Circuit board and manufacturing method thereof

Abstract

A circuit board comprises a first outer circuit layer, a second outer circuit layer, a first internal structure and a second internal structure. The first internal structure and the second internal structure are arranged between the first outer circuit layer and the second outer circuit layer. The first internal structure includes a first metal block extending from the first outer circuit layer to the second internal structure. The second internal structure includes a second metal block, a high-frequency substrate, and a first conductive material. The second metal block penetrates through the high-frequency substrate. The first conductive material is arranged on the first metal block, the second metal block extends from the second outer circuit layer to the first conductive material, and the first conductive material is electrically connected with the first metal block and the second metal block. As the circuit board comprises the plurality of metal blocks which are mutually stacked, the electronic component can achieve a heat dissipation effect through the metal blocks. As the electronic components and the metal blocks are vertically stacked and arranged, a good heat dissipation path is formed, and the heat dissipation effect of the electronic components is improved.

Description

Technical Field

[0001] The present invention relates to a circuit board and a manufacturing method thereof, and in particular to a circuit board with a high-frequency substrate and a manufacturing method thereof. Background Art

[0002] The circuit board of a communication product has an embedded high-frequency substrate, and a metal block (such as a metal copper block) can be set in the high-frequency substrate to solve the heat dissipation problem of electronic components. However, with the development of semiconductor technology, the transceiver design of communication products has become more and more complicated. For example, 5G or 6G communication products have more transceiver circuit designs (such as antennas), and therefore generate more heat energy. However, existing circuit boards are difficult to meet the heat dissipation problems caused by complex transceiver designs. In view of the above, there is an urgent need to develop a circuit board and a manufacturing method thereof to overcome the above problems. Summary of the Invention

[0003] The circuit board provided by the present invention comprises multiple stacked metal blocks, allowing the backsides of electronic components to dissipate heat through these metal blocks. Because the electronic components (such as chips) and these metal blocks are vertically stacked, a good heat dissipation path is formed, thereby enhancing the heat dissipation effect of the electronic components.

[0004] The circuit board provided in at least one embodiment of the present invention includes a first outer circuit layer, a second outer circuit layer, a first internal structure, and a second internal structure. The first internal structure and the second internal structure are arranged between the first outer circuit layer and the second outer circuit layer, the first internal structure is arranged between the first outer circuit layer and the second internal structure, and the second internal structure is arranged between the first internal structure and the second outer circuit layer. The first internal structure includes a first metal block, wherein the first metal block extends from the first outer circuit layer to the second internal structure. The second internal structure includes a second metal block, a high-frequency substrate, and a first conductive material. The second metal block passes through the high-frequency substrate, wherein the high-frequency substrate includes a top circuit layer, a bottom circuit layer, and a substrate body arranged between the top circuit layer and the bottom circuit layer. The first conductive material is arranged on the first metal block, wherein the second metal block extends from the second outer circuit layer to the first conductive material, and the first conductive material electrically connects the first metal block and the second metal block.

[0005] In at least one embodiment of the present invention, a bottom portion of the second metal block protrudes from a bottom surface of the bottom circuit layer of the high-frequency substrate.

[0006] In at least one embodiment of the present invention, the thickness of the high-frequency substrate is smaller than the thickness of the second metal block.

[0007] In at least one embodiment of the present invention, the second internal structure further includes a filling material, the filling material is disposed between the second metal block and the substrate body, and the filling material contacts the first conductive material.

[0008] In at least one embodiment of the present invention, the circuit board further includes an electronic component and a plated through hole. The electronic component is located directly above the second metal block and is electrically connected to the second outer circuit layer. The plated through hole passes through the high-frequency substrate.

[0009] In at least one embodiment of the present invention, the width of the first metal block is greater than the width of the second metal block.

[0010] In at least one embodiment of the present invention, the second internal structure further includes a third metal block and a second conductive material. The second conductive material is disposed on the first metal block, wherein the third metal block extends from the second outer circuit layer to the second conductive material, and the second conductive material electrically connects the first metal block and the third metal block.

[0011] The manufacturing method of the circuit board provided in at least one embodiment of the present invention includes the following steps: providing a first circuit substrate, wherein the first circuit substrate includes a first outer metal layer and a first groove; providing a first metal block, wherein the width of the first metal block is smaller than the width of the first groove; arranging the first metal block in the first groove; providing a second circuit substrate, wherein the second circuit substrate includes a second outer metal layer and a second groove; providing a high-frequency substrate, wherein the width of the high-frequency substrate is smaller than the width of the second groove; arranging the high-frequency substrate in the second groove; fixing the first circuit substrate, the high-frequency substrate and the second circuit substrate together by rivets; removing a portion of the high-frequency substrate and a portion of the high-frequency substrate. A second circuit substrate is provided to form a third groove, wherein the third groove exposes a portion of the top surface of the first metal block; a first conductive material is set at the bottom of the third groove; a second metal block is provided, wherein the width of the second metal block is smaller than the width of the third groove, and the width of the second metal block is smaller than the width of the first metal block; the second metal block is set in the third groove; a first filling material is set around the second metal block; after the second metal block is set in the third groove, a plurality of electroplated through holes are formed in the first circuit substrate and the second circuit substrate; a first outer circuit layer is formed using the first outer metal layer; and a second outer circuit layer is formed using the second outer metal layer.

[0012] In at least one embodiment of the present invention, the method for manufacturing a circuit board further includes: removing the rivet after the second metal block is disposed in the third groove.

[0013] In at least one embodiment of the present invention, the method for manufacturing a circuit board further includes: removing another portion of the high-frequency substrate and another portion of the second circuit substrate to form a fourth groove, wherein the fourth groove exposes the top surface of another portion of the first metal block; disposing a second conductive material at the bottom of the fourth groove; providing a third metal block, wherein the width of the third metal block is smaller than the width of the fourth groove, wherein the width of the third metal block is smaller than the width of the first metal block; disposing the third metal block in the fourth groove; and disposing a second filling material around the third metal block. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The various aspects of the present application are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be understood that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity.

[0015] Figure 1 FIG. 4 is a schematic cross-sectional view of a circuit board according to an embodiment of the present invention.

[0016] Figure 2 FIG. 4 is a schematic cross-sectional view of a circuit board according to another embodiment of the present invention.

[0017] Figure 3A 、 Figure 3B and Figure 3C for Figure 1 Schematic diagram of the cross section of the circuit board at various stages of the process.

[0018] Figure 4A and Figure 4B for Figure 2 Schematic diagram of the cross section of the circuit board at various stages of the process. DETAILED DESCRIPTION

[0019] In the following text, in order to clearly present the technical features of this case, the dimensions (such as length, width, thickness and depth) of the elements (such as circuit layers, insulating layers and metal blocks, etc.) in the drawings will be enlarged in a unequal manner, 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 of the elements, but should cover the dimensions, shapes and deviations thereof 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 angles shown in the drawings may be rounded. Therefore, the elements shown in the drawings of this case are mainly for illustration and are not intended to accurately depict the actual shape of the elements, nor are they intended to limit the scope of the patent application of this case.

[0020] In addition, spatially relative terms such as "below," "beneath," "below," "above," and similar terms are used to facilitate describing the relationship of one element or feature to another element or feature in the figures. Spatially relative terms encompass not only the orientation depicted in the figures, but also other orientations of the device when in use or operation. That is, when the device is oriented differently from the figures (rotated 90 degrees or in other orientations), the spatially relative terms used in this disclosure should be interpreted accordingly.

[0021] It will be understood that although terms such as "first," "second," and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] In this document, the term "from a value to another value" is used as a summary to avoid listing all values ​​within the range. Therefore, a description of a specific numerical range encompasses any value within that range and any smaller numerical ranges defined by any value within that range, just as if the values ​​and smaller numerical ranges were explicitly stated in the specification.

[0023] Figure 1 FIG1 is a schematic cross-sectional view of a circuit board 100 according to one embodiment of the present invention. Circuit board 100 includes a first outer wiring layer 110, a second outer wiring layer 120, a first inner structure 130, and a second inner structure 140. First inner structure 130 and second inner structure 140 are disposed between first outer wiring layer 110 and second outer wiring layer 120. Specifically, first inner structure 130 is disposed between first outer wiring layer 110 and second inner structure 140, and second inner structure 140 is disposed between first inner structure 130 and second outer wiring layer 120. In other words, first outer wiring layer 110, first inner structure 130, second inner structure 140, and second outer wiring layer 120 are stacked along a first direction D1. First outer wiring layer 110, second outer wiring layer 120, first inner structure 130, and second inner structure 140 extend parallel to a second direction D2. The first outer circuit layer 110 and the second outer circuit layer 120 may be, for example, patterned copper metal layers.

[0024] First internal structure 130 includes multiple inner wiring layers 132 and multiple insulating layers 134, which are stacked alternately. Each insulating layer 134 is disposed between every two inner wiring layers 132 to separate the different inner wiring layers and prevent short circuits. Each of the multiple inner wiring layers 132 can be, for example, a copper metal layer. Each of the multiple insulating layers 134 can be made of a composite material containing glass fiber and epoxy resin, such as FR4.

[0025] The first internal structure 130 further includes a first metal block 136, wherein the first metal block 136 extends from the first outer circuit layer 110 to the second internal structure 140. Specifically, the first metal block 136 is embedded within the first internal structure 130. More specifically, the first metal block 136 is embedded within the plurality of inner circuit layers 132 and the plurality of insulating layers 134. The material of the first metal block 136 can be, for example, copper, but is not limited thereto.

[0026] Second internal structure 140 includes multiple inner wiring layers 142 and multiple insulating layers 144, which are stacked alternately. Each insulating layer 144 is disposed between every two inner wiring layers 142 to separate the different inner wiring layers and prevent short circuits. Each of the multiple inner wiring layers 142 can be, for example, a copper metal layer. Each of the multiple insulating layers 144 can be made of a composite material containing glass fiber and epoxy resin, such as FR4.

[0027] Second internal structure 140 further includes a second metal block 145a, a high-frequency substrate 146, and a first conductive material 147a. High-frequency substrate 146 includes a top circuit layer TC, a bottom circuit layer BC, and a substrate body MS disposed between top and bottom circuit layers TC. Top circuit layer TC is disposed between second outer circuit layer 120 and substrate body MS.

[0028] The second metal block 145a of the second internal structure 140 penetrates the high-frequency substrate 146. Figure 1 In the embodiment of FIG, the top surface ts1 of the second metal block 145a is aligned with the top surface ts2 of the top circuit layer TC, and the second outer circuit layer 120 covers the second metal block 145a. Figure 1 In the embodiment, the thickness of the high-frequency substrate 146 is smaller than the thickness of the second metal block 145a, so that the bottom of the second metal block 145a protrudes from the bottom surface bs1 of the bottom circuit layer BC of the high-frequency substrate 146. The material of the second metal block 145a can be, for example, copper, but is not limited thereto.

[0029] The first conductive material 147a of the second internal structure 140 is disposed on the first metal block 136, wherein the second metal block 145a extends from the second outer circuit layer 120 to the first conductive material 147a. The first conductive material 147a electrically connects the first metal block 136 and the second metal block 145a. Specifically, the first conductive material 147a is disposed between the first metal block 136 and the second outer circuit layer 120. The first conductive material 147a can be, for example, copper paste, silver glue, or solder, but is not limited thereto.

[0030] The second internal structure 140 further includes a first filler material 148a, wherein the first filler material 148a is disposed between the second metal block 145a and the substrate body MS, and the first filler material 148a contacts the first conductive material 147a. Specifically, the second internal structure 140 has a hole (not shown), and the width of the second metal block 145a is smaller than the inner diameter of the hole, resulting in a gap between the second metal block 145a and the hole wall. The first filler material 148a fills the gap, thereby being disposed between the second metal block 145a and the substrate body MS, and the first filler material 148a may surround the second metal block 145a. Furthermore, the material of the first filler material 148a may be, for example, a resin material.

[0031] The circuit board 100 further includes a first electronic component 150 and a plated through hole 160. The first electronic component 150 is located directly above the second metal block 145a and is electrically connected to the second outer circuit layer 120. Figure 1 For example, the first electronic component 150 can be electrically connected to the second outer circuit layer 120 using wire bonding. Because the first electronic component 150 is located directly above the second metal block 145a, heat from the first electronic component 150 can be dissipated through the second metal block 145a and the first metal block 136 on the back side. The plated through hole 160 passes through the high-frequency substrate 146.

[0032] like Figure 1 As shown, the width of the first metal block 136 is greater than the width of the second metal block 145a. Since the width of the second metal block 145a (also known as the small metal block) is smaller than the width of the first metal block 136 (also known as the large metal block), the circuit board 100 has a fan-shaped heat dissipation path (i.e., the heat dissipation area increases from top to bottom), thereby improving the heat dissipation effect on electronic components (such as the first electronic component 150).

[0033] Figure 2 FIG. 2 is a schematic cross-sectional view of a circuit board 200 according to another embodiment of the present invention. Figure 2 The circuit board 200 and Figure 1The circuit board 100 has a similar structure, differing in the number of electronic components, small metal blocks (e.g., second metal block 145a), and conductive materials. Specifically, the second internal structure 140 of the circuit board 200 further includes a third metal block 145b, a second conductive material 147b, and a second filler material 148b. The circuit board 200 also includes a second electronic component 170.

[0034] The second conductive material 147b of the second internal structure 140 is disposed on the first metal block 136. The third metal block 145b extends from the second outer circuit layer 120 to the second conductive material 147b. The second conductive material 147b electrically connects the first metal block 136 and the third metal block 145b. Specifically, the second conductive material 147b is disposed between the first metal block 136 and the second outer circuit layer 120. The second conductive material 147b can be, for example, copper paste, silver glue, or solder, but is not limited thereto.

[0035] The third metal block 145b of the second internal structure 140 penetrates the high-frequency substrate 146. The top surface ts3 of the third metal block 145b is aligned with the top surface ts2 of the top circuit layer TC, and the second outer circuit layer 120 covers the third metal block 145b. Figure 2 In the embodiment, the thickness of the high-frequency substrate 146 is less than the thickness of the third metal block 145b, so that the bottom of the third metal block 145b protrudes from the bottom surface bs1 of the bottom circuit layer BC of the high-frequency substrate 146. The material of the third metal block 145b can be, for example, copper, but is not limited thereto.

[0036] The second filling material 148b of the second inner structure 140 is disposed between the third metal block 145b and the substrate body MS, and the second filling material 148b contacts the second conductive material 147b. The second filling material 148b may be made of a resin material, for example.

[0037] The second electronic component 170 of the circuit board 200 is located directly above the third metal block 145b and is electrically connected to the second outer circuit layer 120. Figure 2 For example, the second electronic component 170 can be electrically connected to the second outer circuit layer 120 using wire bonding. Because the second electronic component 170 is located directly above the third metal block 145b, heat from the second electronic component 170 can be dissipated through the third metal block 145b on the back side and the first metal block 136. It is worth noting that both the second metal block 145a and the third metal block 145b are connected to the first metal block 136.

[0038] like Figure 2As shown, the width of the first metal block 136 is greater than the width of the third metal block 145b. Since the width of the third metal block 145b (also known as the small metal block) is smaller than the width of the first metal block 136 (also known as the large metal block), the circuit board 200 has a fan-shaped heat dissipation path (i.e., the heat dissipation area increases from top to bottom), thereby improving the heat dissipation effect for electronic components (such as the first electronic component 150 and the second electronic component 170).

[0039] like Figure 2 As shown, the second metal block 145a and the third metal block 145b are arranged along a second direction D2, wherein the second direction D2 is substantially perpendicular to the first direction D1. The first conductive material 147a and the second conductive material 147b are also arranged along the second direction D2. The first metal block 136, the second metal block 145a, and the third metal block 145b can be cylindrical in shape, but are not limited thereto.

[0040] Figure 3A 、 Figure 3B and Figure 3C for Figure 1 Schematic diagram of the cross section of the circuit board 100 at various stages of the process. Figure 3A A first circuit substrate 310, a second circuit substrate 320, a first metal block 136, a high-frequency substrate 146, and a rivet 330 are provided. The first circuit substrate 310 includes a first outer metal layer 312, a plurality of insulating layers 314, and a first recess R1. The first metal block 136 is disposed in the first recess R1, wherein the width of the first metal block 136 is smaller than the width of the first recess R1.

[0041] It is worth noting that an air gap G is defined between the first metal block 136 and the first circuit substrate 310. The second circuit substrate 320 includes a second outer metal layer 322, multiple insulating layers 324, and a second groove R2. The high-frequency substrate 146 is disposed in the second groove R2, wherein the width of the high-frequency substrate 146 is smaller than the width of the second groove R2. It is worth noting that an air gap G is defined between the high-frequency substrate 146 and the second circuit substrate 320, wherein the air gap G surrounds the first metal block 136. The material of each of the multiple insulating layers 314 and each of the multiple insulating layers 324 can be, for example, a composite material containing glass fiber and epoxy resin, such as FR4.

[0042] It will be appreciated that the first circuit substrate 310 may include multiple inner layer boards, wherein the inner layer boards may be, for example, copper clad laminates (CCLs). The insulating layer 314 is disposed between the multiple inner layer boards. The second circuit substrate 320 may include multiple inner layer boards, wherein the inner layer boards may be, for example, copper clad laminates (CCLs). The insulating layer 324 is disposed between the multiple inner layer boards. In some embodiments, the first groove R1 may be formed by routing, and the second groove R2 may also be formed by routing.

[0043] In some embodiments, the width of the first groove R1 is between 0.2 mm and 0.3 mm greater than the width of the first metal block 136 . In some embodiments, the width of the second groove R2 is between 0.2 mm and 0.4 mm greater than the width of the high-frequency substrate 146 .

[0044] After providing the first circuit substrate 310, the second circuit substrate 320, the first metal block 136, the high-frequency substrate 146, and the rivets 330, the first circuit substrate 310, the high-frequency substrate 146, and the second circuit substrate 320 are secured together using the rivets 330. It should be noted that the rivets 330 are used to temporarily connect the previously separate substrates (i.e., the first circuit substrate 310, the high-frequency substrate 146, and the second circuit substrate 320) so that they remain connected. Once all rivets 330 are removed, the first circuit substrate 310, the high-frequency substrate 146, and the second circuit substrate 320 remain separated from each other.

[0045] Before the first circuit substrate 310, the high-frequency substrate 146, and the second circuit substrate 320 are secured together using rivets 330, holes may be drilled in the first circuit substrate 310 and the second circuit substrate 320 to facilitate the subsequent insertion of rivets 330 to secure the multiple substrates together. In some embodiments, the diameter of the holes is 1.95 mm to 2.05 mm, for example, 2.0 mm.

[0046] After the first metal block 136 is placed in the first groove R1, the high-frequency substrate 146 is placed in the second groove R2, and the first circuit substrate 310, the high-frequency substrate 146, and the second circuit substrate 320 are fixed together by rivets 330, the first circuit substrate 310, the high-frequency substrate 146, the second circuit substrate 320, and the first metal block 136 are pressed together. Figure 3AIn some embodiments, the pressing step is performed at a temperature of 185° C. to 195° C., for example, 190° C. In some embodiments, the pressing step is performed at a pressure of 2.5 MPa to 2.7 MPa, for example, 2.55 MPa, 2.6 MPa, or 2.65 MPa. In some embodiments, the pressing step is performed for a time of 140 to 160 minutes, for example, 145 minutes, 150 minutes, or 155 minutes.

[0047] During the high-temperature and high-pressure lamination step, a portion of the material of the insulating layer 314 flows into the air gap G between the first metal block 136 and the first circuit substrate 310, and a portion of the material of the insulating layer 324 flows into the air gap G between the high-frequency substrate 146 and the second circuit substrate 320. Therefore, after the high-temperature and high-pressure lamination step, the first metal block 136 is embedded in the first circuit substrate 310, and the high-frequency substrate 146 is embedded in the second circuit substrate 320. The first metal block 136 and the high-frequency substrate 146 are both covered by the material of the insulating layer 314 and the insulating layer 324, as shown in FIG. Figure 3B shown.

[0048] Please refer to Figure 3B A portion of the high-frequency substrate 146 and a portion of the second circuit substrate 320 are removed to form a third recess R3, where the third recess R3 exposes a portion of the top surface ts4 of the first metal block 136. In some embodiments, third recess R3 can be formed to a depth reaching the top surface ts4 of the first metal block 136 by machining using computer numerical control (CNC) machining (e.g., profile cutting).

[0049] After forming the third groove R3, a first conductive material 147a is disposed at the bottom of the third groove R3. Figure 3B As shown. In detail, the first conductive material 147a covers the top surface ts4 of the first metal block 136. In some embodiments, the thermal conductivity of the first conductive material 147a is greater than 180 W / m·K. In some embodiments, the thickness of the first conductive material 147a is 0.0875 mm to 0.1125 mm, for example, 0.09 mm, 0.1 mm, or 0.11 mm. In some embodiments, after the first conductive material 147a is set at the bottom of the third groove R3, the first conductive material 147a is heated at 95°C to 105°C for 9 minutes to 11 minutes to remove the solvent of the first conductive material 147a. The heating temperature of the first conductive material 147a is, for example, 100°C. The heating time of the first conductive material 147a may be, for example, 9.5 minutes, 10 minutes, or 10.5 minutes.

[0050] Please refer to Figure 3C, providing a second metal block 145a, wherein the width of the second metal block 145a is smaller than the third groove R3 (please refer to Figure 3B ), and the width of the second metal block 145a is smaller than the width of the first metal block 136. In some embodiments, the third groove R3 (see Figure 3B ) is 0.3mm to 0.5mm larger than the width of the second metal block 145a, for example, 0.35mm, 0.4mm or 0.45mm. The second metal block 145a is arranged in the third groove R3 (see Figure 3B ), such as Figure 3C In some embodiments, the second metal block 145a is first dipped in hot water to hydrolyze the glue, and then the second metal block 145a is placed on the first conductive material 147a, and then a sintering step is performed. In some embodiments, the sintering temperature of the sintering step is 245°C to 255°C, the sintering time is 28 minutes to 32 minutes, and the sintering pressure is 9 MPa to 11 MPa. The sintering temperature may be, for example, 250°C. The sintering time may be, for example, 29 minutes, 30 minutes, or 31 minutes. The sintering pressure may be, for example, 9.5 MPa, 10 MPa, or 10.5 MPa.

[0051] After the second metal block 145a is disposed in the third groove R3, a first filling material 148a is disposed around the second metal block 145a. Figure 3C As shown. In some embodiments, the first filling material 148a is placed around the second metal block 145a by screen printing, and then the first filling material 148a is pre-baked at 105°C to 115°C and maintained for 58 minutes to 62 minutes. The above-mentioned pre-baking temperature can be, for example, 110°C, and the above-mentioned pre-baking time can be, for example, 59 minutes, 60 minutes, or 61 minutes. After the first filling material 148a is filled, the first filling material 148a is baked until the first filling material 148a is hardened. Figure 3C In some embodiments, the top surface ts1 of the second metal block 145a is flush with the top surface ts2 of the top circuit layer TC. In some embodiments, after the second metal block 145a is disposed in the third groove R3, the rivet 330 is removed.

[0052] Please refer to Figure 3C and Figure 1 After the second metal block 145a is disposed in the third groove R3, a plurality of plated through holes 160 are formed on the first circuit substrate 310 and the second circuit substrate 320. The first outer metal layer 312 is used to form the Figure 1 The first outer circuit layer 110 is formed by using the second outer metal layer 322. Figure 1 In some embodiments, the first outer circuit layer 110 and the second outer circuit layer 120 can be formed by a semi-additive process or a subtractive process.

[0053] Figure 4A and Figure 4B for Figure 2 Schematic cross-sectional views of the circuit board 200 at various stages of the process. Figure 4A and Figure 4B The manufacturing method is similar to Figure 3B and Figure 3C Please refer to the manufacturing method. Figure 4A , in providing Figure 3A After removing the first circuit substrate 310, the second circuit substrate 320 (having the third groove R3), the first metal block 136, the high-frequency substrate 146, and the rivet 330, another portion of the high-frequency substrate 146 and another portion of the second circuit substrate 320 are removed to form a fourth groove R4. The fourth groove R4 exposes a portion of the top surface ts4 of the first metal block 136. A second conductive material 147b is then disposed at the bottom of the fourth groove R4.

[0054] Please refer to Figure 4B , providing a third metal block 145b, wherein the width of the third metal block 145b is smaller than the fourth groove R4 (please refer to Figure 4A ), and the width of the third metal block 145b is smaller than the width of the first metal block 136. The second metal block 145a is disposed in the third groove R3 (see Figure 4A ), and set the third metal block 145b in the fourth groove R4 (please refer to Figure 4A ), such as Figure 4B In some embodiments, the third metal block 145b is first dipped in hot water to hydrolyze the glue, and then the third metal block 145b is placed on the second conductive material 147b, and then the sintering step is performed. In some embodiments, the sintering temperature of the sintering step is 245°C to 255°C, the sintering time is 28 minutes to 32 minutes, and the sintering pressure is 9 MPa to 11 MPa. The sintering temperature may be, for example, 250°C. The sintering time may be, for example, 29 minutes, 30 minutes, or 31 minutes. The sintering pressure may be, for example, 9.5 MPa, 10 MPa, or 10.5 MPa.

[0055] After the third metal block 145b is disposed in the fourth groove R4, a second filling material 148b is disposed around the third metal block 145b. Figure 4B As shown. Figure 4B In the embodiment of FIG. 5 , a top surface ts3 of the third metal block 145 b is flush with a top surface ts2 of the top circuit layer TC.

[0056] In summary, the circuit board provided by the present invention includes small metal blocks (such as the second metal block 145a and the third metal block 145b) and a large metal block (such as the first metal block 136) stacked on each other, so that the back of the electronic component can achieve a heat dissipation effect through the small metal blocks and the large metal blocks. Since the electronic components (such as chips), small metal blocks and large metal blocks are arranged in a vertical stack, and the width of the large metal block is greater than the width of the small metal block, the circuit board has a fan-shaped heat dissipation path, thereby improving the heat dissipation effect of the electronic components. In addition, a large metal block can connect multiple small metal blocks and multiple electronic components, so that multiple electronic components with high density distribution in the circuit board still have a good heat dissipation path.

[0057] The features of the various 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 will appreciate that this application can be readily 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 will also appreciate that such equivalent constructions do not depart from the spirit and scope of the present application, and that various variations, substitutions, and modifications may be made herein without departing from the spirit and scope of the present application.

[0058]

Explanation of symbols

[0059] 100: Circuit board

[0060] 110: First outer circuit layer

[0061] 120: Second outer circuit layer

[0062] 130: First internal structure

[0063] 132: Inner circuit layer

[0064] 134: Insulation layer

[0065] 136: First Metal Block

[0066] 140: Second internal structure

[0067] 142: Inner circuit layer

[0068] 144: Insulation layer

[0069] 145a: Second metal block

[0070] 145b: The third metal block

[0071] 146: High frequency substrate

[0072] 147a: first conductive material

[0073] 147b: second conductive material

[0074] 148a: first filling material

[0075] 148b: Second filling material

[0076] 150: First electronic component

[0077] 160:Plated through hole

[0078] 170: Second electronic component

[0079] 200: Circuit board

[0080] 310: first circuit substrate

[0081] 312: first outer metal layer

[0082] 314: Insulation layer

[0083] 320: Second circuit substrate

[0084] 322: Second outer metal layer

[0085] 324: Insulation layer

[0086] 330: Rivet

[0087] TC: Top circuit layer

[0088] MS: Substrate body

[0089] BC: bottom circuit layer

[0090] R1: First groove

[0091] R2: Second groove

[0092] R3: The third groove

[0093] R4: The fourth groove

[0094] ts1,ts2,ts3,ts4: top surface

[0095] bs1: bottom surface

[0096] D1: First direction

[0097] D2: Second direction.

Claims

1. A circuit board, characterized in that: Include: a first outer circuit layer; The second outer circuit layer; a first internal structure; and a second internal structure, wherein the first internal structure and the second internal structure are disposed between the first outer wiring layer and the second outer wiring layer, the first internal structure is disposed between the first outer wiring layer and the second internal structure, and the second internal structure is disposed between the first internal structure and the second outer wiring layer; The first internal structure comprises: a first metal block, wherein the first metal block extends from the first outer circuit layer to the second inner structure; The second internal structure comprises: a second metal block; A high-frequency substrate, wherein the second metal block penetrates the high-frequency substrate, wherein the high-frequency substrate comprises: Top circuit layer; bottom circuit layer; and a substrate body, disposed between the top circuit layer and the bottom circuit layer; and The first conductive material is disposed on the first metal block, wherein the second metal block extends from the second outer circuit layer to the first conductive material, and the first conductive material electrically connects the first metal block and the second metal block. 2 . The circuit board according to claim 1 , wherein a bottom portion of the second metal block protrudes from a bottom surface of the bottom circuit layer of the high-frequency substrate. 3 . The circuit board according to claim 1 , wherein a thickness of the high-frequency substrate is smaller than a thickness of the second metal block. 4 . The circuit board according to claim 1 , wherein the second internal structure further comprises a filling material, the filling material is disposed between the second metal block and the substrate body, and the filling material contacts the first conductive material.

5. The circuit board according to claim 1, wherein Also includes: an electronic component located directly above the second metal block and electrically connected to the second outer circuit layer; and A plated through hole is formed, wherein the plated through hole passes through the high frequency substrate. The circuit board according to claim 1 , wherein a width of the first metal block is greater than a width of the second metal block.

7. The circuit board according to claim 1, wherein the second internal structure further comprises: a third metal block; and The second conductive material is disposed on the first metal block, wherein the third metal block extends from the second outer circuit layer to the second conductive material, and the second conductive material electrically connects the first metal block and the third metal block.

8. A method for manufacturing a circuit board, characterized in that: Include: Providing a first circuit substrate, wherein the first circuit substrate comprises a first outer metal layer and a first groove; Providing a first metal block, wherein a width of the first metal block is smaller than a width of the first groove; placing the first metal block in the first groove; Providing a second circuit substrate, wherein the second circuit substrate comprises a second outer metal layer and a second groove; Providing a high-frequency substrate, wherein a width of the high-frequency substrate is smaller than a width of the second groove; Disposing the high-frequency substrate in the second groove; Fixing the first circuit substrate, the high-frequency substrate, and the second circuit substrate together by rivets; removing a portion of the high-frequency substrate and a portion of the second circuit substrate to form a third groove, wherein the third groove exposes a portion of the top surface of the first metal block; Disposing a first conductive material at the bottom of the third groove; providing a second metal block, wherein a width of the second metal block is smaller than a width of the third groove, and the width of the second metal block is smaller than the width of the first metal block; placing the second metal block in the third groove; Disposing a first filling material around the second metal block; After disposing the second metal block in the third groove, forming a plurality of plated through holes in the first circuit substrate and the second circuit substrate; forming a first outer circuit layer using the first outer metal layer; and The second outer metal layer is used to form a second outer circuit layer.

9. The method for manufacturing a circuit board according to claim 8, wherein: Also includes: After the second metal block is disposed in the third groove, the rivet is removed.

10. The method for manufacturing a circuit board according to claim 8, wherein: Also includes: removing another portion of the high-frequency substrate and another portion of the second circuit substrate to form a fourth groove, wherein the fourth groove exposes another portion of the top surface of the first metal block; Disposing a second conductive material at the bottom of the fourth groove; providing a third metal block, wherein the width of the third metal block is smaller than the width of the fourth groove, wherein the width of the third metal block is smaller than the width of the first metal block; placing the third metal block in the fourth groove; and A second filling material is disposed around the third metal block.

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