Three-dimensional heterogeneous integrated millimeter wave system packaging structure

Abstract

The invention belongs to the technical field of chip packaging, and particularly relates to a three-dimensional heterogeneous integrated millimeter wave system packaging structure which comprises an upper-layer antenna plate and a lower-layer carrier plate, a millimeter wave chip is installed in a groove formed in the bottom of the lower-layer carrier plate, a heat distribution chip is connected to the bottom surface of the millimeter wave chip through small solder balls, and the heat distribution chip is connected with a PCB assembly through small solder balls. No chip is installed in the upper-layer antenna board, and a main control chip and a front-end chip are integrated in the lower-layer support board. On the basis of the heating problem easily caused by the fact that too many chips are integrated on the lower-layer carrier plate, active devices in the front-end chips which are seriously heated are transferred to the heat distribution chips, so that the working heat of the lower-layer carrier plate is dispersed while the size of the front-end chips is reduced, and the heat is prevented from being gathered on the lower-layer carrier plate; the lower carrier plate and the PCB assembly are connected through the small solder balls with small sizes, so that the shortest interconnection distance is achieved, the influence of transmission mode changes on the transmission rate is reduced, and the data transmission speed of a radio frequency system is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of chip packaging, and in particular relates to a three-dimensional heterogeneous integrated millimeter wave system packaging structure. Background Art

[0002] With the rapid development of the fifth generation mobile communication technology (5G), the widely used spectrum below 6GHz can no longer meet people's demand for higher data rates. The millimeter wave (mmW) band can provide a wider absolute frequency bandwidth, which is very attractive for ultra-high data rate applications.

[0003] In order to meet the current requirements of high integration, low loss and high reliability of radio frequency systems, millimeter wave system modules are usually integrated and packaged. For example, the patent with publication number CN116895614A embeds the silicon-based millimeter wave chip into the core layer of the lower chip carrier, so there is no need to dig a cavity for the upper antenna board. To solve the problem of low yield and high cost of multi-chip packaging: the package is divided into an integrated antenna without a chip in the upper part and a multi-module packaging substrate with a chip in the lower part. When a chip is detected to have a problem, only the module with the problem needs to be replaced without replacing the entire package. Since the main control chip and the front-end chip are embedded in the lower carrier board, this method will cause the lower carrier board to integrate too many chips, resulting in serious heating of the lower carrier board, which is easy to cause the lower carrier board to accumulate high temperature, resulting in the PCB board transmitting data to the upper antenna board through the chip of the lower carrier board. The speed is reduced. Summary of the invention

[0004] The purpose of the present invention is to provide a three-dimensional heterogeneous integrated millimeter wave system packaging structure to address the deficiencies in the prior art and to solve the technical problems in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions: a three-dimensional heterogeneous integrated millimeter wave system packaging structure, including an upper antenna board and a lower carrier board, the upper antenna board and the lower carrier board are connected by conventional solder balls, the bottom of the lower carrier board is grooved to install a millimeter wave chip, the bottom surface of the millimeter wave chip is connected to a heat distribution chip by small solder balls, the heat distribution chip is connected to a PCB assembly by small solder balls, no chip is installed inside the upper antenna board, and a main control chip and a front-end chip are integrated in the lower carrier board, wherein the active devices in the front-end chip are transferred to the heat distribution chip; A heat dissipation frame is installed between the PCB assembly and the lower carrier board. The heat dissipation frame encapsulates the heat distribution chip therein. A heat dissipation component is installed on the heat dissipation frame. The heat dissipation component includes micro copper tubes. The micro copper tubes are arranged around the heat distribution chip.

[0006] As a further optimization or improvement of the present solution, the heat dissipation assembly also includes a pipe head, which is connected to the shunt pipe. A connecting pipe is installed on the shunt pipe, and the connecting pipe is connected to the micro copper tube. The pipe head is connected to the cold air pipe. A vent is opened on the shunt pipe. The shunt pipe is connected to a connecting hose through the vent. An air intake pipe with an adjustable angle is installed on the connecting hose.

[0007] As a further optimization or improvement of the present solution, a piston block is installed inside the connecting pipe, and the piston block is connected to the intake pipe via a connecting rod.

[0008] As a further optimization or improvement of the present solution, a movable ball head is installed inside the heat dissipation frame, and an air intake pipe is installed inside the movable ball head.

[0009] As a further optimization or improvement of the present solution, a flow limiting block is installed inside the diverter pipe, a connecting shaft is slidably installed inside the flow limiting block, the connecting shaft is connected to the inner wall of the flow limiting block through a reset spring, a flow limiting plate is rotatably installed on the connecting shaft, one end of the flow limiting plate blocks the vent, the piston block is connected to the push rod through the connecting block, and the push rod passes through the diverter pipe and the flow limiting block respectively to push the connecting shaft.

[0010] As a further optimization or improvement of the present solution, the PCB assembly includes a PCB board and a packaging bar and a connecting device mounted thereon, the packaging bar is cooperatively connected to the heat dissipation frame, and the heat distribution chip is connected to the connecting device via small solder balls.

[0011] As a further optimization or improvement of this solution, the connecting hose is respectively installed at the upper and lower ends of the diversion pipe, and the air inlet pipe is respectively directed toward the cavity connecting the heat distribution chip and the lower carrier board and the cavity connecting the heat distribution chip and the PCB assembly.

[0012] Beneficial effects of the present invention: (1) Based on the problem of heating caused by too many chips integrated on the lower carrier, the present invention transfers the active devices in the front-end chip with serious heat generation to the heat distribution chip, thereby reducing the volume of the front-end chip and dispersing the working heat of the lower carrier to avoid heat accumulation on the lower carrier; Since the active devices of the front-end chip are transferred to the heat-distribution chip, the original single-stage transfer method of the PCB board through the lower carrier board is transformed into a multi-stage transfer method of the PCB board through the heat-distribution chip and the lower carrier board. This solution connects the lower carrier board and the PCB assembly through small-sized solder balls to achieve the shortest interconnection distance, thereby obtaining better high-frequency electrical performance, reducing the impact of changes in the transmission method on the transmission rate, and ensuring the data transmission speed of the RF system.

[0013] (2) When the heat dissipation chip is in normal operation, the heat of the heat dissipation chip is absorbed by the micro copper tube, and the area where the heat dissipation chip is connected to the lower carrier board and PCB components, that is, the location of the small solder balls, is cooled by external cold air to avoid local overheating of the small solder balls; When the heat splitter chip operates at high frequency, the heat generation speed of the heat splitter chip is greater than the conduction speed of the micro copper tube. The increased air pressure in the internal cavity of the micro copper tube pushes the piston block to move outward, and the piston block drives the air intake pipe to rotate toward the position of the heat splitter chip through the connecting rod. At the same time, the piston block pushes the connecting shaft to move through the push rod. The connecting shaft moves and cooperates with the air pressure of the cold air to drive the limiting plate to rotate, so that the limiting plate is separated from the blockage of the vent, increasing the air intake of cold air, so that the cold air is mainly blown toward the position of the heat splitter chip, increasing the heat dissipation efficiency of the heat splitter chip, and ensuring the efficiency of the heat splitter chip under high-frequency operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is an exploded view of the overall structure of the present invention.

[0017] Figure 3 It is a cross-sectional view of the overall structure of the present invention.

[0018] Figure 4 for Figure 3 Schematic diagram of the structure of part A.

[0019] Figure 5 Schematic diagram of the internal structure of the heat dissipation frame.

[0020] Figure 6 for Figure 5 Schematic diagram of the structure of part B.

[0021] Figure 7 for Figure 6 Schematic diagram of the C-site structure.

[0022] The following are marked in the figure: 1. PCB assembly; 101. Packaging strip; 102. Connecting device; 103. PCB board; 2. Upper antenna board; 3. Lower carrier board; 4. Conventional solder balls; 5. Heat dissipation frame; 6. Heat dissipation assembly; 601. Micro copper tube; 602. Connecting tube; 603. Tube head; 604. Diverter tube; 605. Connecting hose; 606. Active ball head; 607. Intake pipe; 608. Piston block; 609. Connecting rod; 610. Connecting block; 611. Push rod; 612. Current limiting block; 613. Coupling; 614. Current limiting plate; 615. Vent; 616. Reset spring; 7. Heat dissipation chip; 8. Small solder balls; 9. Millimeter wave chip. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1-Figure 5 , a three-dimensional heterogeneous integrated millimeter wave system packaging structure, which includes an upper antenna board 2 and a lower carrier board 3, the upper antenna board 2 and the lower carrier board 3 are connected by conventional solder balls 4, the bottom of the lower carrier board 3 is grooved to install a millimeter wave chip 9, the bottom surface of the millimeter wave chip 9 is connected to a heat distribution chip 7 through a small solder ball 8, the heat distribution chip 7 is connected to a PCB component 1 through the small solder ball 8, no chip is installed inside the upper antenna board 2, the lower carrier board 3 is integrated with a main control chip and a front-end chip, wherein the active devices in the front-end chip are transferred to the heat distribution chip 7; A heat dissipation frame 5 is installed between the PCB assembly 1 and the lower carrier board 3 , and the heat dissipation frame 5 encapsulates the heat distribution chip 7 therein. A heat dissipation component 6 is installed on the heat dissipation frame 5 , and the heat dissipation component 6 includes micro copper tubes 601 , which are arranged around the heat distribution chip 7 .

[0025] Specifically, the PCB assembly 1 includes a PCB board 103 and a packaging strip 101 and a connecting device 102 mounted thereon. The packaging strip 101 is cooperatively connected to the heat dissipation frame 5 , and the heat distribution chip 7 is connected to the connecting device 102 via a small solder ball 8 .

[0026] It should be noted that the upper antenna board 2 of the millimeter wave system packaging structure of the prior art is chipless installation, and the main control chip and the front-end chip in the radio frequency system are mainly embedded and installed in the lower carrier board 3 by slotting on the lower carrier board 3; Based on the heating problem easily caused by integrating too many chips on the lower carrier board 3, the present invention transfers active devices such as high-power amplifiers, power limiters and low-noise signal amplifiers in the front-end chip with serious heat generation to the heat-sharing chip 7, thereby reducing the volume of the front-end chip and dispersing the working heat of the lower carrier board 3. Since the active devices of the front-end chip are transferred to the heat-sharing chip 7, the original single-stage transfer mode of the PCB board 103 through the lower carrier board 3 is converted into a multi-stage transfer mode of the PCB board 103 through the heat-sharing chip 7 and the lower carrier board 3. This solution connects the lower carrier board 3 and the PCB assembly 1 through small solder balls 8 of small size solder balls to achieve the shortest interconnection distance, thereby obtaining more excellent high-frequency electrical performance and reducing the influence of changes in the transfer mode on the transfer rate.

[0027] It should be noted that the upper antenna board 2 and the lower carrier board 3 are made of multiple layers of thick silicon wafers combined through a wafer-level gold hot-pressing bonding process. Each layer of silicon wafer has a gold-plated layer on the upper and lower surfaces. The bottom two layers of silicon wafers inside the lower carrier board 3 are used as secondary wiring layers and chip carrier layers. The passive devices of the front-end chip are integrated between the two layers of silicon wafers, such as stripline filters, Wilkinson power dividers, couplers, resistors, capacitors, etc.

[0028] See also Figure 2-Figure 7 The heat dissipation component 6 also includes a pipe head 603, which is connected to a shunt pipe 604. A connecting pipe 602 is installed on the shunt pipe 604. The connecting pipe 602 is connected to the micro copper tube 601. The pipe head 603 is connected to the cold air pipe. A vent 615 is provided on the shunt pipe 604. The shunt pipe 604 is connected to a connecting hose 605 through the vent 615. An air intake pipe 607 with an adjustable angle is installed on the connecting hose 605.

[0029] Specifically, a piston block 608 is installed inside the connecting pipe 602 , and the piston block 608 is connected to the intake pipe 607 via a connecting rod 609 .

[0030] Specifically, a movable ball head 606 is installed inside the heat dissipation frame 5 , and an air intake pipe 607 is installed inside the movable ball head 606 .

[0031] Specifically, a flow limiting block 612 is installed inside the diverter pipe 604, a connecting shaft 613 is slidably installed inside the flow limiting block 612, the connecting shaft 613 is connected to the inner wall of the flow limiting block 612 through a reset spring 616, a flow limiting plate 614 is rotatably installed on the connecting shaft 613, one end of the flow limiting plate 614 blocks the air vent 615, the piston block 608 is connected to the push rod 611 through the connecting block 610, and the push rod 611 passes through the diverter pipe 604 and the flow limiting block 612 respectively to push the connecting shaft 613.

[0032] It should be noted that larger solder balls, due to their larger surface area, can dissipate heat more effectively, which helps to reduce the operating temperature of the chip, thereby maintaining the stability of signal transmission. Since the heat-distributing chip 7 uses small solder balls 8 to connect the lower carrier board 3 and the PCB assembly 1, compared with larger solder balls, smaller solder balls 8 may cause local overheating during application, affecting chip performance and life.

[0033] After the main heat-generating active devices are transferred to the heat-sharing chip 7, the working heat of the lower carrier 3 approaches equilibrium. Even under high-frequency operation, the temperature fluctuation of the lower carrier 3 will not be large. Therefore, only the heat dissipation problem of the heat-sharing chip 7 and the small solder balls 8 thereon needs to be considered.

[0034] Under normal operation, the heat of the heat dissipation chip 7 is absorbed by the micro copper tube 601, and the area where the heat dissipation chip 7 is connected with the lower carrier board 3 and the PCB assembly 1, that is, the location of the small solder ball 8, is cooled by external cold air to avoid local overheating of the small solder ball 8; Specifically, when the heat-dividing chip 7 is in normal operation, cold air enters the shunt pipe 604 through the pipe head 603, and then the shunt pipe 604 transports the cold air from the active ball head 606 toward the small solder ball 8 to dissipate heat for the small solder ball 8 to prevent local overheating of the small solder ball 8. At this time, the working heat of the heat-dividing chip 7 can be effectively conducted through the micro copper tube 601, and then the heat dissipation frame 5 conducts the heat outward to prevent the heat-dividing chip 7 from overheating. At the same time, when the heat-dividing chip 7 is in normal operation, see Figure 7 The flow limiting plate 614 will partially block the vent 615 to limit the delivery of cold air, thereby avoiding condensation on the heat dissipation frame 5 due to excessive cold air delivery leading to a large temperature difference between the inside and outside of the heat dissipation frame 5.

[0035] When the heat splitter chip 7 is in high-frequency operation, the heat generation speed of the heat splitter chip 7 is greater than the conduction speed of the micro copper tube 601. At this time, the air pressure in the internal cavity of the micro copper tube 601 increases dramatically. The internal air pressure of the micro copper tube 601 pushes the piston block 608 to move outward through the connecting tube 602. The piston block 608 drives the air inlet pipe 607 to rotate toward the position of the heat splitter chip 7 through the connecting rod 609. At the same time, the piston block 608 pushes the connecting shaft 613 to move through the push rod 611. The connecting shaft 613 moves and cooperates with the air pressure of the cold air to drive the limiting plate 614 to rotate, so that the limiting plate 614 is separated from the blockage of the vent 615, increasing the air intake of the cold air, so that the cold air is mainly blown toward the position of the heat splitter chip 7, increasing the heat dissipation efficiency of the heat splitter chip 7, and ensuring the efficiency of the heat splitter chip 7 under high-frequency operation.

[0036] See also Figure 5 The connecting hose 605 is respectively installed at the upper and lower ends of the shunt pipe 604, and the air inlet pipe 607 is respectively directed to the cavity where the heat distribution chip 7 is connected to the lower carrier board 3 and the cavity where the heat distribution chip 7 is connected to the PCB assembly 1.

[0037] It should be noted that after the heat splitter chip 7 is installed in the heat dissipation frame 5, the interior of the heat splitter chip 7 is divided into two cavities by the heat dissipation frame 5, namely the upper cavity connecting the heat splitter chip 7 and the lower carrier board 3 and the lower cavity connecting the heat splitter chip 7 and the PCB assembly 1.

[0038] The pipe heads 603 on both sides of the heat dissipation frame 5 are respectively the air inlet and the air outlet. The cold air passes through the pipe head 603, the shunt pipe 604 and the air inlet pipe 607 on one side of the heat dissipation frame 5 and enters the upper and lower cavities respectively, and is discharged by the pipe head 603 on the other side of the heat dissipation frame 5, so as to realize the cooling of the connection parts between the heat distribution chip 7 and the lower carrier board 3 and the connection parts between the heat distribution chip 7 and the PCB assembly 1 through this circulation.

[0039] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates 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 three-dimensional heterogeneous integrated millimeter wave system packaging structure, characterized by: The invention comprises an upper antenna board (2) and a lower carrier board (3), wherein the upper antenna board (2) and the lower carrier board (3) are connected via conventional solder balls (4), a millimeter wave chip (9) is installed on the bottom of the lower carrier board (3) through a groove, a heat distribution chip (7) is connected to the bottom surface of the millimeter wave chip (9) via small solder balls (8), the heat distribution chip (7) is connected to a PCB component (1) via the small solder balls (8), no chip is installed inside the upper antenna board (2), a main control chip and a front-end chip are integrated inside the lower carrier board (3), and active devices in the front-end chip are transferred to the heat distribution chip (7); A heat dissipation frame (5) is installed between the PCB component (1) and the lower carrier board (3), the heat dissipation frame (5) encapsulating the heat distribution chip (7) therein, and a heat dissipation component (6) is installed on the heat dissipation frame (5), the heat dissipation component (6) comprising micro copper tubes (601), and the micro copper tubes (601) are arranged around the heat distribution chip (7).

2. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 1, characterized in that: The heat dissipation component (6) further comprises a pipe head (603), the pipe head (603) being in communication with the shunt pipe (604), a connecting pipe (602) being installed on the shunt pipe (604), the connecting pipe (602) being in communication with the micro copper pipe (601), the pipe head (603) being connected to a cold air pipe, a vent (615) being provided on the shunt pipe (604), the shunt pipe (604) being connected to a connecting hose (605) via the vent (615), and an air intake pipe (607) having an adjustable angle being installed on the connecting hose (605).

3. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 2, characterized in that: A piston block (608) is installed inside the connecting pipe (602), and the piston block (608) is connected to the air intake pipe (607) via a connecting rod (609).

4. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 1, characterized in that: A movable ball head (606) is installed inside the heat dissipation frame (5), and an air intake pipe (607) is installed inside the movable ball head (606).

5. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 3, characterized in that: A flow limiting block (612) is installed inside the flow dividing pipe (604), a connecting shaft (613) is slidably installed inside the flow limiting block (612), the connecting shaft (613) is connected to the inner wall of the flow limiting block (612) via a return spring (616), a flow limiting plate (614) is rotatably installed on the connecting shaft (613), one end of the flow limiting plate (614) blocks the vent (615), the piston block (608) is connected to the push rod (611) via the connecting block (610), and the push rod (611) respectively penetrates the flow dividing pipe (604) and the flow limiting block (612) to push the connecting shaft (613).

6. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 1, characterized in that: The PCB assembly (1) comprises a PCB board (103) and a packaging strip (101) and a connecting device (102) mounted thereon; the packaging strip (101) is cooperatively connected to a heat dissipation frame (5); and the heat distribution chip (7) is connected to the connecting device (102) via a small solder ball (8).

7. The three-dimensional heterogeneous integrated millimeter wave system packaging structure according to claim 2, characterized in that: The connecting hose (605) is respectively installed at the upper and lower ends of the flow distribution pipe (604), and the air inlet pipe (607) is respectively directed toward the cavity where the heat distribution chip (7) is connected to the lower carrier board (3) and the cavity where the heat distribution chip (7) is connected to the PCB assembly (1).

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