Circuit board and manufacturing method thereof

Abstract

A circuit board comprises a main body substrate and an extension substrate. The main body substrate comprises a first external structure, a second external structure and an internal structure. The first external structure includes a first metal member having a first convex portion. The second external structure includes a second metal member having a second convex portion. The internal structure is arranged between the first external structure and the second external structure, wherein the first external structure and the second external structure protrude out of the boundary of the internal structure in the first direction. The side opening is located in the inner structure, the first outer structure and the second outer structure. The extension substrate is separably inserted into the main body substrate from the side opening, so that the thickness of the circuit board can be reduced, the thinning development of the circuit board is facilitated, and the original main body substrate and extension substrate can be reused.

Description

Technical Field

[0001] The present invention relates to a circuit board and a manufacturing method thereof, and in particular to a circuit board in which an extended substrate is arranged on a side of a main substrate and a manufacturing method thereof. Background Art

[0002] Circuit boards are widely used in, for example, Bluetooth modules, wireless fidelity (WiFi) modules, and narrowband internet of things (NB-IoT), wherein the circuit boards may be formed by stacking daughter boards on a main board (also referred to as a motherboard), and the daughter boards may be mounted on the motherboard by welding.

[0003] However, the circuit board formed by stacking the daughter board and the mother board will affect the thickness of the entire circuit board, which is not conducive to the trend of thinning. In addition, the circuit board formed by welding the daughter board and the mother board is not conducive to the reuse of the original daughter board and the mother board. For example, when the daughter board is mistakenly welded to the mother board that does not meet the specifications, the original daughter board and the mother board are difficult to detach and thus difficult to rework, resulting in the daughter board and the mother board being unable to be reused and being forced to be scrapped. In view of the above, there is an urgent need to develop a thin circuit board and a circuit board that can reuse the daughter board and the mother board to overcome the above shortcomings. Summary of the invention

[0004] At least one embodiment of the present invention provides a circuit board having a main substrate and an extension substrate and a manufacturing method thereof, wherein the extension substrate can be arranged on the side of the main substrate, which can reduce the thickness of the circuit board and is conducive to the development of thin circuit boards. In addition, the main substrate also includes two metal pieces arranged opposite to each other, wherein each metal piece has a corresponding convex portion, and the extension substrate can be detachably inserted into the main substrate from the side opening of the main substrate, which is conducive to the reuse of the original main substrate and the extension substrate.

[0005] The circuit board provided by at least one embodiment of the present invention includes a main substrate and an extended substrate. The main substrate includes a first external structure, a second external structure, an internal structure, a first adhesive layer and a second adhesive layer. The first external structure includes a first metal member having a first convex portion. The second external structure includes a second metal member having a second convex portion. The internal structure is arranged between the first external structure and the second external structure, wherein the first external structure and the second external structure protrude from the boundary of the internal structure in a first direction. The internal structure, the first external structure and the second external structure are stacked in a second direction perpendicular to the first direction, and the side opening is located in the internal structure, the first external structure and the second external structure, and the side opening exposes the boundary. The first convex portion has a first curved surface protruding toward the second external structure, and the second convex portion has a second curved surface protruding toward the first external structure, and the first curved surface and the second curved surface are arranged oppositely, and the first convex portion and the second convex portion are both located in the side opening. The first adhesive layer is arranged between the internal structure and the first external structure, and connects the internal structure and the first external structure, wherein the first metal member also has a first extension portion arranged between the first adhesive layer and the first external structure, wherein the first extension portion connects the first convex portion. The second adhesive layer is disposed between the internal structure and the second external structure and connects the internal structure and the second external structure, wherein the second metal member further has a second extension portion disposed between the second adhesive layer and the first external structure, wherein the second extension portion is connected to the second protrusion. The extension substrate is detachably inserted into the main substrate from the side opening.

[0006] In at least one embodiment of the present invention, the internal structure includes a first internal insulating layer, and the extended substrate includes a first circuit layer, a second circuit layer, and a second internal insulating layer. The second internal insulating layer is disposed between the first circuit layer and the second circuit layer, wherein the first circuit layer, the second circuit layer, and the second internal insulating layer are stacked along a second direction. When the extended substrate is inserted into the main substrate from the side opening, the extended substrate is sandwiched between the first metal member and the second metal member, wherein the first protrusion of the first metal member presses the first circuit layer, and the second protrusion of the second metal member presses the second circuit layer.

[0007] In at least one embodiment of the present invention, the first inner insulating layer is aligned with the second inner insulating layer in the first direction.

[0008] In at least one embodiment of the present invention, the first external structure further includes a first groove, the first metal component further includes a first support portion connected to the first protrusion, wherein the first support portion is disposed in the first groove. The second external structure further includes a second groove, the second metal component further includes a second support portion connected to the second protrusion, wherein the second support portion is disposed in the second groove, and the first support portion and the second support portion are located between a first bottom portion of the first groove and a second bottom portion of the second groove.

[0009] In at least one embodiment of the present invention, the extended substrate includes a first circuit layer, a second circuit layer, and a second internal insulating layer. The second internal insulating layer is disposed between the first circuit layer and the second circuit layer, wherein the first circuit layer, the second circuit layer, and the second internal insulating layer are stacked along a second direction. When the extended substrate is separated from the main substrate, the first supporting portion of the first metal member does not contact the first bottom surface of the first groove, and the second supporting portion of the second metal member does not contact the second bottom surface of the second groove.

[0010] In at least one embodiment of the present invention, the minimum distance between the first curved surface of the first protrusion and the second curved surface of the second protrusion is less than or equal to the distance between the surface of the first circuit layer and the surface of the second circuit layer.

[0011] In at least one embodiment of the present invention, the overall thickness of the extension substrate is less than or equal to the height of the side opening of the main substrate.

[0012] A method for manufacturing a circuit board provided by at least one embodiment of the present invention comprises the following steps. A first initial external structure is provided, wherein the first initial external structure comprises a first insulating layer and a first metal member, the first insulating layer comprises a plurality of first grooves, the first metal member comprises a first protrusion, a first extension, and a first support portion, the first extension portion and the first support portion are respectively located at two ends of the first protrusion, and the first extension portion and the first support portion are respectively arranged in a plurality of first grooves in the first insulating layer. A second initial external structure is provided, wherein the second initial external structure comprises a second insulating layer and a second metal member, the second insulating layer comprises a plurality of second grooves, the second metal member comprises a second protrusion, a second extension, and a second support portion, the second extension portion and the second support portion are respectively located at two ends of the second protrusion, and the second extension portion and the second support portion are respectively arranged in a plurality of second grooves in the second insulating layer. An internal structure is provided. The first initial external structure, the internal structure and the second initial external structure are pressed together to form an initial circuit substrate, wherein the initial circuit substrate includes a cavity, and the first protrusion, the first support portion, the second protrusion and the second support portion are located in the cavity, wherein the first protrusion has a first curved surface protruding toward the second protrusion, and the second protrusion has a second curved surface protruding toward the first protrusion. Through holes are formed in the initial circuit substrate so that the first support portion and the second support portion are exposed in the through holes. The through holes are plated. The initial circuit substrate is cut to expose the cavity from the side of the initial circuit substrate and form a circuit board.

[0013] In at least one embodiment of the present invention, a method for manufacturing a first initial external structure comprises the following steps: providing a first substrate including a first insulating layer and a first circuit layer; etching the first circuit layer to form the first circuit layer; forming a plurality of grooves in the first insulating layer; providing a first metal member; embedding a first extension portion and a first support portion of the first metal member in the plurality of grooves in the first insulating layer to form the first initial external structure.

[0014] In at least one embodiment of the present invention, after the through-holes are plated, a solder resist layer is formed to fill the plated through-holes and cover the surface of the initial circuit substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] When read in conjunction with the accompanying drawings, the various aspects of the present application can be best understood according to the following detailed description. It should be understood that, in accordance with standard practice in the industry, the various features are not drawn to scale. In fact, the size of the various features can be arbitrarily increased or reduced for clarity.

[0016] Figures 1A to 1D Schematic cross-sectional view of a main substrate in various stages of a process according to at least one embodiment of the present invention.

[0017] Figure 2 for Figure 1D A side view of the main substrate.

[0018] Figure 3 FIG. 4 is a cross-sectional schematic diagram of an extended substrate according to at least one embodiment of the present invention.

[0019] Figure 4 For a connection according to an embodiment Figure 1D The main substrate and Figure 2 A schematic cross-sectional view of a circuit board with an extended substrate.

[0020] Figure 5 For connection according to another embodiment Figure 1D The main substrate and Figure 2 An enlarged cross-sectional schematic diagram of a circuit board with an extended substrate. DETAILED DESCRIPTION

[0021] In the following text, in order to clearly present the technical features of the present invention, the dimensions (such as length, width, thickness and depth) of the components (such as substrates, circuit layers and through holes, etc.) in the drawings will be enlarged in unequal proportions, and the number of some components will be reduced. Therefore, the description and explanation of the embodiments below are not limited to the number of components in the drawings and the dimensions and shapes presented by the components, but should cover the dimensions, shapes and deviations of the two caused by actual processes and / or tolerances. For example, the flat surface shown in the drawings may have rough and / or nonlinear features, while the acute angles shown in the drawings may be rounded. Therefore, the components presented in the drawings of the present invention are mainly for illustration, and are not intended to accurately depict the actual shape of the components, nor are they used to limit the claims of the present invention.

[0022] In addition, spatially relative terms such as "below," "below," "below," "above," "above," and other similar terms are used to facilitate describing the relationship between one element or feature and another element or feature in the drawings. In addition to the orientation depicted in the drawings, the spatially relative terms also cover other orientations of the device when in use or operation. That is, when the orientation of the device is different from the drawings (rotated 90 degrees or in other orientations), the spatially relative terms used in this disclosure can also be interpreted accordingly.

[0023] It will be understood that, although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the embodiment, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0024] The terms "approximately", "approximately", "essentially", or "substantially" used herein may be selected based on the optical properties, etching properties, mechanical properties, measurement properties, coating properties, or other properties to select a more acceptable deviation range or standard deviation, and may not apply to all properties with one standard deviation. It should be noted that the first direction D1 and the second direction D2 are marked in the drawings of the present case to show the configuration relationship of the components in the drawings, and the first direction D1 and the second direction D2 are substantially perpendicular to each other.

[0025] Figures 1A to 1D Schematic diagram of the cross section of the main substrate in various stages of the process of at least one embodiment of the present invention. Figure 1A The main substrate 100 includes a first initial external structure 110, a second initial external structure 120 and an internal structure 130. The internal structure 130 is disposed between the first initial external structure 110 and the second initial external structure 120. In other words, the first initial external structure 110 and the second initial external structure 120 are disposed on opposite sides of the internal structure 130.

[0026] The first initial external structure 110 includes an insulating layer 112, a circuit layer 114, and a first metal member 116. The circuit layer 114 is disposed on one side of the insulating layer 112, and the first metal member 116 is disposed on the other side of the insulating layer 112. Figure 1A In the embodiment of the present invention, the insulating layer 112 and the circuit layer 114 are distributed along a direction parallel to the first direction D1 and are stacked along a second direction D2, wherein the first direction D1 may be perpendicular to the second direction D2. The first metal member 116 is also stacked along the second direction D2 with the insulating layer 112 and the circuit layer 114. The first metal member 116 may also be referred to as a 3D metal clip.

[0027] The insulating layer 112 includes a plurality of first grooves 115a and 115b. The first metal member 116 includes a first protrusion 116a, a first extension 116b and a first support 116c, and the first extension 116b and the first support 116c are respectively located at two ends of the first protrusion 116a. In other words, one end of the first protrusion 116a is connected to the first extension 116b, and the other end of the first protrusion 116a is connected to the first support 116c. Figure 1A In the embodiment of the present invention, a portion of the first extension portion 116b is located in the first groove 115a, and the first support portion 116c is located in the first bottom of the first groove 115b.

[0028] In an embodiment of the present invention, the method for forming the first initial external structure 110 includes the following steps: providing a substrate including an initial insulating layer and a metal layer, wherein the metal layer is disposed on the initial insulating layer, and the substrate may be a copper clad laminate (CCL). Then, etching the metal layer to form Figure 1A A plurality of first grooves 115a and 115b are formed in the initial insulating layer to form a circuit layer 114. Figure 1A Then, the first extension portion 116b of the first metal member 116 is embedded in the first groove 115a, and the first support portion 116c of the first metal member 116 is disposed in the first groove 115b in the first insulating layer to form a Figure 1A The first initial outer structure 110 is formed by a plurality of layers of the substrate.

[0029] In the present embodiment, the circuit layer 114 is formed by etching a metal layer (e.g., copper foil of a copper foil substrate), so the circuit layer 114 is formed by a subtractive method. However, in some other embodiments, the circuit layer 114 can be formed by an additive method or a semi-additive method. In addition, in the present embodiment, the plurality of first grooves 115a and 115b can be formed by routing or laser ablation.

[0030] In some embodiments, the material of the insulating layer 112 may be an insulating material such as polyimide (PI), glass fiber epoxy resin (FR4), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or polyethylene (PE), but is not limited thereto. In some embodiments, the material of the circuit layer 114 may be a conductive material such as copper, gold or silver, but is not limited thereto. In some embodiments, the material of the first metal member 116 may be a conductive material such as copper, gold or silver, but is not limited thereto. In some embodiments, the material of the first metal member 116 is the same as the material of the circuit layer 114.

[0031] Similar to the first initial external structure 110, the second initial external structure 120 includes an insulating layer 122, a circuit layer 124 and a second metal member 126, wherein the insulating layer 122 includes a plurality of second grooves 125a and 125b. The second metal member 126 includes a second protrusion 126a, a second extension 126b and a second support portion 126c, wherein the second extension 126b and the second support portion 126c are respectively located at two ends of the second protrusion 126a, and the second extension 126b and the second support portion 126c are respectively disposed in the plurality of second grooves 125a and 125b in the insulating layer 122. Figure 1A In the embodiment of the present invention, a portion of the second extension portion 126b is located in the second groove 125a, and the second support portion 126c is located in the second bottom of the second groove 125b.

[0032] It is understandable that in Figure 1A In the embodiment of the present invention, the first initial external structure 110 and the second initial external structure 120 have similar structures, and the internal structure 130 is used as the symmetry axis, so that the first initial external structure 110 and the second initial external structure 120 have substantially mirror-symmetrical structures. The materials of each layer in the second initial external structure 120 are also similar to the materials of each layer in the first initial external structure 110, and will not be repeated here. The method for forming the second initial external structure 120 is also the same as the method for forming the first initial external structure 110, and will not be repeated here.

[0033] The internal structure 130 includes a first internal insulating layer 132 and a circuit layer 134. The circuit layers 134 are respectively located on opposite sides of the first internal insulating layer 132. The first internal insulating layer 132 and the circuit layer 134 are distributed along a direction parallel to the first direction D1 and are stacked along the second direction D2. Figure 1A shown.

[0034] The inner structure 130 is pre-cut (eg, laser cutting or stamping) to form an opening 136, wherein the opening 136 is aligned with the first metal member 116 of the first initial outer structure 110 and the second metal member 126 of the second initial outer structure 120 in the second direction D2. Figure 1A shown.

[0035] The first internal insulating layer 132 has the same or similar material as the insulating layer 112 , the circuit layer 134 has the same or similar material as the circuit layer 114 , and the electroplating layer 133 has the same or similar material as the electroplating layer 113 , which will not be repeated here.

[0036] Please refer to Figure 1A , the main substrate 100 further includes a first adhesive layer 140 and a second adhesive layer 150. The first adhesive layer 140 is disposed between the internal structure 130 and the first initial external structure 110, and is used to connect the internal structure 130 and the first initial external structure 110. The second adhesive layer 150 is disposed between the internal structure 130 and the second initial external structure 120, and is used to connect the internal structure 130 and the second initial external structure 120. The materials of the first adhesive layer 140 and the second adhesive layer 150 can be low flow prepreg or non-flow prepreg. In some embodiments, the first adhesive layer 140 and the second adhesive layer 150 can each include a polymer and glass fiber.

[0037] The first adhesive layer 140 is pre-cut (e.g., laser cutting or stamping) to have an opening 142. Similarly, the second adhesive layer 150 is pre-cut (e.g., laser cutting or stamping) to have an opening 152. The first protrusion 116a, the opening 142, the opening 136, the opening 152, and the second protrusion 126a are aligned with each other in the second direction D2.

[0038] Please refer to Figure 1B , Figure 1B For the general Figure 1A The components are pressed together to form a pressed structure, and then drilling is performed to form a main substrate 100a having a through hole 160. Since the first protrusion 116a, the opening 142, the opening 136, the opening 152 and the second protrusion 126a are aligned with each other in the second direction D2 (please refer to Figure 1A ), therefore, the pressed main substrate 100a has a cavity 170. The first convex portion 116a, the first supporting portion 116c, the second convex portion 126a and the second supporting portion 126c are located in the cavity 170, wherein the first convex portion 116a has a first curved surface cs1 protruding toward the second convex portion 126a, and the second convex portion 126a has a second curved surface cs2 protruding toward the first convex portion 116a.

[0039] It should be noted that, since the first extension portion 116b is bonded between the first initial external structure 110 and the internal structure 130, the first protrusion 116a and the first support portion 116c are suspended on the first groove 115b and in the cavity 170. Similarly, since the second extension portion 126b is bonded between the second initial external structure 120 and the internal structure 130, the second protrusion 126a and the second support portion 126c are suspended on the second groove 125b and in the cavity 170.

[0040] It is worth noting that Figure 1B The through hole 160 in the first metal member 116 exposes the first side wall ss1 of the first extension portion 116b and the second side wall ss2 of the second extension portion 126b of the second metal member 126. Figure 1B In the embodiment, the first side wall ss1 and the second side wall ss2 are substantially coplanar.

[0041] Please refer to Figure 1C ,right Figure 1B The main substrate 100a is plated through the holes and a solder mask is formed to form a Figure 1C It is worth noting that the metal layer (electroplating layer) in the electroplated through hole 180 covers and connects the first side wall ss1 of the first extension portion 116b and the second side wall ss2 of the second extension portion 126b, so that the first metal member 116 and the second metal member 126 can be electrically connected to each circuit layer (for example, the circuit layer 114 and the circuit layer 124).

[0042] After forming the plated through hole 180, the solder mask 190 is filled in the plated through hole 180 and covers the upper surfaces of the circuit layers 114 and 124 to protect the circuit layers 114 and 124 of the main substrate 100b. In some embodiments, the material of the solder mask 190 may include a resin material.

[0043] Please refer to Figure 1D ,right Figure 1C The main substrate 100b is cut to expose the cavity 170 from the side of the main substrate 100b, and form Figure 1D Specifically, since a portion of the main substrate 100b is cut off, the original cavity 170 forms a side opening 170a, wherein the side opening 170a exposes the first protrusion 116a of the first metal member 116 and the second protrusion 126a of the second metal member 126. Figure 1C The first initial outer structure 110 is formed after the above steps. Figure 1D The first outer structure 110a, and Figure 1C The second initial outer structure 120 is formed after the above steps. Figure 1D The second outer structure 120a.

[0044] exist Figure 1D In the embodiment of the present invention, the first external structure 110a and the second external structure 120a protrude from the boundary 130s of the internal structure 130 in the first direction D1. The internal structure 130, the first external structure 110a and the second external structure 120a are stacked in the second direction D2, and the side opening 170a is located in the internal structure 130, the first external structure 110a and the second external structure 120a, and the side opening 170a exposes the boundary 130s of the internal structure 130. In other words, the side opening 170a exposes the boundary 130s of the internal structure 130. In some embodiments, the main substrate 100c can be a printed circuit board (PCB) or a high density interconnect (HDI) board.

[0045] exist Figure 1D In the embodiment, the first protrusion 116a has a first curved surface cs1 protruding toward the second external structure 120a, and the second protrusion 126a has a second curved surface cs2 protruding toward the first external structure 110a, and the first curved surface cs1 and the second curved surface cs2 are arranged opposite to each other, and the first protrusion 116a and the second protrusion 126a are both located in the side opening 170a.

[0046] Please refer to Figure 2 , Figure 2 for Figure 1D 100c is a side view of the main substrate 100c. Figure 2 Two side openings 170a and two pairs of metal parts (a pair of metal parts includes a first metal part 116 and a second metal part 126) are shown, and the solder mask 190 is omitted, wherein the insulating layer 112 and the insulating layer 122 expose the side openings 170a. Figure 2 From the perspective of FIG. 1 , it can be seen that the side opening 170 a exposes the first protrusion 116 a of the first metal member 116 and the second protrusion 126 a of the second metal member 126 . It should be noted that Figure 2 The number of the side openings 170 a and the metal pieces is only used to describe one embodiment. However, in other implementations, fewer or more side openings 170 a and metal pieces may be included.

[0047] Please refer to Figure 3, which is a cross-sectional schematic diagram of an extended substrate 300 according to at least one embodiment of the present invention. The extended substrate 300 includes a second internal insulating layer 312, a circuit layer 314, and a circuit layer 316. The second internal insulating layer 312 is disposed between the circuit layer 314 and the circuit layer 316, wherein the circuit layer 314, the circuit layer 316, and the second internal insulating layer 312 are stacked along a second direction D2, such as Figure 3 shown.

[0048] The extended substrate 300 further includes a plurality of plated through holes 320 and a solder mask 330, wherein the solder mask 330 is filled in the plated through holes 320 and covers a portion of the circuit layer 314 and a portion of the circuit layer 316. It is worth noting that the solder mask 330 does not cover another portion of the circuit layer 314 and another portion of the circuit layer 316. In other words, the surface 314s of the circuit layer 314 and the surface 316s of the circuit layer 316 are exposed to the air. The extended substrate 300 can be separated from Figure 1D The side opening 170a is inserted into the main substrate 100c.

[0049] The second inner insulating layer 312 has a material similar to that of the first inner insulating layer 132, and the circuit layer 314 has a material similar to that of the circuit layer 114, which will not be described again. In some embodiments, the extension substrate 300 may be a flexible printed circuit (FPC) board, a PCB, or a HDI board.

[0050] Please refer to Figure 4 , which is a connection according to an embodiment Figure 1D The main substrate 100c and Figure 2 Schematic cross-sectional view of the circuit board 400 of the extension substrate 300. The circuit board 400 includes the main substrate 100c and the extension substrate 300, and the extension substrate 300 is inserted into the main substrate 100c through the side opening 170a.

[0051] exist Figure 4 In the embodiment of the invention, when the extension substrate 300 is inserted into the main substrate 100c from the side opening 170a, the extension substrate 300 is sandwiched between the first metal member 116 and the second metal member 126, and the first internal insulating layer 132 is aligned with the second internal insulating layer 312 in the first direction D1, wherein the first protrusion 116a of the first metal member 116 presses the first circuit layer 314, and the second protrusion 126a of the second metal member 126 presses the second circuit layer 316. Specifically, the first curved surface cs1 of the first protrusion 116a directly contacts the surface 314s of the first circuit layer 314, and the second curved surface cs2 of the second protrusion 126a directly contacts the surface 316s of the second circuit layer 316, so that the extension substrate 300 is electrically connected to the main substrate 100c.

[0052] It can be understood that, since the first extension portion 116b is used as a fixed axis, the first protrusion 116a and the first support portion 116c are suspended on the first groove 115b, so when the extension substrate 300 is inserted into the main substrate 100c, the first protrusion 116a and the first support portion 116c will have a force toward the insulating layer 112, such as Figure 4 Similarly, since the second extension portion 126b is used as a fixed axis, the second protrusion 126a and the second support portion 126c are suspended on the second groove 125b, so when the extension substrate 300 is inserted into the main substrate 100c, the second protrusion 126a and the second support portion 126c will have a force toward the insulating layer 122, such as Figure 4 drawn.

[0053] exist Figure 4 In the embodiment, when the extension substrate 300 is inserted into the main substrate 100c, the first support portion 116c of the first metal member 116 does not contact the first bottom surface 115bs of the first groove 115b, and the second support portion 126c of the second metal member 126 does not contact the second bottom surface 125bs of the second groove 125b.

[0054] Please refer to Figure 5 , which is a connection according to another embodiment Figure 1D The main substrate 100c and Figure 2 When the extension substrate 300 is inserted into the main substrate 100c, the first support portion 116c of the first metal member 116 contacts the first bottom surface 115bs of the first groove 115b, and the second support portion 126c of the second metal member 126 contacts the second bottom surface 125bs of the second groove 125b.

[0055] In some embodiments, Figure 1D As shown, when the extension substrate 300 is separated from the main substrate 100c, the first support portion 116c of the first metal piece 116 does not contact the first bottom surface 115bs of the first groove 115b, and the second support portion 126c of the second metal piece 126 does not contact the second bottom surface 125bs of the second groove 125b.

[0056] In some embodiments, when the extension substrate 300 is separated from the main substrate 100c, the minimum distance between the first curved surface cs1 of the first convex portion 116a and the second curved surface cs2 of the second convex portion 126a is equal to the distance between the surface 314s of the first circuit layer 314 and the surface 316s of the second circuit layer 316. In other embodiments, when the extension substrate 300 is separated from the main substrate 100c, the minimum distance between the first curved surface cs1 of the first convex portion 116a and the second curved surface cs2 of the second convex portion 126a is less than the distance between the surface 314s of the first circuit layer 314 and the surface 316s of the second circuit layer 316.

[0057] The overall thickness of the extension substrate 300 (including the thickness of the solder mask 330) is less than or equal to the height of the side opening 170a of the main substrate 100c. Figure 4 shown.

[0058] It should be noted that the terms “separable” and / or “detachable” mentioned above indicate that the extended substrate 300 can be repeatedly separated and combined with the main substrate 100c without damaging the overall functions of both the extended substrate 300 and the main substrate 100c, wherein the aforementioned situation of “without damaging the overall function” includes slight scratches caused by friction between the surfaces 314s and 316s, and the first curved surface cs1 and the second curved surface cs2 due to multiple insertion and extraction of the extended substrate 300 and the main substrate 100c.

[0059] In other words, even if the surfaces 314s and 316s, the first curved surface cs1 and the second curved surface cs2 are scratched due to multiple insertions and extractions of the extended substrate 300 and the main substrate 100c, the overall functions of the extended substrate 300 and the main substrate 100c will not be damaged, that is, there will be no significant adverse effect on the electrical connection between the extended substrate 300 and the main substrate 100c.

[0060] In summary, the extension substrate is arranged on the side of the main substrate, which can reduce the thickness of the circuit board and is conducive to the development of thin circuit boards. In addition, the main substrate also includes two metal parts arranged opposite to each other, wherein each metal part has a corresponding protrusion, and the extension substrate can be detachably and / or detachably inserted into the main substrate from the side opening of the main substrate, which is conducive to the reuse of the original main substrate and the extension substrate.

[0061] The features of multiple embodiments are summarized above so that those skilled in the art can better understand the aspects of the present application. Those skilled in the art should understand that the present application can be easily used as a basis for designing or modifying other processes and structures to perform the same purposes and / or achieve the same advantages of the embodiments described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of the present application, and various changes, substitutions and modifications of the present application can be made without departing from the spirit and scope of the present application.

[0062]

Explanation of symbols

[0063] 100, 100a, 100b, 100c: Main substrate

[0064] 110: First initial external structure

[0065] 110a: First external structure

[0066] 112: Insulation layer

[0067] 114: Circuit layer

[0068] 115a, 115b: first groove

[0069] 115bs: First bottom surface

[0070] 116: First metal part

[0071] 116a: first convex part

[0072] cs1: first surface

[0073] 116b: First extension

[0074] ss1: first side wall

[0075] 116c: First support portion

[0076] 120: Second initial external structure

[0077] 120a: Second external structure

[0078] 122: Insulation layer

[0079] 124: Line layer

[0080] 125a, 125b: Second groove

[0081] 125bs: Second bottom surface

[0082] 126: Second metal part

[0083] 126a: Second convex part

[0084] cs2: second surface

[0085] 126b: Second extension

[0086] ss2: Second side wall

[0087] 126c: Second support portion

[0088] 130: Internal structure

[0089] 130s: Boundary

[0090] 132: First inner insulation layer

[0091] 134: Circuit layer

[0092] 140: First adhesive layer

[0093] 150: Second adhesive layer

[0094] 160: Through hole

[0095] 170: Cavity

[0096] 170a: Side opening

[0097] 180: Plated through hole

[0098] 190: Solder mask

[0099] 300: Extended substrate

[0100] 312: Second inner insulation layer

[0101] 314: Circuit layer

[0102] 314s: Surface

[0103] 316: Circuit layer

[0104] 316s: Surface

[0105] 320: Plated through hole

[0106] 330: Solder mask

[0107] 400: Circuit board

[0108] D1: First direction

[0109] D2: Second direction.

Claims

1. A circuit board, characterized in that: Include: The main substrate includes: A first external structure including a first metal member having a first protrusion; A second external structure including a second metal member having a second protrusion; an internal structure disposed between the first external structure and the second external structure, wherein the first external structure and the second external structure protrude from a boundary of the internal structure in a first direction, wherein the inner structure, the first outer structure, and the second outer structure are stacked in a second direction perpendicular to the first direction, and a side opening is located in the inner structure, the first outer structure, and the second outer structure, and the side opening exposes the boundary, The first convex portion has a first curved surface protruding toward the second external structure, and the second convex portion has a second curved surface protruding toward the first external structure, and the first curved surface is arranged opposite to the second curved surface, and the first convex portion and the second convex portion are both located in the side opening; a first adhesive layer disposed between the internal structure and the first external structure and connecting the internal structure and the first external structure, wherein the first metal member further comprises a first extension portion disposed between the first adhesive layer and the first external structure, wherein the first extension portion is connected to the first protrusion; as well as a second adhesive layer disposed between the internal structure and the second external structure and connecting the internal structure and the second external structure, wherein the second metal member further has a second extension portion disposed between the second adhesive layer and the first external structure, wherein the second extension portion is connected to the second protrusion; and The extension substrate is detachably inserted into the main substrate from the side opening.

2. The circuit board according to claim 1, wherein the internal structure comprises a first internal insulating layer, and the extended substrate comprises: The first circuit layer; A second wiring layer; and A second internal insulating layer is disposed between the first circuit layer and the second circuit layer, wherein the first circuit layer, the second circuit layer and the second internal insulating layer are stacked along the second direction; When the extended substrate is inserted into the main substrate from the side opening, the extended substrate is sandwiched between the first metal member and the second metal member, wherein the first protrusion of the first metal member presses the first circuit layer, and the second protrusion of the second metal member presses the second circuit layer. 3 . The circuit board according to claim 2 , wherein the first inner insulating layer is aligned with the second inner insulating layer in the first direction.

4. The circuit board according to claim 1, wherein: The first external structure further includes a first groove, and the first metal member further includes a first supporting portion connected to the first protrusion, wherein the first supporting portion is disposed in the first groove; and The second external structure also includes a second groove, and the second metal part also includes a second supporting portion connected to the second protrusion, wherein the second supporting portion is arranged in the second groove, and the first supporting portion and the second supporting portion are located between the first bottom of the first groove and the second bottom of the second groove.

5. The circuit board according to claim 4, wherein the extended substrate comprises: The first circuit layer; A second wiring layer; and A second internal insulating layer is disposed between the first circuit layer and the second circuit layer, wherein the first circuit layer, the second circuit layer and the second internal insulating layer are stacked along the second direction; When the extension substrate is separated from the main substrate, the first support portion of the first metal member does not contact the first bottom surface of the first groove, and the second support portion of the second metal member does not contact the second bottom surface of the second groove.

6. The circuit board according to claim 2 or 5, wherein the minimum distance between the first curved surface of the first protrusion and the second curved surface of the second protrusion is less than or equal to the distance between the surface of the first circuit layer and the surface of the second circuit layer. 7 . The circuit board according to claim 1 , wherein an overall thickness of the extension substrate is less than or equal to a height of the side opening of the main body substrate.

8. A method for manufacturing a circuit board, characterized in that: Include: Providing a first initial external structure, wherein the first initial external structure comprises a first insulating layer and a first metal member, the first insulating layer comprises a plurality of first grooves, the first metal member comprises a first convex portion, a first extending portion and a first supporting portion, the first extending portion and the first supporting portion are respectively located at two ends of the first convex portion, and the first extending portion and the first supporting portion are disposed in the plurality of first grooves in the first insulating layer; Providing a second initial external structure, wherein the second initial external structure comprises a second insulating layer and a second metal member, the second insulating layer comprises a plurality of second grooves, the second metal member comprises a second convex portion, a second extending portion and a second supporting portion, the second extending portion and the second supporting portion are respectively located at two ends of the second convex portion, and the second extending portion and the second supporting portion are disposed in the plurality of second grooves in the second insulating layer; Provide internal structure; Pressing the first initial external structure, the internal structure, and the second initial external structure to form an initial circuit substrate, wherein the initial circuit substrate comprises a cavity, and the first convex portion, the first supporting portion, the second convex portion, and the second supporting portion are located in the cavity, wherein the first convex portion has a first curved surface convex toward the second convex portion, and the second convex portion has a second curved surface convex toward the first convex portion; forming a through hole in the initial circuit substrate so that the first supporting portion and the second supporting portion are exposed in the through hole; electroplating the through hole; The initial circuit substrate is cut to expose the cavity from one side of the initial circuit substrate and form the circuit board.

9. The method for manufacturing a circuit board according to claim 8, wherein the method for manufacturing the first initial external structure comprises: Providing a first substrate including the first insulating layer and a first circuit layer; Etching the first circuit layer to form a first circuit layer; forming the plurality of grooves in the first insulating layer; providing the first metal member; The first extension portion and the first support portion of the first metal member are embedded in the plurality of grooves in the first insulating layer to form the first initial external structure.

10. The method for manufacturing a circuit board according to claim 8, wherein after the through-holes are electroplated, a solder resist is formed to fill the plated through-holes and cover the surface of the initial circuit substrate.

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