A packaging structure and a method of manufacturing the same

Abstract

This disclosure provides a packaging structure and its fabrication method. The structure includes: a printed circuit board with a recess within it; a heat sink located within the recess of the printed circuit board; and a chip located on the heat sink. This disclosure utilizes a printed circuit board instead of a traditional ceramic substrate, significantly reducing production costs and shortening the manufacturing cycle. Furthermore, the embedded heat sink improves the heat dissipation effect of the package and enhances device performance.

Description

Technical Field

[0001] This disclosure relates to the field of circuit board manufacturing technology, and in particular to a packaging structure and its preparation method. Background Technology

[0002] Microwave SIP (System in Package) packaging technology, as an important breakthrough in modern electronic packaging, has seen tremendous demand in recent years in fields such as radar and communications, driven by the core requirements of miniaturization, anti-interference, and multi-functional integration.

[0003] Traditional microwave SIPs often use HTCC (High-Temperature Co-Fired Ceramic) ceramic substrates and metal frames to form a composite shell. Due to limitations in manufacturing processes and materials, this approach has a long production cycle and high cost. Furthermore, to accommodate the expansion coefficient of the printed circuit board, the packaging interface often uses BGA (Ball Grid Array) technology, which significantly increases the difficulty of heat dissipation. Summary of the Invention

[0004] This disclosure provides a packaging structure and its preparation method to at least solve the above-mentioned technical problems existing in the prior art.

[0005] According to a first aspect of this disclosure, an encapsulation structure is provided, wherein the structure includes: A printed circuit board, wherein a groove is formed in the printed circuit board; A heat sink is located within a recess on the printed circuit board; The chip is located on the heat sink.

[0006] In one possible implementation, the structure further includes: A cover is located on the printed circuit board; a cavity is formed inside the cover, the cavity is disposed opposite to the heat sink, and the cavity exposes the heat sink and the chip.

[0007] In one embodiment, adhesive guide grooves are formed around the perimeter of the printed circuit board, and the area between the adhesive guide grooves and the edge of the printed circuit board is an adhesive bonding area, wherein the adhesive guide grooves are filled with adhesive. The bonding area between the cover and the printed circuit board is fixedly connected by adhesive.

[0008] In one embodiment, the width of the bonding area is 1-2 mm, and the width of the adhesive guide groove is 0.2-0.3 mm.

[0009] In one embodiment, the heat sink is made of copper.

[0010] In one embodiment, the thickness of the heat sink is 1-2 mm and the side length is 3-5 mm.

[0011] In one possible implementation, the structure further includes: The pin portion is located at the bottom of the printed circuit board; A grounding via passes through the printed circuit board and is located on a portion of the pin portion; The chip is connected to the grounding via via a lead.

[0012] In one embodiment, the printed circuit board is a composite structure of hydrocarbon resin, ceramic filler, and glass cloth.

[0013] In one embodiment, the sealing material includes polyetheretherketone (PEEK).

[0014] According to a second aspect of this disclosure, a method for preparing an encapsulation structure is provided, wherein the method includes: Provide printed circuit boards; A groove is formed inside the printed circuit board; A heat sink is placed inside the groove; A chip is formed on the heat sink.

[0015] The packaging structure and its fabrication method disclosed herein utilize a printed circuit board to replace the traditional ceramic substrate, which greatly reduces production costs and shortens the manufacturing cycle. At the same time, the heat sink embedded in the printed circuit board improves the heat dissipation effect of the package and increases the performance of the device.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0017] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0018] Figure 1 A cross-sectional view of the packaging structure provided in the embodiments of this disclosure; Figure 2 A top view of a printed circuit board provided in an embodiment of this disclosure; Figure 3 This is a schematic flowchart illustrating the method for fabricating the packaging structure provided in the embodiments of this disclosure. Detailed Implementation

[0019] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0020] This disclosure provides a packaging structure. Figure 1 A cross-sectional view of the packaging structure provided in the embodiments of this disclosure, such as... Figure 1 As shown, the structure includes: Printed circuit board 10, with a groove (not shown in the figure) inside the printed circuit board 10; The heat sink 20 is located in the recess of the printed circuit board 10; Chip 30 is located on heat sink 20.

[0021] In one embodiment, the printed circuit board 10 can be a high-frequency board RO4350B, which can provide circuit stability and support. The printed circuit board 10 has a composite structure of hydrocarbon resin, ceramic filler and glass cloth, which balances cost and microwave performance, and also ensures the strength of the housing.

[0022] The printed circuit board 10 has a groove, and a heat sink 20 is set in the groove. The heat sink can improve the heat dissipation effect of the package structure. At the same time, the heat sink can serve as an RF ground plane to improve RF transmission performance.

[0023] In one embodiment, the heat sink 20 has a thickness of 1-2 mm and a side length of 3-5 mm. In a preferred embodiment, the heat sink 20 has a thickness of 1 mm and a side length of 3 mm.

[0024] The height of the heat sink 20 is the same as the height of the printed circuit board 10.

[0025] In one embodiment, the heat sink 20 is made of copper, which has a thermal conductivity of 398 W / mK, thus providing better heat dissipation. In other embodiments, the heat sink 20 can be made of other materials that can also provide heat dissipation.

[0026] A chip 30 is mounted on the heat sink 20. Positioning the chip on the heat sink helps reduce the heat generated during operation and improves chip performance.

[0027] like Figure 1As shown, the package structure also includes: a pin portion 50 located at the bottom of the printed circuit board 10; a ground via 60 passing through the printed circuit board 10 and located on a portion of the pin portion 50; and a chip 30 connected to the ground via 60 via a lead 70.

[0028] Pin 50 is a QFN (Quad Flat No-leads Package) pin, which can improve the heat dissipation of the package structure.

[0029] A grounding via 60 is provided on some of the pin portions 50, which can improve radio frequency transmission performance.

[0030] Figure 2 This is a top view of a printed circuit board provided in an embodiment of this disclosure.

[0031] like Figure 2 As shown, adhesive guide grooves 11 are provided around the perimeter of the printed circuit board 10, and the area between the adhesive guide grooves 11 and the edge of the printed circuit board 10 is the bonding area 12.

[0032] In one embodiment, the width d1 of the bonding area 12 is 1~2mm, and the width d2 of the adhesive guide groove 11 is 0.2~0.3mm. In a preferred embodiment, the width d1 of the bonding area 12 is 1mm, and the width d2 of the adhesive guide groove 11 is 0.2mm.

[0033] like Figure 1 As shown, the packaging structure also includes: a cover 40 located on the printed circuit board 10; a cavity 41 is formed inside the cover 40, the cavity 41 is disposed opposite to the heat sink 20, and the cavity 41 exposes the heat sink 20 and the chip 30. The cavity in the cover can improve the heat dissipation effect to a certain extent.

[0034] The sealing material includes polyetheretherketone (PEEK).

[0035] Polyetheretherketone (PEEK) has a long-term operating temperature of up to 260°C, meeting the temperature requirements for device mounting. It combines rigidity and toughness, exhibiting superior fatigue resistance compared to metal alloys and outstanding resistance to alternating stress. It is resistant to strong acids, strong alkalis, and organic solvents, with a water absorption rate of <0.5%. These properties ensure excellent environmental adaptability for capping and good airtightness, while also reducing the processing cycle to one day.

[0036] The cap 40 is made using 3D printing technology.

[0037] In one embodiment, the bonding area 12 between the cover 40 and the printed circuit board 10 is fixedly connected by adhesive, and the adhesive guide groove 11 is filled with adhesive to ensure a more secure connection between the cover and the printed circuit board.

[0038] The cap 40 and the bonding area 12 are bonded with epoxy adhesive. The epoxy adhesive must be applied evenly and smoothly, and fully filled in the adhesive guide groove 11.

[0039] Before the printed circuit board 10 is bonded to the cover 40, it needs to be plasma cleaned. This not only removes contaminants from the surface of the printed circuit board, but more importantly, it increases the roughness of the bonding area and improves the reliability of the package.

[0040] The packaging structure has undergone temperature cycling, vibration, and hermeticity testing. In the temperature cycling test, 3000 cycles from -55℃ to 125℃ were performed, and the results showed no delamination or cracking. In the vibration test, the insertion loss was 0.5dB at 12GHz, and the isolation was >20dB. In the hermeticity test, the helium mass spectrometry leak detection rate was [not specified]. The results of the three tests show that the packaging structure meets the requirements.

[0041] This disclosure also provides a method for preparing a packaging structure. Figure 3 This is a schematic flowchart of the method for fabricating the packaging structure provided in the embodiments of this disclosure, as shown below. Figure 3 As shown, the method includes: Step 301: Provide a printed circuit board; Step 302: Create grooves in the printed circuit board; Step 303: Place the heat sink in the groove; Step 304: Form a chip on the heat sink.

[0042] The preparation method of the packaging structure provided in this disclosure will be further described in detail below with reference to specific embodiments.

[0043] See Figure 1 First, perform step 301 to provide printed circuit board 10.

[0044] In one embodiment, the printed circuit board 10 can be a high-frequency board RO4350B, which can provide circuit stability and support. The printed circuit board 10 has a composite structure of hydrocarbon resin, ceramic filler and glass cloth, which balances cost and microwave performance, and also ensures the strength of the housing.

[0045] Next, steps 302 and 303 are performed to create a groove (not shown in the figure) in the printed circuit board 10; a heat sink 20 is placed in the groove.

[0046] The printed circuit board 10 has a groove, and a heat sink 20 is set in the groove. The heat sink can improve the heat dissipation effect of the package structure. At the same time, the heat sink can serve as an RF ground plane to improve RF transmission performance.

[0047] In one embodiment, the heat sink 20 has a thickness of 1-2 mm and a side length of 3-5 mm. In a preferred embodiment, the heat sink 20 has a thickness of 1 mm and a side length of 3 mm.

[0048] In one embodiment, the heat sink 20 is made of copper, which has a thermal conductivity of 398 W / mK, thus providing better heat dissipation. In other embodiments, the heat sink 20 can be made of other materials that can also provide heat dissipation.

[0049] Next, step 304 is performed to form the chip 30 on the heat sink 20. The chip is positioned on the heat sink, which helps to reduce the heat generated during chip operation and improves chip performance.

[0050] Next, a pin portion 50 is formed at the bottom of the printed circuit board 10. The pin portion 50 is a QFN (Quad Flat No-leads Package) pin, which can improve the heat dissipation of the package structure.

[0051] Next, a ground via 60 is formed through the printed circuit board 10, and the ground via 60 is located on a portion of the pin portion 50. The ground via 60 provided on the portion of the pin portion 50 can improve radio frequency transmission performance.

[0052] Next, a lead 70 is formed from chip 30 to ground via 60, and chip 30 is connected to ground via 60 through lead 70.

[0053] Next, see Figure 2 Adhesive guide grooves 11 are formed around the printed circuit board 10, and the area between the adhesive guide grooves 11 and the edge of the printed circuit board 10 is the bonding area 12.

[0054] In one embodiment, the width d1 of the bonding area 12 is 1~2mm, and the width d2 of the adhesive guide groove 11 is 0.2~0.3mm. In a preferred embodiment, the width d1 of the bonding area 12 is 1mm, and the width d2 of the adhesive guide groove 11 is 0.2mm.

[0055] Next, the printed circuit board 10 is subjected to plasma cleaning. This not only removes contaminants from the surface of the printed circuit board, but more importantly, it increases the roughness of the bonding area and improves the reliability of the package.

[0056] Next, see Figure 1 A cover 40 is provided, and a cavity 41 is provided inside the cover 40.

[0057] The sealing material includes polyetheretherketone (PEEK).

[0058] Polyetheretherketone (PEEK) has a long-term operating temperature of up to 260°C, meeting the temperature requirements for device mounting. It combines rigidity and toughness, exhibiting superior fatigue resistance compared to metal alloys and outstanding resistance to alternating stress. It is resistant to strong acids, strong alkalis, and organic solvents, with a water absorption rate of <0.5%. These properties ensure excellent environmental adaptability for capping and good airtightness, while also reducing the processing cycle to one day.

[0059] The cap 40 is made using 3D printing technology.

[0060] Next, the bonding area 12 between the cover 40 and the printed circuit board 10 is fixedly connected with glue, and the glue guide groove 11 is filled with glue to ensure a more secure connection between the cover and the printed circuit board.

[0061] The cap 40 and the bonding area 12 are bonded with epoxy adhesive. The epoxy adhesive must be applied evenly and smoothly, and fully filled in the adhesive guide groove 11.

[0062] The cavity 41 of the cover 40 is positioned opposite to the heat sink 20, and the cavity 41 exposes the heat sink 20 and the chip 30. The cavity in the cover can improve the heat dissipation effect.

[0063] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0065] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A packaging structure, characterized in that, The structure includes: A printed circuit board, wherein a groove is formed in the printed circuit board; A heat sink is located within a recess on the printed circuit board; The chip is located on the heat sink.

2. The packaging structure according to claim 1, characterized in that, The structure also includes: A cover is located on the printed circuit board; a cavity is formed inside the cover, the cavity is disposed opposite to the heat sink, and the cavity exposes the heat sink and the chip.

3. The packaging structure according to claim 2, characterized in that, The printed circuit board has adhesive guide grooves around its perimeter. The area between the adhesive guide grooves and the edge of the printed circuit board is the bonding area, and the adhesive guide grooves are filled with adhesive. The bonding area between the cover and the printed circuit board is fixedly connected by adhesive.

4. The packaging structure according to claim 3, characterized in that, The width of the bonding area is 1~2mm, and the width of the adhesive guide groove is 0.2~0.3mm.

5. The packaging structure according to claim 1, characterized in that, The heat sink is made of copper.

6. The packaging structure according to claim 1, characterized in that, The thickness of the heat sink is 1~2mm and the side length is 3~5mm.

7. The packaging structure according to claim 1, characterized in that, The structure also includes: The pin portion is located at the bottom of the printed circuit board; A grounding via passes through the printed circuit board and is located on a portion of the pin portion; The chip is connected to the grounding via via a lead.

8. The packaging structure according to claim 1, characterized in that, The printed circuit board is a composite structure of hydrocarbon resin, ceramic filler and glass cloth.

9. The packaging structure according to claim 2, characterized in that, The sealing material includes polyetheretherketone (PEEK).

10. A method for preparing a packaging structure, characterized in that, The method includes: Provide printed circuit boards; A groove is formed inside the printed circuit board; A heat sink is placed inside the groove; A chip is formed on the heat sink.

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