Radiating structure of radio frequency amplifier
By employing silicon diamond heat sinks and microfluidic structures in RF amplifiers, the challenges of diamond processing and solder wetting were solved, achieving efficient heat dissipation and improving the stability and reliability of RF amplifiers.
Patent Information
- Application Number
- CN202422933983.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-28
AI Technical Summary
Diamond is difficult to process in power device packaging, and its surface is not easily wetted by solder, resulting in low heat dissipation efficiency, packaging complexity and high cost.
By employing silicon diamond heat sinks combined with microfluidic structures, high-quality diamond films are formed on silicon-based materials through methods such as chemical vapor deposition. Furthermore, the heat dissipation structure is optimized using metal conductive layers and passivation layers, achieving reliable connection and efficient heat dissipation between the chip and the packaging substrate.
It improves the thermal conductivity of the chip, reduces the operating junction temperature, enhances the stability and reliability of the packaging structure, and reduces packaging costs.
Smart Images
Figure CN223501860U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chip packaging technology, and in particular to a heat dissipation structure for an RF amplifier. Background Technology
[0002] With the rapid development of information technology, chip packaging technology is facing unprecedented challenges and opportunities. While pursuing miniaturization, thinning, and high performance, the power density of chips is constantly increasing, leading to increasingly prominent heat dissipation problems. Traditional packaging materials, such as copper and aluminum, can meet heat dissipation requirements to a certain extent, but their heat dissipation efficiency is insufficient when facing modern electronic devices with high power density and high heat flux density. Therefore, finding a packaging material with higher thermal conductivity, easier processing, and environmental sustainability has become a current research hotspot.
[0003] Diamond, one of the most thermally conductive materials in nature, boasts a thermal conductivity of up to 2200 W / (m·K), far exceeding that of traditional heat dissipation materials. This property gives diamond enormous application potential in the field of power device packaging. However, despite its excellent thermal conductivity, diamond faces numerous challenges in practical applications.
[0004] First, diamonds are difficult to process and cut. Their high hardness makes conventional machining methods inadequate. While high-precision cutting technologies such as laser cutting or ultrasonic cutting can cut diamonds, they are costly and have limited efficiency. Therefore, reducing the processing cost and improving cutting efficiency of diamonds has become a major obstacle to their application in the packaging field.
[0005] Secondly, diamond surfaces are not easily wetted by solder. Solder is crucial for a reliable connection between the chip and the packaging substrate during the packaging process. However, due to the chemical inertness of diamond surfaces, solder struggles to form a strong bond. This not only affects the reliability of the packaging structure but also increases the complexity and cost of the packaging process.
[0006] In view of this, this utility model proposes a novel heat dissipation structure for radio frequency amplifiers, aiming to solve the problems of high processing difficulty and poor solder wetting of diamond in power device packaging. Furthermore, by optimizing the heat dissipation structure design, the heat dissipation efficiency of the radio frequency amplifier is improved, and the operating temperature of the radio frequency amplifier is reduced, thereby enhancing its stability and reliability. Utility Model Content
[0007] The purpose of this invention is to provide a heat dissipation structure for an RF amplifier, which has excellent heat dissipation performance.
[0008] This utility model provides a heat dissipation structure for an RF amplifier, including a chip and a silicon diamond heat sink. The chip is soldered on top of the silicon diamond heat sink, and a microchannel is provided on the side of the silicon diamond heat sink away from the chip.
[0009] As a preferred embodiment of this technical solution, the silicon diamond heat sink includes a diamond layer and a silicon base layer, wherein the silicon base layer is disposed on the side of the diamond layer away from the chip.
[0010] As a preferred embodiment of this technical solution, it further includes a metal conductive layer, which includes a top metal layer, a bottom metal layer and a side metal layer. The top metal layer is disposed between the chip and the diamond layer, the bottom metal layer is disposed on the side of the silicon substrate away from the diamond layer, and the side metal layers are disposed on both sides of the diamond layer and the silicon substrate, and are respectively connected to the top metal layer and the bottom metal layer.
[0011] As a preferred embodiment of this technical solution, a passivation layer is further included, wherein the passivation layer is disposed on the side of the bottom metal layer away from the silicon substrate.
[0012] As a preferred embodiment of this technical solution, it further includes a cap and a packaging substrate, wherein the cap is disposed on the packaging substrate and is used to cover the packaging substrate, and the cap has an inner cavity with an opening facing downward;
[0013] The packaging substrate has an upward-facing groove for accommodating the chip.
[0014] In a preferred embodiment of this technical solution, the thickness of the diamond layer is 10-20 μm, and the thickness of the silicon substrate is 200-800 μm.
[0015] As a preferred embodiment of this technical solution, the depth of the microchannel is 200-800μm.
[0016] In a preferred embodiment of this technical solution, the thickness of the top metal layer and the bottom metal layer is 4-6 μm.
[0017] As a preferred embodiment of this technical solution, the material of the passivation layer includes either silicon dioxide or silicon nitride, and the thickness of the passivation layer is 0.5-1 μm.
[0018] As a preferred embodiment of this technical solution, the cap is made of high-temperature resistant plastic material.
[0019] The radio frequency amplifier heat dissipation structure of this utility model has at least the following beneficial effects:
[0020] This utility model discloses a heat dissipation structure for an RF amplifier, comprising a chip and a silicon diamond heat sink. The chip is soldered on top of the silicon diamond heat sink, and a microfluidic channel is disposed below the silicon diamond heat sink. This RF amplifier heat dissipation structure, using silicon diamond as the heat sink for packaging, not only solves the problems of diamond being difficult to process, inconvenient to cut, and its surface not easily wetted by solder, but also significantly improves the thermal conductivity of the near-end package of the chip's active region. Heat can be rapidly transferred to the liquid in the microfluidic channel through conduction, avoiding localized temperature increases caused by heat accumulation and thus reducing the chip's operating junction temperature. Attached Figure Description
[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of the heat dissipation structure of the radio frequency amplifier of this utility model.
[0023] Explanation of reference numerals in the attached figures:
[0024] 1: Chip; 2: Microchannel; 3: Diamond layer; 4: Silicon base layer; 5: Top metal layer; 6: Bottom metal layer; 7: Side metal layer; 8: Passivation layer; 9: Cap; 10: Packaging substrate. Detailed Implementation
[0025] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0028] Example
[0029] like Figure 1 As shown, this embodiment provides a heat dissipation structure for an RF amplifier, including a chip 1 and a silicon diamond heat sink. The chip 1 is soldered on top of the silicon diamond heat sink, and a microchannel 2 is provided on the side of the silicon diamond heat sink away from the chip 1.
[0030] The RF amplifier heat dissipation structure of this embodiment includes a chip 1 and a silicon diamond heat sink. The chip 1 is soldered on top of the silicon diamond heat sink, and a microfluidic channel 2 is disposed below the silicon diamond heat sink. This RF amplifier heat dissipation structure uses silicon diamond as the heat sink for packaging, which not only solves the problems of diamond being difficult to process, inconvenient to cut, and its surface not being easily wetted by solder, but also significantly improves the thermal conductivity of the near-end package of the active region of the chip 1. Heat can be quickly transferred to the liquid in the microfluidic channel 2 through conduction, avoiding local temperature rise caused by heat accumulation effect, thereby reducing the operating junction temperature of the chip 1.
[0031] Based on the above technical solution, the silicon diamond heat sink specifically includes a diamond layer 3 and a silicon base layer 4, wherein the silicon base layer 4 is disposed on the side of the diamond layer 3 away from the chip 1.
[0032] Specifically, high thermal conductivity and high performance encapsulation can be achieved by depositing a diamond film of a certain thickness onto a silicon-based material. In this process, various methods can be used to ensure good bonding between the diamond film and the silicon-based material, as well as the quality of the film. For example, chemical vapor deposition can be used, and high-quality diamond films can be formed on the silicon-based material by precisely controlling parameters such as the type, concentration, temperature, and pressure of the reactant gases; sputtering deposition can also be used, where high-speed particles bombard a target, causing atoms or molecules on the target surface to be sputtered and deposited onto the silicon-based material; and laser deposition can also be used, where a high-energy laser beam fuses or vaporizes the material on the target surface and deposits it onto the silicon-based material.
[0033] This invention does not impose strict limitations on the deposition method; various factors can be considered and experimental optimization can be carried out.
[0034] The RF amplifier heat dissipation structure of this embodiment also includes a metal conductive layer, which specifically includes a top metal layer 5, a bottom metal layer 6, and a side metal layer 7. The top metal layer 5 is disposed between the chip 1 and the diamond layer 3, the bottom metal layer 6 is disposed on the side of the silicon substrate 4 away from the diamond layer 3, and the side metal layer 7 is disposed on both sides of the diamond layer 3 and the silicon substrate 4, and is connected to the top metal layer 5 and the bottom metal layer 6 respectively.
[0035] Specifically, the top metal layer 5 is disposed between the chip 1 and the diamond layer 3. First, by utilizing the high thermal conductivity of diamond, the top metal layer 5 can effectively conduct the heat generated by the chip 1 to the diamond layer 3, and then dissipate it through heat dissipation structures such as the microchannel 2. Second, the top metal layer 5 is also responsible for the electrical connection between the chip 1 and the packaging structure, overcoming the problem that solder is difficult to firmly bond on the diamond surface, and ensuring normal signal transmission. Finally, as a barrier between the chip 1 and the external environment, the top metal layer 5 can also protect the chip 1 from mechanical damage and chemical corrosion to a certain extent.
[0036] The bottom metal layer 6 is located on the side of the silicon substrate 4 away from the diamond layer 3. It can not only serve as part of the heat dissipation, conducting heat away from the silicon substrate 4, but also serve as a ground layer, providing a stable potential reference for the circuit. In addition, using semiconductor technology, the bottom metal layer 6 can also be processed to form a circuit, fan-out wiring for some electrodes to realize the connection and function of the circuit.
[0037] The side metal layer 7 is disposed on both sides of the diamond layer 3 and the silicon substrate 4, and is connected to the top metal layer 5 and the bottom metal layer 6 to form a complete heat dissipation network. This not only helps to conduct heat from the chip 1 and the diamond layer 3 to a wider heat dissipation area, but the side metal layer 7 also serves as structural support to enhance the stability and reliability of the package structure. Furthermore, in some cases, the side metal layer 7 can also act as an electromagnetic shielding layer to reduce the impact of external electromagnetic interference on the circuit.
[0038] Based on the above technical solution, more preferably, the RF amplifier heat dissipation structure of this embodiment further includes a passivation layer 8. The passivation layer 8 is disposed on the side of the bottom metal layer 6 away from the silicon substrate 4. The passivation layer 8 is a semiconductor hard mask and can serve as the passivation layer 8 of the bottom metal layer 6. It can selectively cover part of the bottom metal layer 6 and expose part of the bottom metal layer 6.
[0039] Based on the above technical solution, the RF amplifier heat dissipation structure of this embodiment further includes a cover 9 and a packaging substrate 10. The cover 9 is disposed on the packaging substrate 10 and serves to cover the packaging substrate 10. The cover 9 has an inner cavity with an opening facing downwards, meaning that there is an air-isolated layer of a certain thickness between the chip 1 and the cover 9 above the chip 1. First, the air isolation layer helps reduce the direct contact between the chip 1 and the cover 9, thereby reducing the heat transferred through thermal conduction. The air isolation layer also acts as a buffer zone, slowing down the rapid heat transfer to the cover 9, allowing heat to be distributed over a wider area, thus helping to reduce the risk of localized overheating of the chip 1. Second, the inner cavity also provides electromagnetic shielding to a certain extent. Since the RF amplifier generates high-frequency electromagnetic waves during operation, these waves may interfere with the normal operation of other circuits or components. Therefore, the presence of the inner cavity creates a relatively closed electromagnetic environment, reducing electromagnetic wave leakage and interference. Finally, the inner cavity also enhances the structural strength of the cover 9. Since the cover 9 needs to withstand certain mechanical and thermal stresses, the presence of the inner cavity can disperse these stresses, making the cover 9 more robust and stable.
[0040] Furthermore, the packaging substrate 10 is provided with an upward-facing groove for accommodating the chip 1. The chip 1 is mounted within the groove, which not only simplifies operation but also effectively shortens the connection length between the chip 1 and the top metal layer 5, thus reducing RF transmission loss. The mounting methods for the chip 1 within the groove include bonding and snap-fitting.
[0041] In another specific embodiment of this utility model, the thickness of the diamond layer 3 is any value between 10-20μm, and the thickness of the silicon base layer 4 is any value between 200-800μm. This utility model does not impose strict limitations on these values.
[0042] Furthermore, since the microchannel 2 is mainly used for dissipating heat, the present invention does not strictly limit the depth and width of the microchannel 2. Specifically, the depth of the microchannel 2 can be any value between 200-800μm.
[0043] In this embodiment, the thickness of the top metal layer 5 and the bottom metal layer 6 is any value between 4 and 6 μm, and preferably 4 μm.
[0044] Based on the above technical solution, it is further preferred that the material of the passivation layer 8 includes either silicon dioxide or silicon nitride, and the thickness of the passivation layer 8 is any value between 0.5-1μm.
[0045] Based on the above technical solution, more preferably, the cover 9 is made of high-temperature resistant plastic material, or it can be made of ceramic material to increase the heat dissipation effect.
[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A heat dissipation structure for an RF amplifier, characterized in that, It includes a chip (1) and a silicon diamond heat sink, wherein the chip (1) is soldered on top of the silicon diamond heat sink, and a microchannel (2) is provided on the side of the silicon diamond heat sink away from the chip (1).
2. The RF amplifier heat dissipation structure according to claim 1, characterized in that, The silicon diamond heat sink includes a diamond layer (3) and a silicon base layer (4), wherein the silicon base layer (4) is disposed on the side of the diamond layer (3) away from the chip (1).
3. The RF amplifier heat dissipation structure according to claim 2, characterized in that, It also includes a metal conductive layer, which includes a top metal layer (5), a bottom metal layer (6) and a side metal layer (7). The top metal layer (5) is disposed between the chip (1) and the diamond layer (3). The bottom metal layer (6) is disposed on the side of the silicon substrate (4) away from the diamond layer (3). The side metal layer (7) is disposed on both sides of the diamond layer (3) and the silicon substrate (4) and is connected to the top metal layer (5) and the bottom metal layer (6) respectively.
4. The RF amplifier heat dissipation structure according to claim 3, characterized in that, It also includes a passivation layer (8) disposed on the side of the bottom metal layer (6) away from the silicon substrate (4).
5. The RF amplifier heat dissipation structure according to claim 1, characterized in that, It also includes a cover (9) and a packaging substrate (10), the cover (9) being disposed on the packaging substrate (10) and used to cover the packaging substrate (10), the cover (9) having an inner cavity with an opening facing downward; The packaging substrate (10) has an upward-facing groove for accommodating the chip (1).
6. The RF amplifier heat dissipation structure according to claim 2, characterized in that, The thickness of the diamond layer (3) is 10-20 μm, and the thickness of the silicon base layer (4) is 200-800 μm.
7. The RF amplifier heat dissipation structure according to claim 1, characterized in that, The depth of the microchannel (2) is 200-800 μm.
8. The RF amplifier heat dissipation structure according to claim 3, characterized in that, The thickness of the top metal layer (5) and the bottom metal layer (6) is 4-6 μm.
9. The RF amplifier heat dissipation structure according to claim 4, characterized in that, The passivation layer (8) is made of either silicon dioxide or silicon nitride, and the thickness of the passivation layer (8) is 0.5-1 μm.
10. The RF amplifier heat dissipation structure according to claim 5, characterized in that, The cap (9) is made of high-temperature resistant plastic.