Circuit board and manufacturing method thereof
By designing grooves and stepped connection lines on the circuit board substrate, combined with the circuit board structure of the heat sink, the miniaturization and high power consumption problems of the embedded chip circuit board are solved, achieving efficient heat dissipation and cost reduction.
Patent Information
- Application Number
- CN202410661755.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-11-25
AI Technical Summary
Existing embedded chip circuit boards face problems such as high manufacturing costs, poor heat dissipation performance, and insufficient layout space in miniaturized and high-power communication devices.
Design a circuit board structure comprising a circuit board, electronic components, and a heat sink. By setting connection lines and heat sinks in grooves on the board, using general soldering materials and board materials, and combining a stepped design, the stability of electrical connections and heat dissipation efficiency can be improved.
It saves circuit board layout space, improves heat dissipation performance, reduces manufacturing costs, increases reliability, and reduces reliance on expensive materials.
Smart Images
Figure CN121013261A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a circuit board and a method for manufacturing the same. Background Technology
[0002] Most current embedded chip circuit boards embed the chip within the circuit board, using microvias to electrically connect the chip to the circuit board. However, this approach not only requires consideration of whether the thickness and type of the chip's surface treatment are suitable for drilling and electroplating processes, but also presents manufacturing cost issues such as die handling equipment, die yield testing, expensive sintering materials, and circuit board substrates with low thermal expansion coefficients.
[0003] Furthermore, with the development of communication technology, the size of the embedded chip circuit board in communication devices (such as mobile phones) is getting smaller and smaller, while the power consumption of the chip is also increasing. Therefore, saving the layout space of the circuit board and improving the heat dissipation performance of the embedded chip circuit board are also goals to be achieved in this technical field. Summary of the Invention
[0004] At least one embodiment of the present invention provides a circuit board that can improve heat dissipation performance and save circuit board layout space, thereby improving reliability and reducing manufacturing costs.
[0005] At least another embodiment of the present invention provides a method for manufacturing the above-described circuit board, which helps to improve the heat dissipation performance of the circuit board and save the layout space of the circuit board, thereby improving reliability and reducing manufacturing costs.
[0006] A circuit board according to at least one embodiment of the present invention includes a circuit board, electronic components, and a heat sink. The circuit board has opposing first surfaces, a second surface, and a recessed groove extending from the second surface toward the first surface. The groove has opposing first sidewalls, a second sidewall, and a bottom portion closer to the first surface than the first and second sidewalls, the width of which is less than the distance between the first and second sidewalls. The circuit board includes a first connection line, a second connection line, a first pad, and a second pad. The first connection line is disposed on the first sidewall, the second connection line is disposed on the second sidewall, the first pad is disposed on the bottom portion and electrically connected to the first connection line, and the second pad is disposed on the bottom portion and electrically connected to the second connection line. The electronic components are disposed in the groove and electrically connected to the first and second connection lines. The heat sink is disposed in the groove, located between the electronic components and the second surface, and thermally coupled to the electronic components.
[0007] In at least one embodiment of the present invention, the circuit board further comprises resin disposed in the groove, located at the bottom and surrounding the heat sink. The groove has a first abutment surface located between the bottom and the first sidewall and a second abutment surface located between the bottom and the second sidewall, and the first abutment surface and the second abutment surface are perpendicular to the first sidewall and the second sidewall, respectively. The first connecting line extends to the first abutment surface and the bottom and contacts the first pad, and the second connecting line extends to the second abutment surface and the bottom and contacts the second pad.
[0008] In at least one embodiment of the present invention, the electronic component has a first side, a second side opposite to the first side, a third side located between the first side and the second side, and a fourth side opposite to the third side, and includes a first external electrode disposed on the first side, a second external electrode disposed on the second side, a third external electrode disposed on the third side, and a heat dissipation portion disposed on the fourth side and thermally coupled to the heat sink. The circuit board further includes a third pad disposed on the bottom and electrically connected to the third external electrode.
[0009] In at least one embodiment of the present invention, the circuit board further includes a first solder layer, a second solder layer, and a third solder layer. The first solder layer is disposed between the first external electrode and the first connection line to electrically connect the first external electrode and the first connection line; the second solder layer is disposed between the second external electrode and the second connection line to electrically connect the second external electrode and the second connection line; and the third solder layer is disposed between the third external electrode and the third pad to electrically connect the third external electrode and the third pad.
[0010] A method for manufacturing a circuit board according to at least one embodiment of the present invention includes providing a copper-clad substrate having opposing first and second initial surfaces, and including a first metal layer and a second metal layer, the first metal layer having a first initial surface and the second metal layer having a second initial surface. A portion of the copper-clad substrate is removed to form a recess, the recess being recessed from the second initial surface toward the first initial surface and having a bottom and opposing first and second sidewalls. A connecting metal layer is formed on the first sidewall, the second sidewall, and the bottom. After forming the connecting metal layer, an electronic component is disposed in the recess, fixed to the connecting metal layer, and electrically connected to the connecting metal layer. After the electronic component is fixed to the connecting metal layer, an initial resin is formed in the recess. A portion of the initial resin is removed to form resin and expose the electronic component. After removing a portion of the initial resin to form resin and expose the electronic component, a heat-dissipating metal layer is formed to thermally couple the electronic component. The first metal layer, the second metal layer, the connecting metal layer, and the heat-dissipating metal layer are patterned.
[0011] In at least one embodiment of the present invention, the step of removing a portion of the copper-clad substrate to form the groove includes removing a portion of the copper-clad substrate to form the first sidewall and the second sidewall. After forming the first sidewall and the second sidewall, a portion of the copper-clad substrate is removed to form the bottom, the width of which is less than the distance between the first sidewall and the second sidewall.
[0012] A circuit board according to at least another embodiment of the present invention includes a circuit board, electronic components, a heat sink, and a locking device. The circuit board has opposing first and second surfaces and a slot penetrating both surfaces. The slot has opposing first and second sidewalls, a first opening and a second opening closer to the first and second surfaces respectively than the first and second sidewalls, a first abutting surface between the first opening and the first sidewall, and a second abutting surface between the first opening and the second sidewall. The first and second abutting surfaces are perpendicular to the first and second sidewalls, respectively. The widths of the first and second openings are greater than the distance between the first and second sidewalls. The circuit board includes a first connection line and a second connection line. The first connection line is disposed on the first abutting surface, and the second connection line is disposed on the second abutting surface. The electronic components are disposed in the slot and electrically connected to the first and second connection lines. The heat sink is disposed in the slot and located between the electronic components and the second surface, and thermally coupled to the electronic components. The locking device secures the electronic components and the heat sink.
[0013] In at least another embodiment of the present invention, the electronic component has a chassis and an extension extending from the chassis and along the normal of the chassis. The chassis has a surface that is opposite to and protrudes from a first end and a second end of the extension, located between the first end and the second end. The electronic component includes a first external electrode, a second external electrode, a third external electrode, and a heat dissipation portion. The first external electrode is disposed at the first end and extends to the surface, the second external electrode is disposed at the second end and extends to the surface, and the third external electrode is disposed on the surface. The heat dissipation portion is disposed on the side of the extension away from the chassis and is thermally coupled to a heat sink.
[0014] In at least another embodiment of the present invention, the electronic component further includes a first solder layer, a second solder layer, and a buffer material. The first solder layer is disposed between the first external electrode and the first connection line to electrically connect the first external electrode and the first connection line; the second solder layer is disposed between the second external electrode and the second connection line to electrically connect the second external electrode and the second connection line; and the buffer material is disposed on the first sidewall and the second sidewall and surrounds the extension.
[0015] In at least another embodiment of the invention, the heat sink has a base and a protrusion with a width smaller than the width of the base and extending from the base and along the normal of the base. The circuit board further includes a thermally conductive layer disposed on the sidewall of the second opening. The electronic component further includes a third solder layer. The third solder layer is disposed between the protrusion and the thermally conductive layer to thermally couple the protrusion and the thermally conductive layer.
[0016] In at least another embodiment of the present invention, the heat sink has a through hole, the extension has a blind hole corresponding to the through hole, and the fastener is disposed in the through hole and the blind hole to secure the electronic component and the heat sink.
[0017] A method for manufacturing a circuit board according to at least another embodiment of the present invention includes providing a copper-clad substrate having opposing first and second initial surfaces, and including a first metal layer and a second metal layer, the first metal layer having a first initial surface and the second metal layer having a second initial surface. A portion of the copper-clad substrate is removed to form a slot penetrating the first and second initial surfaces, and the slot has opposing first and second sidewalls, and a first and second opening portion respectively closer to the first and second initial surfaces than the first and second sidewalls. First and second connection lines are formed on the sidewall of the first opening portion. A thermally conductive layer is formed on the sidewall of the second opening portion. After forming the first and second connection lines and the thermally conductive layer, an electronic component is disposed in the slot and fixed on and electrically connected to the first and second connection lines. After the electronic component is fixed on the first and second connection lines, a heat sink is disposed in the slot and secured to the electronic component and the heat sink with fasteners. After securing the electronic components and heat sink with fasteners, a buffer material is formed on the first and second sidewalls and surrounds the electronic components and heat sink. A solder layer is formed between the thermally conductive layer and the heat sink to thermally couple the thermally conductive layer and the heat sink.
[0018] In at least another embodiment of the present invention, the step of removing a portion of the copper-clad substrate to form the slot includes removing a portion of the copper-clad substrate to form the first opening and the second opening. After forming the first opening and the second opening, a portion of the copper-clad substrate is removed to form the first sidewall and the second sidewall, wherein the width of the first opening and the width of the second opening are respectively greater than the distance between the first sidewall and the second sidewall. Attached Figure Description
[0019] Figure 1 This is a partial cross-sectional schematic diagram of a circuit board according to at least one embodiment of the present invention.
[0020] Figure 2 This is a cross-sectional schematic diagram of an electronic component according to at least one embodiment of the present invention.
[0021] Figures 3A to 3F yes Figure 1 Partial cross-sectional views of the circuit board at different process stages.
[0022] Figure 4 This is a partial cross-sectional schematic diagram of a circuit board according to at least another embodiment of the present invention.
[0023] Figure 5A This is a cross-sectional schematic diagram of an electronic component according to at least another embodiment of the present invention.
[0024] Figure 5B This is a top view schematic diagram of an electronic component according to at least another embodiment of the present invention.
[0025] Figure 6A This is a top view schematic diagram of a heat sink according to at least another embodiment of the present invention.
[0026] Figure 6B Yes, yes Figure 6A A cross-sectional diagram drawn along line A-A'.
[0027] Figures 7A to 7F yes Figure 4 Partial cross-sectional views of the circuit board at different process stages. Detailed Implementation
[0028] In the following text, to clearly present the technical features of the present invention, the dimensions (e.g., length, width, thickness, and depth) of the elements (e.g., layers, films, substrates, and regions) in the accompanying drawings will be enlarged proportionally, and the number of some elements may be reduced. Therefore, the description and explanation of the embodiments below are not limited to the number of elements in the drawings or the size and shape of the elements, but should cover deviations in size, shape, and both caused by actual manufacturing processes and / or tolerances. For example, a flat surface shown in the drawings may have rough and / or non-linear characteristics, and an acute angle shown in the drawings may be rounded. Therefore, the elements presented in the accompanying drawings of the present invention are primarily for illustration and are not intended to precisely depict the actual shape of the elements, nor are they intended to limit the claims of the present invention.
[0029] Secondly, the terms "approximately," "about," or "substantially" used in this invention not only cover explicitly stated numerical values and ranges, but also the permissible deviation range understood by those skilled in the art. This deviation range can be determined by errors generated during measurement, which may arise from limitations of the measurement system or process conditions. For example, two objects (e.g., planes or traces of a substrate) are "substantially parallel" or "substantially perpendicular," where "substantially parallel" and "substantially perpendicular" respectively represent that the parallelism and perpendicularity between the two objects can include non-parallelism and non-perpendicularity caused by the permissible deviation range.
[0030] The spatial relative terms used in this invention, such as "below," "under," "above," and "above," are for the convenience of describing the relative relationship between one element or feature and another, as illustrated in the figures. The true meaning of these spatial relative terms includes other orientations. For example, when the illustration is rotated 180 degrees vertically, the relationship between one element and another may change from "below" or "under" to "above" or "above." Furthermore, the spatial relative descriptions used in this invention should be interpreted in the same way.
[0031] It should be understood that although the present invention may use terms such as "first," "second," and "third" to describe various elements or features, these elements or features should not be limited by these terms. These terms are primarily used to distinguish one element from another, or one feature from another. Furthermore, the term "or" as used in the present invention may, as appropriate, include any combination of one or more of the associated listed items.
[0032] Although this invention uses a series of operations or steps to illustrate the manufacturing method, the order in which these operations or steps are shown should not be construed as a limitation of the invention. For example, some operations or steps may be performed in a different order and / or simultaneously with other steps. Furthermore, each operation or step described herein may comprise several sub-steps or actions.
[0033] Furthermore, the present invention can be implemented or applied through other different specific embodiments, and the details of the present invention can also be combined, modified and changed in various embodiments based on different viewpoints and applications without departing from the concept of the present invention.
[0034] Figure 1 This is a partial cross-sectional schematic diagram of a circuit board according to at least one embodiment of the present invention. Please refer to... Figure 1 The circuit board 10 includes a circuit board 100, electronic components 200, and a heat sink 300. The circuit board 100 has opposing first surfaces S1 and second surfaces S2, and a recess 101 recessed from the second surface S2 toward the first surface S1. The recess 101 has opposing first sidewalls E1 and second sidewalls E2, and a bottom BT that is closer to the first surface S1 than the first sidewalls E1 and second sidewalls E2. The width W of the bottom BT is less than the distance D between the first sidewalls E1 and second sidewalls E2.
[0035] The circuit board 100 includes a first connection line 102, a second connection line 103, a first pad 104, and a second pad 105. The first connection line 102 is disposed on a first sidewall E1, the second connection line 103 is disposed on a second sidewall E2, the first pad 104 is disposed on the bottom BT and electrically connected to the first connection line 102, and the second pad 105 is disposed on the bottom BT and electrically connected to the second connection line 103. The electronic component 200 is disposed in a recess 101 and electrically connected to the first connection line 102 and the second connection line 103. The heat sink 300 is disposed in the recess 101 and is located between the electronic component 200 and the second surface S2 and is thermally coupled to the electronic component 200.
[0036] The electronic component 200 is electrically connected to the circuit board 100 through the first connection line 102 and the second connection line 103 disposed on the first side wall E1 and the second side wall E2 of the recess 101. This reduces the need for conductive vias or conductive blind vias. Since both the electronic component 200 and the heat sink 300 are disposed in the recess 101 of the circuit board 100, the layout space of the circuit board can be saved and the heat dissipation performance can be improved. Furthermore, general soldering materials and general board materials can be used, without the need to use expensive silver sintering materials or low thermal expansion coefficient boards, thereby reducing costs.
[0037] Furthermore, the stepped design formed by the width W of the bottom BT being smaller than the distance D between the first sidewall E1 and the second sidewall E2 can limit the range of the solder layer between the electronic component 200 and the first connection line 102 and the second connection line 103, and a stable electrical connection can be formed between the electronic component 200 and the first connection line 102 and the second connection line 103, thereby improving reliability.
[0038] Please continue reading. Figure 1 The circuit board 10 also includes resin 400 disposed in the recess 101, located at the bottom BT and surrounding the heat sink 300. In some embodiments, the thermal conductivity of the resin 400 is between 3 and 12 W / mK (inclusive), and it can help dissipate heat from the electronic component 200 through the aforementioned placement location. The material of the heat sink 300 may include copper. The heat sink 300 may directly contact the electronic component 200 for thermal coupling, or it may thermally couple the electronic component 200 through a thermally conductive structure disposed between the heat sink 300 and the electronic component 200.
[0039] In addition, such as Figure 1As shown, the groove 101 has a first abutting surface A1 located between the bottom BT and the first side wall E1 and a second abutting surface A2 located between the bottom BT and the second side wall E2. The first abutting surface A1 and the second abutting surface A2 are substantially perpendicular to the first side wall E1 and the second side wall E2, respectively. The first connecting line 102 extends to the first abutting surface A1 and the bottom BT and contacts the first pad 104. The second connecting line 103 extends to the second abutting surface A2 and the bottom BT and contacts the second pad 105.
[0040] Figure 2 This is a cross-sectional schematic diagram of an electronic component according to at least one embodiment of the present invention. Please refer to... Figure 2 The electronic component 200 has a first side L1, a second side L2 opposite to the first side L1, a third side L3 located between the first side L1 and the second side L2, and a fourth side L4 opposite to the third side L3, and includes a first external electrode 201 disposed on the first side L1, a second external electrode 202 disposed on the second side L2, a third external electrode 203 disposed on the third side L3, and a heat dissipation portion 204 disposed on the fourth side L4.
[0041] like Figure 2 As shown, the electronic component 200 further includes a chip 205, a first electrode GE, a second electrode DE, a third electrode SE, a heat dissipation layer HD, conductive leads 206 and 207, and a fourth bonding layer 208. The first electrode GE, the second electrode DE, the third electrode SE, and the heat dissipation layer HD are disposed on the chip 205. The first electrode GE is electrically connected to a first external electrode 201 via conductive lead 206; the second electrode DE is electrically connected to a second external electrode 202 via conductive lead 207; the third electrode SE is electrically connected to a third external electrode 203 via the fourth bonding layer 208; and the heat dissipation layer HD is thermally coupled to a heat dissipation portion 204. The heat dissipation layer HD can directly contact the heat dissipation portion 204 for thermal coupling, or it can be thermally coupled to the heat dissipation portion 204 through a thermally conductive structure disposed between the heat dissipation layer HD and the heat dissipation portion 204.
[0042] In some embodiments, chip 205 may be a power semiconductor device. For example, chip 205 may be a silicon carbide power device, and the first electrode GE, the second electrode DE, and the third electrode SE may be the gate, drain, and source of chip 205, respectively. In addition, the heat sink 204 may be made of copper and have a thickness of not less than 18 micrometers, which can effectively dissipate heat and prevent chip 205 from being damaged during the opening process.
[0043] Please see Figure 1 and Figure 2The first external electrode 201, located on the first side L1, extends to the third side L3 and contacts the first connecting line 102 located on the first contact surface A1. The second external electrode 202, located on the second side L2, extends to the third side L3 and contacts the second connecting line 103 located on the second contact surface A2. This design increases the electrical connection area between the first external electrode 201 and the first connecting line 102, and between the second external electrode 202 and the second connecting line 103, thereby improving reliability.
[0044] like Figure 1 and Figure 2 As shown, the circuit board 100 also includes a third pad 106 disposed on the bottom BT and electrically connected to the third external electrode 203, and a heat dissipation part 204 thermally coupled to the heat sink 300. The heat dissipation part 204 can directly contact the heat sink 300 for thermal coupling, or it can be thermally coupled to the heat sink 300 through a thermally conductive structure disposed between the heat dissipation part 204 and the heat sink 300.
[0045] In addition, the circuit board also includes a first solder layer 107, a second solder layer 108, and a third solder layer 109. In some embodiments, the materials of the first solder layer 107, the second solder layer 108, and the third solder layer 109 may include tin.
[0046] The first solder layer 107 is disposed between the first external electrode 201 and the first connecting line 102 to electrically connect the first external electrode 201 and the first connecting line 102; the second solder layer 108 is disposed between the second external electrode 202 and the second connecting line 103 to electrically connect the second external electrode 202 and the second connecting line 103; and the third solder layer 109 is disposed between the third external electrode 203 and the third pad 106 to electrically connect the third external electrode 203 and the third pad 106.
[0047] Specifically, a first solder layer 107 is disposed between the first external electrode 201 and the first connection line 102 and located on the first sidewall E1; a second solder layer 108 is disposed between the second external electrode 202 and the second connection line 103 and located on the second sidewall E2; and a third solder layer 109 is disposed between the third external electrode 203 and the third pad 106 and located at the bottom BT. In some embodiments, the first pad 104, the second pad 105, and the third pad 106 can be electrically connected to an external circuit.
[0048] Figures 3A to 3F This is a partial cross-sectional view of a circuit board according to at least one embodiment of the present invention at different process stages. First, please refer to... Figure 3AA copper-clad substrate 100' is provided, having opposing first initial surfaces S1' and second initial surfaces S2', and including a first metal layer M1 and a second metal layer M2, wherein the first metal layer M1 has the first initial surface S1' and the second metal layer M2 has the second initial surface S2'. In some embodiments, the materials of the first metal layer M1 and the second metal layer M2 may include copper.
[0049] Please see Figure 3B A portion of the copper-clad substrate 100' is removed to form a groove 101. The groove 101 is recessed from the second initial surface S2' toward the first initial surface S1' and has a bottom BT and opposing first sidewalls E1 and second sidewalls E2.
[0050] In detail, a portion of the copper-clad substrate 100' is first removed to form the first sidewall E1 and the second sidewall E2. Next, after forming the first sidewall E1 and the second sidewall E2, a portion of the copper-clad substrate 100' is removed to form the bottom BT. Since the width W of the bottom BT is less than the distance D between the first sidewall E1 and the second sidewall E2, and the depth of the bottom BT is also less than the height of the first sidewall E1 and the second sidewall E2, the step of removing a portion of the copper-clad substrate 100' to form the first sidewall E1 and the second sidewall E2 can be performed by a machining process, such as a milling process, while the step of removing a portion of the copper-clad substrate 100' to form the bottom BT can be performed by a laser process, which is more precise than a machining process.
[0051] Please see Figure 3C A connecting metal layer M is formed on the first sidewall E1, the second sidewall E2, and the bottom BT. After forming the connecting metal layer M, the electronic component 200 is disposed in the groove 101 and fixed to and electrically connected to the connecting metal layer M. In some embodiments, the connecting metal layer M may also be formed on the first metal layer M1, and the connecting metal layer M formed on the first metal layer M1 has a first surface S1. The material of the connecting metal layer M may include copper, and the connecting metal layer M may be formed by an electroplating process. In addition, fixing the electronic component 200 to the connecting metal layer M may be performed by a welding process, i.e., forming a first welding layer 107, a second welding layer 108, and a third welding layer 109, as shown below. Figure 3C As shown.
[0052] Please see Figure 3D After the electronic component 200 is fixed onto the connecting metal layer M, an initial resin 400' is formed in the groove 101. Next, please refer to... Figure 3E A portion of the initial resin 400' is removed to form resin 400 and expose the electronic components 200. In some embodiments, removing a portion of the initial resin 400' to form resin 400 and expose the electronic components 200 may be performed by a laser process.
[0053] Please see Figure 3F After removing a portion of the initial resin 400' to form resin 400 and expose the electronic component 200, a heat-dissipating metal layer HM is formed to thermally couple the electronic component 200. Next, a first metal layer M1, a second metal layer M2, a connecting metal layer M, and a heat-dissipating metal layer HM are patterned. In some embodiments, the heat-dissipating metal layer HM may also be formed on the second metal layer M2, and the heat-dissipating metal layer HM formed on the second metal layer M2 has a second surface S2. The patterning of the first metal layer M1, the second metal layer M2, the connecting metal layer M, and the heat-dissipating metal layer HM can be performed by an etching process. The heat-dissipating metal layer HM can directly contact the electronic component 200 for thermal coupling, or it can thermally couple the electronic component 200 through a thermally conductive structure formed between the heat-dissipating metal layer HM and the electronic component 200.
[0054] In detail, the step of patterning the first metal layer M1, the second metal layer M2, the connecting metal layer M, and the heat dissipation metal layer HM may include forming, for example, Figure 1 The circuit board 100 shown includes a first connection line 102, a second connection line 103, a first pad 104, a second pad 105, a third pad 106, and a heat sink 300.
[0055] Figure 4 This is a partial cross-sectional schematic diagram of a circuit board according to at least another embodiment of the present invention. Please refer to... Figure 4 The circuit board 10A includes a circuit board 100A, electronic components 200A, a heat sink 300A, and a locking device 500. The circuit board 100A has opposing first surfaces S1 and second surfaces S2 and a slot 101A penetrating the first surface S1 and the second surface S2.
[0056] The slot 101A has a first sidewall E1, a second sidewall E2, a first opening O1 and a second opening O2 that are closer to the first surface S1 and the second surface S2 than the first sidewall E1 and the second sidewall E2, respectively, a first abutting surface A1 located between the first opening O1 and the first sidewall E1, and a second abutting surface A2 located between the first opening O1 and the second sidewall E2. The first abutting surface A1 and the second abutting surface A2 are substantially perpendicular to the first sidewall E1 and the second sidewall E2, respectively. The width W1 of the first opening O1 and the width W2 of the second opening O2 are respectively greater than the distance D between the first sidewall E1 and the second sidewall E2.
[0057] The circuit board 100A includes a first connection line 102A and a second connection line 103A. The first connection line 102A is disposed on a first contact surface A1, and the second connection line 103A is disposed on a second contact surface A2. The electronic component 200A is disposed in the slot 101A and is electrically connected to the first connection line 102A and the second connection line 103A.
[0058] A heat sink 300A is disposed in the slot 101A and is located between the electronic component 200A and the second surface S2, and is thermally coupled to the electronic component 200A. A fastener 500 secures the electronic component 200A and the heat sink 300A. The heat sink 300A can directly contact the electronic component 200A for thermal coupling, or it can be thermally coupled to the electronic component 200A through a thermally conductive structure disposed between the heat sink 300A and the electronic component 200A.
[0059] Electronic component 200A and heat sink 300A are fixed in slot 101A by fastener 500. Slot 101A has a stepped design where the width W1 of the first opening O1 and the width W2 of the second opening O2 are both greater than the distance D between the first sidewall E1 and the second sidewall E2, thus achieving a stable and detachable circuit board. Electronic component 200A is electrically connected to circuit board 100A via first connection line 102A and second connection line 103A provided on the first abutment surface A1 and the second abutment surface A2, respectively. In addition, since electronic component 200A and heat sink 300A are both disposed in slot 101A of circuit board 100A, layout space of circuit board can be saved and heat dissipation performance can be improved.
[0060] Figure 5A This is a cross-sectional schematic diagram of an electronic component according to at least another embodiment of the present invention. Figure 5B This is a top view schematic diagram of an electronic component according to at least another embodiment of the present invention. Please refer to... Figure 4 , Figure 5A and Figure 5B The electronic component 200A has a chassis 200A1 and an extension 200A2 extending from the chassis 200A1 and along the normal of the chassis 200A1. The electronic component 200A includes a first external electrode 201A, a second external electrode 202A, a third external electrode 203A, and a heat dissipation part 204A.
[0061] A heat dissipation unit 204A is disposed on the side of the extension 200A2 away from the chassis 200A1 and is thermally coupled to the heat sink 300A. The heat dissipation unit 204A can directly contact the heat sink 300A for thermal coupling, or it can be thermally coupled to the heat sink 300A through a thermally conductive structure disposed between the heat dissipation unit 204A and the heat sink 300A. Furthermore, the materials of the heat sink 300A and the heat dissipation unit 204A may include copper.
[0062] The chassis 200A1 has a first end T1 and a second end T2 that are opposite to and protrude from the extension 200A2, and a surface S located between the first end T1 and the second end T2. That is, the width of the chassis 200A1 is greater than the width of the extension 200A2. A first external electrode 201A is disposed at the first end T1 and extends to the surface S, a second external electrode 202A is disposed at the second end T2 and extends to the surface S, and a third external electrode 203A is disposed on the surface S.
[0063] like Figure 5B As shown, since the first external electrode 201A, the second external electrode 202A, and the third external electrode 203A are all disposed on the same surface S of the electronic component 200A, electrical testing can be easily performed. In some embodiments, the surface S of the electronic component 200A may be coplanar with the first surface S1 of the circuit board 100A, and the first external electrode 201A, the second external electrode 202A, and the third external electrode 203A may be directly used as pads for electrically connecting external circuits.
[0064] like Figure 5A As shown, the electronic component 200A also includes a chip 205, a first electrode GE, a second electrode DE, a third electrode SE, a heat dissipation layer HD, conductive leads 206 and 207, and a fourth bonding layer 208. Figure 5A The aforementioned components of electronic component 200A and Figure 2 The electronic components 200 with the same designation have the same structure, material and relative positional relationship, so the same technical features will not be described again here.
[0065] Please continue reading. Figure 4 and Figure 5A The circuit board 10A also includes a first solder layer 107A, a second solder layer 108A, and a buffer material 400A. The first solder layer 107A is disposed between the first external electrode 201A and the first connecting line 102A to electrically connect the first external electrode 201A and the first connecting line 102A. The second solder layer 108A is disposed between the second external electrode 202A and the second connecting line 103A to electrically connect the second external electrode 202A and the second connecting line 103A. The buffer material 400A is disposed on the first sidewall E1 and the second sidewall E2 and surrounds the extension 200A2.
[0066] In detail, the first connecting line 102A and the second connecting line 103A are respectively disposed on the first contact surface A1 and the second contact surface A2, and extend to the side wall of the first opening O1. The chassis 200A1 of the electronic component 200A is disposed in the first opening O1. The first solder layer 107A and the second solder layer 108A are each L-shaped and are respectively disposed between the first external electrode 201A located at the first end T1 of the chassis 200A1 and the first connecting line 102A, and between the second external electrode 202A located at the second end T2 of the chassis 200A1 and the second connecting line 103A.
[0067] Figure 6A This is a top view schematic diagram of a heat sink according to at least another embodiment of the present invention. Figure 6B Yes, yes Figure 6A A schematic cross-sectional view drawn along line A-A'. Please refer to [link / reference]. Figure 4 , Figure 6A and Figure 6B The heat sink 300A has a base 300A1 and a protrusion 300A2 with a width smaller than that of the base 300A1 and extending from the base 300A1 along the normal of the base 300A1. The circuit board 100A also includes a thermally conductive layer 110 disposed on the sidewall of the second opening O2.
[0068] The circuit board 10A also includes a third solder layer 109A. The third solder layer 109A is disposed between the protrusion 300A2 and the thermally conductive layer 110 to thermally couple the protrusion 300A2 and the thermally conductive layer 110. Furthermore, the buffer material 400A surrounds not only the extension 200A2 of the electronic component 200A, but also the protrusion 300A2 of the heat sink 300A. In some embodiments, the materials of the first solder layer 107A, the second solder layer 108A, and the third solder layer 109A may include tin.
[0069] like Figure 6A and Figure 6B As shown, the heat sink 300A has one or more through holes TH penetrating the heat sink 300A. For example... Figure 5A As shown, the extension 200A2 of electronic component 200A has a blind hole BH corresponding to the through hole TH of heat sink 300A. For example... Figure 4 As shown, the fastener 500 is disposed in the through hole TH and the blind hole BH to secure the electronic component 200A and the heat sink 300A. In some embodiments, the fastener 500 may be a screw, the through hole TH has a threaded structure (not shown), and the fastener 500 and the through hole TH are detachably connected by internal and external threads.
[0070] Figures 7A to 7F yes Figure 4 Partial cross-sectional views of the circuit board at different process stages. First, the steps of providing the copper-clad substrate 100' are... Figure 3ASince the components, materials, processes, and relative positions in the steps are the same, the technical features will not be described or illustrated here.
[0071] Next, please refer to Figures 7A to 7C A portion of the copper-clad substrate 100' is removed to form a slot 101A. The slot 101A penetrates the first initial surface S1' and the second initial surface S2', and has opposing first sidewalls E1 and E2, and a first opening O1 and a second opening O2 that are closer to the first initial surface S1' and the second initial surface S2', respectively, than the first sidewall E1 and the second sidewall E2. A first connection line 102A and a second connection line 103A are formed on the sidewall of the first opening O1. A thermally conductive layer 110 is formed on the sidewall of the second opening O2.
[0072] In detail, such as Figure 7A As shown, a portion of the copper-clad substrate 100' is removed to form a first opening O1 and a second opening O2. Figure 7B As shown, after forming the first opening O1 and the second opening O2, a metal layer MA is formed in the first opening O1 and the second opening O2. Next, the first metal layer M1, the second metal layer M2, and the metal layer MA are patterned. In some embodiments, the metal layer MA may be formed on both the first metal layer M1 and the second metal layer M2, and the metal layer MA formed on the first metal layer M1 has a first surface S1, while the metal layer MA formed on the second metal layer M2 has a second surface S2.
[0073] The step of removing a portion of the copper-clad substrate 100' to form the first opening O1 and the second opening O2 can be performed by a machining process, such as a milling machine. The material of the metal layer MA may include copper, and the metal layer MA can be formed by an electroplating process. The patterning of the first metal layer M1, the second metal layer M2, and the metal layer MA can be performed by an etching process.
[0074] like Figure 7C As shown, after forming the patterned first metal layer M1, second metal layer M2, and metal layer MA, a portion of the copper-clad substrate 100' is removed to form the first sidewall E1 and the second sidewall E2. A portion of the metal layer MA is also removed to form the first connection line 102A and the second connection line 103A on the sidewall of the first opening O1, and to form the thermally conductive layer 110 on the sidewall of the second opening O2. The width W1 of the first opening O1 and the width W2 of the second opening O2 are both greater than the distance D between the first sidewall E1 and the second sidewall E2, as shown. Figure 1 As shown.
[0075] Please see Figure 7DAfter forming the first connection line 102A, the second connection line 103A, and the heat-conducting layer 110, the electronic component 200A is disposed in the slot 101A and fixed on the first connection line 102A and the second connection line 103A, and electrically connected to the first connection line 102A and the second connection line 103A. The electronic component 200A can be fixed on the first connection line 102A and the second connection line 103A by a soldering process, forming the first solder layer 107A and the second solder layer 108A, as shown below. Figure 7D As shown.
[0076] Please see Figure 7E After the electronic component 200A is fixed on the first connection line 102A and the second connection line 103A, the heat sink 300A is placed in the slot 101A and the electronic component 200A and the heat sink 300A are locked with the fastener 500.
[0077] Please see Figure 7F After securing the electronic component 200A and the heat sink 300A with fastener 500, a buffer material 400A is formed on the first sidewall E1 and the second sidewall E2, surrounding the electronic component 200A and the heat sink 300A. Next, a third solder layer 109A is formed between the thermally conductive layer 110 and the heat sink 300A to thermally couple the thermally conductive layer 110 and the heat sink 300A, as shown below. Figure 4 As shown.
[0078] In summary, in the circuit board and its manufacturing method according to at least one embodiment of the present invention, the electronic components are electrically connected to the circuit board through connection lines disposed in the grooves or slots of the circuit board, which reduces the use of conductive vias or conductive blind vias. Since both the electronic components and the heat sink are disposed in the grooves or slots of the circuit board, layout space of the circuit board can be saved and heat dissipation performance can be improved. Furthermore, common soldering materials and common board materials can be used, without necessarily requiring the use of expensive silver sintering materials or low thermal expansion coefficient boards, thereby reducing costs. Through the stepped design of the grooves or slots, a stable electrical connection can be formed between the electronic components and the circuit board, thereby improving reliability. In addition, the electronic components and the heat sink are fixed in the slots of the circuit board using fasteners, thereby realizing a detachable circuit board.
[0079] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.
[0080] [Symbol Explanation]
[0081] 10, 10A: Circuit board
[0082] 100, 100A: Circuit board
[0083] 100':Copper clad substrate
[0084] 101: Groove
[0085] 101A: Slotting
[0086] 102, 102A: First connecting line
[0087] 103, 103A: Second connecting lines
[0088] 104: First bonding pad
[0089] 105: Second pad
[0090] 106: Third pad
[0091] 107, 107A: First weld layer
[0092] 108, 108A: Second weld layer
[0093] 109, 109A: Third weld layer
[0094] 110: Thermal conductive layer
[0095] 200, 200A: Electronic components
[0096] 200A1: Chassis
[0097] 200A2: Extension Section
[0098] 201, 201A: First external electrode
[0099] 202, 202A: Second external electrode
[0100] 203, 203A: Third external electrode
[0101] 204, 204A: Heat dissipation section
[0102] 205: Chip
[0103] 206, 207: Conductive leads
[0104] 208: Fourth Welding Layer
[0105] 300, 300A: Heat sink
[0106] 300A1: Base
[0107] 300A2: Protrusion
[0108] 400: Resin
[0109] 400': Initial resin
[0110] 400A: Cushioning material
[0111] 500: Locking fastener
[0112] A-A': line
[0113] A1: First contact surface
[0114] A2: Second contact surface
[0115] BH: Blind Hole
[0116] BT: Bottom
[0117] D: Distance
[0118] DE: Second electrode
[0119] E1: First sidewall
[0120] E2: Second sidewall
[0121] GE: First electrode
[0122] HD: Heat dissipation layer
[0123] HM: Heat dissipation metal layer
[0124] L1: First side
[0125] L2: Second side
[0126] L3: Third side
[0127] L4: Fourth side
[0128] M: Connecting metal layer
[0129] M1: First metal layer
[0130] M2: Second metal layer
[0131] MA: Metal layer
[0132] O1: First opening
[0133] O2: Second opening
[0134] S: Surface
[0135] S1: First surface
[0136] S1': First initial surface
[0137] S2: Second surface
[0138] S2': Second initial surface
[0139] SE: Third electrode
[0140] T1: First end
[0141] T2: Second end
[0142] TH: Through hole
[0143] W, W1, W2: Width.
Claims
1. A circuit board, characterized in that, include: A circuit board has opposing first surfaces, second surfaces, and a recessed groove extending from the second surface toward the first surface. The groove has opposing first sidewalls, second sidewalls, and a bottom portion closer to the first surface than the first and second sidewalls. The width of the bottom portion is less than the distance between the first and second sidewalls. The circuit board includes: The first connecting line is disposed on the first side wall; The second connecting line is disposed on the second side wall; A first contact pad is disposed on the bottom and electrically connected to the first connection line; as well as The second pad is disposed on the bottom and electrically connected to the second connection line; An electronic component is disposed in the groove and electrically connected to the first connection line and the second connection line; as well as A heat sink is disposed in the groove and located between the electronic component and the second surface, and is thermally coupled to the electronic component.
2. The circuit board according to claim 1, characterized in that, It also includes resin disposed in the groove and located at the bottom and surrounding the heat sink, wherein the groove has a first abutment surface located between the bottom and the first sidewall and a second abutment surface located between the bottom and the second sidewall, and the first abutment surface and the second abutment surface are perpendicular to the first sidewall and the second sidewall, respectively; the first connecting line extends to the first abutment surface and the bottom and contacts the first pad; and the second connecting line extends to the second abutment surface and the bottom and contacts the second pad.
3. The circuit board according to claim 1, characterized in that, The electronic component has a first side, a second side opposite to the first side, a third side located between the first side and the second side, and a fourth side opposite to the third side, and includes: The first external electrode is disposed on the first side; The second external electrode is disposed on the second side; A third external electrode is disposed on the third side, wherein the circuit board further includes a third pad disposed on the bottom and electrically connected to the third external electrode; and A heat dissipation unit is disposed on the fourth side and thermally coupled to the heat dissipation block.
4. The circuit board according to claim 3, characterized in that, Also includes: A first welding layer is disposed between the first external electrode and the first connection line to electrically connect the first external electrode and the first connection line; The second welding layer is disposed between the second external electrode and the second connection line to electrically connect the second external electrode and the second connection line; as well as A third welding layer is disposed between the third external electrode and the third pad to electrically connect the third external electrode and the third pad.
5. A method for manufacturing a circuit board, characterized in that, include: A copper-clad substrate is provided, wherein the copper-clad substrate has opposing first initial surfaces and second initial surfaces, and includes a first metal layer and a second metal layer, wherein the first metal layer has the first initial surface and the second metal layer has the second initial surface; A portion of the copper-clad substrate is removed to form a groove, wherein the groove is recessed from the second initial surface toward the first initial surface and has a bottom and opposing first and second sidewalls; A connecting metal layer is formed on the first sidewall, the second sidewall, and the bottom; After the connecting metal layer is formed, electronic components are placed in the groove, fixed on the connecting metal layer, and electrically connected to the connecting metal layer. After the electronic component is fixed onto the connecting metal layer, an initial resin is formed in the groove; Remove a portion of the initial resin to form a resin and expose the electronic components; After removing a portion of the initial resin to form the resin and exposing the electronic components, a heat-dissipating metal layer is formed to thermally couple the electronic components. as well as The first metal layer, the second metal layer, the connecting metal layer, and the heat dissipation metal layer are patterned.
6. The method for manufacturing a circuit board according to claim 5, characterized in that, The step of removing a portion of the copper-clad substrate to form the groove includes: Removing a portion of the copper-clad substrate to form the first sidewall and the second sidewall; and After forming the first sidewall and the second sidewall, a portion of the copper-clad substrate is removed to form the bottom, wherein the width of the bottom is less than the distance between the first sidewall and the second sidewall.
7. A circuit board, characterized in that, include: A circuit board has opposing first surfaces, second surfaces, and a slot penetrating the first and second surfaces. The slot has opposing first and second sidewalls, a first opening and a second opening that are respectively closer to the first and second surfaces than the first and second sidewalls, a first abutting surface between the first opening and the first sidewall, and a second abutting surface between the first opening and the second sidewall. The first and second abutting surfaces are perpendicular to the first and second sidewalls, respectively. The widths of the first and second openings are respectively greater than the distance between the first and second sidewalls. The circuit board includes: A first connecting line is disposed on the first contact surface; as well as The second connecting line is disposed on the second contact surface; An electronic component is disposed in the slot and electrically connected to the first connection line and the second connection line; A heat sink is disposed in the slot and located between the electronic component and the second surface, and is thermally coupled to the electronic component; as well as The fastener secures the electronic components and the heat sink.
8. The circuit board according to claim 7, characterized in that, The electronic component has a chassis and an extension extending from the chassis and along a normal to the chassis. The chassis has a surface opposite to and protruding from a first end and a second end of the extension, located between the first end and the second end. The electronic component includes: A first external electrode is disposed at the first end and extends to the surface; A second external electrode is disposed at the second end and extends to the surface; A third external electrode is disposed on the surface; and A heat dissipation unit is disposed on the side of the extension away from the chassis and is thermally coupled to the heat dissipation block.
9. The circuit board according to claim 8, characterized in that, Also includes: A first welding layer is disposed between the first external electrode and the first connection line to electrically connect the first external electrode and the first connection line; The second welding layer is disposed between the second external electrode and the second connection line to electrically connect the second external electrode and the second connection line; as well as A cushioning material is disposed on the first sidewall and the second sidewall and surrounds the extension.
10. The circuit board according to claim 8, characterized in that, The heat sink has a base and a protrusion with a width smaller than the width of the base and extending from the base along the normal of the base. The circuit board further includes a heat-conducting layer disposed on the sidewall of the second opening. The circuit board further includes: A third welding layer is disposed between the protrusion and the heat-conducting layer to thermally couple the protrusion and the heat-conducting layer.
11. The circuit board according to claim 8, characterized in that, The heat sink has a through hole, the extension has a blind hole corresponding to the through hole, and the fastener is disposed in the through hole and the blind hole to secure the electronic component and the heat sink.
12. A method for manufacturing a circuit board, characterized in that, include: A copper-clad substrate is provided, wherein the copper-clad substrate has opposing first initial surfaces and second initial surfaces, and includes a first metal layer and a second metal layer, wherein the first metal layer has the first initial surface and the second metal layer has the second initial surface; A portion of the copper-clad substrate is removed to form a slot, wherein the slot penetrates the first initial surface and the second initial surface and has opposing first sidewalls, second sidewalls, and a first opening and a second opening that are closer to the first initial surface and the second initial surface than the first sidewall and the second sidewall, respectively. A first connection line and a second connection line are formed on the sidewall of the first opening; A thermally conductive layer is formed on the sidewall of the second opening; After forming the first connection line, the second connection line and the heat-conducting layer, the electronic component is placed in the slot and fixed on the first connection line and the second connection line and electrically connected to the first connection line and the second connection line. After the electronic component is fixed on the first connection line and the second connection line, the heat sink is placed in the slot and the electronic component and the heat sink are locked with fasteners. After the electronic component and the heat sink are secured with the fasteners, a buffer material is formed on the first sidewall and the second sidewall and surrounds the electronic component and the heat sink; as well as A welding layer is formed between the thermally conductive layer and the heat sink to thermally couple the thermally conductive layer and the heat sink.
13. The method for manufacturing a circuit board according to claim 12, characterized in that, The step of removing a portion of the copper-clad substrate to form the slot includes: Removing a portion of the copper-clad substrate to form the first opening and the second opening; and After forming the first opening and the second opening, a portion of the copper-clad substrate is removed to form the first sidewall and the second sidewall, wherein the width of the first opening and the width of the second opening are respectively greater than the distance between the first sidewall and the second sidewall.