A heat dissipation structure for three-dimensional interconnection of a radio frequency microsystem

Abstract

The present invention belongs to the technical field of radio frequency microsystems, and specifically relates to a heat dissipation structure for three-dimensional interconnection of radio frequency microsystems, which includes a packaging box and an upper SiP and a lower SiP installed inside the packaging box. The packaging box includes a top plate and a bottom plate, and the top plate and the bottom plate are connected by a sealing rubber head. A sealing block is slidably installed between the top plate and the bottom plate, and the sealing block abuts against the sealing rubber head. During the process of the cover in the present invention encapsulating the upper SiP and the lower SiP, the cover squeezes the sealing block, causing the sealing block to slide towards the inside of the packaging box. At this time, the sealing block will drive the sealing rubber head to seal the connection position of the upper SiP and the lower SiP and isolate the BGA solder balls. When the coolant is injected into the inside of the packaging box, the coolant can directly contact the lower SiP and the upper SiP, ensuring the heat dissipation efficiency of the coolant for the lower SiP and the upper SiP.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency microsystems, and particularly relates to a heat dissipation structure for three-dimensional interconnection of radio frequency microsystems. Background Art

[0002] As an advanced integrated packaging technology under the trend of system miniaturization, radio frequency microsystem integration technology has become a major basic technology leading the development of equipment and promoting electronic technology innovation. It is an important technical platform supporting the ability transformation of electronic information equipment in the fields of sensing and communication, and is also one of the core technologies in the current research of electronic information technology.

[0003] Existing high-power radio frequency microsystems are realized by packaging radio frequency chips into two SiPs, upper and lower. Signal interconnection between the upper and lower SiPs is achieved through ball grid array packaging BGA or SMD, such as the Chinese patent with the publication number CN114613751B. The higher the power of the radio frequency microsystem, the higher its power consumption and the more serious the heat generation. The conventional heat dissipation method is to lay microchannels at the bottom of the radio frequency chip. However, high-power radio frequency microsystems are packaged in a vertically integrated manner, which results in poor heat dissipation effect of the microchannels on the upper SiP. To solve the above problems, there is a method of immersion liquid cooling for heat dissipation of high-power radio frequency microsystems in the prior art, such as the Chinese patent with the publication number CN110010570A. Since the upper and lower SiPs are connected through ball grid array packaging, before liquid cooling, special treatment needs to be carried out on the ball grid array connecting the upper and lower SiPs, and special coolant as well as supporting equipment and containers are required, resulting in a substantial increase in cost and being not conducive to popular use. Summary of the Invention

[0004] The purpose of the present invention is to provide a heat dissipation structure for three-dimensional interconnection of radio frequency microsystems aiming at the deficiencies of the prior art to solve the technical problems in the prior art.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A heat dissipation structure for three-dimensional interconnection of radio frequency microsystems, which includes a packaging box and an upper SiP and a lower SiP installed inside the packaging box. The upper SiP and the lower SiP are connected by BGA solder balls, and a cover is installed on the packaging box;

[0006] The packaging box includes a top plate and a bottom plate, which are connected by a sealing rubber head. The sealing rubber head is aligned with the connection part of the upper SiP and the lower SiP. A sealing block is slidably installed between the top plate and the bottom plate, and the sealing block abuts against the sealing rubber head;

[0007] An outlet and an inlet are respectively arranged on the top plate and the bottom plate. A liquid flow hole is opened on the sealing block far from the inlet. Liquid flow grooves are opened on the top plate and the bottom plate, and the liquid flow hole is communicated with the liquid flow grooves.

[0008] As a further optimization or improvement of this solution, the upper SiP and the lower SiP are respectively located inside the top plate and the bottom plate, and the lower SiP is hermetically connected to the bottom plate.

[0009] As a further optimization or improvement of this solution, sealing sheets are installed on the top plate and the bottom plate, and the sealing sheets are in contact with the sealing blocks.

[0010] As a further optimization or improvement of this solution, a speed regulation component is installed inside the top plate. The speed regulation component includes a flow regulation plate and a slot. The flow regulation plate is rotatably installed on the top plate, and a slot is opened on the top plate, and the slot is located at the flow regulation plate;

[0011] An endothermic cavity plate is installed on the cover. The endothermic cavity plate contacts the top of the upper SiP. A connecting cavity tube is installed on the endothermic cavity plate. The connecting cavity tube is communicated with the endothermic cavity plate. An elastic diaphragm is installed on the connecting cavity tube. The connecting cavity tube is inserted into the slot, and the elastic diaphragm is in contact with the flow regulation plate.

[0012] As a further optimization or improvement of this solution, a number of microchambers are provided inside the endothermic cavity plate. Two connecting cavity tubes are respectively installed at both ends of each microchamber. The connecting cavity tubes are all inserted into the slot, and the elastic diaphragms on the connecting cavity tubes are all in contact with the flow regulation plate.

[0013] As a further optimization or improvement of this solution, the sealing rubber head abuts against the connection position of the upper SiP and the lower SiP; when installing the cover, the cover drives the sealing block to squeeze towards the inside of the packaging box, so that the sealing block drives the top plate to seal the connection ends of the upper SiP and the lower SiP.

[0014] Advantages of the present invention:

[0015] (1) During the encapsulation of the upper SiP and the lower SiP by the cover in the present invention, the cover squeezes the sealing block, so that the sealing block slides towards the inside of the packaging box. At this time, the sealing block will drive the sealing rubber head to seal the connection position of the upper SiP and the lower SiP and isolate the BGA solder balls. When injecting the coolant into the packaging box, the coolant can directly contact the lower SiP and the upper SiP, ensuring the heat dissipation efficiency of the coolant for the lower SiP and the upper SiP.

[0016] Compared with microchannel heat dissipation, the present invention improves the heat dissipation efficiency of the upper SiP by directly contacting the upper SiP and the lower SiP with the coolant, avoiding the problem of poor heat dissipation effect of the upper SiP located at the top;

[0017] Compared with the heat dissipation method of immersion liquid cooling, in the process of using the cover to package the upper SiP and the lower SiP in the present invention, the BGA solder balls between the upper SiP and the lower SiP are sealed by the way of the cover squeezing the sealing block and the sealing rubber head, so as to improve the sealing effect of the connection part between the upper SiP and the lower SiP, and there is no need to waterproof the BGA solder balls anymore. At the same time, the coolant in the present invention can be replaced by other coolants. Compared with the special coolant used in immersion liquid cooling, the present invention can greatly reduce the use cost and is convenient for popularization and use.

[0018] (2)When the upper SiP and the lower SiP in the present invention are operating, the heat of the upper SiP is transferred to the heat absorption cavity plate, causing the gas inside the heat absorption cavity plate to expand, and then driving the elastic diaphragm to bulge. At this time, the elastic diaphragm on the connecting cavity tube drives the flow regulating plate to rotate. When the coolant passes through the flow regulating plate, the passing diameter of the coolant decreases. With the coolant flow rate unchanged, the speed of the coolant passing through the flow regulating plate increases. Therefore, the cooling efficiency of the coolant for the upper SiP relatively increases, making the cooling efficiency of the coolant for the upper SiP and the lower SiP as consistent as possible, avoiding the phenomenon of local temperature increase during the operation of the radio frequency microsystem, and improving the stability of the radio frequency microsystem operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 It is a schematic diagram of the installation structure of the packaging box and the cover.

[0021] Figure 2 It is a schematic diagram of the overall structure of the present invention.

[0022] Figure 3 It is a cross-sectional view of the packaging box structure.

[0023] Figure 4 It is for Figure 3 A partial structure schematic diagram of part A.

[0024] Figure 5 It is a schematic diagram of the internal structure of the packaging box.

[0025] Figure 6 It is for Figure 5 A partial structure schematic diagram of part B.

[0026] Figure 7 It is for Figure 5 A partial structure schematic diagram of part C.

[0027] Figure 8 It is a schematic diagram of the bottom structure of the cover.

[0028] Figure 9 It is a schematic diagram of the microchamber structure.

[0029] Figure 10 This is a sectional view of the overall structure of the present invention.

[0030] Figure 11 This is a mating diagram of the connecting cavity tube and the flow regulating plate.

[0031] In the figure, the markings are as follows: 1. Encapsulation box; 10. Liquid inlet; 11. Liquid outlet; 12. Sealing block; 13. Top plate; 14. Bottom plate; 15. Sealing rubber head; 16. Sealing sheet; 17. Liquid flow hole; 18. Liquid flow groove; 2. Cover; 3. Upper SiP; 4. Lower SiP; 5. Speed regulating assembly; 51. Flow regulating plate; 52. Slot; 53. Heat absorption cavity plate; 54. Microchamber; 55. Connecting cavity tube; 56. Elastic diaphragm; 6. BGA solder ball. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0033] See Figures 1-6 , a heat dissipation structure for three-dimensional interconnection of a radio frequency microsystem, which includes an encapsulation box 1 and an upper SiP 3 and a lower SiP 4 installed inside the encapsulation box 1. The upper SiP 3 and the lower SiP 4 are connected by BGA solder balls 6, and a cover 2 is installed on the encapsulation box 1;

[0034] The encapsulation box 1 includes a top plate 13 and a bottom plate 14, and the top plate 13 and the bottom plate 14 are connected by a sealing rubber head 15. The sealing rubber head 15 is aligned with the connection between the upper SiP 3 and the lower SiP 4. A sealing block 12 is slidably installed between the top plate 13 and the bottom plate 14, and the sealing block 12 abuts against the sealing rubber head 15;

[0035] A liquid outlet 11 and a liquid inlet 10 are respectively provided on the top plate 13 and the bottom plate 14. A liquid flow hole 17 is opened on the sealing block 12 away from the liquid inlet 10, and liquid flow grooves 18 are opened on the top plate 13 and the bottom plate 14. The liquid flow hole 17 and the liquid flow grooves 18 are communicated.

[0036] Specifically, the upper SiP 3 and the lower SiP 4 are respectively located inside the top plate 13 and the bottom plate 14, and the lower SiP 4 is hermetically connected to the bottom plate 14.

[0037] It should be noted that during installation, the radio frequency chip needs to be first encapsulated inside the upper SiP3 and the lower SiP4, and then the upper SiP3 and the lower SiP4 are connected through the BGA solder balls 6. Next, the upper SiP3 and the lower SiP4 are installed inside the packaging box 1, so that the bottom of the lower SiP4 is hermetically connected to the bottom plate 14. Finally, the cover 2 is installed on the packaging box 1. During this process, the cover 2 presses the sealing block 12, causing the sealing block 12 to slide towards the inside of the packaging box 1. At this time, the sealing block 12 drives the sealing rubber head 15 to seal the connection position of the upper SiP3 and the lower SiP4 and isolate the BGA solder balls 6. At this time, the coolant is injected into the bottom plate 14 through the liquid inlet 10. The coolant first passes through the lower SiP4 and dissipates heat from the lower SiP4, and then the coolant enters the top plate 13 through the liquid flow holes 17 and the liquid flow grooves 18. Then the coolant dissipates heat from the upper SiP3 through the top plate 13, and finally the coolant is output from the liquid outlet 11. The flow path of the coolant is as shown in Figure 10 the arrow in. During this process, the coolant can directly contact the lower SiP4 and the upper SiP3, ensuring the heat dissipation effect of the coolant on the lower SiP4 and the upper SiP3. Compared with microchannel heat dissipation, the present invention improves the heat dissipation efficiency of the upper SiP3 by directly contacting the upper SiP3 and the lower SiP4 with the coolant, avoiding the problem of poor heat dissipation effect of the upper SiP3 located at the top. Compared with the heat dissipation method of immersion liquid cooling, during the process of encapsulating the upper SiP3 and the lower SiP4 with the cover 2 in the present invention, the BGA solder balls 6 between the upper SiP3 and the lower SiP4 are sealed by the cover 2 pressing the sealing block 12 and the sealing rubber head 15, improving the sealing effect of the connection part between the upper SiP3 and the lower SiP4, and there is no need to waterproof the BGA solder balls 6 anymore. At the same time, the coolant in the present invention can be replaced with other coolants. Compared with the special coolant used in immersion liquid cooling, the present invention can greatly reduce the use cost and is convenient for popularization.

[0038] See Figure 6 , a sealing sheet 16 is installed on the top plate 13 and the bottom plate 14, and the sealing sheet 16 contacts the sealing block 12.

[0039] Specifically, the sealing rubber head 15 abuts against the connection part of the upper SiP3 and the lower SiP4; when installing the cover 2, the cover 2 drives the sealing block 12 to squeeze towards the inside of the packaging box 1, causing the sealing block 12 to drive the top plate 13 to seal the connection end of the upper SiP3 and the lower SiP4.

[0040] It should be noted that a sealing sheet 16 is installed on the top plate 13 and the bottom plate 14. The sealing block 12 is connected to the top plate 13 and the bottom plate 14 through the sealing sheet 16. The sealing sheet 16 can provide a sealing effect for the sealing block 12. When the coolant passes through the liquid flow holes 17 and the liquid flow grooves 18, the sealing sheet 16 can prevent the coolant from flowing out of the inside of the packaging box 1.

[0041] Figures 7-11 , a speed regulation component 5 is installed inside the top plate 13. The speed regulation component 5 includes a flow regulation plate 51 and a slot 52. The flow regulation plate 51 is rotatably installed on the top plate 13, and the slot 52 is formed on the top plate 13, and the slot 52 is located at the flow regulation plate 51;

[0042] An endothermic cavity plate 53 is installed on the cover 2. The endothermic cavity plate 53 contacts the top of the upper SiP3. A connecting cavity tube 55 is installed on the endothermic cavity plate 53. The connecting cavity tube 55 communicates with the endothermic cavity plate 53. An elastic diaphragm 56 is installed on the connecting cavity tube 55. The connecting cavity tube 55 is inserted into the slot 52, and the elastic diaphragm 56 contacts the flow regulation plate 51.

[0043] It should be noted that since the coolant first passes through the bottom plate 14 to dissipate heat from the lower SiP4, and then the coolant enters the top plate 13 to dissipate heat from the upper SiP3. In fact, when the coolant passes through the bottom plate 14, the coolant will absorb the heat of the lower SiP4. When the coolant enters the top plate 13, the cooling effect of the coolant will be relatively reduced. Therefore, in actual use, the cooling effect of the coolant on the upper SiP3 is not as good as that on the lower SiP4. This causes the inconsistency of the cooling effects of the coolant on the upper SiP3 and the lower SiP4, resulting in the phenomenon of local temperature increase during the operation of the radio frequency microsystem, which in turn affects the system operation. Therefore, in the present invention, by installing the speed regulation component 5 on the packaging box 1 and the cover 2, during the process of using the cover 2 to package the upper SiP3 and the lower SiP4, the connecting cavity tubes 55 on the endothermic cavity plate 53 are respectively inserted into the slots 52 on the top plate 13. When the cover 2 is packaged, the endothermic cavity plate 53 at the bottom of the cover 2 abuts against the top of the upper SiP3.

[0044] When the upper SiP3 and the lower SiP4 are operating, the heat of the upper SiP3 is transferred to the endothermic cavity plate 53, causing the gas inside the endothermic cavity plate 53 to expand, thereby driving the elastic diaphragm 56 to bulge. See Figure 11 , at this time, the elastic diaphragm 56 on the connecting cavity tube 55 drives the flow regulation plate 51 to rotate. At this time, when the coolant passes through the flow regulation plate 51, the passing diameter of the coolant decreases. When the flow rate of the coolant remains unchanged, the passing speed of the coolant through the flow regulation plate 51 increases. Therefore, the cooling efficiency of the coolant on the upper SiP3 relatively increases, making the cooling efficiencies of the coolant on the upper SiP3 and the lower SiP4 as consistent as possible, making their working temperatures balanced, and avoiding the phenomenon of local temperature increase during the operation of the radio frequency microsystem.

[0045] See Figures 9-11 , a number of microchambers 54 are arranged inside the endothermic cavity plate 53. Two connecting cavity tubes 55 are respectively installed at both ends of each microchamber 54. The connecting cavity tubes 55 are all inserted into the slots 52, and the elastic diaphragms 56 on the connecting cavity tubes 55 all contact the flow regulation plate 51.

[0046] It should be noted that there are several microchambers 54 in the heat absorption cavity plate 53. The several microchambers 54 can divide the upper SiP3 into various regions. When the working temperatures of the various regions of the upper SiP3 are different, each microchamber 54 can adjust the angle of the corresponding flow regulating plate 51 through the connecting cavity tube 55 and the elastic diaphragm 56, so that when the coolant passes through the corresponding flow regulating plate 51, the flow velocity of the coolant changes accordingly, so that the working temperatures of the various regions of the upper SiP3 can be kept consistent, and the operation efficiency of the RF microsystem is improved.

[0047] The implementation principle of the present invention is as follows:

[0048] During installation, the RF chip needs to be first packaged inside the upper SiP3 and the lower SiP4, and then the upper SiP3 and the lower SiP4 are connected through the BGA balls 6. Then, the upper SiP3 and the lower SiP4 are installed in the packaging box 1, so that the bottom of the lower SiP4 is hermetically connected to the bottom plate 14. Finally, the cover 2 is installed on the packaging box 1. During this process, the cover 2 presses the sealing block 12, causing the sealing block 12 to slide towards the inside of the packaging box 1. At this time, the sealing block 12 will drive the sealing rubber head 15 to seal the connection position of the upper SiP3 and the lower SiP4 and isolate the BGA balls 6. At this time, the coolant is injected into the bottom plate 14 through the liquid inlet 10. The coolant first passes through the lower SiP4 and dissipates heat from the lower SiP4. Then, the coolant enters the top plate 13 through the liquid flow holes 17 and the liquid flow grooves 18. Then, the coolant dissipates heat from the upper SiP3 through the top plate 13. Finally, the coolant is output from the liquid outlet 11. The flow trajectory of the coolant is as Figure 10 shown by the arrow in the figure. During this process, the coolant can directly contact the lower SiP4 and the upper SiP3, ensuring the heat dissipation effect of the coolant on the lower SiP4 and the upper SiP3.

[0049] When the upper SiP3 is operating, the heat of the upper SiP3 is transferred to the heat absorption cavity plate 53, causing the gas inside the heat absorption cavity plate 53 to expand, and then driving the elastic diaphragm 56 to bulge. See Figure 11 Figure. At this time, the elastic diaphragm 56 on the connecting cavity tube 55 drives the flow regulating plate 51 to rotate. At this time, when the coolant passes through the flow regulating plate 51, the passing diameter of the coolant decreases. When the flow velocity of the coolant remains unchanged, the passing speed of the coolant through the flow regulating plate 51 increases. Therefore, the cooling efficiency of the coolant on the upper SiP3 relatively increases, making the cooling efficiency of the coolant on the upper SiP3 and the lower SiP4 as consistent as possible, making its working temperature balanced, and avoiding the phenomenon of local temperature increase during the operation of the RF microsystem.

[0050] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A heat dissipation structure for three-dimensional interconnection of radio frequency microsystems, characterized in that: It comprises a packaging box (1) and an upper SiP (3) and a lower SiP (4) installed inside the packaging box (1), wherein the upper SiP (3) and the lower SiP (4) are connected via a BGA solder ball (6), and a sealing cover (2) is installed on the packaging box (1); The packaging box (1) comprises a top plate (13) and a bottom plate (14); the top plate (13) and the bottom plate (14) are connected via a sealing rubber head (15); the sealing rubber head (15) is aligned with the connection between the upper SiP (3) and the lower SiP (4); a sealing block (12) is slidably installed between the top plate (13) and the bottom plate (14); the sealing block (12) contacts the sealing rubber head (15); The top plate (13) and the bottom plate (14) are respectively provided with a liquid outlet (11) and a liquid inlet (10); the sealing blocks (12) are respectively provided on two sides of the packaging box (1), namely, a sealing block (12) on a side close to the liquid inlet (10) and a sealing block (12) on a side away from the liquid inlet (10); a liquid flow hole (17) is provided on the sealing block (12) away from the liquid inlet (10); a liquid flow groove (18) is provided on the top plate (13) and the bottom plate (14); and the liquid flow hole (17) and the liquid flow groove (18) are longitudinally aligned and connected; Cooling liquid is injected into the bottom plate (14) through the liquid inlet (10). The cooling liquid first passes through the lower SiP (4) and dissipates heat to the lower SiP (4). Then, the cooling liquid enters the top plate (13) through the liquid flow hole (17) and the liquid flow groove (18). Then, the cooling liquid passes through the top plate (13) to dissipate heat to the upper SiP (3). Finally, the cooling liquid is output from the liquid outlet (11).

2. The heat dissipation structure of a three-dimensional interconnected radio frequency microsystem according to claim 1, characterized in that: The upper SiP (3) and the lower SiP (4) are located inside the top plate (13) and the bottom plate (14) respectively, and the lower SiP (4) is sealed and connected to the bottom plate (14).

3. The heat dissipation structure of a three-dimensional interconnected radio frequency microsystem according to claim 1, characterized in that: A sealing sheet (16) is installed on the top plate (13) and the bottom plate (14), and the sealing sheet (16) is in contact with the sealing block (12).

4. The heat dissipation structure of a three-dimensional interconnected radio frequency microsystem according to claim 1, characterized in that: The top plate (13) has a speed regulating assembly (5) installed inside, the speed regulating assembly (5) comprising a flow regulating plate (51) and a slot (52), the flow regulating plate (51) is rotatably mounted on the top plate (13), the slot (52) is provided on the top plate (13), and the slot (52) is located on the flow regulating plate (51); A heat absorption cavity plate (53) is mounted on the cover (2), the heat absorption cavity plate (53) contacts the top of the upper SiP (3), a connecting cavity tube (55) is mounted on the heat absorption cavity plate (53), the connecting cavity tube (55) is connected to the heat absorption cavity plate (53), an elastic diaphragm (56) is mounted on the connecting cavity tube (55), the connecting cavity tube (55) is inserted into the slot (52), and the elastic diaphragm (56) contacts the flow regulating plate (51).

5. The heat dissipation structure of a three-dimensional interconnected radio frequency microsystem according to claim 4, characterized in that: A plurality of micro chambers (54) are arranged inside the heat absorption chamber plate (53), and two connecting chamber tubes (55) are respectively installed at both ends of each micro chamber (54). The connecting chamber tubes (55) are all inserted into the slots (52), and the elastic membranes (56) on the connecting chamber tubes (55) are all in contact with the flow regulating plate (51).

6. The heat dissipation structure of a three-dimensional interconnected radio frequency microsystem according to claim 1, characterized in that: The sealing rubber head (15) abuts against the connection between the upper SiP (3) and the lower SiP (4); when the cover (2) is installed, the cover (2) drives the sealing block (12) to be pressed into the interior of the packaging box (1), so that the sealing block (12) drives the top plate (13) to seal the connection end between the upper SiP (3) and the lower SiP (4).

Images