CN221783196U - Chip and millimeter wave radar - Google Patents

Abstract

The utility model relates to a chip and a millimeter wave radar. The chip comprises: a bare chip; a rewiring layer disposed opposite the die; one or more first radio frequency channels are arranged between the bare chip and the rerouting layer; at least 3 first isolation units corresponding to any one first radio frequency channel are arranged between the bare chip and the rerouting layer, and the at least 3 first isolation units are arranged around the corresponding first radio frequency channel; one end of each first isolation unit is connected with the bare chip, and the other end of each first isolation unit is connected with the rewiring layer.

Description

Chip and millimeter wave radar

Technical Field

The utility model relates to the field of chip design, in particular to a chip and a millimeter wave radar.

Background

With the increasing development of scientific technology, intelligent driving technology is beginning to be popularized in daily life. Intelligent driving is an important grip combining industrial revolution and informatization, and rapid development changes the flow modes of people, resource elements and products, and subverts the life of people. The sensor plays a key role in intelligent driving, and is a channel for an intelligent system of the automobile to acquire external information. In order to obtain distance, speed and angle information of the target, the vision system of the car is typically equipped with radar sensors.

The radar sensor can complete information acquisition through receiving and transmitting signals. In order to ensure the transmission performance of the radio frequency signals, it is necessary to ensure that the channel used for transmitting the radio frequency signals in the radar sensor has a high isolation, so how to improve the isolation of the channel in the radar sensor is a problem to be solved.

Disclosure of utility model

In order to solve any technical problem and achieve the purpose of the embodiment of the application, the embodiment of the application provides a chip and a millimeter wave radar.

A chip, comprising:

A bare chip;

A rewiring layer disposed opposite the die; one or more first radio frequency channels are arranged between the bare chip and the rerouting layer;

At least 3 first isolation units corresponding to any one first radio frequency channel are arranged between the bare chip and the rerouting layer, and the at least 3 first isolation units are arranged around the corresponding first radio frequency channel; one end of each first isolation unit is connected with the bare chip, and the other end of each first isolation unit is connected with the rewiring layer.

In some alternative embodiments, the first isolation unit includes a first pad located in the die adjacent to a surface of the redistribution layer, a second pad located in the redistribution layer adjacent to a surface of the die, and a first conductive unit connecting the first pad and the second pad.

In some alternative embodiments, the first conductive element is a copper pillar.

In some alternative embodiments, the first pad and the second pad are ground pads, or pads without signal transmission, or pads for transmitting signals other than radio frequency signals.

In some optional embodiments, a plurality of first bonding pads corresponding to the same first radio frequency channel are connected into an integral ring shape;

And/or a plurality of second bonding pads corresponding to the same first radio frequency channel are connected into an integral ring shape.

In some alternative embodiments, a package substrate is disposed opposite to a side of the rewiring layer facing away from the die, and one or more second radio frequency channels are disposed between the rewiring layer and the package substrate;

at least 3 second isolation units corresponding to any one second radio frequency channel are arranged between the rewiring layer and the packaging substrate, and the at least 3 second isolation units are arranged around the corresponding second radio frequency channel; one end of each second isolation unit is connected with the rewiring layer, and the other end of each second isolation unit is connected with the packaging substrate.

In some alternative embodiments, the second isolation unit includes a third pad in the redistribution layer adjacent to a surface of the package substrate, a fourth pad in the package substrate adjacent to a surface of the redistribution layer, and a second conductive unit connecting the first pad and the second pad.

In some alternative embodiments, the third pad and the fourth pad are ground pads, or pads without signal transmission, or pads for transmitting signals other than radio frequency signals.

In some optional embodiments, a plurality of third bonding pads corresponding to the same second radio frequency channel are connected into an integral ring shape;

And/or a plurality of fourth bonding pads corresponding to the same second radio frequency channel are connected into an integral ring shape.

In some alternative embodiments, the second conductive element is a solder ball or a copper pillar.

A millimeter wave radar provided with the chip described above.

One of the above technical solutions has the following advantages or beneficial effects:

At least 3 first isolation structures or second isolation structures can interfere leakage paths of radio frequency signals, and compared with signal leakage caused by two first isolation units/two second isolation units, leakage of radio frequency signals in a radio frequency channel is effectively reduced, and the purpose of improving isolation of a packaging layer of the channel is achieved.

Drawings

FIG. 1 is a schematic diagram of a chip packaged by FCCSP technology;

FIG. 2 is a schematic diagram of a chip packaged by eWLB process;

FIG. 3 is a schematic layout diagram of the chip shown in FIG. 1;

FIG. 4 is a schematic diagram of the deployment of a copper pillar structure of a radio frequency channel between a die 10 and a redistribution layer 20;

FIG. 5 is a schematic illustration of an electromagnetic field formed by the copper pillar structure of FIG. 4;

Fig. 6 is a schematic diagram of the disposition of a solder ball structure with a radio frequency channel between the die 10 and the redistribution layer 20;

FIG. 7 is a schematic illustration of an electromagnetic field formed by the solder ball structure of FIG. 6;

FIG. 8 is a schematic diagram of a chip according to an embodiment of the present application;

FIG. 9 is a schematic diagram of the deployment of the first isolation unit 50 shown in FIG. 8;

FIG. 10 is a schematic diagram of an electric field confined by the first isolation structure of FIG. 9;

Fig. 11 is a schematic structural diagram of the first isolation unit 50 shown in fig. 8;

FIG. 12 is another schematic diagram of the chip shown in FIG. 8;

FIG. 13 is a schematic diagram of the deployment of the second isolation unit 60 shown in FIG. 12;

FIG. 14 is a schematic diagram of the electric field bound by the second isolation unit 60 shown in FIG. 13;

Fig. 15 is a schematic structural diagram of the second isolation unit 60 shown in fig. 12;

fig. 16 is a schematic diagram of each pad provided in the embodiment of the present application being a ground pad GND 1;

Fig. 17 is a schematic diagram of a plurality of pads connected to an integral grounding area GND2 in one turn of the same rf channel according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of the embodiments of the present application will be given with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in various embodiments of the present application, numerous technical details have been set forth in order to provide a better understanding of the present application. The claimed application may be practiced without these specific details and with various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not be construed as limiting the specific implementation of the present application, and the embodiments can be mutually combined and referred to without contradiction.

In the radar field, the isolation of the channel generally includes the isolation of the channel inside the chip, the isolation of the channel at the packaging level, and the isolation of the channel at the antenna level. The scheme provided by the embodiment of the application achieves the purpose of improving the isolation of the channel by improving the isolation of the packaging layer, so as to improve the transmission performance of the radio frequency signal.

Fig. 1 is a schematic diagram of a chip packaged by FCCSP process. As shown in fig. 1, the chip includes a Die 10 (Die), a rewiring layer 20 (Re-Distributed Layer, rewiring layer), and a package Substrate 30 (submount); wherein:

a die 10 for performing a transceiving operation on a radio frequency signal;

A rewiring layer 20 disposed opposite the die 10, wherein copper pillars 12 (copper pillars) are disposed between the rewiring layer 20 and the die 10;

The package substrate 30 is disposed opposite to the redistribution layer 20, wherein a surface of the package substrate 30 adjacent to the redistribution layer 20 and a surface of the package substrate 30 remote from the redistribution layer 20 are both provided with copper layers, and a solder ball 23 (ball) is disposed between the package substrate 30 and the redistribution layer 20.

The copper pillars 12 and the solder balls 23 provided in the chip are used for transmitting radio frequency signals of the radio frequency channel.

Fig. 2 is a schematic diagram of a chip packaged by the eWLB process. As shown in fig. 2, unlike that shown in fig. 1, the chip does not include the package substrate 30, but includes only the die 10 and the rewiring layer 20, wherein the copper pillars 12 are disposed between the rewiring layer 20 and the die 10.

The chips shown in fig. 1 or 2 may be placed on a printed circuit board 40 (Printed Circuit Board, PCB) to complete the chip deployment.

Fig. 3 is a schematic layout diagram of the chip shown in fig. 1. As shown in fig. 3, the package substrate 30 is disposed opposite to the PCB40, wherein the solder balls 23 are disposed between the PCB40 and the package substrate 30, and wherein the surface of the PCB40 adjacent to the package substrate 30 is provided with the antenna unit ANT. The antenna unit ANT is configured to perform a transmitting operation on a radio frequency signal output by the chip, and provide the received radio frequency signal to the chip.

Taking an example of a radio frequency signal emission scenario, referring to the schematic diagram in fig. 3, it can be seen that the radio frequency signal output by the die 10 is output to the rewiring layer 20 through the copper pillar 12 disposed between the die 10 and the rewiring layer 20, is transmitted to the packaging substrate 30 through the solder ball 23 disposed between the rewiring layer 20 and the packaging substrate 30, and is transmitted through the transmission path inside the packaging substrate 30, so as to achieve the purpose of outputting the radio frequency signal by the chip. And then, the radio frequency signals are transmitted through the solder balls 23 between the package substrate 30 and the PCB40, and are output to the antenna unit ANT through the wirings of the PCB40 and the antenna unit ANT, and the antenna unit ANT completes the transmission of the radio frequency signals.

In the structure of the chip, since the chip can support one or more radio frequency channels, each radio frequency channel has a respective copper pillar structure between the die 10 and the redistribution layer 20 for transmitting radio frequency signals of the respective radio frequency channel; similarly, each rf channel also has a respective solder ball structure between the redistribution layer 20 and the package substrate 30 for transmitting rf signals of the respective rf channel.

Fig. 4 is a schematic diagram of the deployment of a copper pillar structure of a radio frequency channel between a die 10 and a redistribution layer 20. As shown in fig. 4, 3 pads are disposed on the surface of the die 10 adjacent to the rewiring layer 20, 3 pads corresponding to the 3 pads of the die 10 one by one are disposed on the surface of the rewiring layer 20 adjacent to the die 10, and 3 groups of pads are formed, wherein copper pillars 12 are disposed between each group of pads.

In the copper pillar structure shown in fig. 4, copper pillars 12 located at the middle position are used for transmitting radio frequency signals, and copper pillars 12 located at two sides are used for isolating the radio frequency signals.

Fig. 5 is a schematic diagram of an electric field formed by the copper pillar structure shown in fig. 4. Ext> asext> shownext> inext> fig.ext> 5ext>,ext> thereext> areext> twoext> GSGext> structuresext>,ext> GSGext> -ext> aext> andext> GSGext> -ext> bext>,ext> respectivelyext>,ext> arrangedext> forext> radioext> frequencyext> channelsext>.ext> Ext> sinceext> theext> twoext> GNDext> structuresext> doext> notext> completelyext> surroundext> theext> firstext> radioext> frequencyext> channelext> (ext> Signalext> -ext> aext> /ext> Bext>)ext>,ext> theext> isolationext> betweenext> theext> twoext> firstext> radioext> frequencyext> channelsext> isext> poorext>,ext> andext> theext> formext> ofext> electricext> fieldext> andext> leakageext> underext> thisext> structureext> canext> beext> seenext> fromext> theext> arrowsext> inext> theext> GSGext> -ext> aext> structureext> andext> theext> GSGext> -ext> Bext> structureext> inext> fig.ext> 5ext>.ext>

Fig. 6 is a schematic diagram showing the disposition of a solder ball structure between the redistribution layer 20 and the substrate 30 by an rf channel. As shown in fig. 6, 3 pads are disposed on the surface of the redistribution layer 20 adjacent to the package substrate 30, 3 pads corresponding to the 3 pads of the die 10 one by one are disposed on the surface of the package substrate 30 adjacent to the redistribution layer 20, and 3 groups of pads are formed, wherein solder balls 23 are disposed between each group of pads.

Fig. 7 is a schematic diagram of an electromagnetic field formed by the solder ball structure shown in fig. 6. Ext> asext> shownext> inext> fig.ext> 7ext>,ext> thereext> areext> twoext> GSGext> structuresext>,ext> GSGext> -ext> aext> andext> GSGext> -ext> bext>,ext> respectivelyext>,ext> arrangedext> forext> radioext> frequencyext> channelsext>.ext> Ext> sinceext> theext> twoext> GNDext> structuresext> doext> notext> completelyext> surroundext> theext> secondext> radioext> frequencyext> channelext> (ext> Signalext> -ext> aext> /ext> Bext>)ext> structureext>,ext> theext> isolationext> betweenext> theext> twoext> radioext> frequencyext> channelsext> isext> poorext>,ext> andext> theext> formext> ofext> electricext> fieldext> andext> leakageext> inext> thisext> structureext> canext> beext> seenext> fromext> theext> arrowsext> inext> theext> GSGext> -ext> aext> structureext> andext> theext> GSGext> -ext> Bext> structureext> inext> fig.ext> 7ext>.ext>

Based on the analysis, the problem of signal coupling exists between adjacent radio frequency channels in the prior chip packaging structure, and the isolation between the channels is poor; in view of the above problems, embodiments of the present application provide solutions including:

Fig. 8 is a schematic structural diagram of a chip according to an embodiment of the present application, and fig. 9 is a schematic layout diagram of the first isolation unit 50 shown in fig. 8. As shown in fig. 8-9, the chip includes a die 10, a rewiring layer 20 disposed opposite the die 10, with one or more first radio frequency channels between the die 10 and the rewiring layer 20; wherein at least 3 first isolation units 50 corresponding to any one first radio frequency channel are arranged between the bare chip 10 and the rerouting layer 20, three or more first isolation units 50 are arranged around the corresponding first radio frequency channel, one end of each first isolation unit 50 is connected with the surface of the bare chip 10 adjacent to the rerouting layer 20, and the other end is connected with the surface of the rerouting layer 20 adjacent to the bare chip 10.

In the structure shown in fig. 8, three or more first isolation units 50 are used to isolate signal coupling between adjacent first radio frequency channels.

In this embodiment, four first isolation units are correspondingly disposed on each first rf channel, as shown in fig. 9, however, in other embodiments, the number of first isolation units correspondingly enclosed by each first rf channel may be three, or five, etc., which is not limited herein and may be adjusted according to specific needs.

As can be seen by comparing the structure shown in fig. 8 with the structure shown in fig. 4, the structure shown in fig. 4 is provided with 2 copper pillars for isolating radio frequency signals, and the structure shown in fig. 8 is provided with at least 3 first isolating units 50 for isolating radio frequency signals. As the number of the isolation units 50 increases, more first isolation units 50 surround the first rf channel, so that the electromagnetic field is bound between the first isolation units 50 and the rf channel S, leakage is reduced, and isolation between different channels is improved.

Fig. 9 is a schematic layout diagram of the first isolation unit 50 shown in fig. 8. As shown in fig. 9, a first radio frequency channel S1 is provided between the die 10 and the redistribution layer 20; at least 3 first isolation units 50 are disposed around the first rf channel S1; the distance between each first isolation unit 50 and the first radio frequency channel S1 is equal, and the distance between any two first isolation units 50 is equal.

In practical applications, the distance between each first isolation unit 50 and the first rf channel S1 may be unequal, and the distance between any two first isolation units 50 may be unequal.

In fig. 9, the number of the first isolation units 50 is 4 as an example, and in practical application, the number of the first isolation units 50 may be 3 or more, and the number may be odd or even.

As can be seen from the structure shown in fig. 9, the at least 3 first isolation units 50 are disposed around the first rf channel S1, so as to effectively improve the isolation effect of the rf signal and improve the isolation of the package structure.

Fig. 10 is a schematic diagram of an electromagnetic field formed by the first isolation structure shown in fig. 9. As shown in fig. 10, as compared with the electromagnetic field shown in fig. 5, in fig. 10, as the number of the isolation units 50 increases, more first isolation units 50 surround the first rf channel, so that the electromagnetic field is bound between the first isolation units 50 and the rf channel S1, leakage is reduced, and isolation between different channels is improved, and compared with the structure shown in fig. 5, isolation formed by at least 3 first isolation structures in fig. 8 is significantly improved.

Fig. 11 is a schematic structural diagram of the first isolation unit 50 shown in fig. 8. The first isolation unit 50 includes a first pad 51 located in the die 10 adjacent to the surface of the rerouting layer 20, a second pad 53 located in the rerouting layer 20 adjacent to the surface of the die 10, and a first conductive unit 52 located between the first and second pads 51, 53.

Further, the first conductive unit 52 includes a copper pillar.

As can be seen from comparison of the structure shown in fig. 4, the structure of the first isolation unit 50 shown in fig. 11 is similar to that shown in fig. 4, and is configured based on a common package specification.

Fig. 12 is another schematic structure of the chip shown in fig. 8. As shown in fig. 12, the chip is further provided with a package substrate 30 opposite to the rewiring layer 20; one or more second radio frequency channels are provided between the redistribution layer 20 and the package substrate 30; wherein:

At least 3 second isolation units 60 corresponding to any one of the second radio frequency channels are arranged between the rerouting layer 20 and the packaging substrate 30, wherein one end of each second isolation unit 60 is connected with the surface of the rerouting layer 20 adjacent to the packaging substrate 30, and the other end is connected with the surface of the packaging substrate 30 adjacent to the rerouting layer 20.

In the structure shown in fig. 12, the second isolation unit 60 is used to isolate the adjacent second rf channel between the package substrate 30 and the redistribution layer 20.

As can be seen by comparing the structure shown in fig. 12 with the structure shown in fig. 6, the structure shown in fig. 6 is provided with 2 second isolation units for isolating radio frequency signals, and the structure shown in fig. 12 is provided with at least 3 second isolation units 60 for isolating radio frequency signals. As the number of the isolation units 60 increases, more second isolation units 60 surround the second rf channel S2, so that the electromagnetic field is bound between the second isolation units 60 and the rf channel S2, leakage is reduced, and isolation between different channels is improved.

Fig. 13 is a schematic diagram of the deployment of the second isolation unit 60 shown in fig. 12. As shown in fig. 12, a second rf channel S2 is disposed between the redistribution layer 20 and the package substrate 30, and the distance between each second isolation unit 60 and the second rf channel S2 is equal, and the distance between any two second isolation units 60 is equal.

In practical applications, the distance between each first isolation unit 50 and the second rf channel S2 may be unequal, the distance between any two second isolation units 60 may be unequal, and the distance between the second isolation units 60 and the second rf channel S2 may be unequal.

The number of the second isolation units 60 may be 3 or more, and may be an odd number or an even number.

As can be seen from the structure shown in fig. 13, the at least 3 second isolation units 60 are disposed around the second rf channel S2.

Fig. 14 is a schematic view of an electromagnetic field formed by the second isolation unit 60 shown in fig. 13. As can be seen from comparing the electromagnetic field shown in fig. 14 with that shown in fig. 7, as the number of the isolation units 60 increases, more second isolation units 60 surround the second rf channel, so that the electromagnetic field is bound between the second isolation units 60 and the rf channel S2, the leakage is reduced, the isolation between different channels is improved, and the isolation of the structure formed by at least 3 second isolation units 60 in fig. 12 is significantly improved compared with the structure shown in fig. 6.

Fig. 15 is a schematic structural diagram of the second isolation unit 60 shown in fig. 12. As shown in fig. 12, the second isolation unit 60 includes a third pad 61 located in the rerouting layer 20 adjacent to the surface of the package substrate 30, a fourth pad 63 located in the package substrate 30 adjacent to the surface of the rerouting layer 20, and a second conductive unit 62 located between the third pad 61 and the fourth pad 63.

Further, the second conductive unit 62 includes a solder ball.

As can be seen from comparison with the structure shown in fig. 6, the structure of the second isolation unit 60 shown in fig. 15 is similar to that shown in fig. 6, and is configured based on a common package specification.

Fig. 16 is a schematic diagram of the ground pad GND1 provided by the embodiment of the present application as each pad (the first pad 51, the second pad 52, the third pad 61, the fourth pad 63). In fig. 16, 4 grounding pads are set around the same rf channel, and in practical application, the number of grounding pads is not limited.

Fig. 17 shows an alternative embodiment of fig. 16, in which four ground pads surrounding the same rf channel may be connected to form an integral ground area GND2, as shown in fig. 17.

The embodiment of the application also provides a millimeter wave radar which is provided with the chip.

Specifically, the millimeter wave radar can be used in a vision system of an automobile, so that the vision system of the automobile can detect target objects and barrier information in the surrounding environment of a driving area, and a control system of the automobile can send out warning information in time. For example, when the electronic device is used for collision avoidance and early warning of a vehicle, scene information acquired by the radar sensor in a driving area of the vehicle can be acquired, and obstacle information contained in a detection area of the radar sensor can be obtained. And generating a target early warning signal under the condition that the early warning trigger condition is met according to the obstacle information of the target obstacle.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of carrying out the application and that various changes in form and details may be made therein without departing from the spirit and scope of the application.

Claims (11)

1. A chip, comprising:

A bare chip;

A rewiring layer disposed opposite the die; one or more first radio frequency channels are arranged between the bare chip and the rerouting layer;

At least 3 first isolation units corresponding to any one first radio frequency channel are arranged between the bare chip and the rerouting layer, and the at least 3 first isolation units are arranged around the corresponding first radio frequency channel; one end of each first isolation unit is connected with the bare chip, and the other end of each first isolation unit is connected with the rewiring layer.

2. The chip of claim 1, wherein:

The first isolation unit includes a first pad located in the die adjacent to a surface of the rerouting layer, a second pad located in the rerouting layer adjacent to a surface of the die, and a first conductive unit connecting the first pad and the second pad.

3. The chip of claim 2, wherein:

the first conductive unit is a copper column.

4. The chip of claim 2, wherein:

The first bonding pad and the second bonding pad are grounding bonding pads, bonding pads without signal transmission, or bonding pads for transmitting other signals except radio frequency signals.

5. The chip of claim 3 or 4, wherein:

a plurality of first bonding pads corresponding to the same first radio frequency channel are connected into an integral ring shape;

And/or a plurality of second bonding pads corresponding to the same first radio frequency channel are connected into an integral ring shape.

6. The chip of claim 2, wherein the chip further comprises:

A package substrate arranged opposite to one surface of the rewiring layer, which is opposite to the bare chip, wherein one or more second radio frequency channels are arranged between the rewiring layer and the package substrate;

at least 3 second isolation units corresponding to any one second radio frequency channel are arranged between the rewiring layer and the packaging substrate, and the at least 3 second isolation units are arranged around the corresponding second radio frequency channel; one end of each second isolation unit is connected with the rewiring layer, and the other end of each second isolation unit is connected with the packaging substrate.

7. The chip of claim 6, wherein:

The second isolation unit includes a third pad located in the rerouting layer adjacent to a surface of the package substrate, a fourth pad located in the package substrate adjacent to a surface of the rerouting layer, and a second conductive unit connecting the first pad and the second pad.

8. The chip of claim 7, wherein:

The third pad and the fourth pad are grounded pads, or pads without signal transmission, or pads for transmitting other signals except radio frequency signals.

9. The chip of claim 7 or 8, wherein:

a plurality of third bonding pads corresponding to the same second radio frequency channel are connected into an integral ring shape;

And/or a plurality of fourth bonding pads corresponding to the same second radio frequency channel are connected into an integral ring shape.

10. The chip of claim 7, wherein:

The second conductive unit is a tin ball or a copper column.

11. A millimeter wave radar, characterized in that a chip as claimed in any one of claims 1 to 10 is provided.