High-tolerance vertical interconnection structure for SiP packaging radio frequency array direct connection port

Abstract

The invention relates to the technical field of radio frequency microwaves, and particularly discloses a high-tolerance vertical interconnection structure for a SiP packaging radio frequency array direct connection port, which comprises a substrate, a BGA, a packaging structure, a thermal interface layer and a metal mounting base which are stacked from top to bottom, a TXV-like coaxial radio frequency transmission structure and a radio frequency transmission line connected with the TXV-like coaxial radio frequency transmission structure are arranged in the packaging structure; an elastic contact quasi-coaxial radio frequency transmission structure which is in contact fit with the TXV quasi-coaxial radio frequency transmission structure is arranged in the metal mounting base; and the other end of the elastic contact type coaxial radio frequency transmission structure passes through the metal mounting base and is connected with an antenna radio frequency port and a rear-end radio frequency emission excitation or radio frequency receiver port. According to the invention, the radio frequency connection links are effectively reduced, the insertion loss is greatly reduced, the return loss is increased, the signal transmission performance is improved, and the heat dissipation capability of multiple groups of packaging structures is improved.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency microwave technology, and more specifically, to a high-tolerance vertical interconnect structure for a direct-connect port of a SiP packaged radio frequency array. Background Art

[0002] With the rapid development of electronic system technologies such as communications, radar, reconnaissance and electronic countermeasures, the need to integrate the RF of systems such as communications, navigation, reconnaissance and electronic countermeasures into the same RF aperture is becoming more and more urgent. Digital multi-beam active phased array antennas have fast beam scanning, strong anti-interference ability, strong multi-target ability, and large airspace coverage, becoming an important technical means to upgrade the electronic performance of various aircraft platforms. With the improvement of the broadband RF application system capabilities of active phased array antennas, active RF channel arrays need to integrate a large number of RF functions, the integration scale of circuits has been greatly improved, and the heat generation of heat-generating devices such as RF transceiver array power amplifiers has been greatly increased, resulting in a significant increase in the volume and weight of RF phased array antennas, making it increasingly difficult to solve the heat dissipation problem.

[0003] Silicon-based, glass-based MEMS or ceramic RF SiP (System in Package) technology integrates bare chips with different functions into the package. The RF input and output connection paths are short, the RF performance is good, the integration density is high, and the cost is low. It has unique advantages in the field of RF circuit integration and has become a hot spot for RF microwave and millimeter wave circuit integration. However, as the transmission power of the RF transceiver front end increases, heat dissipation becomes a key problem that needs to be solved urgently in SiP packaging; on the other hand, the increase in transmission power causes the increase in power consumption of the power supply, and the importance of transmission efficiency is particularly prominent. Among them, the loss of the output port of the transceiver component will directly affect the transmission efficiency of the active array. For every 0.1dB increase in the loss of the power output port connection, the transmission efficiency will lose about 1 percentage point. Therefore, the traditional method of attaching the RF SiP surface to a multi-layer printed circuit board and then interconnecting the RF transceiver component array to the antenna radiation array through the multi-layer printed circuit board increases the connection path length and conversion link of the RF signal; at the same time, because the multi-layer board increases the thermal resistance from the package to the antenna radiation surface or the metal heat sink, it has a relatively large negative impact on the heat dissipation of the RF transceiver front end, and it is difficult to meet the heat dissipation requirements of the high-power RF transceiver front end.

[0004] The pads on the package surface are directly connected to the RF port of the antenna, which omits the intermediate transition connection link through the multi-layer substrate. At the same time, the rapid lateral and longitudinal heat diffusion and heat conduction achieved by directly contacting the metal mounting base through the thermal interface layer solves the problem of shortest path low-loss connection and low thermal resistance contact.

[0005] The RF transceiver assembly requires a multi-layer printed circuit board to provide multiple electrical signals such as RF excitation, amplitude and phase, transceiver control, power supply, etc. The RF transceiver assembly needs to be mounted on the multi-layer printed circuit board first, and then connected to the antenna RF port. Due to the error of the printed circuit board layout and the error of the metal mounting base interface position, the performance of the package and the antenna RF port may be degraded or even short-circuited. Therefore, it is necessary to greatly improve the tolerance of the position offset error of the package interface in the two-dimensional direction. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-tolerance vertical interconnection structure for a direct-connection port of a SiP packaged RF array, which reduces the RF connection links, greatly reduces the insertion loss, increases the return loss, improves the signal transmission performance, and increases the heat dissipation capacity of multiple groups of packages when the RF signal input and output ends of one or more groups of RF SiP packages within an ultra-wide operating frequency range are connected to multiple groups of RF ports on an external two-dimensional plane;

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] A high-tolerance vertical interconnect structure for a direct-connect port of a SiP packaged radio frequency array, comprising a substrate, a BGA, a packaging structure, a thermal interface layer, and a metal mounting base stacked from top to bottom;

[0009] A TXV-type coaxial radio frequency transmission structure and a radio frequency transmission line connected to the TXV-type coaxial radio frequency transmission structure are arranged in the packaging structure;

[0010] An elastic contact type coaxial radio frequency transmission structure that contacts and cooperates with the TXV type coaxial radio frequency transmission structure is arranged in the metal mounting base;

[0011] The other end of the elastic contact coaxial RF transmission structure passes through the metal mounting base and is connected to the antenna RF port, the rear RF transmission excitation or the RF receiver port;

[0012] The other end of the TXV type coaxial radio frequency transmission structure is soldered on the substrate through BGA.

[0013] In some possible implementations, the TXV-type coaxial radio frequency transmission structure is a TGV-type coaxial radio frequency transmission structure, a TCV-type coaxial radio frequency transmission structure, or a TSV-type coaxial radio frequency transmission structure;

[0014] The TXV-type coaxial radio frequency transmission structure is connected to the radio frequency transmission line, and comprises a TXV inner conductor hole and a plurality of groups of TXV outer conductor holes surrounding the outer side of the TXV inner conductor hole and forming a gap between the TXV inner conductor hole and the TXV inner conductor hole.

[0015] In some possible implementations, the TXV-like coaxial RF transmission structure further includes an inner conductor hole pad 1 arranged at an end of the TXV inner conductor hole close to the substrate, an inner conductor hole pad 2 arranged at an end of the TXV inner conductor hole away from the substrate, a grounding conductor 1 arranged at an end of the TXV outer conductor hole close to the substrate, and a grounding conductor 2 arranged at an end of the TXV outer conductor hole away from the substrate; an inner-outer conductor hole gap 1 is formed between the grounding conductor 1 and the inner conductor hole pad 1, and an inner-outer conductor hole gap 2 is formed between the grounding conductor 2 and the inner conductor hole pad 2; the TXV inner conductor hole and the TXV outer conductor hole constitute a quasi-coaxial structure.

[0016] In some possible embodiments, the elastic contact coaxial RF transmission structure includes an inner conductor column that contacts and cooperates with the inner conductor hole pad 2, and multiple groups of outer conductor columns that surround the outer side of the inner conductor column and form a coaxial structure; the outer conductor column contacts and cooperates with the ground conductor 2.

[0017] In some possible implementations, the axes of the TXV inner conductor hole, the inner conductor column, and the inner conductor hole pad 2 are parallel to each other or on the same straight line.

[0018] In some possible implementations, a hollow area for mounting a second inner conductor hole pad, a second inner and outer conductor hole gap, and a second grounding conductor is provided on the thermal interface layer.

[0019] In some possible implementations, the diameter of the inner conductor hole pad 2 is d 04 , d 04 =d 05 -0.15mm-S 20 ;

[0020] Among them, d 05 S is the diameter of the circle where the center of the TXV outer conductor hole is located; 20 is the size of the gap between the inner and outer conductor holes, S 20 =0.3mm~0.5mm.

[0021] In some possible implementations, the span of the substrate is LK, LK≤300 mm;

[0022] The distance between the inner conductor column and the second ground conductor, and the distance between the outer conductor column and the second inner conductor hole pad are S 21 , S 21 =0.1mm-0.15mm.

[0023] In some possible implementations, when LK≤100 mm, the distance S between the inner conductor column and the second ground conductor, and between the outer conductor column and the second inner conductor hole pad is 21 Both are 0.1mm;

[0024] When 100mm<LK≤300mm, the distance S between the inner conductor column and the second ground conductor, and between the outer conductor column and the second inner conductor hole pad is 21 Both are 0.15mm.

[0025] In some possible embodiments, the packaging structure is a multi-layer structure; including a plurality of metal dielectric layers stacked in layers, and a glass dielectric layer arranged between two adjacent metal dielectric layers; the metal dielectric layer and the glass dielectric layer located thereon form a packaging substrate; the TXV-type coaxial RF transmission structure passes through at least one layer of the packaging substrate and contacts and cooperates with the elastic contact-type coaxial RF transmission structure.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention enlarges the diameter of the inner and outer conductor columns of the TGV pad, uses elastic coaxials such as wool buttons, and simultaneously presses a flexible thermal interface layer on the package contact surface to solve the problems of multiple groups of high-power packages, multiple groups or array radio frequency interfaces being directly connected with antenna radiation units or rear ends at low losses over a large span, connection reliability, and high-power heat dissipation.

[0028] The present invention uses the elastic contact of the elastic contact coaxial RF transmission structure to provide RF connection, uses the metal mounting base of the RF interface as a low thermal resistance heat conduction path, and realizes reliable connection of more than 1,000 RF ports with a span size of more than 240 mm by expanding the diameter of the inner conductor hole pad 2 and the size of the inner and outer conductor hole gap 2, greatly reducing the connection loss of the RF transceiver component to the antenna radiation unit, greatly improving the power capacity of the RF transceiver component, and improving the tolerance of the RF connection of the RF transceiver component SiP package to the radiation unit to the installation tolerance to more than ±0.4 mm;

[0029] The present invention adopts the method of enlarging the diameter of the inner conductor hole pad 2 and the size of the inner and outer conductor hole gap 2, thereby greatly improving the tolerance of array-type RF interconnection to errors in layout, package surface mounting, mounting base structure, etc., at the expense of minimal RF performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the internal structure of the present invention;

[0031] Figure 2 It is a top view schematic diagram of a TXV type coaxial radio frequency transmission structure and an elastic contact type coaxial radio frequency transmission structure of the present invention;

[0032] Figure 3 It is a structural schematic diagram of the packaging structure and the TXV type coaxial radio frequency transmission structure in the present invention;

[0033] Figure 4 for Figure 2A partial enlarged schematic diagram;

[0034] Figure 5 It is a structural schematic diagram of the packaging structure and the TXV type coaxial radio frequency transmission structure in Example 1;

[0035] Figure 6 It is a structural schematic diagram of a radio frequency transmission line, a ground conductor, a gap between inner and outer conductor holes, and a pad for an inner conductor hole;

[0036] Figure 7 It is a structural schematic diagram of a second ground conductor, a second gap between inner and outer conductor holes, and a second pad for an inner conductor hole;

[0037] Figure 8 It is a schematic diagram of the structure of the inner conductor column and the outer conductor column;

[0038] Fig. 9 When the diameter of the inner conductor hole pad is 0.3 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0039] Fig.10 When the diameter of the inner conductor hole pad is 0.4 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0040] Fig.11 When the diameter of the inner conductor hole pad is 0.5 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0041] Fig.12 When the diameter of the inner conductor hole pad is 0.6 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0042] Fig.13 When the diameter of the inner conductor hole pad is 0.7 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0043] Fig.14 When the diameter of the inner conductor hole pad is 0.8 mm, the insertion loss and return loss simulation results are obtained under different inner and outer conductor hole gaps.

[0044] Figure 15-17 The simulation results of insertion loss and return loss under different misalignment sizes of TXV coaxial RF transmission structure and elastic contact coaxial RF transmission structure;

[0045] Fig.18 It is a schematic diagram of the distance between the inner conductor column and the second ground conductor of the elastic contact type coaxial radio frequency transmission structure, and the outer conductor column and the second inner conductor hole pad of the elastic contact type coaxial radio frequency transmission structure in the present invention;

[0046] Fig.19It is a schematic diagram of the TXV type coaxial RF transmission structure and the elastic contact type coaxial RF transmission structure tolerating the misalignment of ±0.5mm in a single direction and ±0.4mm in a two-dimensional direction;

[0047] Among them: 1. Substrate; 2. BGA; 3. Packaging structure; 4. Thermal interface layer; 5. Metal mounting base; A1. TXV type coaxial RF transmission structure; T01. TXV inner conductor hole; T02. TXV outer conductor hole; P01. Inner conductor hole pad one; P02. Inner and outer conductor hole gap one; P03. Grounding conductor one; P11. Pad three; P12. Inner and outer conductor hole gap three; P13. Grounding conductor three; P21. Inner conductor hole pad two; P22. Inner and outer conductor hole gap two; P23. Grounding conductor two; A2. Elastic contact type coaxial RF transmission structure; M01. Inner conductor column; M02. Outer conductor column; W01. RF transmission line. DETAILED DESCRIPTION

[0048] The present invention is described in detail below.

[0049] like Figure 1-Figure 19 As shown:

[0050] A high-tolerance vertical interconnect structure for a direct-connect port of a SiP packaged radio frequency array, comprising a substrate 1, a BGA 2, a package structure 3, a thermal interface layer 4, and a metal mounting base 5 stacked from top to bottom;

[0051] A TXV-type coaxial radio frequency transmission structure A1 and a radio frequency transmission line W01 connected to the TXV-type coaxial radio frequency transmission structure A1 are arranged in the packaging structure 3;

[0052] An elastic contact type coaxial radio frequency transmission structure A2 is arranged in the metal mounting base 5 and contacts and cooperates with the TXV type coaxial radio frequency transmission structure A1;

[0053] The other end of the elastic contact coaxial RF transmission structure A2 passes through the metal mounting base 5 and is connected to the antenna RF port, the rear RF transmission excitation or the RF receiver port;

[0054] The other end of the TXV type coaxial RF transmission structure A1 is soldered on the substrate 1 through BGA2; the substrate 1 can be a multi-layer substrate.

[0055] Specifically, the packaging structure 3 is a plurality of groups, which are surface mounted side by side on the substrate 1, and the TXV type coaxial RF transmission structure A1 will be respectively arranged in each group of packaging structures 3; the surface mounting of the packaging structure 3 adopts a reflow soldering process, and can be a BGA2 or other form of pinless packaging, such as a QFN package; at the same time, the length and width dimensions of the surface mounted packaging structure 3 are not limited, and usually, each group of packaging structures 3 should have the same height; if the height difference of the mounted packaging structures 3 is large, it is necessary to design a metal mounting base 5 with a heat conductive deposit of different thicknesses or a concave-convex shape matching the height dimension of the packaging structure 3 according to the height dimension of the packaging structure 3 and the heat dissipation requirements; accordingly, the length of the elastic connection on the metal mounting base 5 should be designed according to the packaging height matching;

[0056] The RF input or output port of the packaging structure 3 adopts a TXV-type coaxial RF transmission structure A1 and an elastic contact-type coaxial RF transmission structure A2 located in the metal mounting base 5 by elastic contact, and the other end of the elastic contact-type coaxial RF transmission structure A2 is connected to the antenna RF port, the rear-end RF transmission excitation or the RF receiver port; adopting this setting will reduce the RF connection links, greatly reduce the insertion loss, increase the return loss, improve the signal transmission performance, and increase the heat dissipation capacity of multiple groups of packages;

[0057] In some possible implementations, the TXV-type coaxial radio frequency transmission structure A1 is a TGV-type coaxial radio frequency transmission structure, a TCV-type coaxial radio frequency transmission structure, or a TSV-type coaxial radio frequency transmission structure;

[0058] The TXV quasi-coaxial RF transmission structure A1 is connected to the RF transmission line W01, and includes a TXV inner conductor hole T01, a plurality of TXV outer conductor holes T02 surrounding the outer side of the TXV inner conductor hole T01 and forming a gap with the TXV inner conductor hole T01, an inner conductor hole pad P01 arranged at one end of the TXV inner conductor hole T01 close to the substrate 1, an inner conductor hole pad P21 arranged at one end of the TXV inner conductor hole T01 away from the substrate 1, a grounding conductor P03 arranged at one end of the TXV outer conductor hole T02 close to the substrate 1, and a grounding conductor P23 arranged at one end of the TXV outer conductor hole T02 away from the substrate 1; an inner-outer conductor hole gap P02 is formed between the grounding conductor P03 and the inner conductor hole pad P01, and an inner-outer conductor hole gap P22 is formed between the grounding conductor P23 and the inner conductor hole pad P21; the TXV inner conductor hole T01 and the TXV outer conductor hole T02 form a quasi-coaxial structure;

[0059] The elastic contact coaxial RF transmission structure A2 comprises an inner conductor column M01 in contact with the inner conductor hole pad P21, and multiple groups of outer conductor columns M02 surrounding the outer side of the inner conductor column M01 and forming a coaxial structure; the outer conductor column M02 is in contact with the ground conductor P23; specifically, the inner conductor column M01 and the outer conductor column M02 of the elastic contact coaxial RF transmission structure A2 are both elastic elements with a diameter of 0.3mm-0.7mm, such as wool buttons, micro springs, and spring needles;

[0060] The multiple groups of RF ports on the surface of one side of the packaging structure 3 close to the metal mounting base 5 form RF connections with the inner conductor column M01 and the outer conductor column M02 of the elastic contact coaxial RF transmission structure A2 integrated on the metal mounting base 5 by pressure contact through the inner conductor hole pad 2 P21 and the grounding conductor 2 P23.

[0061] Furthermore, the inner conductor column M01 is 1 group, and the outer conductor column M02 is 3-9 groups; the inner conductor column M01 and the outer conductor column M02 are isolated and structurally supported by an insulating medium such as polyethylene; the inner conductor column M01 and the outer conductor column M02 are fixed in the insulating medium, and the diameter of the ring formed by multiple groups of outer conductor columns M02 is determined according to the dielectric constant of the insulating medium, the size and number of the elastic elements, and the simulation results.

[0062] The TXV inner conductor hole T01 will be connected to the RF transmission line W01 in the packaging structure 3; the circular ring where the center of the multiple groups of TXV outer conductor holes T02 are located will be set on the outside of the TXV inner conductor hole T01 and form a quasi-coaxial structure with the TXV inner conductor hole T01, which can achieve RF shielding; the TXV outer conductor hole T02 is connected to the grounding conductor P23, and the inner and outer conductor hole gap P22 formed by etching the surface metal provides insulation isolation between the inner conductor hole pad P21 and the grounding conductor P23; the TXV inner conductor hole T01 and the TXV outer conductor hole T02 can be ceramic through-holes, silicon through-holes, and glass through-holes; the inner conductor hole pad P21, the inner and outer conductor hole gap P22, and the grounding conductor P23 form a concentric ring structure;

[0063] In some possible implementations, the axes of the TXV inner conductor hole T01, the inner conductor post M01, and the inner conductor hole pad 2 P21 are parallel to each other or on the same straight line;

[0064] The TXV inner conductor hole T01 is not preset at the center position of the inner conductor hole pad P21, while the inner conductor column M01 is preset at the center position of the inner conductor hole pad P21, only because of the position offset caused by structural errors such as the welding position of the packaging structure 3 on the substrate 1, the positioning of the substrate 1, and the elastic contact coaxial RF transmission structure A2 on the metal mounting base 5.

[0065] In some possible embodiments, the thermal interface layer 4 is a flexible thermally conductive pad whose thickness in a natural state is 0.3 mm to 1 mm; a hollow area for installing an inner conductor hole pad 2 P21, an inner and outer conductor hole gap 2 P22, and a grounding conductor 2 P23 is provided on the thermal interface layer 4; that is, except for the inner conductor hole pad 2 P21 and the grounding conductor 2 P23 adjacent inner area on the lower surface of the packaging structure 3, the rest of the lower surface of the packaging structure 3 is in contact with the metal mounting base 5 through the thermal interface layer 4. This arrangement will provide a low thermal resistance heat dissipation channel and at the same time have the function of buffering the pressure between the packaging structure 3 and the substrate 1, which is caused by the structural connection between the substrate 1 and the metal mounting base 5.

[0066] In some possible implementations, the diameter of the inner conductor hole pad P21 is d 04 , d 04 =d 05 -0.15mm-S 20 ;

[0067] Among them, d 05 S is the diameter of the circle where the center of the TXV outer conductor hole T02 is located; 20 is the size of the gap between the inner and outer conductor holes P22, S 20 =0.3mm~0.5mm;

[0068] By adopting the above arrangement, the diameter of the inner conductor hole pad 2 P21 and the size of the inner and outer conductor hole gap 2 are effectively increased compared with the prior art, thereby improving the tolerance of the RF port connection of the packaging structure 3 to manufacturing and installation errors.

[0069] In some possible implementations, in order to obtain a higher yield and reliability for multiple groups of SiP packaged RF array direct connection ports, in actual use, sufficient distance should be reserved from the inner conductor column M01 to the ground conductor 2 P23, and from the outer conductor column M02 to the inner conductor hole pad 2 P21 to prevent short circuit; this distance to prevent short circuit needs to be determined based on the total span size of the RF port array that needs to be interconnected on the multi-layer substrate 1. The larger the span size, the larger the distance to prevent short circuit should be; specifically, the span of the substrate 1 is LK, LK≤300mm;

[0070] like Fig.18 As shown, the distance between the inner conductor post M01 and the ground conductor P23, and the distance between the outer conductor post M02 and the inner conductor hole pad P21 are both S 21 , S 21 =0.1mm-0.15mm.

[0071] Furthermore, when LK≤100 mm, the distance S between the inner conductor post M01 and the second ground conductor P23, and the distance S between the outer conductor post M02 and the second inner conductor hole pad P21 is 21Both are 0.1mm;

[0072] When 100mm<LK≤300mm, the distance S between the inner conductor column M01 and the ground conductor P23, and the distance S between the outer conductor column M02 and the inner conductor hole pad P21 21 Both are 0.15mm.

[0073] In some possible embodiments, the packaging structure 3 is a multi-layer structure; including a plurality of metal dielectric layers stacked in layers, and a glass dielectric layer arranged between two adjacent metal dielectric layers; the metal dielectric layer and the glass dielectric layer located thereon form a packaging substrate; the TXV-type coaxial RF transmission structure A1 passes through at least one layer of the packaging substrate and contacts and cooperates with the elastic contact-type coaxial RF transmission structure A2.

[0074] In the present invention, multiple groups of packaging structures 3 are assembled on the substrate 1 by using the BGA2 surface mounting method. The multiple groups of packaging structures 3 and the substrate 1 form a whole. The substrate 1 is screwed to the metal mounting base 5 to achieve the structural connection between the radio frequency and the antenna radiation unit.

[0075] The present invention utilizes the pressure of the screw-mounted structure connection to make the TXV-type coaxial RF transmission structure A1 in the packaging structure 3 located on the surface of one side of the packaging structure 3 close to the metal mounting base 5 and the RF port (M01-M02) array of the elastic contact-type coaxial RF transmission structure A2 on the metal mounting base 5 closely and reliably contact each other, thereby realizing direct connection of multiple groups of packaging structures 3 to the RF ports on the antenna radiation surface, replacing the connection form of multiple transfers through the connector on the transfer substrate 1 in the prior art, shortening the connection path and reducing the connection loss;

[0076] Secondly, the multiple groups of packaging structures 3 assembled on the substrate 1 increase the diameter of the inner conductor hole pad 2 P21 and the size of the inner and outer conductor hole gap 2 P22. Based on the low sensitivity of the inner conductor hole pad 2 P21, the inner and outer conductor hole gap 2 P22, and the ground conductor 2 P23 to the RF port impedance, the ends of the inner conductor column M01 and the outer conductor column M02 have a larger tolerance size for misalignment with the inner conductor hole pad 2 P21 and the ground conductor 2 P23 located on the surface of the packaging structure 3 on one side close to the metal mounting base 5 in a two-dimensional plane without causing a short circuit, thereby achieving high-reliability RF interconnection of the RF port of the packaging structure 3 with a large span size in a two-dimensional plane.

[0077] Thirdly, by also utilizing the pressure of the screw-mounted structure connection, the thermal interface layer 4 made of the flexible thermally conductive pad is in contact with the metal mounting base 5 to achieve efficient heat dissipation of the multiple packaging structures 3 .

[0078] The present invention utilizes the characteristics of low sensitivity to port impedance of the inner conductor hole pad 2 P21 and the inner and outer conductor hole gap 2 P22 on the surface of the packaging structure 3. By expanding the diameter of the inner conductor hole pad 2 P21 and the size of the inner and outer conductor hole gap 2 P22, on the RF port contact surface, even if the RF port of the elastic contact coaxial RF transmission structure A2 deviates from the center of the inner conductor hole pad 2 P21, it can still ensure good RF performance, thereby ensuring the reliability of the RF vertical interconnection between the RF ports (P21-P22-P23) of multiple groups of packaging structures 3 with a larger span size and the RF ports of the elastic contact coaxial RF transmission structure A2 on the metal mounting base 5.

[0079] The center positions of the inner conductor post M01 and the inner conductor hole pad P21 are offset, and the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 are enlarged, so as to increase the distance between the inner conductor post M01 and the outer conductor post M02, that is, the diameter of the ring formed by multiple groups of outer conductor posts M02, and to increase the tolerance of the packaging structure 3 to the antenna radiation element RF direct connection to mounting, mechanical installation, processing and other tolerances; under the condition that the impedance of the TXV coaxial RF transmission structure A1 and the elastic contact coaxial RF transmission structure A2 is within the range of ±5% of 50Ω, there should be no obvious change in RF loss and transmission standing wave.

[0080] The capacitance of the TXV coaxial RF transmission structure A1 located in the inner and outer conductor hole gap P22 area on the surface of the packaging structure 3 close to the metal mounting base 5 is determined by the gap width and the air medium. When the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 increase, the capacitance increases slightly due to the unchanged thickness of the conductor film, so the port impedance changes very little, and the parameters of the RF feedthrough TXV coaxial RF transmission structure A1 of the packaging structure 3 and the elastic contact coaxial RF transmission structure A2 on the metal mounting base 5 do not change; therefore, the parasitic capacitance of the TXV coaxial RF transmission structure A1 located on the surface of the packaging structure 3 close to the metal mounting base 5 from the inner conductor hole pad P21 to the ground conductor P23 and the outer conductor column M02 all change slightly; that is, the present invention increases the diameter d of the inner conductor hole pad P21 by enlarging the diameter d of the inner conductor hole pad P21. 04 The size of the gap between the inner and outer conductor holes P22 has little effect on the RF performance.

[0081] Embodiment 1:

[0082] like Figure 1 , Figure 5 As shown, a high-tolerance vertical interconnect structure for a direct-connect port of a SiP packaged RF array, wherein the TXV-type coaxial RF transmission structure A1 adopts the TGV-type coaxial RF transmission structure, and the elastic contact-type coaxial RF transmission structure A2 adopts the wool button-type coaxial RF transmission structure, and the two cooperate to form a transition structure;

[0083] Specifically, Figure 5 As shown, the packaging structure 3 is a four-layer stacked glass-based MEMS packaging structure; the glass-based MEMS packaging structure includes multiple metal dielectric layers and multiple glass dielectric layers, the glass dielectric layer is located between two adjacent metal dielectric layers, and the multiple metal dielectric layers are J30, J31, J32, J33, and J34 from top to bottom; wherein, J30 and J34 are respectively located on the upper surface and the lower surface of the packaging structure 3, J32 is the signal layer in the packaging structure 3, which is provided with a radio frequency transmission line W01; the multiple glass dielectric layers are L30, L31, L32, and L33 from top to bottom; in this embodiment, the TXV-type coaxial radio frequency transmission structure A1 will pass through two layers of packaging substrates, for which three pads P11 and three grounding conductors P13 will be added, and three inner and outer conductor hole gaps P12 will be formed.

[0084] The TXV inner conductor hole T01 and the TXV outer conductor hole T02 pass through the glass dielectric layer L32 and the glass dielectric layer L33 in sequence, and the inner conductor hole pad 2 P21 and the ground conductor 2 P23 are located on the lower surface of the packaging structure 3; the top ends of the inner conductor column M01 and the outer conductor column M02 are in contact with the inner conductor hole pad 2 P21 and the ground conductor 2 P23 respectively.

[0085] The glass dielectric layer is alkali-free glass dielectric AF32, with a relative dielectric constant of 5.1 and a loss factor of 0.0035. Each layer of glass substrate 1 is 300 μm thick. The gap between the RF transmission line W01 and the metal dielectric layer J32 is s 01 The width of the RF transmission line W01 is 50 μm, and the width of the RF transmission line W01 is 80 μm; the RF transmission line W01 is connected to the TXV inner conductor hole T01; the TXV inner conductor hole T01 passes through the glass dielectric layer L32 to connect to the pad three P11 on the metal layer J33, and the TXV inner conductor hole T01 passes through the glass dielectric layer L33 to connect to the inner conductor hole pad two P21 on the lower surface of the packaging structure 3, and the other end of the TXV inner conductor hole T01 is connected to the inner conductor hole pad one P01 on the metal dielectric layer J32;

[0086] Seven TXV outer conductor holes T02 penetrating the glass dielectric layer L32 and eight TXV outer conductor holes T02 penetrating the glass dielectric layer L33 are designed on the glass dielectric layer L32 to serve as the outer conductor structure of the TGV-type coaxial RF transmission structure; one group of the eight TXV outer conductor holes T02 penetrating the glass dielectric layer L33 is blocked by the RF transmission line W01 and cannot pass through, so there are only seven TXV outer conductor holes T02 penetrating the glass dielectric layer L32.

[0087] The ground plane of the RF transmission line W01 is connected to the ground conductor one P03 of the TGV coaxial RF transmission structure, the seven TXV outer conductor holes T02 pass through the glass dielectric layer L32 to be connected to the ground conductor three P13 of the metal dielectric layer J33, and the eight TXV outer conductor holes T02 pass through the glass dielectric layer L33 to be connected to the ground conductor two P23 on the package surface; all the TXV outer conductor holes T02 are symmetrical with respect to the inner conductor hole pad one P01 and are distributed at equal angles with respect to the center line of the inner conductor hole pad one P01.

[0088] like Figure 6-Figure 8 As shown in the simulation model, the elastic contact coaxial RF transmission structure A2 adopts a diameter d 06 A hair button with a diameter of 0.5 mm is used as the inner conductor column M01, and 6 hair buttons are used as the outer conductor column M02 to realize the function of the grounding shielding column. The outer conductor column M02 is symmetrically distributed relative to the inner conductor column M01. The diameter d formed by the center line of the outer conductor column M02 is 07 It is a 2.05mm ring.

[0089] During simulation modeling, the inner conductor column M01 is first fixed concentrically with the inner conductor hole pad P21, and the transmission effect of enlarging the diameter of the inner conductor hole pad P21 and the inner and outer conductor hole gap P22 is verified through simulation.

[0090] Simulation models and parameters, such as Figure 9-14 As shown, the diameter d of the inner conductor hole pad P21 is set 04 They are 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm and 0.8mm respectively. The size of the gap between the inner and outer conductor holes P22 is s 20 Different parameters were set; the results showed that the diameter d of the inner conductor hole pad P21 04 Below 0.8mm, the size of the gap between the inner and outer conductor holes P22 is s 20 When the diameter of the inner conductor hole pad P21 varies from 0.1mm to 0.5mm (the diameter of the inner conductor hole pad P21 exceeds 0.6mm, and the inner and outer conductor hole gap P22 cannot reach 0.5mm due to the limitation of the grounding TGV through-hole process), the maximum value of the port dB is lower than -15dB; and then removing the case where the inner conductor hole pad P21 and the inner and outer conductor hole gap P22 are 0.1mm, the maximum value of the port reflection is lower than -20dB; it can be seen that the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 vary within a large range, which will not significantly affect the RF transmission performance of the transition structure of the TGV-type coaxial to the button-type coaxial.

[0091] Through simulation, the transmission effect of enlarging the diameter of the inner conductor hole pad P21, the size of the inner and outer conductor hole gap P22, and the misalignment (or offset) of the center of the inner conductor column M01 and the center of the inner conductor hole pad P21 is verified, and the S parameters of the transition structure model are used to characterize the RF transmission performance; Figure 15 to Figure 17 The simulation results shown verify that enlarging the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 has little effect on the transmission performance; the simulation results verify that the center of the misaligned (or offset) button-like coaxial RF transmission structure and the center of the inner conductor hole pad P21 are within ±0.2mm, and the transmission performance is also slightly affected. When the position of the inner conductor hole pad P21 is greatly offset (maximum ±0.2mm) in the present invention, the RF transmission result is less affected. At the high-end frequency point (13GHz) of the simulated bandwidth, the loss increases from 0.33dB to 0.52dB, and the maximum reflection value is close to -28dB.

[0092] The present invention can be used for low-loss, high-reliability RF interconnection applications between DC-30GHz multiple groups of non-uniformly arranged SiP packages or package arrays with RF input or output ports and multiple groups of non-uniformly arranged or arrayed RF ports; the concentricity deviation of the TXV coaxial RF transmission structure A1 and the elastic contact coaxial RF transmission structure A2 reaches more than ±0.2mm, and under normal processing and assembly accuracy (the overall position accuracy is less than 0.3%), it can meet the RF port of the package structure with a lateral span of up to 90mm, and directly connect from the package to the antenna radiation unit or to the rear-end local oscillator and RF signal.

[0093] The present invention increases the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22, and utilizes the expansion and contraction of the longitudinal strain pressure of the elastic contact coaxial RF transmission structure A2, thereby realizing high-reliability RF direct interconnection of large-scale RF array ports based on the package surface pad, reducing the connection loss of the RF T / R component, and improving the connection scale and RF connection reliability of the "tile-type" RF T / R component of the active phased array antenna. From the simulation results, it can be seen that the insertion loss of a complete TGV-type coaxial-hair button-type coaxial transition structure is lower than -0.052dB in the full frequency band from 0.8GHz to 13GHz, and the reflection is less than -28dB.

[0094] In order to obtain a greater tolerance for the port alignment deviation, the diameter d of the inner conductor column M01 of the elastic contact-like coaxial RF transmission structure A2 is 06The size is 0.63mm, and the diameter of the outer conductor column M02 is 0.5mm; the diameter of the circle where the center of the multiple groups of outer conductor columns M02 is located is 2.6mm; the number of TXV inner hole T01 through holes is increased to 2, the diameter of the inner conductor hole pad P21 is increased to 0.8mm, and the size of the inner and outer conductor hole gap P22 is expanded to 1.8mm; when the position is offset by ±0.5mm or offset by ±0.4mm in both directions of the two-dimensional plane, the elastic contact type coaxial radio frequency transmission structure A2 and the TXV type coaxial radio frequency transmission structure A1 are not short-circuited; combined with Figure 9-14 From the simulation results, it can be seen that when the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 increase synchronously, it is more conducive to reducing reflection and obtaining better port performance; it can be seen that the trend of changing with the diameter of the inner conductor hole pad P21 and the size of the inner and outer conductor hole gap P22 is conducive to obtaining a larger tolerance.

[0095] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A high-tolerance vertical interconnect structure for direct connection ports of SiP packaged radio frequency arrays, characterized in that: It includes a substrate, a BGA, a packaging structure, a thermal interface layer, and a metal mounting base stacked from top to bottom; A TXV-type coaxial radio frequency transmission structure and a radio frequency transmission line connected to the TXV-type coaxial radio frequency transmission structure are arranged in the packaging structure; An elastic contact type coaxial radio frequency transmission structure that contacts and cooperates with the TXV type coaxial radio frequency transmission structure is arranged in the metal mounting base; The other end of the elastic contact coaxial RF transmission structure passes through the metal mounting base and is connected to the antenna RF port, the rear RF transmission excitation or the RF receiver port; The other end of the TXV type coaxial radio frequency transmission structure is soldered on the substrate through BGA.

2. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 1, characterized in that: The TXV coaxial radio frequency transmission structure is a TGV coaxial radio frequency transmission structure, a TCV coaxial radio frequency transmission structure or a TSV coaxial radio frequency transmission structure; The TXV-type coaxial radio frequency transmission structure is connected to the radio frequency transmission line, and comprises a TXV inner conductor hole and a plurality of groups of TXV outer conductor holes surrounding the outer side of the TXV inner conductor hole and forming a gap between the TXV inner conductor hole and the TXV inner conductor hole.

3. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 2, characterized in that: The TXV-like coaxial radio frequency transmission structure also includes an inner conductor hole pad 1 arranged at one end of the TXV inner conductor hole close to the substrate, an inner conductor hole pad 2 arranged at one end of the TXV inner conductor hole away from the substrate, a grounding conductor 1 arranged at one end of the TXV outer conductor hole close to the substrate, and a grounding conductor 2 arranged at one end of the TXV outer conductor hole away from the substrate; an inner and outer conductor hole gap 1 is formed between the grounding conductor 1 and the inner conductor hole pad 1, and an inner and outer conductor hole gap 2 is formed between the grounding conductor 2 and the inner conductor hole pad 2; the TXV inner conductor hole and the TXV outer conductor hole constitute a quasi-coaxial structure.

4. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 3, characterized in that: The elastic contact quasi-coaxial radio frequency transmission structure comprises an inner conductor column which contacts and cooperates with the second inner conductor hole pad, and a plurality of groups of outer conductor columns which surround the outer side of the inner conductor column and form a quasi-coaxial structure; the outer conductor column contacts and cooperates with the second grounding conductor.

5. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 4, characterized in that: The axes of the TXV inner conductor hole, the inner conductor column and the inner conductor hole pad 2 are parallel to each other or on the same straight line.

6. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 3, characterized in that: A hollow area for mounting a second inner conductor hole pad, a second inner and outer conductor hole gap, and a second grounding conductor is arranged on the thermal interface layer.

7. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 3, characterized in that: The diameter of the inner conductor hole pad 2 is d 04 , d 04 =d 05 -0.15mm-S 20 ; Among them, d 05 S is the diameter of the circle where the center of the TXV outer conductor hole is located; 20 is the size of the gap between the inner and outer conductor holes, S 20 =0.3mm~0.5mm.

8. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 4, characterized in that: The span of the substrate is LK, LK≤300mm; The distance between the inner conductor column and the second ground conductor, and the distance between the outer conductor column and the second inner conductor hole pad are S 21 , S 21 =0.1mm-0.15mm.

9. A high tolerance vertical interconnect structure for direct connection ports of SiP packaging radio frequency arrays according to claim 8, characterized in that: When LK≤100mm, the distance S between the inner conductor column and the ground conductor 2, and the distance S between the outer conductor column and the inner conductor hole pad 2 21 Both are 0.1mm; When 100mm<LK≤300mm, the distance S between the inner conductor column and the second ground conductor, and between the outer conductor column and the second inner conductor hole pad is 21 Both are 0.15mm.

10. A high-tolerance vertical interconnect structure for a direct-connect port of a SiP packaged radio frequency array according to any one of claims 1 to 8, characterized in that: The packaging structure is a multi-layer structure; it includes multiple metal dielectric layers stacked in layers, and a glass dielectric layer arranged between two adjacent metal dielectric layers; the metal dielectric layer and the glass dielectric layer located above it form a packaging substrate; the TXV-type coaxial RF transmission structure passes through at least one packaging substrate and contacts and cooperates with the elastic contact-type coaxial RF transmission structure.

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