A broadband SIP three-dimensional interconnected transmission structure

Abstract

The present invention discloses a broadband SIP three-dimensional interconnection transmission structure, which includes an upper board transmission structure, a lower board transmission structure, and a ball array; the upper board transmission structure includes a coplanar waveguide, a coplanar waveguide to a quasi-coaxial matching disk, a first type of coaxial, and a quasi-coaxial to ball array matching disk, and the lower board transmission structure includes a ball array to quasi-coaxial matching disk, a second type of coaxial, a quasi-coaxial to stripline matching disk, and a stripline; the ball array includes a radio frequency ball at the center and ground balls arranged in an array around the radio frequency ball. The first and second types of coaxial include a radio frequency inner core and ground holes arranged around the radio frequency inner core, and the radio frequency inner core is welded and installed in alignment with the radio frequency ball; both the ball array to quasi-coaxial matching disk and the quasi-coaxial to ball array matching disk include a center pad, a second anti-pad, and a transmission ground. The upper and lower board transmission structures are welded to the radio frequency balls of the ball array through the center pads, and the transmission grounds are welded through the ground balls of the ball array. The present invention can achieve broadband radio frequency transmission characteristics and improve the integration degree of electronic devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency and microwave, and particularly relates to a broadband SIP three-dimensional interconnection transmission structure. Background Art

[0002] Currently, the integration degree of electronic devices is getting higher and higher. The traditional brick-like two-dimensional module has a large volume and can no longer meet the development requirements. The microwave module needs to develop towards the goals of being lightweight, miniaturized, highly integrated, and broadband. With the continuous progress of current technology, advanced packaging interconnection technologies have been widely used. The module develops from the traditional two-dimensional architecture to a three-dimensional architecture, and multiple chips, devices, etc. are integrated together through advanced packaging technologies to form a micro-system with independent functions.

[0003] The development of the micro-system requires a matching interconnection technology. Traditional radio frequency cables, connectors, and pin buttons have a large volume and a low interconnection density, and cannot meet the requirements of lightweight, miniaturization, and broadband of the module. There is an urgent need to solve the high-density interconnection requirements brought by high integration under broadband applications. Summary of the Invention

[0004] The purpose of the present invention is to provide a broadband SIP three-dimensional interconnection transmission structure, which can achieve broadband radio frequency transmission characteristics and improve the integration degree of electronic devices.

[0005] One aspect of the present invention provides a broadband SIP three-dimensional interconnection transmission structure, which includes an upper board transmission structure, a lower board transmission structure, and a ball array. The upper board transmission structure is connected to the lower board transmission structure through the ball array;

[0006] The upper board transmission structure includes a coplanar waveguide, a coplanar waveguide to coaxial-like matching disk, a first type of coaxial, and a coaxial to ball array matching disk. The lower board transmission structure includes a ball array to coaxial-like matching disk, a second type of coaxial, a coaxial to stripline matching disk, and a stripline;

[0007] The ball array includes a radio frequency ball located at the center of the array and ground balls arranged in a rectangular array around the radio frequency ball. The first type of coaxial and the second type of coaxial include a radio frequency inner core and ground holes evenly arranged around the radio frequency inner core. The radio frequency inner core is welded in place with the radio frequency ball;

[0008] The upper board transmission structure and the lower board transmission structure include multiple metal layers, and each metal layer is provided with a first anti-welding pad. The first anti-welding pad forms a radio frequency signal path with the radio frequency inner core and the ground holes;

[0009] Both the ball array to the quasi-coaxial matching disk and the quasi-coaxial to ball array matching disk include a center pad, a second anti-pad, and a transmission ground. The upper board transmission structure and the lower board transmission structure are welded to the RF balls of the ball array through the center pad, and the transmission grounds are welded through the ground balls of the ball array.

[0010] Preferably, the RF inner core includes a first type of coaxial RF inner core and a second type of coaxial RF inner core. The grounding holes include a first grounding hole and a second grounding hole surrounding the first type of coaxial RF inner core, and a third grounding hole and a fourth grounding hole surrounding the second type of coaxial RF inner core.

[0011] Preferably, the upper board transmission structure is an 8-layer board composed of 8 metal layers, and the lower board transmission structure is a 4-layer board composed of 4 metal layers.

[0012] Preferably, the first type of coaxial RF inner core is a metallized through hole from the 1st metal layer to the 8th metal layer, the first grounding hole is a metallized through hole from the 1st metal layer to the 8th metal layer, and the second grounding hole is a metallized blind hole from the 2nd metal layer to the 8th metal layer;

[0013] The second type of coaxial RF inner core is a metallized through hole from the 1st metal layer to the 4th metal layer, the third grounding hole is a metallized through hole from the 1st metal layer to the 4th metal layer, and the fourth grounding hole is a metallized blind hole from the 1st metal layer to the 2nd metal layer.

[0014] Preferably, the broadband SIP three-dimensional interconnection transmission structure further includes RF ground holes and RF holes, which are arranged around the coplanar waveguide and the microstrip line to ensure signal transmission in a relatively enclosed area.

[0015] Preferably, both the upper board transmission structure and the lower board transmission structure are made of the high-frequency circuit board CLTE-XT.

[0016] Preferably, the ball diameter of the ground ball is 0.5 mm, the ball pitch is 0.8 mm, and the center section impedance of the ball array is 50 ohms.

[0017] Preferably, the signal transmission direction of the coplanar waveguide and the signal transmission direction of the microstrip line are set to 180°.

[0018] Preferably, the structural impedance of the first type of coaxial and the second type of coaxial is set to 50 ohms.

[0019] According to the broadband SIP three-dimensional interconnection transmission structure in the above aspect of the present invention, wideband RF transmission characteristics can be achieved, and the integration degree of electronic devices can be improved. Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the present invention, the following will briefly introduce the drawings used in the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings:

[0021] Figure 1 is a schematic diagram of a broadband SIP three-dimensional interconnection transmission structure according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of an upper board transmission structure according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of a lower board transmission structure according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of a ball array according to an embodiment of the present invention;

[0025] Figure 5 is a cross-sectional schematic diagram of the first and second types of coaxial according to an embodiment of the present invention;

[0026] Figure 6 is a schematic diagram of a coaxial-like to ball array matching disk and a ball array to coaxial-like matching disk according to an embodiment of the present invention;

[0027] Figure 7 is a standing wave curve graph according to an embodiment of the present invention;

[0028] Figure 8 is a differential loss curve graph according to an embodiment of the present invention;

[0029] Figure 9 is a schematic diagram of a SiP interconnection assembly application according to an embodiment of the present invention. Specific Embodiments

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0031] An embodiment of the present invention provides a broadband SIP three-dimensional interconnection transmission structure, as Figures 1 - 3As shown in the figure, the broadband SIP three-dimensional interconnection transmission structure of the embodiment of the present invention includes an upper board transmission structure 1, a lower board transmission structure 2, and a ball array 3. Among them, the upper board transmission structure 1 includes a coplanar waveguide 4, a coplanar waveguide to quasi-coaxial matching disk 5, a first type of coaxial 7, and a quasi-coaxial to ball array matching disk 6; the lower board transmission structure 2 includes a ball array to quasi-coaxial matching disk 16, a second type of coaxial 25, a quasi-coaxial to stripline matching disk 8, and a stripline 9. The upper board transmission structure 1 and the lower board transmission structure 2 are connected by the ball array 3. Radio frequency ground holes and radio frequency holes 26 are arranged around the coplanar waveguide 4 and the stripline 9 to ensure signal transmission in a relatively enclosed area. Both the upper board transmission structure 1 and the lower board transmission structure 2 are made of a high-frequency circuit board CLTE-XT.

[0032] Both the upper board transmission structure 1 and the lower board transmission structure 2 include multiple metal layers, and the number of metal layers is not fixed and can be freely set according to actual needs in actual use. In this embodiment, the upper board transmission structure 1 is an 8-layer board composed of 8 metal layers 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, and 1-8, and the lower board transmission structure 2 is a 4-layer board composed of 4 metal layers 2-1, 2-2, 2-3, and 2-4.

[0033] As Figure 4 shown in the figure, the ball array 3 is composed of a radio frequency ball 23 at the center of the array and ground balls 24 arranged in a rectangular array around it. The ball diameter of the ground balls 24 is 0.5 mm, and the ball pitch is 0.8 mm. The center section impedance of the ball array 3 is 50 ohms. The ball array 3 realizes the connection of radio frequency signals and at the same time plays a supporting role for the upper board transmission structure 1.

[0034] As Figure 5 shown in the figure, both the first type of coaxial 7 and the second type of coaxial 25 are composed of a radio frequency inner core 17 and ground holes 18 uniformly arranged around the radio frequency inner core 17 at a certain distance. At the same time, a first anti-welding pad 19 is provided on each layer, jointly constituting a radio frequency signal path. The structural impedance of the first type of coaxial 7 and the second type of coaxial 25 is set to 50 ohms, ensuring the impedance consistency before and after the change of the number of upper and lower boards, and realizing the free setting of the number of layers of this broadband transmission structure. During the installation process, the radio frequency inner cores 17 in the first type of coaxial 7 and the second type of coaxial 25 are accurately aligned and welded to the radio frequency balls 23 of the ball array 3.

[0035] The radio frequency inner core 17 includes the radio frequency inner core 15 of the first type of coaxial 7 and the radio frequency inner core of the second type of coaxial 25. The ground holes 18 include the first ground holes 11 and the second ground holes 12 around the radio frequency inner core 15 of the first type of coaxial 7 and the third ground holes 14 and the fourth ground holes 13 around the radio frequency inner core of the second type of coaxial 25.

[0036] For the first type of coaxial 7, the RF inner core 15 is a metallized via hole from the 1st metal layer 1-1 to the 8th metal layer 1-8. The first ground hole 11 is a metallized via hole from the 1st metal layer 1-1 to the 8th metal layer 1-8. The second ground hole 12 is a metallized blind hole from the 2nd metal layer 1-2 to the 8th metal layer 1-8. For the second type of coaxial 25, the RF inner core is a metallized via hole from the 1st metal layer 2-1 to the 4th metal layer 2-4. The third ground hole 14 is a metallized via hole from the 1st metal layer 2-1 to the 4th metal layer 2-4. The fourth ground hole 13 is a metallized blind hole from the 1st metal layer 2-1 to the 2nd metal layer 2-2.

[0037] As Figure 6 shown, both the ball array to the coaxial-like matching disk and the coaxial-like to the ball array matching disk include a center pad 20, a second anti-pad 21, and a transmission ground 22. The upper board transmission structure 1 and the lower board transmission structure 2 are welded to the RF balls 23 of the ball array 3 through the center pad 20, and the transmission grounds 22 are welded through the ground balls 24 of the ball array 3, ensuring good connection and signal transmission effect between the upper board transmission structure 1 and the lower board transmission structure 2.

[0038] The upper board transmission structure 1 and the lower board transmission structure 2 can be adjusted at any angle in the RF signal transmission direction. In the embodiment of the present invention, the signal transmission directions of the coplanar waveguide 4 and the stripline 9 are set to 180°.

[0039] The entire transmission structure forms a good grounding and signal shielding effect through RF ground holes, coaxial-like ground holes 18, and ground balls 24, ensuring high-quality signal transmission.

[0040] Figure 7 and Figure 8 respectively reflect the standing wave and insertion loss of the broadband SIP three-dimensional interconnection transmission structure in the embodiment of the present invention. It can be seen that the standing wave in the DC-52GHz range is not higher than 1.28, and the insertion loss is better than 0.195, proving that the transmission structure in the embodiment of the present invention has good broadband RF transmission characteristics, and the transmission structure is small in volume and can meet the requirements of high integration of electronic devices.

[0041] Figure 9 shows the application of the transmission structure in the embodiment of the present invention in SIP interconnection assembly. The upper board transmission structure 1 is respectively placed in module A and module B, and the lower board transmission structure 2 is placed in the motherboard. Module A and module B are connected to the motherboard through the ball array. The RF signal is transmitted through the upper board transmission structure in module A to the ball array, transmitted through the ball array to the stripline, transmitted through the stripline in the motherboard to the ball array at module B, and then transmitted to the upper board transmission structure inside module B to realize signal interconnection and assembly of the SIP module on the motherboard.

[0042] According to the broadband SIP three-dimensional interconnection transmission structure of the above embodiments of the present invention, the in-board signals are converted from horizontal transmission to coaxial-like vertical direction transmission, and the electrical connection and physical support are realized through ball arrays between the boards, completing the transition of radio frequency signals from horizontal transmission to vertical transmission and then to horizontal transmission. It can flexibly realize broadband three-dimensional signal transmission interconnection, and can be widely applied to the internal interconnection of multi-layer SIPs. At the same time, it can also be used for the port lead-out structure when SIPs are assembled on the motherboard and the interconnection and assembly structure between SIPs.

[0043] The broadband SIP three-dimensional interconnection transmission structure of the embodiments of the present invention has good matching effect, can achieve good radio frequency transmission, meets the requirements of current electronic devices for broadband performance, well solves the problem that the previous ones could not cover the broadband, and at the same time has a small volume, which is beneficial to the improvement of the integration degree of electronic devices.

[0044] Only some exemplary embodiments of the present invention have been described above by way of illustration. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the protection scope of the claims of the present invention.

Claims

1. A broadband SIP three-dimensional interconnection transmission structure, characterized in that: It includes an upper plate transmission structure, a lower plate transmission structure and a ball array, wherein the upper plate transmission structure and the lower plate transmission structure are connected via the ball array; The upper plate transmission structure includes coplanar waveguide, coplanar waveguide to quasi-coaxial matching plate, first type coaxial, quasi-coaxial to ball array matching plate, and the lower plate transmission structure includes ball array to quasi-coaxial matching plate, second type coaxial, quasi-coaxial to stripline matching plate, and stripline; The ball array includes a radio frequency ball located at the center of the array and a ground ball arranged in a rectangular array around the radio frequency ball. The first type coaxial and the second type coaxial include a radio frequency inner core and ground holes evenly arranged around the radio frequency inner core. The radio frequency inner core and the radio frequency ball are welded and installed in position. The upper plate transmission structure and the lower plate transmission structure include a plurality of metal layers, each metal layer is provided with a first anti-pad, and the first anti-pad, the RF inner core and the grounding hole form a RF signal path; The ball array to quasi-coaxial matching plate and the quasi-coaxial to ball array matching plate both include a central pad, a second anti-pad and a transmission ground, the upper plate transmission structure and the lower plate transmission structure are welded to the RF ball of the ball array via the central pad, and the transmission grounds are welded via the ground ball of the ball array; The RF inner core includes a first type of coaxial RF inner core and a second type of coaxial RF inner core, and the grounding holes include a first grounding hole and a second grounding hole surrounding the first type of coaxial RF inner core and a third grounding hole and a fourth grounding hole surrounding the second type of coaxial RF inner core; The upper plate transmission structure is an 8-layer plate composed of 8 metal layers, and the lower plate transmission structure is a 4-layer plate composed of 4 metal layers; The RF inner core of the first type of coaxial cable is a metallized through hole from the first metal layer to the eighth metal layer, the first grounding hole is a metallized through hole from the first metal layer to the eighth metal layer, and the second grounding hole is a metallized blind hole from the second metal layer to the eighth metal layer; The RF inner core of the second type of coaxial cable is a metallized through hole from the first metal layer to the fourth metal layer, the third grounding hole is a metallized through hole from the first metal layer to the fourth metal layer, and the fourth grounding hole is a metallized blind hole from the first metal layer to the second metal layer.

2. The broadband SIP three-dimensional interconnection transmission structure according to claim 1 is characterized in that: It also includes radio frequency ground holes and radio frequency holes, which are arranged around the coplanar waveguide and the strip line to ensure that the signal is transmitted in a relatively closed area.

3. The broadband SIP three-dimensional interconnection transmission structure according to claim 1 is characterized in that: The upper plate transmission structure and the lower plate transmission structure are both made of a high-frequency circuit board CLTE-XT.

4. The broadband SIP three-dimensional interconnection transmission structure according to claim 1 is characterized in that: The ball diameter of the ground ball is 0.5 mm, the ball spacing is 0.8 mm, and the central cross-sectional impedance of the ball array is 50 ohms.

5. The broadband SIP three-dimensional interconnection transmission structure according to claim 1 is characterized in that: The signal transmission direction of the coplanar waveguide and the signal transmission direction of the strip line are set to 180°.

6. The broadband SIP three-dimensional interconnection transmission structure according to claim 1, characterized in that: The structural impedance of the first type coaxial and the second type coaxial is set to 50 ohms.

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