CN115084814B - Transmit-receive front-end packaging module, preparation method and microwave communication system - Google Patents

Abstract

The invention provides a receiving and transmitting front end packaging module, a preparation method and a microwave communication system, wherein the receiving and transmitting front end packaging module comprises: a plurality of embedded chips embedded in the multilayer substrate and a circulator packaged with the embedded chips; the multi-layer substrate at least comprises an upper-layer substrate, a middle substrate and a lower-layer substrate, wherein a first reserved cavity is arranged on the lower-layer substrate and is used for placing a metal carrier of the circulator, a plurality of embedded cavities are arranged on the middle substrate and are used for placing embedded chips, and a second reserved cavity is also arranged on the middle substrate and is used for fixing ferrite of the circulator; an upper substrate for closing the embedded cavities is arranged on all the embedded cavities, and a permanent magnet is also arranged on the substrate on the ferrite; the second reserved cavity is communicated with the first reserved cavity; the embedded chips are electrically connected through interconnection through holes arranged on the lower substrate and the middle substrate. The transceiver front-end packaging module provided by the invention has higher integration level, and can meet the requirement of the advanced degree of a microwave communication system.

Description

Transceiver front-end packaging module, preparation method and microwave communication system

Technical Field

The present invention relates to the field of semiconductor chip packaging, and in particular to a transceiver front-end packaging module, a preparation method and a microwave communication system.

Background technique

The transceiver front end is the part following the antenna in phased array components and wireless communication systems, which receives and transmits antenna signals. Usually, the transceiver front end not only needs to have a wide bandwidth and high isolation, but also has high requirements for its miniaturization, lightweight integration, and high-frequency integration.

At present, active chips and passive components are mounted on the surface of the circuit substrate. Among them, for some microwave modules, the active chip is semi-buried, that is, a groove is made on the surface of the circuit substrate. When performing micro-assembly, the chip is bonded to the bottom of the groove. The circulator is a multi-port device, and the transmission direction of its electromagnetic wave can only be transmitted in a single direction, and the reverse direction is isolated. In modern radar and microwave multi-channel communication systems, the circulator has become a necessary device for single-direction transmission.

However, in traditional components, the active channel and the circulator are interconnected by bonding or welding. This interconnection method increases the size of the RF front end and is not conducive to the current demand for miniaturized integration of the RF front end.

Summary of the invention

The embodiments of the present invention provide a transceiver front-end packaging module, a preparation method and a microwave communication system to solve the current problem of low integration of radio frequency front-ends.

In a first aspect, an embodiment of the present invention provides a transceiver front-end packaging module, comprising: a multi-layer substrate, a plurality of pre-embedded chips and a circulator embedded in the multi-layer substrate; wherein:

The multi-layer substrate comprises at least an upper substrate, an intermediate substrate and a lower substrate;

The circulator includes a metal carrier, a ferrite and a permanent magnet, wherein the metal carrier is arranged in a first reserved cavity on the lower substrate, the ferrite is arranged in a second reserved cavity on the middle substrate, and the permanent magnet is arranged on the upper substrate, wherein the second reserved cavity is connected to the first reserved cavity;

The embedded chip is arranged in the embedding cavity on the middle substrate, and the upper substrate closes all the embedding cavities; the embedded chip is electrically connected through interconnection through holes arranged on the lower substrate and the middle substrate.

In a possible implementation, the intermediate substrate includes at least a first intermediate substrate and a second intermediate substrate, the first intermediate substrate is located on the lower substrate, and the second intermediate substrate is located on the first intermediate substrate;

The first intermediate substrate and the second intermediate substrate are provided with buried cavities communicating with each other, an upper substrate is provided on the buried cavity of the second intermediate substrate, and a permanent magnet is provided on the second intermediate substrate on the ferrite.

In a possible implementation manner, an opening of the buried cavity on the second intermediate substrate is larger than an opening of the buried cavity on the first intermediate substrate that is in communication with the buried cavity.

Optionally, the buried cavity on the second intermediate substrate is coaxially arranged with the buried cavity on the first intermediate substrate.

In a possible implementation, a pad is provided on the bonding surface between the embedding cavity of the second intermediate substrate and the embedding cavity of the first intermediate substrate, and the pad is used for bonding with the embedded chip.

In a possible implementation, the metal carrier and ferrite of the circulator are fixed by a gold-tin sintering process, and the permanent magnet is fixed by bonding with a conductive adhesive.

In a possible implementation, interconnected three-dimensional vertical interconnection through holes are provided on the lower substrate and the first intermediate substrate for signal transmission; and the interconnection through holes are connected to pads provided on the bonding surfaces of the second intermediate substrate and the first intermediate substrate.

In a possible implementation, the embedded chip is fixed to the lower substrate by bonding with nano-sintered silver or conductive adhesive.

In a second aspect, an embodiment of the present invention provides a method for preparing a transceiver front-end packaging module, comprising:

A first reserved cavity is formed on the lower substrate, a plurality of first buried cavities and a second reserved cavity are formed on the first intermediate substrate, and a second buried cavity is formed on the second intermediate substrate;

Preparing vertical interconnection through holes at corresponding positions on the lower substrate and the first intermediate substrate, and filling the interconnection through holes with conductors;

Bonding the lower substrate, the first intermediate substrate and the second intermediate substrate to form a first packaging module; wherein the first reserved cavity is formed on the second reserved cavity, the first buried cavity is formed on the second buried cavity, and the first buried cavity and the second buried cavity form a chip buried cavity;

Installing the embedded chip into the chip embedding cavity and wire bonding the embedded chip and the first intermediate substrate to achieve electrical connection;

Bonding the upper substrate to the first packaging module, the upper substrate seals the chip embedding cavity, and no upper substrate is arranged on the second intermediate substrate on the second reserved cavity;

A ferrite is installed in the second reserved cavity, a metal carrier is installed in the first reserved cavity, and a permanent magnet is installed on the second intermediate substrate on the ferrite.

In a third aspect, an embodiment of the present invention provides a microwave communication system, comprising the transceiver front-end packaging module described in the first aspect or any possible implementation of the first aspect.

The embodiment of the present invention provides a transceiver front-end packaging module, a preparation method and a microwave communication system. By packaging a circulator and a pre-embedded chip together, the integration is high and no other assembly processes need to be introduced, so that the microwave parameter design value is more consistent with the theoretical value.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic structural diagram of a transceiver front-end packaging module provided by an embodiment of the present invention;

2A-2F are flowcharts of preparing a transceiver front-end packaging module provided in an embodiment of the present invention.

Detailed ways

In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

As described in the background art, in traditional components, active channels and circulators are interconnected by bonding or welding, which cannot meet the current demand for miniaturized integration of RF front-ends.

In addition, for some microwave modules, it is necessary to select active chips for semi-embedding, that is, to make grooves on the surface of the substrate, and to bond the chip to the bottom of the groove during micro-assembly. However, this cannot effectively improve the surface wiring capacity, and after the circuit micro-assembly is completed, the circuit needs to be protected by integrated packaging, metal packaging, etc. These packaging materials not only greatly increase the weight of the circuit, but also increase the process complexity, and increase the process cycle and production cost of the module.

In order to solve the problems of the prior art, an embodiment of the present invention provides a transceiver front-end packaging module, a preparation method and a microwave communication system. The transceiver front-end packaging module provided by the embodiment of the present invention is first introduced below.

A transceiver front-end packaging module comprises a multi-layer substrate, a plurality of pre-embedded chips embedded in the multi-layer substrate, and a circulator packaged together with the pre-embedded chips.

The multilayer substrate at least includes an upper substrate, an intermediate substrate and a lower substrate, and the circulator includes a metal carrier, a ferrite and a permanent magnet. A first reserved cavity is provided on the lower substrate for placing the metal carrier of the circulator, a plurality of embedded cavities are provided on the intermediate substrate for placing embedded chips, and a second reserved cavity is provided for fixing the ferrite of the circulator. An upper substrate for sealing the embedded cavities is provided on all embedded cavities, and a permanent magnet is also provided on the substrate on the ferrite. The second reserved cavity is connected to the first reserved cavity. The embedded chip is electrically connected through interconnection through holes provided on the lower substrate and the intermediate substrate.

Specifically, the pre-embedded chip can be one or more of the power amplifier chip, limiting amplifier chip, low noise amplifier chip, etc. The user can select according to the actual function of the required transceiver front-end packaging module, which is not limited here. In addition, the number of chips is not limited, and it can be one or more, which can be selected according to the actual usage.

In order to improve the reliability and wiring capability of the transceiver front-end packaging module, the intermediate substrate may include at least a first intermediate substrate and a second intermediate substrate, the first intermediate substrate is located on the lower substrate, and the second intermediate substrate is located on the first intermediate substrate. The first intermediate substrate and the second intermediate substrate are both provided with interconnected buried cavities, the upper substrate is provided on the buried cavity of the second intermediate substrate, and a permanent magnet is provided on the second intermediate substrate on the ferrite.

The embedded chip is led out through bonding wires and interconnecting through holes to achieve electrical connection. The metal carrier, ferrite and permanent magnet together form a circulator.

By setting an embedded cavity on the first intermediate substrate and the second intermediate substrate, and installing the chip in the embedded cavity on the first intermediate substrate, the embedded chip is then bonded to the wire on the second intermediate substrate by wire bonding to achieve electrical connection between the embedded chip and the outside. Finally, an upper substrate is set on the embedded cavity to achieve packaging of the embedded chip without the need for further packaging later.

In order to facilitate the bonding of the embedded chip and the wire on the second intermediate substrate, the opening of the embedded cavity on the second intermediate substrate can be larger than the opening of the embedded cavity on the first intermediate substrate that is connected to the embedded cavity, so as to facilitate bonding. Further, in order to facilitate the installation and bonding of the embedded chip, the embedded cavity on the second intermediate substrate can be coaxially arranged with the embedded cavity on the first intermediate substrate.

A pad is provided on the bonding surface of the embedded cavity of the second intermediate substrate and the embedded cavity of the first intermediate substrate, and the pad is used to bond with the embedded chip. Since the opening of the embedded cavity on the second intermediate substrate is larger than the opening of the embedded cavity on the first intermediate substrate that is connected to the embedded cavity, a pad can be provided at the bonding surface of the two intermediate substrates, and the embedded chip can be bonded to the pad through a gold wire.

The pads are electrically connected to the interconnection through-holes, thereby realizing electrical connection between the chip and the outside. Specifically, interconnection through-holes are provided on the lower substrate and the first intermediate substrate, which are interconnected and vertical, for signal transmission. The interconnection through-holes are connected to pads provided on the bonding surfaces of the second intermediate substrate and the first intermediate substrate.

In some embodiments, the upper substrate, the middle substrate and the lower substrate are bonded together by gold-gold low temperature bonding. The metal carrier and ferrite of the circulator are fixed by a gold-tin sintering process, and the permanent magnet is fixed by conductive adhesive bonding. The embedded chip and the lower substrate are fixed by nano-sintered silver or conductive adhesive bonding.

In some embodiments, the substrate may be a silicon substrate or a silicon carbide substrate or a combination thereof. Since an upper substrate must be provided on the embedding cavity for installing the embedded chip, but an upper substrate may not be provided on the ferrite, the sizes of the lower substrate, the first intermediate substrate and the second intermediate substrate may be the same, and the size of the upper substrate may be smaller than the sizes of the other substrates.

FIG1 shows a transceiver front-end packaging module provided by an embodiment of the present invention, including a four-layer substrate, two pre-embedded chips and a ring body.

The four substrates are respectively a lower substrate 11, a first intermediate substrate 12, a second intermediate substrate 13 and an upper substrate 14, and the four substrates are bonded by a gold-gold low temperature bonding process. A first reserved cavity is provided on the lower substrate 11 for mounting a metal carrier 31 of a circulator, and an interconnection through hole 21 is also provided, and the interconnection through hole 21 is connected to the interconnection through hole 21 on the first intermediate substrate. The interconnection through hole 21 is a three-dimensional vertical interconnection through hole, which can be used for signal transmission.

A plurality of embedded cavities are provided on the first intermediate substrate 12 and the second intermediate substrate 13, and the embedded cavities are used to place the pre-embedded chips. The opening of the embedded cavity on the second intermediate substrate 13 is larger than the opening of the embedded cavity on the first intermediate substrate 12 that is connected to the embedded cavity. The pre-embedded chip is installed in the embedded cavity on the first intermediate substrate 12, and the pre-embedded chip is fixed to the lower substrate 11 by using nano-sintered silver or conductive adhesive.

Pads 22 are provided on both sides of the embedded cavity at the bonding surface 15 between the first intermediate substrate 12 and the second intermediate substrate 13 for bonding the embedded chip to the pads 22 using gold wires, and the pads 22 are connected to the interconnection through holes 21, thereby realizing electrical connection between the chip and the outside.

In addition, a second reserved cavity is provided on the first intermediate substrate 12 for fixing the ferrite 32 of the circulator. An upper clip plate 14 is provided on the embedding cavity of the second intermediate substrate for sealing the embedded chip. A permanent magnet 33 is provided on the second intermediate substrate 13 on the ferrite 32. The permanent magnet 33, the ferrite 32 and the metal carrier 31 form a ring body. The metal carrier 31 and the ferrite 32 of the circulator are fixed by a gold-tin sintering process, and the permanent magnet 33 is fixed by conductive adhesive bonding.

Therefore, the ring body and the embedded chip are packaged as one body, thereby realizing an integrated design and reducing the package size.

On the other hand, the present invention also provides a method for preparing a transceiver front-end packaging module, and Figures 2A-2F show a schematic diagram of the preparation process of several main steps of a method for preparing a transceiver front-end packaging module provided by an embodiment of the present invention. Among them, Figure 2F is a schematic diagram of the structure of a single transceiver front-end packaging module after cutting, and the vertical dotted lines in Figures 2A-2E are subsequent cutting lines.

The specific preparation method includes: making a first reserved cavity 41 on the lower substrate 11, making a plurality of first buried cavities 42 and a second reserved cavity 43 on the first intermediate substrate 12, and making a second buried cavity 44 on the second intermediate substrate 13. Vertical interconnection through holes 21 are prepared at corresponding positions on the lower substrate 11 and the first intermediate substrate 12, and conductors are filled in the interconnection through holes.

The lower substrate 11, the first intermediate substrate 12 and the second intermediate substrate 13 are bonded to form a first packaging module. The first reserved cavity 41 is the second reserved cavity 43, the first buried cavity 42 is the second buried cavity 44, and the first buried cavity 42 and the second buried cavity 44 form a chip buried cavity. The embedded chip is installed in the chip buried cavity, and the embedded chip and the bonding surface 15 of the first intermediate substrate 12 and the second intermediate substrate 13 are wire-bonded to achieve electrical connection. The bonding surface 15 is provided with a pad 22, and the pad 22 is used to electrically connect the interconnection through hole 21. After the chip is bonded to the pad, the chip is electrically connected to the outside.

The upper substrate 14 is bonded to the first packaging module, the upper substrate 14 seals the chip embedding cavity, and the upper substrate 13 is not arranged on the second intermediate substrate 13 on the second reserved cavity 43. After the substrate is cut, a single module is formed, and then the ferrite 32 is installed in the second reserved cavity 43 in the single module, the metal carrier 31 is installed in the first reserved cavity, and the permanent magnet 33 is installed on the second intermediate substrate on the ferrite 32.

Among them, the upper substrate 14, the first intermediate substrate 12, the second intermediate substrate 13 and the lower substrate 11 are formed by gold-gold low temperature bonding. The metal carrier 31 and the ferrite 32 of the circulator are fixed by a gold-tin sintering process, and the permanent magnet 33 is fixed by conductive adhesive. The embedded chip and the lower substrate 11 are fixed by nano-sintered silver or conductive adhesive.

Substrate cutting can be done by mechanical cutting or laser stealth cutting.

It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

In addition, the present invention also provides a microwave communication system, including the above-mentioned transceiver front-end packaging module, which not only realizes the integrated packaging of the ring body and the chip, but also the embedded chip does not need to be integrated again or metal packaged after the circuit micro-assembly is completed. Not only is the integration of the obtained microwave communication system high, but the weight of the entire system is also greatly reduced.

The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims (8)

1. A transceiver front-end package module, comprising: the device comprises a multilayer substrate, a plurality of embedded chips embedded in the multilayer substrate and a circulator; wherein,

The multi-layer substrate at least comprises an upper layer substrate, a middle substrate and a lower layer substrate;

the circulator comprises a metal carrier, ferrite and a permanent magnet, wherein the metal carrier is arranged in a first reserved cavity on the lower substrate, the ferrite is arranged in a second reserved cavity of the middle substrate, and the permanent magnet is arranged on the upper substrate, and the second reserved cavity is communicated with the first reserved cavity;

The embedded chips are arranged in embedded cavities on the middle substrate, and the upper substrate seals all the embedded cavities; the embedded chip is electrically connected through an interconnection through hole arranged on the lower substrate and the middle substrate;

the intermediate substrate at least comprises a first intermediate substrate and a second intermediate substrate, wherein the first intermediate substrate is positioned on the lower substrate, and the second intermediate substrate is positioned on the first intermediate substrate;

the first intermediate substrate and the second intermediate substrate are provided with embedded cavities which are mutually communicated, the embedded cavity of the second intermediate substrate is provided with an upper substrate, the second intermediate substrate on the ferrite is provided with a permanent magnet, and the opening of the embedded cavity on the second intermediate substrate is larger than the opening of the embedded cavity which is communicated with the embedded cavity and is positioned on the first intermediate substrate.

2. The transceiver front-end package module of claim 1, wherein the buried cavity on the second intermediate substrate is coaxially disposed with the buried cavity on the first intermediate substrate.

3. The transceiver front-end package module of claim 1, further comprising a bonding pad on a bonding surface of the embedded cavity of the second intermediate substrate and the embedded cavity of the first intermediate substrate, the bonding pad being configured to bond with the embedded chip.

4. The transceiver front-end package module of claim 1, wherein the metal carrier and ferrite of the circulator are fixed by a gold-tin sintering process, and the permanent magnet is fixed by a conductive adhesive.

5. The transceiver front-end package module of claim 3, wherein three-dimensional vertical interconnection through holes which are communicated with each other are arranged on the lower substrate and the first intermediate substrate for signal transmission; and the interconnection through hole is connected with a bonding pad arranged on the bonding surface of the second intermediate substrate and the first intermediate substrate.

6. The transceiver front-end package module of claim 1, wherein the pre-buried chip and the lower substrate are fixed by nano-sintered silver or conductive adhesive.

7. The preparation method of the transceiver front-end packaging module is characterized by comprising the following steps of:

manufacturing a first reserved cavity on a lower substrate, manufacturing a plurality of first embedded cavities and second reserved cavities on a first intermediate substrate, and manufacturing a second embedded cavity on a second intermediate substrate;

preparing vertical interconnection through holes at corresponding positions on the lower substrate and the first intermediate substrate, and filling conductors in the interconnection through holes;

Bonding the lower substrate, the first intermediate substrate and the second intermediate substrate to form a first packaging module; the first reserved cavity is the second reserved cavity, the first embedded cavity is the second embedded cavity, and the first embedded cavity and the second embedded cavity form a chip embedded cavity;

Installing an embedded chip into the chip embedded cavity, and conducting wire bonding on bonding surfaces between the embedded chip and the first intermediate substrate and between the embedded chip and the second intermediate substrate to realize electric communication;

Bonding an upper substrate with the first packaging module, wherein the upper substrate seals the chip embedded cavity, and no upper substrate is arranged on a second intermediate substrate on the second reserved cavity;

and ferrite is arranged in the second reserved cavity, a metal carrier is arranged in the first reserved cavity, and a permanent magnet is arranged on a second intermediate substrate on the ferrite.

8. A microwave communication system comprising a transceiver front-end package module as claimed in any one of claims 1 to 6.