Embedded radio frequency chip packaging method and structure

Abstract

The invention relates to the technical field of chip packaging, and discloses an embedded radio frequency chip packaging method and structure, and the method comprises the steps: S100, etching a glass substrate to form a frame, and manufacturing a conductive blind hole in the glass substrate; s200, manufacturing a mounting cavity for embedding a radio frequency chip on the glass substrate to obtain a glass core frame; s300, pasting a bonding layer on the bottom surface of the glass core frame, and arranging the radio frequency chip on the top surface of the bonding layer in the mounting cavity; step S400, covering one surface or two surfaces of the radio frequency chip with a sealing glue layer and pressing; and step S500, manufacturing a signal export hole in signal connection with the radio frequency chip in the sealing glue layer. The glass core frame in the design can keep the size of the packaging body stable due to the low thermal expansion coefficient and the conductive blind holes capable of rapidly discharging heat in the glass core frame, and thermal deformation of the packaging body is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to an embedded radio frequency chip packaging method and structure. Background Art

[0002] With the rapid development of modern communication technology, RF chips have become an indispensable core component in wireless communication equipment. Its performance is directly related to the signal reception, transmission and processing capabilities of communication equipment, which in turn affects the stability and reliability of the entire communication system. However, RF chips will generate significant heat accumulation under high-intensity working conditions. This problem not only directly weakens the working efficiency of RF chips, such as causing signal distortion and gain reduction, but also causes serious thermal stress to the packaging structure inside the chip during the packaging process, which in turn causes significant changes in the size of the package body.

[0003] The dimensional change of the packaging structure is extremely unfavorable for RF chips. On the one hand, it may cause the connection between the chip and the external circuit to loosen or break, affecting the quality of signal transmission; on the other hand, the dimensional change may also destroy the precise layout inside the chip, such as the position accuracy of key components such as antennas and filters, thereby further deteriorating communication performance. Therefore, how to effectively manage the heat generated by the RF chip during operation, ensure the thermal stability of the packaging structure, and control the dimensional change has become a major challenge facing current RF chip packaging technology. Although the existing RF chip packaging structure has taken heat dissipation design into consideration to a certain extent, such as the use of heat dissipation components such as heat sinks and heat pipes, and the optimization of the packaging process, these measures still seem to be inadequate when faced with the high heat load of high-performance RF chips.

[0004] Therefore, providing a radio frequency chip packaging structure with high thermal stability and small dimensional change has become an urgent problem to be solved. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing an embedded radio frequency chip package, aiming to solve the technical problems of low thermal stability and easy size change of the radio frequency chip package structure.

[0006] To achieve the above-mentioned purpose, the present invention provides an embedded RF chip packaging method, comprising the following steps: Step S100: etching a frame on a glass substrate and making a conductive blind hole on the glass substrate; Step S200: making a mounting cavity for embedding the RF chip on the glass substrate to obtain a glass core frame; Step S300: attaching an adhesive layer to the bottom surface of the glass core frame, and setting the RF chip on the top surface of the adhesive layer in the mounting cavity; Step S400: covering one or both sides of the RF chip with a sealing layer and pressing them together; Step S500: making a signal lead-out hole in the sealing layer that is connected to the signal of the RF chip.

[0007] Preferably, in step S100, the cut incoming glass plate is covered with copper foil on both sides and etched to produce conductive circuits to obtain a glass substrate, and a coding mark is printed on the incoming glass substrate before etching the frame.

[0008] Preferably, in step S100, during the process of etching the frame: a first positioning hole is drilled on the glass substrate, and the frame pattern and the conductive blind hole pattern are etched according to the position of the first positioning hole.

[0009] Preferably, in step S100, drilling is performed on the etching pattern of the conductive blind hole, burrs in the hole are removed, copper is sputtered in the hole to fill the conductive medium, the entire glass substrate is electroplated for thickening, and finally the glass substrate is browned.

[0010] Preferably, in step S200, an alignment target is etched on the glass substrate, the position of the installation cavity is determined according to the alignment target, and finally the installation cavity is manufactured by laser burning grooves at a preset position by positioning the alignment target.

[0011] Preferably, in step S300, the adhesive layer is made of materials including polyimide, polyester and polyvinyl chloride. After the adhesive layer is attached to the bottom surface of the glass core frame, an automatic placement machine is used to mount the RF chip on the adhesive layer in the mounting cavity. The offset accuracy of the automatic placement machine is ±10um.

[0012] Preferably, in step S400, a first sealing layer is provided on the top surface of the glass core frame for first pressing and curing, and the first sealing layer is bonded to the top surface of the RF chip;

[0013] The adhesive layer is peeled off, and a second sealing layer is attached to the bottom surface of the glass core frame for a second pressing and curing, wherein the second sealing layer is attached to the bottom surface of the radio frequency chip.

[0014] Preferably, in step S500, the position coordinates of the signal lead-out hole are located by X-ray and a second positioning hole is made in the second sealing layer by laser burning. After removing the drilling stains, the second positioning hole is filled with metal copper by copper plating to form the signal lead-out hole.

[0015] Preferably, the method further includes step 510 after step S500, wherein an outer layer circuit is produced by etching a side of the glass core frame away from the mounting cavity, and the package of the RF chip is subjected to automatic optical inspection, and the glass core frame is subjected to solder mask treatment and surface treatment in sequence according to the inspection results.

[0016] The present invention also provides an embedded RF chip packaging structure, comprising: a RF chip; a glass core frame, the glass core frame is provided with a conductive blind hole and a mounting cavity for embedding the RF chip, the conductive blind hole is electrically connected to the RF chip; the RF chip is arranged in the mounting cavity; a first sealing layer, covering the top surface of the glass core frame, filling the mounting cavity and wrapping the top edge of the RF chip; a second sealing layer, covering the bottom surface of the glass core frame and adhering to the bottom surface of the RF chip, the second sealing layer and the first sealing layer are elastic; a signal lead-out hole, penetrated in the second sealing layer, the signal lead-out hole is filled with metal copper to achieve signal conduction with the RF chip.

[0017] In the technical solution provided by the present invention, compared with the organic substrate frame currently used in the mainstream, the glass core frame in the technical solution has a glass plate with a low CTE (thermal expansion coefficient) and a conductive blind hole for heat dissipation and communication. During the packaging process, even in the face of a high temperature environment, the glass core frame can maintain dimensional stability due to the low thermal expansion coefficient and the conductive blind hole for rapid heat dissipation, effectively reducing the thermal deformation of the package. At the same time, the combination of the RF chip and the sealing layer (pp layer) enhances the mechanical strength of the package, overcoming the disadvantage that the glass substrate itself is brittle and easily damaged under impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0019] Figure 1 A schematic diagram of a process flow of an embodiment of a method for packaging an embedded radio frequency chip according to the present invention;

[0020] Figure 2 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0021] Figure 3 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0022] Figure 4 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0023] Figure 5 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0024] Figure 6A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0025] Figure 7 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0026] Figure 8 A schematic diagram of the structure of the processing process of an embodiment of the embedded radio frequency chip package of the present invention;

[0027] Fig. 9 This is a schematic diagram of the finished product structure of an embodiment of the embedded radio frequency chip package of the present invention.

[0028] In the figure: 1. RF chip; 2. Glass core frame; 21. Mounting cavity; 22. Conductive blind hole; 23. Glass substrate; 3. Adhesive layer; 4. Sealing layer; 41. First sealing layer; 42. Second sealing layer; 5. Signal lead-out hole; 6. Protective layer. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element, or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are only for illustrative purposes. In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; the meaning of "multiple" is two or more. The term "include" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may be present or added.

[0030] In addition, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection between two components. All technical and scientific terms used in this specification have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0031] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] To achieve the above purpose, please refer to Figures 1 to 9 The present invention provides a method for packaging an embedded radio frequency chip 1, comprising the following steps: step S100: etching a frame on a glass substrate 23, and making a metallized conductive blind hole 22 for signal conduction on the glass substrate 23; step S200: making a mounting cavity 21 for embedding the radio frequency chip 1 on the glass substrate 23 to obtain a glass core frame 2; step S300: attaching an adhesive layer 3 to the bottom surface of the glass core frame 2, and setting the radio frequency chip 1 on the top surface of the adhesive layer 3 in the mounting cavity 21; step S400: covering one or both sides of the radio frequency chip 1 with a sealing layer 4 and pressing them; step S500: making a signal lead-out hole 5 in the sealing layer 4 for connecting the signal of the radio frequency chip 1.

[0033] In the technical solution provided by the present invention, compared with the organic substrate frame currently used in the mainstream, the glass core frame 2 in the present technical solution has a glass plate with a low CTE (thermal expansion coefficient) and a conductive blind hole 22 for heat dissipation and communication embedded therein. During the packaging process, even in the face of a high temperature environment, the glass core frame 2 can maintain dimensional stability due to the low thermal expansion coefficient and the conductive blind hole 22 for rapid heat dissipation, effectively reducing the thermal deformation of the package. At the same time, the combination of the RF chip 1 and the sealing layer 4 (pp layer) enhances the mechanical strength of the package, overcoming the disadvantage that the glass substrate 23 itself is relatively brittle and easily damaged under impact.

[0034] Please refer to Figure 1 and Figure 2In this embodiment, in step S100, the cut incoming glass plate is covered with copper foil on both sides and etched to make a conductive circuit to obtain a glass substrate 23. Before etching the frame, the incoming glass substrate 23 is coded. In the process of etching the frame: a first positioning hole is drilled on the glass substrate 23, and the frame pattern and the pattern of the conductive blind hole 22 are etched according to the position of the first positioning hole. Drill holes on the etching pattern of the conductive blind hole 22, remove the burrs in the hole, sputter copper in the hole to fill the conductive medium, and electroplate the entire glass substrate 23 to thicken it, and finally brown the glass substrate 23. Coding can ensure that each glass substrate 23 has a unique identity during the production process, which is convenient for tracking and management, and reduces quality problems caused by confusion or misoperation. The drilled first positioning hole provides an accurate reference point for the subsequent frame etching step. After metallization and copper paste filling in the glass plate using the TGV process, a conductive blind hole 22 is obtained, which can be connected to the RF chip 1 through the process of internal circuit production, metal holes, and pad connection. It can also be connected to internal passive devices, such as capacitors and resistors to complete the circuit connection. The browning treatment increases the bonding force between the glass substrate 23 and the subsequent packaging materials (such as the sealing layer 4 composed of semi-cured film material) by changing the microstructure and chemical properties of the surface of the glass substrate 23. This enhanced bonding force helps to ensure the close fit between the layers of materials during the packaging process, thereby improving the overall integrity and strength of the packaging structure.

[0035] Please refer to Figure 2 and Figure 4 In step S200, a positioning target is etched on the glass substrate 23, and the position of the mounting cavity 21 is determined according to the positioning target. Finally, the mounting cavity 21 is made by laser burning grooves at a preset position by positioning the positioning target. The position of the RF chip 1 in the process of embedding the mounting cavity 21 may be affected by many factors, such as the unevenness of the surface of the glass core frame 2, the size deviation of the chip, etc. These factors may lead to errors in the embedding position of the laser positioning and burning grooves, and the presence of the positioning target can greatly reduce these errors and improve the accuracy of assembly.

[0036] Please refer to Figure 2 and Figure 4 In step S300, the adhesive layer 3 is made of materials including polyimide, polyester and polyvinyl chloride. After the adhesive layer 3 is attached to the bottom surface of the glass core frame 2, the RF chip 1 is mounted on the adhesive layer 3 in the mounting cavity 21 using an automatic placement machine, and the offset accuracy of the automatic placement machine is ±10um. Polyimide, polyester and polyvinyl chloride have excellent thermal stability and mechanical strength, and can firmly fix the RF chip 1 in the mounting cavity 21. With the high-precision automatic placement machine, theoretically, the deviation of the preset installation position of the RF chip 1 in the mounting cavity 21 will not exceed 10um.

[0037] Please refer to Figure 5 and Figure 7 In this embodiment, in step S400, a first sealing layer 41 is provided on the top surface of the glass core frame 2 for the first pressing and curing, and the first sealing layer 41 is bonded to the top surface of the RF chip 1; the adhesive layer 3 is peeled off, and a second sealing layer 42 is bonded to the bottom surface of the glass core frame 2 for the second pressing and curing, and the second sealing layer 42 is bonded to the bottom surface of the RF chip 1. The main component of the sealing layer 4 can be polypropylene (PP), wherein the first sealing layer 41 and the second sealing layer 42 together wrap the side edges of the RF chip 1, realize the upper and lower packaging of the RF chip 1, and also form a closed electromagnetic environment, which helps to reduce the interference of the external electromagnetic field on the RF chip 1. In addition, the sealing layer 4 has good elasticity and buffering properties, and can absorb and disperse vibration and impact energy from the outside, thereby protecting the RF chip 1 from damage.

[0038] Please refer to Figure 8 and Fig. 9 In this embodiment, in step S500, the position coordinates of the signal lead-out hole 5 are located by X-ray and a second positioning hole is made in the second sealing layer 42 by laser hole burning. After removing the drilling stains, the second positioning hole is filled with metal copper by copper plating to form the signal lead-out hole 5. The step after step S is also included, in which the outer layer circuit is etched on the side of the glass core frame 2 away from the mounting cavity 21, and the package of the RF chip 1 is automatically optically inspected, and the glass core frame 2 is sequentially subjected to solder mask treatment and surface treatment according to the inspection results. In this process, X-ray technology is used to determine the precise position of the signal lead-out hole 5 on the glass core frame 2, laser hole burning technology is used to make the second positioning hole, and the subsequent copper plating process is used to fill the metal copper to form the signal lead-out hole 5. These steps ensure the high precision and high quality of the hole, thereby ensuring the stability of the electrical connection between the RF chip 1 and the external circuit through the signal lead-out hole 5. The solder-proof treatment can protect the circuit from the high temperature and chemicals during the welding process, thereby extending the service life of the electronic product; the surface treatment improves the durability, corrosion resistance and compatibility of the glass core frame 2 with other components, especially the compatibility of other circuits in the signal connection with the signal output hole 5, further improving the overall performance of the electronic product.

[0039] Please refer to Figures 1 to 9The present invention also provides an embedded RF chip 1 packaging structure, comprising: a RF chip 1; a glass core frame 2, the glass core frame 2 is provided with a conductive blind hole 22 and a mounting cavity 21 for embedding the RF chip 1, the conductive blind hole 22 is electrically connected to the RF chip 1; the RF chip 1 is arranged in the mounting cavity 21; a first sealing layer 41, covering the top surface of the glass core frame 2, filling the mounting cavity 21 and wrapping the top edge of the RF chip 1; a second sealing layer 42, covering the bottom surface of the glass core frame 2 and attached to the bottom surface of the RF chip 1, the second sealing layer 42 and the first sealing layer 41 are elastic; a signal lead-out hole 5, penetrating the second sealing layer 42, the signal lead-out hole 5 is filled with metal copper to achieve signal conduction with the RF chip 1. This design utilizes the high thermal stability of the glass plate in the glass core frame 2, and combined with the conductive blind hole 22, it can quickly dissipate the heat generated by the RF chip 1 in the installation cavity 21 while reducing the thermal deformation of the package body, wherein the sealing layer 4 can effectively wrap the RF chip 1, and also provide a buffer protection for the RF chip 1 to effectively protect the RF chip 1, and the surface of the sealing layer 4 is covered with a protective layer 6 with insulating ability, which can effectively protect the internal structure. In summary, this structure has the advantages of compact structure, stable and reliable, high signal transmission efficiency, and good heat dissipation performance.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for packaging an embedded radio frequency chip, characterized in that: Includes steps: Step S100: etching a frame on a glass substrate (23), and making a conductive blind hole (22) on the glass substrate (23); Step S200: manufacturing a mounting cavity (21) for embedding the radio frequency chip (1) on a glass substrate (23) to obtain a glass core frame (2); Step S300: affixing an adhesive layer (3) on the bottom surface of the glass core frame (2), and placing the radio frequency chip (1) on the top surface of the adhesive layer (3) in the mounting cavity (21); Step S400: Covering one or both sides of the radio frequency chip (1) with a sealing layer (4) and pressing them together; Step S500: making a signal lead-out hole (5) in the sealing glue layer (4) for connecting with the signal of the radio frequency chip (1).

2. The embedded radio frequency chip packaging method according to claim 1, characterized in that: In step S100, the cut incoming glass plate is covered with copper foil on both sides and etched to produce conductive circuits to obtain a glass substrate (23). Before etching the frame, a code mark is printed on the incoming glass substrate (23).

3. The embedded radio frequency chip packaging method according to claim 2, characterized in that: In step S100, during the frame etching process: a first positioning hole is drilled on the glass substrate (23), and a frame pattern and a pattern of the conductive blind via (22) are etched according to the position of the first positioning hole.

4. The embedded radio frequency chip packaging method according to claim 3, characterized in that: In step S100, drilling is performed on the etching pattern of the conductive blind hole (22), and after removing the burrs in the hole, copper is sputtered in the hole to fill the conductive medium, and the entire glass substrate is electroplated for thickening, and finally the glass substrate (23) is browned.

5. The embedded radio frequency chip packaging method according to any one of claims 1 to 4, characterized in that: In step S200, an alignment target is etched on the glass substrate (23), the position of the mounting cavity (21) is determined according to the alignment target, and finally the mounting cavity (21) is manufactured by laser burning grooves at a preset position by positioning the alignment target.

6. The embedded radio frequency chip packaging method according to claim 5, characterized in that: In step S300, the adhesive layer (3) is made of materials including polyimide, polyester and polyvinyl chloride. After the adhesive layer (3) is attached to the bottom surface of the glass core frame (2), an automatic chip mounter is used to mount the radio frequency chip (1) onto the adhesive layer (3) in the mounting cavity (21). The offset accuracy of the automatic chip mounter is ±10um.

7. The embedded radio frequency chip packaging method according to claim 6, characterized in that: In step S400, a first sealing layer (41) is provided on the top surface of the glass core frame (2) for first pressing and curing, wherein the first sealing layer (41) is bonded to the top surface of the radio frequency chip (1); The adhesive layer (3) is peeled off, and a second sealing layer (42) is affixed to the bottom surface of the glass core frame (2) for a second pressing and curing, wherein the second sealing layer (42) is affixed to the bottom surface of the radio frequency chip (1).

8. The embedded radio frequency chip packaging method according to claim 7, characterized in that: In step S500, the position coordinates of the signal lead-out hole (5) are located by X-ray and a second positioning hole is made in the second sealing glue layer (42) by laser burning. After removing the drilling stains, the second positioning hole is filled with metal copper by copper plating to form the signal lead-out hole (5).

9. The embedded radio frequency chip packaging method according to claim 8, characterized in that: The method further includes step 510 after step S500, in which an outer layer circuit is produced by etching a side of the glass core frame (2) away from the mounting cavity (21), and the package of the radio frequency chip (1) is subjected to automatic optical inspection, and the glass core frame (2) is subjected to solder mask treatment and surface treatment in sequence according to the inspection results.

10. An embedded radio frequency chip packaging structure, characterized in that: include: Radio frequency chip (1); A glass core frame (2), the glass core frame (2) being provided with a conductive blind hole (22) and a mounting cavity (21) for embedding the radio frequency chip (1), the conductive blind hole (22) being electrically connected to the radio frequency chip (1); the radio frequency chip (1) being arranged in the mounting cavity (21); A first sealing glue layer (41) is coated on the top surface of the glass core frame (2), fills the mounting cavity (21) and wraps around the top edge of the radio frequency chip (1); A second sealing glue layer (42) is covered on the bottom surface of the glass core frame (2) and adhered to the bottom surface of the radio frequency chip (1), and the second sealing glue layer (42) and the first sealing glue layer (41) are elastic; A signal lead-out hole (5) is provided through the second sealing glue layer (42), and the signal lead-out hole (5) is filled with metal copper to achieve signal conduction with the radio frequency chip (1).

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