CN212113698U

CN212113698U - High heat conduction heat abstractor

Info

Publication number: CN212113698U
Application number: CN202021213059.6U
Authority: CN
Inventors: 魏涛; 钱吉裕; 吴进凯; 秦超; 阮文州
Original assignee: CETC 14 Research Institute
Current assignee: CETC 14 Research Institute
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-12-08
Anticipated expiration: 2030-06-28

Abstract

The utility model provides a high heat conduction heat dissipation device, which consists of a high heat conduction bottom plate, a surrounding frame and a cover plate from bottom to top in sequence; at least one layer of HTCC substrate is arranged on the high-heat-conductivity bottom plate and in the enclosing frame, and at least one surface of the upper surface and the lower surface of the single-layer HTCC substrate is used for placing a heating device; and a heating device is not arranged on one side of the HTCC substrate connected with the high-heat-conduction bottom plate. The utility model provides a high heat conduction heat abstractor utilizes HTCC base plate and diamond aluminum bottom plate of large tracts of land, has solved the high heat flux density of microwave power module and has generated heat the heat dissipation problem of chip.

Description

High heat conduction heat abstractor

Technical Field

The utility model relates to a microwave power module field especially relates to a high heat conduction heat abstractor.

Background

The microwave power module is widely applied to the military and civil fields of radar, electronic countermeasure, communication and the like, the integration level and the power are continuously improved along with the development of GaN three-generation semiconductor materials, the heat productivity of the microwave power module is improved in multiples, the heat flux density of an X-waveband power chip reaches 200W/cm2 or even higher, and great challenges are provided for the heat dissipation capacity of the module, particularly the heat conduction.

At present, in the domestic military or civil field, the heat sink of the microwave power module heating chip mostly adopts tungsten copper, copper-molybdenum copper and other second-generation heat management materials, for example, the copper-molybdenum copper heat sink material mentioned in patent CN201310001249.X "laminated structure heat sink material and preparation method" adopts three-layer composition to realize the preparation of molybdenum copper or tungsten copper heat sink. The patent CN200910213372.1 discloses a copper-molybdenum-copper heat sink material and a preparation method thereof. The packaging shell is made of a one-to-three-generation thermal management material such as kovar, aluminum silicon and the like, for example, the kovar alloy packaging shell mentioned in patent CN201810044629.4, "a manufacturing method of kovar alloy wall for electronic packaging", and the aluminum silicon shell packaging material mentioned in patent CN201510812388.x, "a manufacturing method of gradient aluminum silicon electronic packaging material". In part of high-end application fields, heat sink materials of fourth generation such as diamond aluminum, diamond copper and the like are gradually applied, for example, the heat sink material mentioned in patent CN201710434894.9 "a diamond-aluminum composite material used as an electronic packaging material", and the heat sink material mentioned in patent CN201520980982.5 "diamond copper heat sink material". Although the thermal conductivity of the diamond-based composite material is as high as about 600W/m/K, which is about 3 times that of aluminum, the diamond-based composite material has the defects of difficult processing and high cost due to the existence of diamond particles, and a flat plate structure can be realized only by a grinding method. For the packaging shell of the microwave power module, power supply and radio frequency interfaces are required to be designed so as to install the connecting terminal, fine and complex structures such as threads, chamfers and stepped holes are inevitably formed, and the fine and complex structures can be completed only by machining, so that the application of the diamond-based composite material on the packaging shell is limited, and the application of the diamond-based composite material on the packaging shell is not reported.

In addition, the LTCC substrate is very widely applied in the microwave power module, along with the expansion of the functions and the improvement of the integration level of the substrate, the available area of the heat sink of the power chip is gradually reduced, and the area of the heat sink is even equivalent to that of the chip in high frequency bands such as Ka, and the heat diffusion function is not exerted. Under the requirement of High thermal conductivity, HTCC (High Temperature co-fired Ceramic) substrates are also gradually used, such as the substrate material mentioned in CN201811144572.1, "a four-channel microwave T/R module", and the HTCC substrate mentioned in CN201520794769.5, "a High density package structure of TR module", also have the problem of insufficient heat sink heat spreading area.

In summary, in order to improve the heat dissipation capability of the high-power microwave power module, it is urgently needed to solve the technical problem of how to realize the application of the diamond-based high-heat-conduction material as the packaging shell and how to improve the heat dissipation capability of the heat sink.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems and provides a high heat conduction heat dissipation device which is composed of a high heat conduction bottom plate, a surrounding frame and a cover plate from bottom to top in sequence; at least one layer of HTCC substrate is arranged on the high-heat-conductivity bottom plate and in the enclosing frame, and at least one surface of the upper surface and the lower surface of the single-layer HTCC substrate is used for placing a heating device; and a heating device is not arranged on one side of the HTCC substrate connected with the high-heat-conduction bottom plate.

Further, the heat generating device is a chip, and the power of any chip except the lowest chip is not greater than that of the chip below the chip.

Furthermore, the high-thermal-conductivity bottom plate is made of a diamond-aluminum composite material, and the difference value of the thermal expansion coefficients of the HTCC substrate and the high-thermal-conductivity bottom plate is greater than or equal to-3 ppm/K and less than or equal to 3 ppm/K.

Further, the HTCC substrate is a layer, a cavity is formed in the upper surface of the HTCC substrate, the cavity is used for placing chips, the surfaces of the chips in the cavity are located between the upper surface and the lower surface of the HTCC substrate, and the chips are distributed in a staggered mode in the vertical direction.

Furthermore, a plurality of layers of HTCC substrates are arranged in the enclosing frame, and the HTCC substrates are stacked on the high-heat-conductivity bottom plate; except the chips arranged on the upper surface of the uppermost HTCC substrate, other chips are arranged through the cavities on the surface of the HTCC substrate, the surfaces of the chips in the cavities are positioned between the upper surface and the lower surface of the HTCC substrate, and the chips are distributed in a staggered manner in the vertical direction.

Furthermore, the bottom surface of the enclosing frame is provided with a positioning pin, and the high heat conduction bottom plate is punched at a corresponding position to be matched and positioned with the positioning pin.

Compared with the prior art, the utility model, possess following advantage:

(1) by utilizing the large-area HTCC substrate, the problem that the heat diffusion of the high-heat-flow-density heating chip of the microwave power module is difficult is solved;

(2) the diamond/aluminum composite bottom plate is utilized, the problem of high heat conduction temperature of the shell of the microwave power module is solved, meanwhile, secondary heat diffusion is effectively carried out, the heat flow density is further reduced, and the contact temperature rise between the module and a cold plate is reduced;

(3) through adopting the bottom plate, enclosing frame and apron and the compound connection of different grade type materials, solved the microwave power module and directly adopted the engineering use problems such as difficult processing, density are big, with high costs that high heat conduction material produced.

Drawings

Fig. 1 is an overall assembly view of the first embodiment.

Fig. 2 is an exploded view of the first embodiment.

Fig. 3 is an assembly view of the enclosure frame and the high thermal conductivity base plate according to the first embodiment.

Fig. 4 is a schematic diagram of a conventional heat transfer manner of a microwave power module.

Fig. 5 is a schematic diagram of a heat transfer mode of a microwave power module to which the present invention is applied.

Fig. 6 is a partial schematic view of the first embodiment.

Fig. 7 is a sectional view taken along line a-a of fig. 6.

The reference numerals in the figures denote the following meanings:

the high-heat-conductivity high-power LED lamp comprises a cover plate 1, a surrounding frame 2, a high-heat-conductivity bottom plate 3, an upper HTCC substrate 4, a lower HTCC substrate 5, a low-power chip 6 and a high-power chip 7.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any implementation. Additionally, some aspects of the present disclosure may be used alone or in any suitable combination with other aspects of the present disclosure.

Example one

The utility model provides a high heat conduction heat abstractor's schematic diagram is shown in fig. 1, fig. 2, the device comprises high heat conduction bottom plate 3, enclose frame 2 and apron 1 from bottom to top in proper order. An upper HTCC substrate 4 and a lower HTCC substrate 5 are encapsulated in the device; the HTCC substrate 4 and the lower HTCC substrate 5 are provided with a low-power chip 6 and a high-power chip 7.

The high-thermal-conductivity bottom plate 3 is made of a diamond aluminum composite material, and the thermal expansion coefficient of the bottom plate is matched with that of the HTCC substrate by adjusting the volume fraction of diamond. The thermal expansion coefficient of the HTCC substrate is 4-5ppm/K (ppm/K is a temperature coefficient), when the volume fraction of diamond in diamond aluminum reaches more than 70%, the thermal expansion coefficient of the diamond aluminum composite material can reach about 7ppm/K, and the requirement that the difference of the thermal expansion coefficients of two layers of welding interfaces is more than or equal to-3 ppm/K and less than or equal to 3ppm/K is met. The surface of the high heat-conducting bottom plate 3 can be directly formed with an aluminum metal layer in a preparation process such as high-pressure casting, and if a pressure infiltration process is adopted, the metal layer needs to be ground and plated again, and if titanium plating and copper plating are adopted, the requirement of large-area connection with an HTCC substrate by soldering is met. The thickness of the single-side aluminum metal layer or the metal plating layer is controlled to be 50um, the thickness of the single-side aluminum metal layer or the metal plating layer is equivalent to that of a common gold-tin solder, the total thickness of the two sides is about 100um, the aluminum foil layer accounts for about 5 percent according to the total thickness of a common bottom plate of 2mm, the influence on the thermal expansion coefficient of the whole bottom plate is small, the thermal matching of the bottom plate and the HTCC substrate can be ensured, and the requirements of welding on surface metallization are. The high heat conduction bottom plate and the surrounding frame are connected by soft soldering.

The upper HTCC substrate 4 has a far heat transfer path, and since the upper layer is not blocked, the upper surface can be surface-mounted or welded with the small power chip 6, or the small power chip 6 can be welded through the cavity 5-1, as shown in fig. 6 and 7, the surface of the cavity 5-1 is located between the upper and lower surfaces of the HTCC substrate. The lower HTCC substrate 5 is close in heat transfer path and can be welded with the high-power chips 7 arranged in an array, the upper surface of the lower HTCC substrate 5 needs to be welded with the lower surface of the upper HTCC substrate 4 in a large area, only the upper surface of the lower HTCC substrate 5 needs to be provided with the concave cavity 5-1, the high-power chips 7 are welded in the concave cavity 5-1, and the height of the chips welded in the concave cavity 5-1 is lower than that of the HTCC substrate 4. The lower HTCC substrate 5 is welded with the high heat conduction bottom plate 3, and no chip is placed on the welding surface. The lower HTCC substrate 5 and the upper HTCC substrate 4 are connected by BGA or soldered in a large area. The heat transfer path is (low power chip 6 → upper HTCC substrate 4) → (high power chip 7 → lower HTCC substrate 5) → high thermal conductivity bottom plate 3. The small power chips 6 and the large power chips 7 are distributed in a staggered manner in the vertical direction to form a reasonable heat dissipation path.

The enclosure frame 2 and the cover plate 1 have various matching options. If the low cost is considered preferentially, the enclosure frame 2 can be selected from Al6061, the enclosure frame is generated in the preparation process of the high-heat-conduction bottom plate 3, such as high-pressure casting or pressure infiltration, the metal layer is prevented from being plated again, and the cover plate 1 is selected from Al 4047; if the prior consideration is compatible with the original packaging shell technology of aluminum silicon and the like, the enclosure frame 2 can be made of aluminum silicon alloy (AlSi50), the enclosure frame is welded with the high-heat-conductivity bottom plate 3 after being plated with nickel and gold, and the cover plate 1 is made of aluminum silicon alloy (AlSi 27); for example, the enclosure frame 2 may be made of titanium alloy (TC4) in consideration of high strength and high reliability, the connection method may be similar to that of aluminum-silicon alloy, and the cover plate 1 may be made of titanium alloy (TA 2). The surrounding frame 2 and the cover plate 1 are connected by adopting a laser gas seal welding process. As shown in fig. 3, when the enclosure frame 2 is made of aluminum-silicon alloy or titanium alloy, in order to ensure accurate fixation of the large-size enclosure frame and the high thermal conductivity base plate 3 during welding, the bottom surface of the enclosure frame 2 is provided with a circular or quadrilateral positioning pin 2-1, and the high thermal conductivity base plate 3 is provided with a hole at a corresponding position for positioning in a matching manner. The enclosure frame 2 and the high thermal conductivity base plate 3 are connected by soldering.

The integral connection process of the device comprises two-step welding and one-step sealing welding, and specifically comprises the following steps:

firstly, welding the high-thermal-conductivity bottom plate 3 and the surrounding frame 2, positioning and matching, using a tool clamp, adopting the highest welding temperature, selecting gold-tin solder, and forming the packaging shell without the cover plate 1 at the welding temperature of about 283 ℃.

Secondly, connecting the chips and the HTCC substrate on the HTCC substrate by using gold-tin solder or conductive silver adhesive which can resist the temperature of more than 300 ℃, wherein the connection comprises the connection of a high-power chip 7, a lower HTCC substrate 5, a low-power chip 6 and an upper HTCC

substrate

4, and 2 single-layer HTCC substrates with heating chips are formed; and then, superposing the 2 single-layer HTCCs with the heating chips, and welding the single-layer HTCCs with the packaging shell in a large area, wherein tin-lead solder can be selected, and the welding temperature is about 183 ℃.

And finally, laser gas sealing welding is carried out on the cover plate 1 and the packaging shell, so that the air tightness requirement when the microwave power module is applied is ensured.

Example two

The embodiment is basically the same as the first embodiment, and is different in that a cavity 5-1 is formed in the lower surface of the upper HTCC substrate, a small power chip 6 is welded in the cavity 5-1, and the surface of the small power chip 6 is located between the upper surface and the lower surface of the HTCC substrate.

EXAMPLE III

The present embodiment is substantially the same as the first embodiment, except that the HTCC substrate in the present embodiment is a single layer. And a small power chip 6 is pasted or welded on the upper surface of the single-layer HTCC substrate, and a chip is not arranged on the surface connected with the high heat conduction bottom plate 3.

The utility model utilizes the large area HTCC substrate, solves the problem of heat diffusion of the high heat flux density heating chip of the microwave power module;

the utility model utilizes the diamond/aluminum composite bottom plate to solve the problem of high heat conduction temperature of the shell of the microwave power module, and simultaneously, the heat flux density is further reduced by effective secondary heat diffusion, and the contact temperature rise between the module and the cold plate is reduced;

the utility model discloses an adopt the different grade type material the bottom plate, enclose frame and apron and composite connection, solved the microwave power module and directly adopted the processing that high heat conduction material produced difficult, density is big, engineering use problem such as with high costs.

Fig. 4 shows a conventional heat transfer method with a narrow heat transfer path and a large thermal resistance, and a third embodiment of the present invention is shown in fig. 5 with a wide heat transfer path, a low heat flow and a small thermal resistance.

To sum up, compared with the traditional molybdenum-copper heat sink and aluminum, aluminum-silicon or aluminum-carbon-silicon packaging shell, the high-heat-conductivity heat dissipation device provided by the utility model has the advantages that the effective heat transfer path is wide, the high heat flux density at the chip can be quickly reduced to the low heat flux density, the total heat transfer resistance is small, the composite structure design of the special bottom plate, the enclosing frame and the cover plate is adopted, the production and processing requirements of easy processing, light weight, economy, air tightness and the like are met, and good prerequisite is created for the cold plate or the radiator of subsequent heat exchange,

the above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A high heat conduction heat dissipation device is characterized in that the device consists of a high heat conduction bottom plate (3), a surrounding frame (2) and a cover plate (1) from bottom to top in sequence; at least one layer of HTCC substrate is arranged on the high-heat-conductivity bottom plate (3) and in the enclosing frame (2), and at least one surface of the upper surface and the lower surface of the single-layer HTCC substrate is used for placing a heating device; and a heating device is not arranged on one side of the HTCC substrate connected with the high heat conduction bottom plate (3).

2. A heat sink with high thermal conductivity as claimed in claim 1, wherein the heat generating device is a chip, and the power of any chip except the lowest chip is not greater than that of the chip below the chip.

3. The high thermal conductivity heat sink according to claim 2, wherein the high thermal conductivity base plate (3) is a diamond-aluminum composite, and the difference between the thermal expansion coefficients of the HTCC substrate and the high thermal conductivity base plate (3) is equal to or greater than-3 ppm/K and equal to or less than 3 ppm/K.

4. The HTCC substrate of claim 3, wherein said HTCC substrate is a layer, and the upper surface of said HTCC substrate is provided with a cavity (5-1), said cavity (5-1) is used for placing a chip, and the surface of the chip in said cavity (5-1) is located between the upper surface and the lower surface of the HTCC substrate.

5. The high thermal conductivity heat sink according to claim 3, wherein multiple layers of HTCC substrates are disposed in the enclosure frame (2), and the HTCC substrates are stacked on the high thermal conductivity bottom plate (3); except the chips arranged on the upper surface of the uppermost HTCC substrate, other chips are arranged through a cavity (5-1) on the surface of the HTCC substrate, the surfaces of the chips in the cavity (5-1) are positioned between the upper surface and the lower surface of the HTCC substrate, and the chips are distributed in a staggered mode in the vertical direction.

6. The high heat conduction and dissipation device as claimed in claim 4 or 5, wherein the bottom surface of the enclosure frame (2) is provided with positioning pins (2-1), and holes are punched at corresponding positions of the high heat conduction bottom plate (3) to be matched with the positioning pins (2-1) for positioning.