Modular millimeter wave radar radio frequency chip with off-chip storage unit

Abstract

The invention provides a modular millimeter wave radar radio frequency chip with an off-chip storage unit, and belongs to the technical field of millimeter wave radar chips. The modular millimeter-wave radar radio frequency chip comprises a radio frequency circuit unit, a radio frequency antenna unit, an off-chip storage unit and a chip package, the radio frequency antenna unit is stacked on the radio frequency circuit unit and the off-chip storage unit, the off-chip storage unit is connected with the radio frequency circuit unit, and the radio frequency antenna unit is connected with the radio frequency circuit unit; the radio frequency circuit unit, the radio frequency antenna unit and leads among the units are all sealed in the chip package, and solder balls used for connecting the radio frequency antenna unit and the radio frequency circuit unit are exposed out of the chip package. According to the invention, while the integration level of the millimeter-wave radar radio frequency chip is improved, the diversified preparation requirements of the millimeter-wave radar chip for the storage capacity are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of millimeter wave radar chips, and in particular relates to a modular millimeter wave radar radio frequency chip with an off-chip storage unit. Background Art

[0002] With the development of new energy vehicles, millimeter-wave radar technology has been widely used. Millimeter-wave radar chips are mainly used in scenarios such as front radar and corner radar for vehicle external perception, and cabin personnel status monitoring.

[0003] With the rise of 4D radar technology, the resolution, detection distance and computational complexity of millimeter-wave radar have been further improved, and traditional MCUs have been unable to meet the computing requirements of complex algorithms of on-chip systems.

[0004] In order to improve the integration of radar chips, there is a solution that uses SoC+MMIC chip and on-chip antenna method, so that a single chip can integrate radar algorithms and RF transmission functional units.

[0005] In order to improve the computing power of a single chip, there is a plan to use an integrated CPU to replace the original MCU computing unit to further improve the computing power of the radar module.

[0006] However, the storage units (such as DDR, FLASH) of the above solutions are generally in the form of external plug-ins, and the storage space needs to be expanded through a DRAM bus controller, an SPI interface or an eMMC interface.

[0007] The existing method of integrating DRAM and FLASH storage units on-chip can improve the integration of radar chips, but the capacity of DRAM and FLASH is generally determined when the chip is taped out. It is difficult to meet the personalized needs of different types of millimeter-wave radar chips for different DRAM capacities and FLASH storage spaces in the board-level circuit production process. There is a contradiction between high integration and personalized customization. Summary of the invention

[0008] In order to solve the problems in the prior art, the present invention proposes a modular millimeter wave radar radio frequency chip with an off-chip storage unit.

[0009] The technical solution proposed by the present invention is as follows:

[0010] On the one hand, the present invention proposes a modular millimeter wave radar radio frequency chip with an off-chip storage unit, including a radio frequency circuit unit, a radio frequency antenna unit, an off-chip storage unit and a chip package;

[0011] The radio frequency circuit unit and the off-chip storage unit are located in the same plane, the radio frequency antenna unit is stacked on the radio frequency circuit unit and the off-chip storage unit, and the off-chip storage unit and the radio frequency circuit unit, as well as the radio frequency antenna unit and the radio frequency circuit unit are electrically interconnected through leads;

[0012] The radio frequency circuit unit, the radio frequency antenna unit and the leads between the units are all sealed in the chip package; the leads between the off-chip storage unit and the radio frequency circuit unit, one end of which is connected to the off-chip storage unit and extends out of the chip package;

[0013] The off-chip storage unit adopts a double-sided chip, with pads on the front and back sides, each pad having a solder ball, and the front pads are connected to the leads extending out of the chip package through the solder balls; the radio frequency circuit unit is electrically connected to the external PCB substrate, and a plurality of pads with non-blocked disk holes are arranged at positions corresponding to the pads on the back side of the off-chip storage unit on the PCB substrate, and the pads with non-blocked disk holes are fixedly connected to the pads on the back side of the off-chip storage unit through solder balls.

[0014] On the other hand, the present invention proposes a method for assembling the above modular millimeter wave radar radio frequency chip, comprising:

[0015] According to the circuit design of the millimeter wave radar radio frequency chip, the radio frequency circuit unit, the radio frequency antenna unit, and a plurality of off-chip storage units of different capacities are prepared respectively;

[0016] The radio frequency circuit unit and the radio frequency antenna unit are connected by wires, and a wire for connecting an off-chip storage unit is provided on the radio frequency circuit unit;

[0017] The radio frequency circuit unit, the radio frequency antenna unit and the lead are sealed in a chip package, and one end of the lead used for connecting the off-chip storage unit is extended out of the chip package;

[0018] Printing solder balls on the front pads of the off-chip storage unit and on the pads of the PCB substrate used for connecting the radio frequency circuit unit and the off-chip storage unit;

[0019] Select an off-chip storage unit of appropriate capacity according to the requirements, arrange the RF circuit unit and the off-chip storage unit on the same plane on the PCB substrate, and stack the RF antenna unit on the RF circuit unit and the off-chip storage unit;

[0020] Reflow soldering is performed, during which the solder balls melt, wherein the solder balls on the back of the off-chip storage unit flow into the back of the PCB substrate through the non-blocked plate holes, and the solder balls on the front of the off-chip storage unit fix the off-chip storage unit under the radio frequency antenna unit through surface tension;

[0021] The reflow temperature is lowered to solidify the solder balls, thereby forming a fixed connection between the RF circuit unit, the RF antenna unit, the off-chip storage unit, and the PCB substrate.

[0022] The present invention has the following beneficial effects:

[0023] The solution described in the present invention is mainly aimed at the millimeter-wave radar chip that integrates RF transmission and SoC computing. It adopts modular off-chip storage and modularly splits the SoC computing and storage (RAM, ROM) parts according to specific stacking and production and processing methods to achieve high integration of radar chips and replaceable capacity storage units without increasing the PCB layout area. While improving the integration of the next generation of millimeter-wave radar chips, this solution can also determine different capacities of RAM (such as DDR) and ROM (such as FLASH) space according to different needs in the production process, further improving the flexibility of chip manufacturing and production links, and meeting the diverse preparation needs of millimeter-wave radar chips for storage capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of modular stacking of the millimeter wave radar radio frequency chip of the present invention;

[0025] Figure 2 This is a schematic diagram of the modular production and processing of the millimeter wave radar radio frequency chip of the present invention;

[0026] Figure 3 This is a schematic diagram of the non-blocked disk hole set during the production and processing of the millimeter wave radar radio frequency chip of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described and illustrated below in conjunction with specific embodiments. The embodiments are merely exemplary of the present disclosure and do not define the scope of limitation. The technical features of each embodiment of the present invention may be combined accordingly without conflicting with each other.

[0028] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The present invention provides a modular millimeter wave radar radio frequency chip with an off-chip storage unit, comprising a radio frequency circuit unit, a radio frequency antenna unit, an off-chip storage unit and a chip package;

[0031] The radio frequency circuit unit is specifically a monolithic microwave integrated circuit (MMIC) chip;

[0032] The radio frequency antenna unit is connected to the radio frequency circuit unit through a lead wire;

[0033] The off-chip storage unit includes a read-only memory (ROM) module and a random access memory (RAM) module, which are connected to the radio frequency circuit unit through leads;

[0034] Chip packaging is used to package radio frequency circuit units and radio frequency antennas.

[0035] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] A modular millimeter wave radar RF chip with an off-chip storage unit, such as Figure 1 As shown, it includes a radio frequency circuit unit 1, a radio frequency antenna unit 2, an off-chip storage unit and a chip package 5. The radio frequency circuit unit 1 specifically adopts an MMIC chip for realizing calculation; the radio frequency antenna unit 2 and the off-chip storage unit 3 are both connected to the radio frequency circuit unit 1 through metal leads, and the radio frequency antenna unit 2 is used to realize the sending and receiving of radio frequency signals in the chip circuit; the off-chip storage unit is used to realize the data storage function of the chip circuit, including a ROM module 3 (such as DDR) and a RAM (such as FLASH) module 4; the chip package 5 is used to encapsulate the radio frequency circuit unit 1 and the radio frequency antenna unit 2, and the off-chip storage unit is arranged outside the chip package 5, so as to facilitate the replacement of the storage unit after tape-out.

[0037] The RF antenna unit 2 exists in the form of an on-chip integrated antenna. The RF circuit unit 1 and the RF antenna unit 2 are arranged in an upper and lower stack, the chip area occupied by the RF antenna unit 2 is recorded as A, and the area occupied by the RF circuit unit 1 is recorded as B, and the area A is larger than the area B. The RF circuit unit 1 and the RF antenna unit 2 are separated by a metal substrate 6. The metal substrate 6 serves as a shielding layer to prevent the RF circuit unit 1 from generating unnecessary RF radiation interference to the RF antenna unit 2. The area of ​​the metal substrate 6 is slightly larger than the area of ​​the RF antenna unit 2.

[0038] The chip package 5 contains a radio frequency circuit unit 1, a radio frequency antenna unit 2 and a metal substrate 6 therebetween. Since the chip area A occupied by the radio frequency antenna unit 2 is larger than the chip area B occupied by the radio frequency circuit unit 1, there is a gap in the lower half of the chip package 5. The gap is located on both sides of the radio frequency circuit unit 1. The ROM module 3 and the RAM module 4 are respectively arranged in the packaging gaps on both sides of the radio frequency circuit unit 1. The radio frequency circuit unit 1, the ROM module 3 and the RAM module 4 are located on the same plane.

[0039] The ROM module 3 and the RAM module 4 are both designed as replaceable modules, wherein the chip area occupied by the ROM module 3 is recorded as C, the chip area occupied by the RAM module 4 is recorded as D, and the sum of the areas of B, C and D is the chip area of ​​the modular millimeter wave radar radio frequency chip of the present invention. The ROM module 3 and the RAM module 4 are located under the radio frequency antenna unit 2. The ROM module 3, the RAM module 4 and the radio frequency circuit unit 1 are electrically connected to the PCB substrate through BGA solder balls.

[0040] Furthermore, both the ROM module 3 and the RAM module 4 are double-sided chips, and both the upper and lower surfaces are provided with pads that are conductive to their internal circuits. The pads on the lower surface are electrically connected to the PCB substrate through BGA solder balls, and such BGA solder balls on the lower surface mainly play an auxiliary supporting role; the pads on the upper surface are electrically connected to the RF circuit unit 1 through BGA solder balls and metal leads for power supply and high-speed signal connection. The leads for electrical connection between the ROM module 3, the RAM module 4 and the RF circuit unit 1 are sealed in the chip package 5 to prevent problems such as loose leads and poor contacts from affecting circuit performance; however, the BGA solder balls on the upper surfaces of the ROM module 3 and the RAM module 4 are exposed outside the chip package 5, which facilitates the realization of the replaceable function of the off-chip storage unit.

[0041] Furthermore, in order to reduce the difficulty of soldering, solder pads with non-blocking holes in the disk are provided at positions corresponding to the solder pads on the lower surfaces of the ROM module 3 and the RAM module 4 on the PCB substrate, such as Figure 3 The ROM module 3 and the RAM module 4 are fixed on the PCB substrate by connecting the pads with the non-blocked plate holes and the corresponding pads on the off-chip storage unit through BGA solder.

[0042] Based on the above scheme, in response to the needs of diversified millimeter-wave radar RF chips with different storage capacities, the design scheme of the present invention can simplify the chip preparation process, reduce the preparation cost, and significantly improve the efficiency of millimeter-wave radar RF chip preparation.

[0043] The method for assembling the modular millimeter wave radar radio frequency chip with an off-chip storage unit comprises the following steps:

[0044] According to the circuit design of the millimeter wave radar RF chip, the RF circuit unit 1, the RF antenna unit 2, the metal substrate 6 and a plurality of off-chip storage units of different capacities are prepared respectively; the off-chip storage units of different capacities are matched with the RF circuit unit 1 and the RF antenna unit 2 to meet the diversified requirements of chip storage capacity in different usage scenarios;

[0045] The radio frequency circuit unit 1 and the radio frequency antenna unit 2 are connected by wires, and a wire for connecting an off-chip storage unit is provided on the radio frequency circuit unit 1;

[0046] The radio frequency circuit unit 1, the radio frequency antenna unit 2, the metal substrate 6 and the lead wire are sealed in the chip package 5, and one end of the lead wire used for connecting the off-chip storage unit is extended out of the chip package 5; the off-chip storage unit is not included in the package to facilitate replacement;

[0047] Printing solder balls on the front pads of the off-chip storage unit and on the pads of the PCB substrate used for connecting the radio frequency circuit unit 1 and the off-chip storage unit;

[0048] Select an off-chip storage unit of appropriate capacity according to the requirements, arrange the RF circuit unit 1 and the off-chip storage unit on the same plane on the PCB substrate, and stack the RF antenna unit 2 on the RF circuit unit 1 and the off-chip storage unit;

[0049] Reflow soldering is performed. During the reflow soldering process, the solder balls melt, and the solder balls on the back of the off-chip memory unit flow into the back of the PCB substrate through the non-blocked plate holes, such as Figure 2 As shown, the solder ball on the front side of the off-chip storage unit suspends and fixes the off-chip storage unit below the radio frequency antenna unit 2 through the surface tension;

[0050] The reflow temperature is lowered to solidify the solder balls, and the RF circuit unit 1, the RF antenna unit 2, the off-chip storage unit, and the PCB substrate are solidified to form a whole, and are tested to be able to work normally.

[0051] Based on the above method, the present invention modularizes the SoC computing part and the storage (RAM, ROM) part for the millimeter-wave radar chip that integrates the radio frequency signal transmission function and the SoC computing function. In the production process, different capacities of RAM and ROM space can be determined according to the requirements of different types of chips, thereby further improving the flexibility of chip manufacturing and production links and meeting diverse customer needs.

[0052] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A modular millimeter wave radar radio frequency chip with an off-chip storage unit, characterized in that: It includes a radio frequency circuit unit, a radio frequency antenna unit, an off-chip storage unit and a chip package; The radio frequency circuit unit and the off-chip storage unit are located in the same plane, the radio frequency antenna unit is stacked on the radio frequency circuit unit and the off-chip storage unit, and the off-chip storage unit and the radio frequency circuit unit, as well as the radio frequency antenna unit and the radio frequency circuit unit are electrically interconnected through leads; The radio frequency circuit unit, the radio frequency antenna unit and the leads between the units are all sealed in the chip package; the leads between the off-chip storage unit and the radio frequency circuit unit, one end of which is connected to the off-chip storage unit and extends out of the chip package; The off-chip storage unit adopts a double-sided chip, with pads on the front and back sides, each pad having a solder ball, and the front pads are connected to the leads extending out of the chip package through the solder balls; the radio frequency circuit unit is electrically connected to the external PCB substrate, and a plurality of pads with non-blocked disk holes are arranged at positions corresponding to the pads on the back side of the off-chip storage unit on the PCB substrate, and the pads with non-blocked disk holes are fixedly connected to the pads on the back side of the off-chip storage unit through solder balls.

2. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: The off-chip storage unit includes a ROM module and a RAM module, and the ROM module and the RAM module are respectively arranged on both sides of the radio frequency circuit unit.

3. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: The non-blocked plate hole is used to make the solder balls between the non-blocked plate hole and the back pad of the off-chip storage unit flow into the back of the PCB substrate through capillary action during the reflow soldering process of the radio frequency chip, thereby fixing the off-chip storage unit and the PCB substrate.

4. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: The radio frequency circuit unit adopts an MMIC chip.

5. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: On the PCB substrate, the area occupied by the radio frequency antenna unit is larger than the area occupied by the radio frequency circuit unit.

6. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: A metal substrate is provided between the radio frequency circuit unit and the radio frequency antenna unit to prevent the radio frequency circuit unit from generating radio frequency radiation interference to the radio frequency antenna unit.

7. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: The area of ​​the metal substrate is larger than the area of ​​the radio frequency antenna unit.

8. The modular millimeter wave radar radio frequency chip with an off-chip storage unit according to claim 1, characterized in that: The metal substrate is sealed in the chip package.

9. A method for assembling the modular millimeter wave radar radio frequency chip according to claim 1, characterized in that: Methods include: According to the circuit design of the millimeter wave radar radio frequency chip, the radio frequency circuit unit, the radio frequency antenna unit, and a plurality of off-chip storage units of different capacities are prepared respectively; The radio frequency circuit unit and the radio frequency antenna unit are connected by wires, and a wire for connecting an off-chip storage unit is provided on the radio frequency circuit unit; The radio frequency circuit unit, the radio frequency antenna unit and the lead are sealed in a chip package, and one end of the lead used for connecting the off-chip storage unit is extended out of the chip package; Printing solder balls on the front pads of the off-chip storage unit and on the pads of the PCB substrate used for connecting the radio frequency circuit unit and the off-chip storage unit; Select an off-chip storage unit of appropriate capacity according to the requirements, arrange the RF circuit unit and the off-chip storage unit on the same plane on the PCB substrate, and stack the RF antenna unit on the RF circuit unit and the off-chip storage unit; Reflow soldering is performed, during which the solder balls melt, wherein the solder balls on the back of the off-chip storage unit flow into the back of the PCB substrate through the non-blocked plate holes, and the solder balls on the front of the off-chip storage unit fix the off-chip storage unit under the radio frequency antenna unit through surface tension; The reflow temperature is lowered to solidify the solder balls, thereby forming a fixed connection between the RF circuit unit, the RF antenna unit, the off-chip storage unit, and the PCB substrate.

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