the magnetic material layers and the second magnetic pole of the other magnetic material layer.

2. The circuit board as claimed in claim 1 further comprises: a flexible connection structure disposed between the circuit substrates and connecting the circuit substrates, wherein one of the circuit substrates is electrically connected to the other circuit substrate through the flexible connection structure.

3. The circuit board as claimed in claim 2, wherein the flexible connection structure further comprises: a conductive material connecting the circuit substrate, wherein the circuit layer of one of the circuit substrates is connected to the circuit layer of the other circuit substrate through the conductive material; and a bonding layer covering an outer surface of the conductive material.

4. The circuit board of claim 1, wherein one of the circuit substrates further comprises: a conductive layer disposed between the magnetic material layer and the circuit layer; an insulating substrate disposed between the circuit layer and the conductive layer; and a bonding layer disposed between the insulating substrate and the magnetic material layer.

5. The circuit board of claim 4, further comprising: a first electronic component disposed on one of the circuit substrates, wherein the one of the circuit substrates is located between the first electronic component and the other of the circuit substrates; and a flexible conductive structure disposed between the other of the circuit substrates and the first electronic component, wherein the flexible conductive structure extends from one of the circuit substrates through the gap layer and to the conductive layer of the other of the circuit substrates, and the first electronic component is electrically connected to at least one of the circuit substrates through the flexible conductive structure.

6. The circuit board of claim 1, wherein each of the circuit substrates further comprises: a plurality of through holes distributed within the circuit layer and the magnetic material layer, and communicating with opposite sides of the circuit substrate.

7. The circuit board of claim 1 further comprises: a cover layer disposed on one of the circuit substrates, wherein one of the circuit substrates is located between the cover layer and the other of the circuit substrates.

8. A method of manufacturing a circuit board, comprising: providing an insulating substrate; forming a conductive layer on the insulating substrate; forming a first magnetic material layer on the conductive layer, wherein the first magnetic material layer has a first magnetic pole and a second magnetic pole of opposite polarity, wherein the first magnetic pole is located between the conductive layer and the second magnetic pole; forming a removable material on the first magnetic material layer, wherein the first magnetic material layer is located between the conductive layer and the removable material; forming a second magnetic material layer on the removable material, wherein the removable material is located between the second magnetic material layer and the first magnetic material layer; forming a first circuit layer on the second magnetic material layer, wherein the second magnetic material layer is located between the first circuit layer and the removable material; and after forming the first circuit layer, forming a plurality of flexible conductive structures in the first magnetic material layer, the removable material, and the second magnetic material layer, wherein the flexible conductive structures are electrically connected to the conductive layer.

9. The method of claim 8, further comprising: after forming the flexible conductive structure, forming a metal layer on the insulating substrate; after forming the flexible conductive structure, forming a plurality of flexible connection structures in the first magnetic material layer, the removable material, the second magnetic material layer, and the insulating substrate, wherein the flexible connection structures connect the first circuit layer and the metal layer; after forming the flexible connection structures, patterning the metal layer to form a second circuit layer, wherein the first circuit layer is electrically connected to the second circuit layer through the flexible connection structures; and after forming the second circuit layer, removing the removable material to form a gap layer between the first magnetic material layer and the second magnetic material layer.

10. The method of claim 9, wherein forming the flexible connection structure comprises: removing a portion of the first magnetic material layer, the removable material, and the second magnetic material layer to form a plurality of first openings, wherein the first openings expose the first circuit layer; filling an insulating material within the first openings to form a bonding layer, wherein the bonding layer completely covers an inner wall of the first opening; after forming the bonding layer, removing a portion of the bonding layer to form a plurality of second openings, wherein the second openings expose the first circuit layer; and after forming the second openings, filling a conductive material within the second openings, wherein the conductive material is electrically connected to the first circuit layer.

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