Heat dissipation structure of double-sided circuit board
The heat dissipation structure for double-sided circuit boards addresses inefficiencies by incorporating a metal heat sink and copper foil electroplating, enhancing thermal conductivity and current handling, resulting in improved heat dissipation and shock resistance.
Patent Information
- Application Number
- CN202420541300.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-03-20
AI Technical Summary
Existing double-sided circuit boards using multilayer ceramic substrates face challenges in heat dissipation efficiency due to low thermal conductivity and difficulty in handling large current shocks, as alumina ceramics have a thermal conductivity of about 20 W/KM, while copper's conductivity is 400 W/KM, leading to suboptimal performance.
A heat dissipation structure for double-sided circuit boards featuring a top and bottom circuit layer with a metal heat sink attached to the substrate, a copper foil integrated with a metal electroplating layer, and a jumper wire avoiding the heat sink, connected via metallized vias, enhancing thermal conductivity and current capacity.
The structure improves heat dissipation efficiency and current carrying capacity, utilizing high thermal conductivity materials like diamond or aluminum nitride substrates, and a quasi-double-layer process, achieving better thermal conductivity and shock resistance.
Smart Images
Figure CN222192638U_ABST
Abstract
Description
[Technical field]
[0001] The utility model relates to a printed circuit board, in particular to a heat dissipation structure of a double-sided circuit board. [Background Technology]
[0002] Ceramic substrates have been widely used in the fields of electronic packaging and power device heat dissipation due to their excellent thermal conductivity, electrical insulation and high temperature resistance. For ceramic substrates of double-sided circuit boards, multilayer ceramic substrates made by LTCC process can be used to increase the number of layers to improve the heat conduction path, thereby improving the overall heat dissipation efficiency. However, the thermal conductivity of alumina ceramics is about 20W / KM, while the thermal conductivity of copper is about 400W / KM. In comparison, the heat dissipation effect of double-layer circuit boards using multilayer ceramic substrates is still not ideal, and the conductivity of the LTCC process is relatively small, making it difficult to withstand large current shocks. [Summary of the invention]
[0003] The technical problem to be solved by the utility model is to provide a heat dissipation structure of a double-sided circuit board with good heat dissipation effect.
[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is a heat dissipation structure of a double-sided circuit board, the double-sided circuit board includes a top circuit layer, a substrate and a bottom circuit layer, the bottom circuit layer includes a circuit area and a heat dissipation area, the circuit area includes a bottom circuit, and the heat dissipation area includes at least one metal heat sink attached to the bottom surface of the substrate, and the height of the metal heat sink is greater than the height of the bottom circuit.
[0005] The heat dissipation structure of the double-sided circuit board described above includes a bottom solder resist layer, which covers the outer surface of the bottom circuit. The height of the metal heat sink is equal to or greater than the height of the bottom solder resist layer, and the substrate is a ceramic substrate.
[0006] In the heat dissipation structure of the double-sided circuit board described above, the bottom circuit includes a jumper wire of the top circuit layer, and the jumper wire is located in the avoidance hole of the metal heat sink to form an island.
[0007] In the heat dissipation structure of the double-sided circuit board described above, the area of the metal heat dissipation region is larger than the area of the circuit region, and the thickness of the circuit in the top circuit layer is greater than the thickness of the bottom circuit.
[0008] In the heat dissipation structure of the double-sided circuit board described above, the metal heat dissipation body includes a copper foil integrated with the bottom circuit before etching and a metal electroplating layer electroplated on the outside of the copper foil.
[0009] In the heat dissipation structure of the double-sided circuit board described above, the metal heat sink is electrically connected to the equipotential point of the top circuit layer through the metallized vias or the bottom circuit on the substrate.
[0010] The heat dissipation structure of the double-sided circuit board described above includes a heat sink, which is connected to the double-sided circuit board, and the outer surface of the metal heat sink is in contact with the joint surface of the heat sink.
[0011] The double-layer circuit board of the utility model utilizes the metal heat sink attached to the bottom surface of the substrate to improve the heat dissipation efficiency, and the double-sided circuit board has a good heat dissipation effect. [Drawings]
[0012] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0013] Figure 1 It is a front view schematic diagram of a double-sided circuit board according to an embodiment of the utility model.
[0014] Figure 2 It is a top view schematic diagram of a double-sided circuit board according to an embodiment of the utility model.
[0015] Figure 3 It is a bottom view schematic diagram of a double-sided circuit board according to an embodiment of the utility model.
[0016] Figure 4 It is a bottom view schematic diagram of a double-sided circuit board before the bottom surface is covered with a solder resist layer according to an embodiment of the utility model.
[0017] Figure 5 yes Figure 2 BB section view in.
[0018] Figure 6 yes Figure 4 CC section view in.
[0019] Figure 7 yes Figure 1 AA section view in.
[0020] Figure 8 It is a cross-sectional view of a double-sided circuit board with a heat sink according to an embodiment of the utility model. [Specific implementation method]
[0021] The heat dissipation structure of the double-sided circuit board of the utility model embodiment is as follows Figures 1 to 8 As shown, the double-sided circuit board includes a top circuit layer 1, a ceramic substrate 2, a bottom circuit 41 layer and a bottom solder resist layer 3, the bottom circuit 41 layer includes a circuit area 4 and a heat dissipation area 5, the circuit area 4 includes a bottom circuit 41, the heat dissipation area 5 includes two metal heat dissipators 51 attached to the bottom surface of the ceramic substrate 2, the bottom solder resist layer 3 covers the outer surface of the bottom circuit 41, and the height of the metal heat dissipator 51 is equal to or greater than the height of the bottom solder resist layer 3. The area of the metal heat dissipation area 5 is greater than the area of the circuit area 4.
[0022] The thickness of the circuit in the top circuit layer 1 is greater than that of the bottom circuit. The signal circuit is arranged in the bottom circuit layer and the main circuit is arranged in the top circuit layer to improve the current carrying capacity of the double-layer circuit board.
[0023] The bottom circuit 41 includes a jumper 411 of the top circuit layer 1 . The jumper 411 is located in an avoidance hole 511 in the middle of the metal heat sink 51 to form an isolated island.
[0024] The metal heat sink 51 includes a copper foil 512 which is integrated with the bottom circuit 41 before etching and a metal plating layer 513 which is electroplated on the outside of the copper foil.
[0025] The metal heat sink 51 is electrically connected to the equipotential point of the top circuit layer 1 through the metallized vias 21 and / or the bottom circuit 41 on the ceramic substrate 2 .
[0026] Double-sided circuit boards can be equipped with heat sinks, such as Figure 8 As shown, the heat sink 6 is connected to the double-sided circuit board by screws, buckles or thermal conductive adhesive, and the outer surface of the metal heat sink 51 is in contact with the joint surface of the heat sink 6 .
[0027] The ceramic substrate 2 of the above embodiment of the utility model can adopt a high thermal conductivity ceramic substrate such as diamond, aluminum nitride, silicon nitride, etc., and a quasi-double-layer process is used to replace the multi-layer ceramic process, which has a simple structure and greatly optimized cost and process; a metal heat sink attached to the bottom surface of the high thermal conductivity ceramic substrate is used to improve the heat dissipation efficiency, and the double-sided circuit board has a good heat dissipation effect and greatly improved thermal conductivity.
Claims
1. A heat dissipation structure of a double-sided circuit board, the double-sided circuit board comprising a top circuit layer, a substrate and a bottom circuit layer, characterized in that: The bottom circuit layer includes a circuit area and a heat dissipation area. The circuit area includes the bottom circuit. The heat dissipation area includes at least one metal heat sink attached to the bottom surface of the substrate. The height of the metal heat sink is greater than the height of the bottom circuit.
2. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: It comprises a bottom solder resist layer, which covers the outer surface of the bottom circuit. The height of the metal heat sink is equal to or greater than the height of the bottom solder resist layer. The substrate is a ceramic substrate.
3. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: The bottom surface circuit includes a jumper wire of the top surface circuit layer, and the jumper wire is located in the avoidance hole of the metal heat sink to form an isolated island.
4. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: The area of the metal heat dissipation region is larger than the area of the circuit region, and the thickness of the circuit in the top circuit layer is larger than the thickness of the bottom circuit.
5. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: The metal heat sink comprises a copper foil which is integrated with the bottom circuit before etching and a metal electroplating layer which is electroplated on the outside of the copper foil.
6. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: The metal heat sink is electrically connected to the equipotential point of the top circuit layer through the metallized via hole or the bottom circuit on the substrate.
7. The heat dissipation structure of the double-sided circuit board according to claim 1, characterized in that: The invention comprises a radiator, which is connected to a double-sided circuit board, and the outer surface of a metal radiator is fitted with a joint surface of the radiator.