Radio frequency chip package structure and PCB board

Abstract

The utility model relates to a radio frequency chip packaging structure and PCB board. The radio frequency chip packaging structure includes: substrate, the edge of the bottom layer of substrate has PCB pad, PCB board, PCB board has PCB via hole in, the surface of PCB board has the transition pad connected with PCB via hole, PIN pad connected with PCB pad, PIN pad and transition pad are integral structure, and partially or completely overlap.

Description

Technical Field

[0001] This utility model relates to the field of radio frequency chip technology, and in particular to radio frequency chip packaging structure and PCB board. Background Technology

[0002] As chip integration density continues to increase, the packaging requirements for integrated circuits become more stringent. Many important functions between the chip and the PCB, such as protection, support, and heat dissipation, are now handled by the packaging substrate. A typical substrate simply transmits electrical signals (including radio frequency (RF) and power signals) between the chip and the PCB via traces. A transition structure exists on the PCB surface, with one end connected to the substrate and the other end transitioning downwards to connect to the transmission lines inside the PCB. This transition structure lies between the PCB and the substrate, and is usually located at the edge of the substrate, making effective shielding difficult. This results in some electromagnetic energy radiating outwards when RF signals pass through this transition structure, causing electromagnetic leakage and electromagnetic crosstalk. Utility Model Content

[0003] The purpose of this invention is to provide a radio frequency chip packaging structure and PCB board, and to solve the technical problems of electromagnetic leakage and interference at the connection between the substrate and the PCB board in radio frequency chip packaging.

[0004] The first embodiment of this utility model discloses a radio frequency chip packaging structure, including:

[0005] A substrate, wherein the bottom edge of the substrate has PCB pads;

[0006] A substrate, wherein the bottom edge of the substrate has PCB pads;

[0007] A PCB board having PCB vias, and the surface of the PCB board having transition pads connected to the PCB vias and PIN pads connected to the PCB pads; the PIN pads and the transition pads are an integral structure and partially or completely overlap; the PIN pads are rectangular and the transition pads are circular.

[0008] According to an embodiment of the present invention, the PIN pads partially or completely overlap with the PCB pads.

[0009] According to an embodiment of the present invention, the area of ​​the PIN pad is larger than the area of ​​the transition pad.

[0010] According to an embodiment of the present invention, the PIN pad is part of the transition pad.

[0011] According to an embodiment of the present invention, it further includes a radio frequency chip, which is located on the top surface of the substrate and electrically connected to the substrate.

[0012] According to an embodiment of the present invention, the radio frequency chip includes a millimeter-wave chip.

[0013] The second embodiment of this utility model discloses a PCB board, which has PCB vias and transition pads connected to the PCB vias and PIN pads connected to the PCB pads on its surface; the PIN pads and the transition pads are an integral structure and partially or completely overlap.

[0014] The main differences and effects of this utility model embodiment compared with the prior art are as follows:

[0015] In this invention, the PIN pad and the transition pad are an integral structure and partially or completely overlap; this reduces electromagnetic leakage and interference at the PIN port and improves the isolation of the RF port. Attached Figure Description

[0016] Figure 1 This illustrates a radio frequency chip package structure according to an embodiment of this application.

[0017] Figure 2 A perspective view of multiple conductive layers of a PCB board according to an embodiment of this application is shown.

[0018] Figure 3 A top view of the conductive layer on the top layer of a PCB board according to an embodiment of this application is shown.

[0019] Figure 4 A schematic diagram showing the arrangement of PIN pads and transition pads in the prior art is provided.

[0020] Figure 5 An ISO isolation curve between PIN pads and transition pads on a PCB board according to an embodiment of the present invention is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0022] It should be noted that the various schematic diagrams of the substrate structure in this application are intended to illustrate different inventive concepts and related technical solutions of this utility model. In the specific description of each inventive concept, the schematic diagrams mainly highlight features related to the inventive concept, but this does not mean that the substrate structure does not contain structures beyond those shown in the diagrams. Those skilled in the art, based on the teachings of this utility model, can clearly understand that other feasible substrate structures can be included. For example, when describing the inventive technical solution related to the grounding connection post, the diagrams mainly show the features related to the grounding connection post; when describing the inventive technical solution of mutual isolation between power supplies, the diagrams mainly show the features related to mutual isolation between power supplies. Those skilled in the art, based on the teachings of this utility model, can understand that the substrate structure can simultaneously include both types of structures, and they can be arranged according to the actual situation of the substrate, provided that the essence of the utility model is satisfied.

[0023] Figure 1 A schematic diagram of an RF chip packaging structure according to an embodiment of this application is shown, illustrating a substrate 101, an RF chip 102, and a PCB board 103. The substrate 101 serves as a transition component between the RF chip 102 and the PCB board 103. The substrate 101 includes multiple conductive layers, with dielectric layers between adjacent conductive layers.

[0024] In this application, the radio frequency chip is a millimeter-wave radio frequency chip, but is not limited to millimeter-wave radio frequency chips. The teachings of this application apply to all radio frequency chip packaging structures with high isolation requirements, and all fall within the protection scope of this utility model.

[0025] Substrates, RF chips, and PCBs typically consist of alternating stacked dielectric and conductive layers. The conductive layer can be a single layer of conductive material or contain conductive structures for signal transmission, power distribution, electrical connections between components, or grounding. These conductive structures are separated by an insulating dielectric material. The conductive structures can be formed from metals such as copper, aluminum, silver, and gold. The dielectric layer provides electrical insulation and, depending on the specific application, may include conductive plugs (vias) to enable electrical connections between components on the upper and lower conductive layers.

[0026] In a conductive layer, conductive materials with specific patterns can form conductive paths extending within the layer plane for applications such as radio frequency signal transmission and power supply.

[0027] Electrical connections between different conductive layers in the vertical direction can be achieved using vias. For example, holes are drilled through multiple conductive layers in the direction they are stacked, and metal is plated inside the holes to form conductive metallized vias. During this process, a ring of holes can be prepared around the vias in the conductive layers to increase process tolerance and improve the mechanical and electrical properties at the connection between the metallized via and the conductive layer. For example, the ring of holes can increase the area at the connection between the metallized via and the conductive layer, preventing excessive impedance.

[0028] To address the technical problems of electromagnetic leakage and interference at the connection between the substrate and the PCB board in RF chip packaging, embodiments of this application disclose an RF chip packaging structure that provides optimized isolation between RF ports between the substrate and the PCB board. This RF chip packaging structure will be described below.

[0029] Based on the radio frequency chip packaging structure of this utility model, and continuing with reference to... Figure 1 The substrate 101 has at least a surface conductive layer 1011, a middle conductive layer 1015, and a bottom conductive layer 1018. The conductive layer 1011 has RF pads 1012, on which RF connection posts 1013 are soldered for connection to an RF chip 102. The RF chip 102 can be a millimeter-wave chip. The RF pads 1012 are connected to a substrate transmission line 1016 of the conductive layer 1015 via a first substrate via 1014, and the substrate transmission line 1016 is connected to a PCB pad 1019 on the conductive layer 1018 via a second substrate via 1017. The PCB pads 1019 are used to connect to a PCB board 103. The top conductive layer 1031 of the PCB board 103 has connection pads 1032 for connection to the aforementioned PCB pads 1019.

[0030] The specific structure of the PCB board is as follows: Figure 2 As shown, the PCB board 200 includes conductive layer 201, conductive layer 202, conductive layer 203, and conductive layer 204. Figure 3 A top view of the conductive layer at the top of the PCB board is shown. The conductive layer 201 has connecting pads 205 that connect to PCB pads on the conductive layer at the bottom of the substrate. The connecting pads 205 partially or completely overlap with the PCB pads. The PCB board has PCB vias 206, and the connecting pads 205 connect to the PCB vias 206. Figure 3 As shown, the portion of the connecting pad 205 that connects to the PCB pad is the PIN pad 205a, and the portion that connects to the PCB via 206 is the transition pad 205b. The transition pad 205b connects to the interior of the PCB board, for example, Figure 2The conductive layer 202 is shown to have a transmission line 207, with a transition pad 205b connected to the transmission line 207 via a PCB via 206. The PIN pad 205a and the transition pad 205b are a single, continuous conductive pattern on the conductive layer 201. There is no additional trace or connecting element between them. They can be a single, complete metal area formed during manufacturing. This design avoids introducing additional seams, solder joints, or narrow traces between two functional areas, thus ensuring the continuity of the current path and the integrity of the structure, reducing electromagnetic leakage and electromagnetic crosstalk.

[0031] Regarding PIN pads and transition pads, in one example, such as Figure 4 As shown, there is a short trace 303 between PIN pad 301 and transition pad 302. Since PIN pad 301 and transition pad 302 are not typically a single unit, and PCB pads are not located at the edge of the substrate's bottom layer, there is a distance between PIN pad 301 and transition pad 302, which are connected to the PCB pads. This short trace 303 is a conductive path provided to connect the physically separated PIN pad 301 and transition pad 302. This short trace 303 itself has a certain length, width, and thickness, which, in addition to introducing additional inductance and capacitance, also causes unnecessary radiation, thus deteriorating the isolation. To reduce this deterioration in isolation, this invention brings PIN pad 205a and transition pad 205b as close as possible, so that PIN pad 205a and transition pad 205b partially or completely overlap.

[0032] Optionally, such as Figure 3 As shown, PIN pad 205a is rectangular, and transition pad 205b is circular; the area of ​​PIN pad 205a is larger than the area of ​​transition pad 205b; PIN pad 205a and transition pad 205b completely overlap. However, the shapes of PIN pad 205a and transition pad 205b are not limited to the rectangle and circle shown in the figure. Depending on the shape of the connected PCB pads and soldering requirements, PIN pad 205a can also be circular, elliptical, or any other suitable shape. Similarly, depending on the type of PCB via 206 and manufacturing process, transition pad 205b can also be square or teardrop-shaped, etc.

[0033] Figure 3This illustration shows only one possible arrangement of the relative positional relationship between the PIN pad and the transition pad, where the PIN pad 205a and the transition pad 205b completely overlap. "Complete overlap" here can mean one encompasses the other; for example, the transition pad 205b may be part of the PIN pad 205a, meaning the transition pad 205b is physically separated from the PIN pad 205a; or the PIN pad 205a may be part of the transition pad 205b, meaning the PIN pad 205a is physically separated from the transition pad 205b; or a portion of the transition pad 205b may be used to perform the function of the PIN pad without a clear distinction in physical shape; or a portion of the PIN pad 205a may be used to perform the function of the transition pad without a clear distinction in physical shape. In this embodiment, the PIN pad 205a and the transition pad 205b are physically a single unit, eliminating the need for additional traces as a connection structure and thus eliminating electromagnetic leakage sources caused by connection traces.

[0034] However, the relative positional relationship between PIN pads and transition pads is not limited to... Figure 3 The overlap shown is not complete; rather, the two can partially overlap. "Partial overlap" here means that the PIN pad and the transition pad share a common contact area, but one does not completely contain the other. For example, only a portion (such as a semi-circular area) of the circular transition pad 205b may overlap with the rectangular PIN pad 205a. In the relative positional relationship of this embodiment, the PIN pad 205a and the transition pad 205b are in physical contact, eliminating the need for additional traces as a connection structure and reducing electromagnetic leakage caused by connection traces.

[0035] Any direct electrical connection with low impedance and short distance between the PIN pad and the transition pad, avoiding long and thin traces to reduce electromagnetic leakage and interference at the PIN port, falls under the concept of this utility model.

[0036] Figure 5 This diagram illustrates the ISO port isolation between PIN pads and transition pads on a PCB board according to an embodiment of the present invention, compared with corresponding isolation levels in the prior art. The solid line represents the ISO port isolation curve according to the embodiment of the present application; the dashed line represents the ISO port isolation curve in the prior art. Figure 5 As can be seen, compared with the prior art, the ISO port isolation between the PIN pads and the transition pads on the PCB board of this utility model is improved by about 15dB at 40GHz.

[0037] The PCB board provided by this utility model is not limited to Figure 1 and Figure 2The structure shown is illustrated. Generally, in this invention, the PCB board is a multilayer printed circuit board, serving as the component that carries the RF chip package structure and enables its connection to external circuits. Specifically, the PCB board has multiple conductive layers, with dielectric layers between adjacent conductive layers. The number of conductive and dielectric layers is not limited here. This multilayer structure provides space for laying out complex RF transmission lines, power layers, and ground layers. One of the multiple conductive layers (e.g., Figure 2 One or more conductive layers (202) can be used to lay radio frequency transmission lines for transmitting radio frequency signals inside the PCB board. One or more of the conductive layers are set as ground layers (e.g., Figure 2 Conductive layer 204 in the PCB can be used as a reference ground layer for radio frequency transmission lines or as the main ground layer of the PCB. One or more of the conductive layers can also be configured as power layers (e.g., Figure 2 (Conductive layer 203 in the middle). Electrical connections are achieved between different conductive layers through vias.

[0038] It is understood that the specific embodiments described herein are merely for illustrative purposes and not for limiting the scope of this application. Furthermore, for ease of description, the accompanying drawings show only the parts relevant to this application, and not all of the structures or processes. It should be noted that similar reference numerals and letters in this specification denote similar items in the accompanying drawings.

[0039] It should be understood that although the terms "first," "second," etc., may be used herein to describe various features, these features should not be limited by these terms. The use of these terms is merely for distinction and should not be construed as indicating or implying relative importance. For example, without departing from the scope of the exemplary embodiments, a first feature may be referred to as a second feature, and similarly, a second feature may be referred to as a first feature.

[0040] In the description of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0041] The illustrative embodiments of this application include, but are not limited to, radio frequency chip packaging structures and PCB boards.

[0042] Various aspects of the illustrative embodiments will be described using terminology commonly employed by those skilled in the art to convey the essence of their work to others skilled in the art. However, it will be apparent to those skilled in the art that some alternative embodiments will be practiced using the features partially described. Specific figures and configurations are set forth for purposes of explanation in order to provide a more thorough understanding of the illustrative embodiments. However, it will be apparent to those skilled in the art that alternative embodiments may be practiced without specific details. In some other instances, well-known features have been omitted or simplified herein to avoid obscuring the illustrative embodiments of this application.

[0043] References to "embodiments," "illustrative embodiments," etc., in this specification indicate that the described embodiments may include specific features, structures, or properties; however, each embodiment may or may not necessarily include specific features, structures, or properties. Furthermore, these phrases are not necessarily directed at the same embodiment. Additionally, when specific features are described in conjunction with specific embodiments, the knowledge of those skilled in the art can influence the combination of these features with other embodiments, whether or not those embodiments are explicitly described.

[0044] Unless the context otherwise specifies, the terms “comprising,” “having,” and “including” are synonyms. The phrase “A and / or B” means “(A), (B), or (A and B).”

[0045] In the accompanying drawings, some structures may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order is not necessary. Rather, in some embodiments, these features may be illustrated in a manner and / or order different from that shown in the illustrative drawings. Furthermore, the structures included in a particular drawing do not mean that all embodiments need to include such features; in some embodiments, these features may not be included or may be combined with other features.

[0046] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, the use of the technical solutions of this application is not limited to the various applications mentioned in the embodiments of this application. Various structures and modifications can be easily implemented with reference to the technical solutions of this application to achieve the various beneficial effects mentioned herein. Within the scope of knowledge possessed by those skilled in the art, all changes made without departing from the spirit of this application should be considered within the scope of this patent application.

Claims

1. A radio frequency chip packaging structure, characterized in that, include: A substrate, wherein the bottom edge of the substrate has PCB pads; A PCB board having PCB vias, and the surface of the PCB board having transition pads connected to the PCB vias and PIN pads connected to the PCB pads; the PIN pads and the transition pads are an integral structure and partially or completely overlap.

2. The radio frequency chip packaging structure according to claim 1, characterized in that, The PIN pads are rectangular, and the transition pads are circular.

3. The radio frequency chip packaging structure according to claim 1, characterized in that, The PIN pads partially or completely overlap with the PCB pads.

4. The radio frequency chip packaging structure according to claim 3, characterized in that, The PIN pad is part of the transition pad.

5. The radio frequency chip packaging structure according to claim 1, characterized in that, The area of ​​the PIN pad is larger than the area of ​​the transition pad.

6. The radio frequency chip packaging structure according to claim 1, characterized in that, It also includes a radio frequency (RF) chip, which is located on the top surface of the substrate and electrically connected to the substrate.

7. The radio frequency chip packaging structure according to claim 1, characterized in that, The radio frequency chip includes a millimeter-wave chip.

8. A PCB board, wherein the PCB board has PCB vias, characterized in that, The surface of the PCB board has transition pads connected to the PCB vias and PIN pads connected to the substrate; the PIN pads and the transition pads are an integral structure and partially or completely overlap.

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