CN216055143U

CN216055143U - Radar chip flip-chip signal transmission structure

Info

Publication number: CN216055143U
Application number: CN202122609050.8U
Authority: CN
Inventors: 邓俊; 屈操; 吴楚; 刘建华
Original assignee: Wuxi Weifu High Technology Group Co Ltd
Current assignee: Wuxi Weifu High Technology Group Co Ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-03-15
Anticipated expiration: 2031-10-28

Abstract

The utility model provides a signal structure for flip-chip transmission of a radar chip, which comprises: the antenna comprises a radar chip, a first PCB, a second PCB, a radiation unit, a metal block and an antenna unit; the metal block comprises a column part and a flat part extending from the upper end of the column part to one side; one end of the second PCB and one end of the first PCB are respectively fixed with the upper end and the lower end of the metal block upright post part; the radar chip is welded on the lower surface of the first PCB in an inverted mode, the radar chip is connected with one end of a microstrip line arranged on the lower surface of the first PCB, and the other end of the microstrip line is connected with a gap arranged on the lower surface of the first PCB; a waveguide cavity is arranged in the upright post part of the metal block, a radiation unit is arranged on the upper surface of the first PCB at the lower end of the waveguide cavity, and the radiation unit corresponds to the gap; a gap is formed in the lower surface of a second PCB at the upper end of the waveguide cavity, and an antenna unit is arranged on the upper surface of the second PCB. The utility model can realize low-loss signal transmission.

Description

Radar chip flip-chip signal transmission structure

Technical Field

The utility model belongs to the technical field of microwave and millimeter wave communication, and particularly relates to a radar chip flip-chip signal transmission structure.

Background

With the wide application of wireless communication systems in the microwave and millimeter wave frequency band, the requirements of millimeter wave radar systems for small size, light weight, high integration level and good heat dissipation are becoming more and more severe. However, the imaging radar chip has many transceiving channels, high integration level, large power consumption and poor heat dissipation, so that the chip cannot work for a long time. The flip chip welding transmission signal can be realized by vertically punching on a PCB at present, but in a millimeter wave frequency band, the signal transmission capability through a vertical through hole is deteriorated along with the increase of the thickness of a laminated layer of the PCB. The quality of the via hole is directly related to the processing technology of the PCB factory. The loss introduced by the transmission of the signal through the via hole reduces the gain of the antenna, thereby reducing the detection performance of the millimeter wave radar.

Disclosure of Invention

Aiming at the defects in the prior art, the embodiment of the utility model provides a radar chip flip-chip signal transmission structure which can realize low-loss signal transmission. In order to achieve the technical purpose, the embodiment of the utility model adopts the technical scheme that:

the embodiment of the utility model provides a signal structure for flip-chip transmission of a radar chip, which comprises: the antenna comprises a radar chip, a first PCB, a second PCB, a radiation unit, a metal block and an antenna unit;

the metal block comprises a column part and a flat part extending from the upper end of the column part to one side;

one end of the second PCB and one end of the first PCB are respectively fixed with the upper end and the lower end of the metal block upright post part;

the radar chip is welded on the lower surface of the first PCB in an inverted mode, the radar chip is connected with one end of a microstrip line arranged on the lower surface of the first PCB, and the other end of the microstrip line is connected with a gap arranged on the lower surface of the first PCB;

a waveguide cavity is arranged in the upright post part of the metal block, and a radiation unit is arranged on the upper surface of the first PCB at the lower end of the waveguide cavity and corresponds to the gap; a gap is formed in the lower surface of the second PCB at the upper end of the waveguide cavity, an antenna unit is arranged on the upper surface of the second PCB, and the gap corresponds to the antenna unit.

Furthermore, a plurality of PCBs are arranged below the metal block flat part on the first PCB, and the PCBs and the first PCB form a laminated PCB; and a component mounting space is arranged between the laminated PCB and the metal block flat part.

Further, components are mounted on the top surface of the topmost layer of the stacked PCB.

Furthermore, the top surface of the metal block column part and the top surface of the flat part are the same plane; the second PCB board with the metal block stand portion closely laminates with flat portion top surface.

Further, the lower surface of first PCB board is equipped with the radiating block, the radar chip is arranged in the holding chamber of radiating block, and laminates with the radiating block through the heat conduction material.

Furthermore, a wave absorbing unit is arranged on one side of the antenna unit on the upper surface of the second PCB.

The technical scheme provided by the embodiment of the utility model has the following beneficial effects:

1) low loss transmission of radio frequency/microwave signals may be achieved through the waveguide cavity.

2) The structure can vertically transmit signals in a three-dimensional manner, is not limited by the thickness of a PCB (printed circuit board) and can reduce the layout size.

3) Compared with the layout that the radar chip and the antenna are arranged on the same plane, the structure can effectively reduce the radiation influence of the feeder line and the radar chip on the antenna.

4) The structure can ensure that the radar chip has good heat dissipation effect, and greatly prolongs the service life of the chip.

Drawings

Fig. 1 is a schematic structural diagram in an embodiment of the present invention.

Fig. 2 is an antenna pattern in an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

As shown in fig. 1, an embodiment of the present invention provides a signal structure for flip-chip transmission of a radar chip, including: the antenna comprises a radar chip 1, a first PCB, a second PCB, a radiation unit 7, a metal block 8 and an antenna unit 11;

in the structure shown in fig. 1, the first PCB comprises a 1 st dielectric substrate 13 and a metal layer 6 distributed on the upper and lower surfaces thereof; the second PCB comprises an n +1 dielectric substrate 18 and a metal layer 6 distributed on the lower surface of the substrate;

the metal block 8 comprises a column part 801 and a flat part 802 extending from the upper end of the column part 801 to one side;

one end of the second PCB and one end of the first PCB are respectively fixed with the upper end and the lower end of the upright part 801 of the metal block 8; in particular, it can be assembled and fixed by means of the bolt 12 shown in fig. 1;

the radar chip 1 is welded on the lower surface of the first PCB in an inverted mode, the radar chip 1 is connected with one end of a microstrip line 4 arranged on the lower surface of the first PCB, and the other end of the microstrip line 4 is connected with a gap 5 arranged on the lower surface of the first PCB; in fig. 1, solder balls 3 on a radar chip 1 are shown attached to the lower surface of a first PCB board when the chip is flip-chip bonded;

a waveguide cavity 9 is arranged in the upright column part 801 of the metal block 8, a radiation unit 7 is arranged on the upper surface of the first PCB at the lower end of the waveguide cavity 9, and the radiation unit 7 corresponds to the gap 5; a gap 10 is formed in the lower surface of a second PCB at the upper end of the waveguide cavity 9, an antenna unit 11 is arranged on the upper surface of the second PCB, and the gap 10 corresponds to the antenna unit 11;

in the above structure, the transmission process of the rf/microwave signal is as follows: radio frequency/microwave signals from a radar chip 11 on a first PCB are coupled to a radiation unit 7 through a microstrip line 4 and a gap 5, then pass through a waveguide cavity 9, and are coupled to an antenna unit 11 on a second PCB through a gap 10 to be transmitted to a space; the radiation unit 7 is used for converting the quasi-TEM fundamental wave transmitted on the microstrip line 4 into a TE10 fundamental wave which can be transmitted by the waveguide cavity;

preferably, a plurality of PCBs are arranged below the flat part 802 of the metal block 8 on the first PCB, and the plurality of PCBs and the first PCB form a stacked PCB; in the example shown in fig. 1, the plurality of PCB boards include a 2 nd dielectric substrate 15 and a metal layer 6 distributed on the upper and lower surfaces thereof, a third dielectric substrate 16 and a metal layer 6 … … nth dielectric substrate 17 distributed on the upper and lower surfaces thereof and a metal layer 6 distributed on the upper and lower surfaces thereof; the first PCB and the layers of the plurality of PCBs are combined through prepregs 14; the number of layers of the PCB boards can be determined according to actual requirements; a component mounting space is arranged between the laminated PCB and the flat part 802 of the metal block 8, and components are mounted on the upper surface of the topmost layer of the laminated PCB; the compactness of a signal structure of the radar chip flip transmission is improved by laminating the PCB;

preferably, the top surface of the metal block upright column part 801 and the top surface of the flat part 802 are the same plane; the second PCB board is closely attached to the top surfaces of the metal block upright part 801 and the flat part 802; the assembling firmness degree can be enhanced;

preferably, the lower surface of the first PCB is assembled with a heat dissipation block 20, and the radar chip 1 is located in the accommodating cavity of the heat dissipation block 20 and is attached to the heat dissipation block 20 through a heat conduction material 2; the heat dissipation block 20 can perform a good heat dissipation function on the radar chip 1 in operation; the heat conduction material 2 can be selected from heat conduction silicone grease or heat conduction paste;

preferably, a wave absorbing unit 19 is arranged on one side of the antenna unit 11 on the upper surface of the second PCB, and the wave absorbing unit 19 is used for absorbing interference of a reflected signal to the radar antenna; the wave absorbing unit 19 may specifically adopt a wave absorbing material or an artificial magnetic conductor structure with a wave absorbing effect.

As can be seen from the simulation result of fig. 2, the gain of the radar antenna with two rectangular patch units is about 11dBi, which indicates that the signal can be transmitted with low loss through the structure.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. A radar chip flip-chip signal transmission structure, comprising: the antenna comprises a radar chip (1), a first PCB, a second PCB, a radiation unit (7), a metal block (8) and an antenna unit (11);

the metal block (8) comprises a column part (801) and a flat part (802) extending from the upper end of the column part (801) to one side;

one end of the second PCB and one end of the first PCB are respectively fixed with the upper end and the lower end of the upright part (801) of the metal block (8);

the radar chip (1) is welded on the lower surface of the first PCB in an inverted mode, the radar chip (1) is connected with one end of a microstrip line (4) arranged on the lower surface of the first PCB, and the other end of the microstrip line (4) is connected with a gap (5) arranged on the lower surface of the first PCB;

a waveguide cavity (9) is arranged in the upright column part (801) of the metal block (8), a radiation unit (7) is arranged on the upper surface of the first PCB at the lower end of the waveguide cavity (9), and the radiation unit (7) corresponds to the gap (5); a gap (10) is formed in the lower surface of a second PCB at the upper end of the waveguide cavity (9), an antenna unit (11) is arranged on the upper surface of the second PCB, and the gap (10) corresponds to the antenna unit (11).

2. The radar chip flip-chip signal transmitting structure of claim 1,

a plurality of PCBs are arranged below the flat part (802) of the metal block (8) on the first PCB, and the PCBs and the first PCB form a laminated PCB; and a component mounting space is arranged between the laminated PCB and the flat part (802) of the metal block (8).

3. The radar chip flip-chip signal transmission structure of claim 2,

and components are assembled on the upper surface of the topmost layer of the laminated PCB.

4. The radar chip flip-chip signal transmitting structure of claim 1,

the top surface of the metal block upright column part (801) and the top surface of the flat part (802) are the same plane; the second PCB board is tightly attached to the top surfaces of the metal block upright part (801) and the flat part (802).

5. The radar chip flip-chip signal transmitting structure of claim 1,

the lower surface of first PCB board is equipped with radiating block (20), radar chip (1) is arranged in the holding chamber of radiating block (20), and laminates with radiating block (20) through heat conduction material (2).

6. The radar chip flip-chip signal transmitting structure of claim 1,

and a wave absorbing unit (19) is arranged on one side of the antenna unit (11) on the upper surface of the second PCB.