Package substrate for radio frequency components and radio frequency module package structure

Abstract

The application provides a packaging substrate for a radio frequency element and a radio frequency module packaging structure, the packaging substrate for the radio frequency element comprising a substrate body, a radio frequency transmission pad and a ground pad being arranged on a surface of the substrate body, the ground pad being arranged at the periphery of the radio frequency transmission pad, and the radio frequency transmission pad and the ground pad being arranged in a spaced manner, and a ring-shaped isolation space being formed between the radio frequency transmission pad and the ground pad. The packaging substrate cancels the existing BGA pad design, does not use BGA solder balls, and adopts a direct welding mode of the pad through welding material, so as to avoid problems such as solder ball cracks or breakage, low glue heat conduction efficiency and the like.

Description

Technical Field

[0001] This invention relates to the field of packaging structure technology, and in particular to a packaging substrate and a packaging structure for radio frequency components. Background Technology

[0002] System-in-Package (SiP) is a semiconductor packaging technology that integrates multiple components such as chips, sensors, and analog-to-digital converters into a single package to achieve system functions. It features small size and low power consumption and can be widely used in wireless communication modules, portable communication products, etc.

[0003] In the packaging design of radio frequency (RF) components (such as RF chips), the design of the pads on the packaging substrate is crucial, as it directly determines the loss of RF signals transmitted by the RF component and the RF grounding situation. Currently, there are generally two design schemes for the pads of such packaging substrates on the market: The first type uses a long strip pad design similar to QFN (Quad Flat No-leads Package). This QFN pad design will result in some RF signal loss and some radiated interference. QFN pad design can be used for RF components with low loss requirements and low operating frequency bands.

[0004] The second type is to use a concentric circle pad design similar to BGA (Ball Grid Array). This BGA pad design has better EMI (Electromagnetic Interference) radiated interference power than the QFN pad design. Therefore, most RF components that operate under high power and high frequency conditions currently use the BGA pad design.

[0005] BGA pad design involves placing solder balls on the surface of the package substrate. During soldering, the solder balls melt and connect the package substrate and the circuit board, achieving both mechanical and electrical connections. However, this BGA pad design has several problems in practical use: the solder balls are prone to stress cracking after multiple thermal stress cycles, affecting the reliability of the electrical connection. Furthermore, the solder balls require the use of underfill adhesive during soldering. Since underfill adhesives are typically epoxy or silicone-based, mismatch between them and the copper layer at the bottom of the pad can easily occur, leading to solder ball breakage. Additionally, due to the low thermal conductivity of underfill adhesives, high-power devices are prone to device or package failure after multiple thermal cycles. Summary of the Invention

[0006] The purpose of this invention is to provide a packaging substrate for radio frequency components that eliminates the existing BGA pad design and does not use BGA solder balls. Instead, it uses a direct soldering method with soldering materials on the pads, thereby avoiding problems such as solder ball cracking or breakage and low thermal conductivity of adhesive.

[0007] The present invention provides a packaging substrate for radio frequency components, including a substrate body. The surface of the substrate body is provided with radio frequency transmission pads and ground pads. The ground pads are disposed around the radio frequency transmission pads and are spaced apart from the ground pads, forming an annular isolation space between the radio frequency transmission pads and the ground pads.

[0008] In one possible implementation, the RF transmission pad is circular and the isolation space is annular.

[0009] In one feasible manner, a plurality of conductive micro-protrusions are spaced apart on the surface of the grounding pad.

[0010] In one possible implementation, the diameter of the conductive microbump is D1, and the diameter of the RF transmission pad is D2, 1 / 3. D2≤D1≤D2.

[0011] In one possible implementation, the center-to-center distance between two adjacent conductive microbumps is L1, the diameter of the conductive microbump is D1, and the radius of the conductive microbump is r, where r ≤ L1 ≤ 2. D1.

[0012] In one possible implementation, the plurality of conductive microbumps includes at least a plurality of first conductive microbumps, which are uniformly spaced and arranged around the periphery of the isolation space.

[0013] In one possible implementation, the distance between the outer wall of the first conductive microprotrusion and the outer ring edge of the isolation space is L2, and the radius of the conductive microprotrusion is r, 0≤L2≤r.

[0014] In one possible implementation, the plurality of conductive microbumps further includes a plurality of second conductive microbumps disposed on the side of the plurality of first conductive microbumps away from the isolation space.

[0015] In one feasible manner, at least 75% of the surface area of ​​the grounding pad is provided with the conductive micro-protrusions.

[0016] In one possible implementation, conductive microbumps are provided on the surface of the radio frequency transmission pad.

[0017] In one possible implementation, the diameter of the conductive microbumps is smaller than the diameter of the RF transmission pads.

[0018] In one possible implementation, the conductive microbumps have the same height as the conductive microbumps; And / or, the height of the conductive microbumps and the conductive micro-bumps are both 0.05mm~1mm.

[0019] The present invention also provides an RF module packaging structure, including an RF chip, an adapter board, and a packaging substrate for RF components as described above. The RF chip is disposed on the side of the substrate body away from the RF transmission pad, and the RF chip is electrically connected to the RF transmission pad and the ground pad. The adapter board is disposed on the side of the substrate body away from the RF chip, and the RF transmission pad and the ground pad are both soldered to the adapter board by soldering material.

[0020] The present invention provides a packaging substrate for radio frequency (RF) components, which has RF transmission pads and ground pads on its surface. These pads are directly soldered to an adapter board using soldering material, eliminating the need for existing BGA pad designs. This avoids problems such as solder ball cracking or breakage, low thermal conductivity of the adhesive, and reduces manufacturing complexity. Furthermore, to prevent the soldering material at the ground pad from molten and overflowing onto the RF transmission pad during soldering, thus preventing a short circuit, an annular isolation space is provided between the RF transmission pads and the ground pad. This isolation space is designed to prevent soldering material from overflowing, thereby avoiding short circuits between the RF transmission pads and the ground pad during soldering. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the packaging substrate in an embodiment of the present invention.

[0022] Figure 2 for Figure 1 A schematic diagram of the structure after removing the conductive micro-bumps and conductive micro-protrusions.

[0023] Figure 3 for Figure 1 Side view.

[0024] Figure 4 for Figure 3 A magnified view of a portion of location A in the diagram.

[0025] Figure 5 This is a schematic diagram of the packaging substrate in another embodiment of the present invention.

[0026] Figure 6This is a partially enlarged schematic diagram of a side view of the packaging substrate in another embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the radio frequency module packaging structure in an embodiment of the present invention.

[0028] Figure 8 for Figure 7 A schematic diagram of the connection structure between the intermediate packaging substrate and the adapter board. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention. It should be noted that the drawings are all in simplified form and use non-precise ratios, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0030] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] The directional terms such as "up," "down," "left," "right," "front," "back," "top," and "bottom" (if present) used in the specification and claims of this invention are defined by the position of the structures in the drawings and the relative positions of the structures, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional terms should not limit the scope of protection claimed by this invention.

[0032] like Figures 1 to 4 and Figure 7 and Figure 8 As shown, this embodiment of the invention provides a packaging substrate 1 for radio frequency (RF) components, which can be soldered to an adapter board 3. The packaging substrate 1 includes a substrate body 11, on the surface of which are provided RF transmission pads 12 and ground pads 13. The RF transmission pads 12 are used to transmit RF signals, and the ground pads 13 are used to transmit ground current and also serve a heat dissipation function. The ground pads 13 are disposed around the RF transmission pads 12, and the RF transmission pads 12 and 13 are spaced apart, forming an annular isolation space 10 around the RF transmission pads 12.

[0033] In this embodiment, the RF transmission pad 12 has a circular structure, and the isolation space 10 has a ring-shaped structure. The isolation space 10 and the RF transmission pad 12 are concentrically arranged, that is, their centers coincide. Of course, when the RF transmission pad 12 has other shapes, the isolation space 10 can also be a ring-shaped structure of other shapes.

[0034] In this embodiment, there are multiple RF transmission pads 12, which are spaced apart, and each RF transmission pad 12 is surrounded by an isolation space 10. In this embodiment, there are two RF transmission pads 12, but in other embodiments, there may be more.

[0035] In this design, both the RF transmission pad 12 and the ground pad 13 are typically copper layers, meaning that both are made of copper. The ground pad 13 is a large-area copper layer. For example, the substrate body 11 includes a first surface 110, on which both the RF transmission pad 12 and the ground pad 13 are disposed. In addition to the area where the RF transmission pad 12 and the isolation space 10 are located, the other areas of the first surface 110 are also provided with ground pads 13, thus achieving large-area grounding and greater heat dissipation of the ground pad 13.

[0036] The substrate body 11 is made of an insulating material, such as PTFE (polytetrafluoroethylene) + glass fiber. No pads are provided on the surface of the substrate body 11 at the location corresponding to the isolation space 10; that is, the surface of the substrate body 11 is exposed through the isolation space 10. Therefore, the RF transmission pad 12 and the ground pad 13 are mutually insulated. When fabricating the isolation space 10, a full copper layer can be formed on the surface of the substrate body 11 by electroplating, and then a localized portion of the copper layer can be etched (e.g., wet etching) to remove the copper between the RF transmission pad 12 and the ground pad 13, thereby obtaining the isolation space 10.

[0037] In this embodiment, the packaging substrate 1 eliminates the existing BGA pad design, that is, no BGA solder balls are set on the RF transmission pad 12 and the ground pad 13, thereby avoiding the problems of stress cracking of BGA solder balls during the soldering process in the prior art, as well as the problems of BGA solder ball breakage, low thermal conductivity, and device or package failure after thermal cycling caused by the use of glue. Moreover, since BGA solder balls are not used for soldering, the process difficulty can be reduced.

[0038] In this embodiment, the RF transmission pad 12 and ground pad 13 on the packaging substrate 1 are directly soldered to the adapter board 3 via soldering material 4. Specifically, the adapter board 3 can be a circuit board (PCB), a ceramic substrate, etc., and the soldering material 4 is generally a material such as solder paste. The surface of the adapter board 3 is provided with a first pad 31 and a second pad 32, which are insulated from each other. During soldering, the soldering material 4 can be printed on the surface of the first pad 31 and the second pad 32 using a stencil. Then, the packaging substrate 1 and the adapter board 3 are attached so that the first pad 31 and the second pad 32 correspond to the RF transmission pad 12 and the ground pad 13, respectively. Then, the soldering material 4 is melted and connected between the first pad 31 and the RF transmission pad 12 and between the second pad 32 and the ground pad 13 by reflow soldering, thereby realizing the mechanical and electrical connection between the packaging substrate 1 and the adapter board 3. Because the second pad 32 and the ground pad 13 have large areas, a large area of ​​solder material 4 will be placed on the second pad 32 during soldering. In order to prevent the large area of ​​solder material 4 at the second pad 32 / ground pad 13 from melting and overflowing onto the RF transmission pad 12 (i.e., "solder overflow") during the soldering process, which would cause a short circuit between the RF transmission pad 12 and the ground pad 13, an annular isolation space 10 is set between the RF transmission pad 12 and the ground pad 13. This isolation space 10 plays a role in isolating and preventing the solder material 4 from overflowing (even if a small amount of solder material 4 overflows, it will not flow onto the RF transmission pad 12), so as to avoid a short circuit between the RF transmission pad 12 and the ground pad 13 during the soldering process.

[0039] like Figures 1 to 4 and Figure 7 and Figure 8 As shown, in one embodiment, since the packaging substrate 1 and the adapter board 3 are directly soldered using soldering material 4, and the RF transmission pad 12 has an "island" structure (i.e., there is a large area of ​​grounding pad 13 around the RF transmission pad 12), if the pads on the packaging substrate 1 and the pads on the adapter board 3 are directly surface-mounted during soldering without any gaps, there will be no exhaust channel between the pads on the packaging substrate 1 and the pads on the adapter board 3. After the soldering material 4 (solder paste) is printed, the gas generated after the soldering material 4 melts (e.g., the flux, solvent, etc. in the soldering material 4 will evaporate and generate gas after heating) cannot be smoothly discharged, resulting in "trapped gas". That is, the gas is trapped in the soldering material 4, which will lead to a large solder void rate (solder voids refer to pores, micropores, or cavities formed inside or at the interface of the solder joint, which will affect mechanical strength and current transmission efficiency, etc.), resulting in the inability to meet the solder void rate requirements (especially for the RF transmission pad 12, which has higher requirements for solder void rate).

[0040] Therefore, in this embodiment, a plurality of conductive micro-protrusions 14 are spaced apart on the surface of the grounding pad 13. These conductive micro-protrusions 14 can be evenly spaced (i.e., the spacing between adjacent conductive micro-protrusions 14 is equal). The conductive micro-protrusions 14 protrude from the surface of the grounding pad 13 towards the side away from the substrate body 11, and are fixedly connected to the grounding pad 13. The conductive micro-protrusions 14 are welded to the adapter plate 3 using welding material 4. That is, the grounding pad 13 is electrically and mechanically connected to the second pad 32 on the adapter plate 3 through the plurality of conductive micro-protrusions 14. When selecting the material of the conductive micro-protrusions 14, it must not only meet the requirements of conductivity but also be resistant to oxidation and able to firmly bond with the welding material 4. Furthermore, the melting point of the conductive micro-protrusions 14 needs to be greater than the melting point of the welding material 4 (i.e., the melting point of the conductive micro-protrusions 14 is greater than the welding temperature) so that the conductive micro-protrusions 14 will not melt during welding. Specifically, the conductive micro-protrusions 14 can be made of conductive materials such as copper or titanium.

[0041] The advantages of setting conductive micro-protrusions 14 on the grounding pad 13 include: 1. By setting conductive micro-protrusions 14, direct surface contact between the pads on the packaging substrate 1 and the pads on the adapter plate 3 can be avoided. This creates an exhaust channel between the packaging substrate 1 and the adapter plate 3 (i.e., the packaging substrate 1 and the adapter plate 3 are spaced apart vertically), allowing the gas generated after the welding material 4 melts during the welding process to be smoothly discharged through the exhaust channel, thereby reducing or avoiding the phenomenon of "trapped gas," lowering the welding void rate, and reducing the welding difficulty. 2. The grounding pad 13 is electrically connected to the adapter plate 3 through multiple conductive micro-protrusions 14, which enhances the grounding continuity of the grounding pad 13 and ensures electrical performance. 3. [Further details omitted] Figure 8 As shown, during soldering, in addition to being sandwiched between the conductive micro-bumps 14 and the second pad 32 on the adapter plate 3, the soldering material 4 also adheres to the sidewall of the conductive micro-bumps 14 (the soldering material 4 generally forms a trapezoidal structure), thereby increasing the connection area between the soldering material 4 and the conductive micro-bumps 14, and thus improving the mechanical connection strength and overcurrent performance. 4. By setting the conductive micro-bumps 14, the printing thickness of the soldering material 4 (solder paste) can be reduced when printing, that is, a thinner soldering material 4 can be printed on the adapter plate 3, thereby reducing the risk of a short circuit between the RF transmission pad 12 and the ground pad 13 caused by the melting of a large area of ​​soldering material 4 at the second pad 32 spilling onto the first pad 31 / RF transmission pad 12 / conductive micro-bumps 15.

[0042] like Figures 1 to 4As shown, in one embodiment, the conductive micro-bump 14 has a circular cross-section and a rectangular longitudinal section, meaning the conductive micro-bump 14 has a cylindrical structure (the cross-section refers to the cross-section of the conductive micro-bump 14 obtained by cutting it with a plane parallel to the surface of the substrate body 11; the longitudinal section refers to the cross-section of the conductive micro-bump 14 obtained by cutting it with a plane perpendicular to the surface of the substrate body 11). Of course, as... Figure 6 As shown, in other embodiments, the conductive micro-protrusion 14 can also be in other shapes, such as a frustum-shaped structure (i.e., the cross-section of the conductive micro-protrusion 14 is circular and the longitudinal section of the conductive micro-protrusion 14 is trapezoidal); of course, the conductive micro-protrusion 14 can also be a cuboid structure, etc.

[0043] like Figures 1 to 4 As shown, in one embodiment, the diameters of the conductive microbumps 14 are the same, the diameter of the conductive microbumps 14 is D1, and the diameter of the RF transmission pads 12 is D2, 1 / 3. D2≤D1≤D2, meaning the diameter of the conductive microbump 14 is 1 / 3 to 1 times the diameter of the RF transmission pad 12.

[0044] like Figures 1 to 4 As shown, in one embodiment, the center-to-center distance between any two adjacent conductive micro-protrusions 14 is L1 (center-to-center distance refers to the distance between the centers of two adjacent conductive micro-protrusions 14. In this embodiment, the center-to-center distance is also the distance between the centers of two adjacent conductive micro-protrusions 14), the diameter of the conductive micro-protrusion 14 is D1, and the radius of the conductive micro-protrusion 14 is r, where r ≤ L1 ≤ 2. D1, or L1, is greater than or equal to the radius of the conductive micro-bump 14, and less than or equal to twice the diameter of the conductive micro-bump 14. If L1 is too small, the venting gap between the conductive micro-bumps 14 will be too small, which is not conducive to venting during soldering; if L1 is too large, the conductive micro-bumps 14 will be too sparsely distributed, which is not conducive to grounding continuity and the mechanical connection strength between the packaging substrate 1 and the adapter plate 3.

[0045] like Figures 1 to 4 As shown, in one embodiment, the plurality of conductive micro-bumps 14 include at least a plurality of first conductive micro-bumps 141, which are uniformly spaced and arranged around the periphery of the isolation space 10 and close to the isolation space 10. In addition to reducing the solder void rate as described above, the plurality of first conductive micro-bumps 141 can also form a grounding isolation ring around the RF transmission pad 12, thereby isolating external signals (such as external power signals) from the RF transmission pad 12, ensuring that the high-frequency RF signal on the RF transmission pad 12 is transmitted within the grounding isolation ring, avoiding interference from external signals to the RF signal, and ensuring the transmission stability of the RF signal.

[0046] like Figures 1 to 4 As shown, in one embodiment, the distance between the outer wall of the first conductive micro-protrusion 141 and the outer ring edge of the isolation space 10 is L2 (L2 is also the minimum distance between the outer wall of the first conductive micro-protrusion 141 and the outer ring edge of the isolation space 10), and the radius of the conductive micro-protrusion 14 is r, 0≤L2≤r. Wherein, when L2 is 0, the outer wall of the first conductive micro-protrusion 141 is tangent to the outer ring edge of the isolation space 10.

[0047] Specifically, if L2 is too large, meaning the distance between the first conductive micro-protrusion 141 and the outer ring edge of the isolation space 10 is too far, the first conductive micro-protrusion 141 will not be able to achieve a good signal isolation effect. Ideally, when L2 is 0, the first conductive micro-protrusion 141 can achieve a better signal isolation effect; however, due to process limitations, the outer wall of the first conductive micro-protrusion 141 is difficult to be tangent to the outer ring edge of the isolation space 10. Therefore, this application limits 0 ≤ L2 ≤ r, which can both ensure the signal isolation effect and reduce the process difficulty.

[0048] like Figure 5 As shown, in another embodiment, the plurality of conductive microbumps 14 further include a plurality of second conductive microbumps 142. The plurality of second conductive microbumps 142 are disposed on the side of the plurality of first conductive microbumps 141 away from the isolation space 10, that is, the plurality of second conductive microbumps 142 are disposed on the periphery of the plurality of first conductive microbumps 141, and the plurality of second conductive microbumps 142 are evenly spaced. By disposing of second conductive microbumps 142 in other areas of the grounding pad 13, the number and distribution position of the conductive microbumps 14 can be increased, thereby further improving the grounding continuity of the grounding pad 13 and the mechanical connection strength between the package substrate 1 and the adapter plate 3.

[0049] In one implementation, at least 75% of the surface area of ​​the grounding pad 13 is provided with conductive micro-bumps 14, that is, the area of ​​the grounding pad 13 with conductive micro-bumps 14 is greater than or equal to 75% of the total surface area of ​​the grounding pad 13. This ensures that there are a sufficient number of conductive micro-bumps 14 and increases the distribution position of the conductive micro-bumps 14, which can guarantee the grounding continuity of the grounding pad 13 and the mechanical connection strength between the package substrate 1 and the adapter plate 3.

[0050] like Figures 1 to 4 and Figure 7 and Figure 8As shown, in one embodiment, the surface of the RF transmission pad 12 is provided with conductive microbumps 15. The conductive microbumps 15 protrude from the surface of the RF transmission pad 12 towards the side away from the substrate body 11, and are fixedly connected to the RF transmission pad 12. The conductive microbumps 15 are welded to the adapter plate 3 through welding material 4, that is, the RF transmission pad 12 is electrically and mechanically connected to the first pad 31 on the adapter plate 3 through the conductive microbumps 15. The conductive microbumps 15 and the conductive microprotrusions 14 are the same or similar in terms of material, structure, and function, except for their different positions. When selecting the material of the conductive microbumps 15, it must not only meet the requirements of conductivity, but also be resistant to oxidation and able to bond firmly to the welding material 4; moreover, the melting point of the conductive microbumps 15 needs to be greater than the melting point of the welding material 4 (that is, the melting point of the conductive microbumps 15 is greater than the welding temperature), so that the conductive microbumps 15 will not melt during welding. The conductive microbumps 15 can be made of conductive materials such as copper and titanium.

[0051] The advantages of providing conductive microbumps 15 on the RF transmission pads 12 include: 1. The conductive microbumps 15 prevent direct surface contact between the pads on the package substrate 1 and the pads on the adapter board 3, thereby reducing or avoiding "air trapping" during soldering, lowering the solder void rate, and reducing soldering difficulty. 2. The RF transmission pads 12 are electrically connected to the adapter board 3 through the highly conductive microbumps 15, thereby improving signal transmission continuity. 3. [Further details omitted] Figure 8 As shown, during soldering, in addition to being sandwiched between the conductive microbump 15 and the first pad 31 on the adapter plate 3, the soldering material 4 also adheres to the sidewall of the conductive microbump 15 (the soldering material 4 generally forms a trapezoidal structure), thereby increasing the connection area between the soldering material 4 and the conductive microbump 15, and thus improving the mechanical connection strength and overcurrent performance. 4. By setting the conductive microbump 15, the printing thickness of the soldering material 4 (solder paste) can be reduced when printing, that is, a thinner soldering material 4 can be printed on the adapter plate 3, thereby reducing the risk of the soldering material 4 at the first pad 31 melting and overflowing onto the second pad 32 / conductive microbump 14, causing a short circuit between the RF transmission pad 12 and the ground pad 13.

[0052] like Figures 1 to 4 As shown, in one embodiment, the conductive microbump 15 has a circular cross-section and a rectangular longitudinal section, meaning the conductive microbump 15 has a cylindrical structure. Of course, as... Figure 6 As shown, in other embodiments, the conductive microbumps 15 can also be other shapes, such as a frustum-shaped structure (i.e., the cross-section of the conductive microbumps 15 is circular and the longitudinal section of the conductive microbumps 15 is trapezoidal); of course, the conductive microbumps 15 can also be a cuboid structure, etc.

[0053] like Figures 1 to 4 and Figure 8 As shown, in one embodiment, the diameter of the conductive microbump 15 is smaller than the diameter of the RF transmission pad 12, meaning the outer wall of the RF transmission pad 12 protrudes outward relative to the outer wall of the conductive microbump 15. This arrangement is intended to prevent the solder material 4 from adhering to the sidewall of the conductive microbump 15 during soldering. If the diameter of the conductive microbump 15 is large, the solder material 4 on the sidewall of the conductive microbump 15 may come into contact with the conductive microprotrusion 14 or the solder material 4 on the sidewall of the conductive microprotrusion 14, potentially causing a short circuit between the RF transmission pad 12 and the ground pad 13. By reducing the diameter of the conductive microbump 15, the risk of a short circuit between the RF transmission pad 12 and the ground pad 13 due to solder overflow can be reduced.

[0054] like Figures 1 to 4 As shown, in one embodiment, the height H1 of the conductive micro-bump 14 and the height H2 of the conductive micro-bump 15 can be determined according to the printing thickness of the welding material 4. For example, the height H1 of the conductive micro-bump 14 and the height H2 of the conductive micro-bump 15 can be 1 / 2 to 2 / 3 of the printing thickness of the welding material 4. The height H1 of the conductive micro-bump 14 can be 0.05 mm to 1 mm, and the height H2 of the conductive micro-bump 15 can be 0.05 mm to 1 mm. The heights of the conductive micro-bump 14 and the conductive micro-bump 15 can be the same or different.

[0055] As one implementation method, the conductive microbumps 14 and conductive microbumps 15 can be manufactured by electroplating, magnetron sputtering, printing, or other methods.

[0056] like Figure 7 and Figure 8 As shown, this embodiment also provides an RF module packaging structure, including an RF chip 2, an adapter board 3, and the aforementioned packaging substrate 1 for RF components. The RF chip 2, the packaging substrate 1, and the adapter board 3 are stacked sequentially. The RF chip 2 is disposed on the side of the substrate body 11 away from the RF transmission pad 12, and the RF chip 2 is electrically connected to the RF transmission pad 12 and the ground pad 13 on the surface of the substrate body 11. Specifically, the corresponding pins on the RF chip 2 can be electrically connected to the RF transmission pad 12 and the ground pad 13 through existing wire bonding methods (the electrical connection method between the RF chip 2 and the packaging substrate 1 is prior art and will not be described in detail here). The adapter board 3 is disposed on the side of the substrate body 11 away from the RF chip 2. The RF transmission pad 12 and the ground pad 13 are both welded to the adapter board 3 through soldering material 4. Specifically, the conductive microbumps 15 on the RF transmission pad 12 and the conductive microbumps 14 on the ground pad 13 are respectively welded to the first pad 31 and the second pad 32 on the adapter board 3 through soldering material 4.

[0057] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A packaging substrate for radio frequency components, comprising a substrate body (11), characterized in that, The substrate body (11) has a radio frequency transmission pad (12) and a ground pad (13) on its surface. The ground pad (13) is disposed around the radio frequency transmission pad (12), and the radio frequency transmission pad (12) and the ground pad (13) are spaced apart. An annular isolation space (10) is formed between the radio frequency transmission pad (12) and the ground pad (13).

2. The packaging substrate for radio frequency components as described in claim 1, characterized in that, The radio frequency transmission pad (12) has a circular structure, and the isolation space (10) has a ring structure.

3. The packaging substrate for radio frequency components as described in claim 1, characterized in that, The surface of the grounding pad (13) is provided with a plurality of conductive micro-protrusions (14) spaced apart.

4. The packaging substrate for radio frequency components as described in claim 3, characterized in that, The diameter of the conductive microbump (14) is D1, and the diameter of the RF transmission pad (12) is D2, 1 / 3. D2≤D1≤D2.

5. The packaging substrate for radio frequency components as described in claim 3, characterized in that, The center-to-center distance between two adjacent conductive micro-protrusions (14) is L1, the diameter of the conductive micro-protrusion (14) is D1, and the radius of the conductive micro-protrusion (14) is r, where r ≤ L1 ≤ 2. D1.

6. The packaging substrate for radio frequency components as described in claim 3, characterized in that, The plurality of conductive micro-protrusions (14) include at least a plurality of first conductive micro-protrusions (141), which are evenly spaced and arranged around the periphery of the isolation space (10).

7. The packaging substrate for radio frequency components as described in claim 6, characterized in that, The distance between the outer wall of the first conductive micro-protrusion (141) and the outer ring edge of the isolation space (10) is L2, and the radius of the conductive micro-protrusion (14) is r, 0≤L2≤r.

8. The packaging substrate for radio frequency components as described in claim 6, characterized in that, The plurality of conductive micro-bumps (14) further include a plurality of second conductive micro-bumps (142), which are disposed on the side of the plurality of first conductive micro-bumps (141) away from the isolation space (10).

9. The packaging substrate for radio frequency components as described in claim 3, characterized in that, The grounding pad (13) has conductive micro-protrusions (14) on its surface covering at least 75% of the area.

10. The packaging substrate for radio frequency components as described in any one of claims 3-9, characterized in that, The surface of the radio frequency transmission pad (12) is provided with conductive microbumps (15).

11. The packaging substrate for radio frequency components as described in claim 10, characterized in that, The diameter of the conductive microbump (15) is smaller than the diameter of the radio frequency transmission pad (12).

12. The packaging substrate for radio frequency components as described in claim 10, characterized in that, The conductive micro-bumps (14) have the same height as the conductive micro-bumps (15); And / or, the height of the conductive micro-bumps (14) and the conductive micro-bumps (15) is 0.05mm~1mm.

13. A radio frequency module packaging structure, characterized in that, The package includes an RF chip (2), an adapter board (3), and a packaging substrate (1) for an RF component as described in any one of claims 1-12. The RF chip (2) is disposed on the side of the substrate body (11) away from the RF transmission pad (12), and the RF chip (2) is electrically connected to the RF transmission pad (12) and the ground pad (13). The adapter board (3) is disposed on the side of the substrate body (11) away from the RF chip (2), and the RF transmission pad (12) and the ground pad (13) are both welded to the adapter board (3) by welding material (4).

Images