QFN packaging structure and manufacturing method thereof

Abstract

The invention relates to the related technical field of QFN packaging, in particular to a QFN packaging structure and a manufacturing method thereof.The QFN packaging structure comprises a packaging structure body, a cooling fin and a pin, the packaging structure body is used for packaging a chip structure, and a cooling fin mounting groove is reserved in the lower side face of the packaging structure body; pin mounting grooves are reserved in the side edge and the edge of the lower side face of the packaging structure body, the cooling fins are mounted in the cooling fin mounting grooves in an embedded mode, the upper surfaces of the cooling fins and the lower surface of the chip structure are mounted in an attached mode, and the pins are mounted in the pin mounting grooves in an embedded mode; according to the packaging structure, the cooling fins are arranged, it is guaranteed that the upper surfaces of the cooling fins are attached to the lower surface of the chip structure, the heat conduction plate is arranged on the main board where the packaging structure body is installed, and therefore the heat conduction plate is attached to the cooling fins, and operation heat of the chip structure is guided to the heat conduction plate through the cooling fins; therefore, the operation temperature of the chip structure is effectively controlled, and the operation effect of the chip structure is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the technical field related to QFN packaging, and in particular to a QFN packaging structure and a manufacturing method thereof. Background Art

[0002] QFN is one of the surface mount packages. It is worth noting that the QFN package is completely different from the LCC package. The LCC still has epitaxial pins, but the pins are bent to the bottom, while the QFN package does not have any epitaxial pins at all. The existing Chinese patent document with the publication number CN113192920B discloses a pin structure of a QFN package, which includes a frame base and a plastic encapsulation material. The frame base is provided with a base island fixing area and an etching area, and the etching area is located on the periphery of the base island fixing area; the base island fixing area includes a chip and a base island for fixing the chip, and the chip is connected to the top surface of the base island; a half-etched base island bracket is provided between the etching area and the base island, and the etching area includes a plurality of pins, each of which has a half-etched edge area at its edge, and a half-etched groove is provided in the edge area; the chip is connected to the pins via bonding wires, and the etching area, base island fixing area, and bonding wires are all plastic-encapsulated in the plastic encapsulation material, and the edge area and the groove in the edge area are filled with the plastic encapsulation material; However, the packaging structure in the above solution does not have a dedicated heat dissipation structure, which results in poor heat dissipation effect of the chip structure during actual operation, thereby affecting the processing efficiency of the chip to a certain extent. Therefore, the present invention proposes a QFN packaging structure and a manufacturing method thereof to solve the above problem. Summary of the Invention

[0003] The object of the present invention is to provide a QFN package structure and a manufacturing method thereof to solve the problems raised in the above background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a QFN packaging structure, comprising: A packaging structure body, which is used to package the chip structure, has a heat sink mounting groove reserved on the lower side of the packaging structure body, and pin mounting grooves reserved on the side and lower side edges of the packaging structure body; A heat sink is mounted in the heat sink mounting groove, with the upper surface of the heat sink being mounted in contact with the lower surface of the chip structure; The pins are embedded in the pin installation grooves and are electrically connected to the chip structure.

[0005] Preferably, the packaging structure body is positioned on the main board during actual installation, and a heat conducting plate and a pin docking seat are embedded and installed on the main board. The heat conducting plate and the heat sink are aligned, and when the packaging structure body is actually installed, the heat conducting plate and the heat sink are fitted together.

[0006] Preferably, the pin is hook-mounted.

[0007] Preferably, the pin docking seat is arranged corresponding to the pin, and when the packaging structure body is actually installed, the pin docking seat is arranged in contact with the pin, and the lower end surface of the pin is connected to the pin docking seat by soldering.

[0008] Preferably, an alignment groove is provided on the upper surface of the pin docking seat, the width of the alignment groove matches the width of the pin, the lower side of the pin protrudes from the lower side of the packaging structure body, and when the packaging structure body is actually installed, the pin is fitted in the alignment groove.

[0009] Preferably, a primary drainage groove is provided at the bottom of the alignment groove, and a secondary drainage groove is provided on the lower surface of the pin. The primary drainage groove and the secondary drainage groove are arranged correspondingly. When the pin is soldered to the pin docking seat, the liquefied soldering liquid flows into the gap between the primary drainage groove and the secondary drainage groove.

[0010] Preferably, the bottom of the primary drainage groove is tilted downward toward the heat transfer plate, and the bottom of the secondary drainage groove is parallel to the bottom of the primary drainage groove.

[0011] Preferably, a thermal grease storage groove is provided at a center position on the lower surface of the heat sink, and a thermal grease block is provided in the thermal grease storage groove.

[0012] Preferably, a three-level drainage groove is opened on the side of the thermal grease storage tank, and the three-level drainage groove is arranged in a circle around the circumference of the thermal grease storage tank, and the three-level drainage groove does not completely penetrate to the edge of the heat sink.

[0013] A manufacturing method for a QFN packaging structure is used to manufacture the above-mentioned QFN packaging structure. The manufacturing method is to integrally package a heat sink, pins, and chip structure on the packaging structure body, fill the thermal grease storage groove on the lower surface of the heat sink with thermal grease, and allow the thermal grease to solidify into a thermal grease block.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. A QFN package structure consisting of a package structure body, a heat sink, and pins is provided, so that the upper surface of the heat sink is mounted in contact with the lower surface of the chip structure, and a heat conducting plate is provided on the motherboard where the package structure body is mounted. The heat conducting plate and the heat sink are mounted in contact with each other, so that the heat of the chip structure is directed to the heat conducting plate through the heat sink, thereby effectively controlling the operating temperature of the chip structure and effectively ensuring the operating performance of the chip structure. 2. By providing an alignment groove on the upper surface of the pin docking seat, the alignment of the pin and the pin docking seat is facilitated, and the alignment groove can effectively prevent the position deviation of the pin and the pin docking seat during soldering, thereby improving the welding convenience of the pin and the pin docking seat; 3. By opening a primary drainage groove at the bottom of the alignment groove and a secondary drainage groove on the lower surface of the pin, the soldering liquid can flow into the primary drainage groove and the secondary drainage groove when the pin is soldered to the pin docking seat, thereby effectively ensuring the soldering area and effectively improving the soldering strength between the pin and the pin docking seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the actual connection of the present invention; Figure 3 for Figure 2 A schematic diagram of the structure at center A; Figure 4 This is a bottom side view of the packaging structure of the present invention; Figure 5 Schematic diagram of the upper surface of the main board; Figure 6 Schematic diagram of the pin docking seat structure; Figure 7 This is a schematic diagram of the pin structure of the present invention; Figure 8 This is a schematic diagram of the connection between the pin and the pin docking seat of the present invention; Figure 9 for Figure 8 A magnified schematic diagram of the structure at point B in the middle; Figure 10 A half-sectional view of the heat sink of the present invention; Figure 11 for Figure 10 Enlarged schematic diagram of the structure at point C in the middle.

[0016] In the figure: packaging structure body 1, heat sink 2, pin 3, chip structure 4, heat sink mounting groove 5, pin mounting groove 6, mainboard 7, heat conduction plate 8, pin docking seat 9, alignment groove 10, primary drainage groove 11, secondary drainage groove 12, thermal grease storage groove 13, tertiary drainage groove 14, thermal grease block 15. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] See also Figures 1-11 , the present invention provides the following three preferred embodiments: Example 1: A QFN packaging structure includes a packaging structure body 1, a heat sink 2 and pins 3. The packaging structure body 1 is used to encapsulate the chip structure 4. A heat sink mounting groove 5 is reserved on the lower side of the packaging structure body 1, and pin mounting grooves 6 are reserved at the side and lower side edges of the packaging structure body 1. The heat sink 2 is embedded in the heat sink mounting groove 5, and the upper surface of the heat sink 2 is mounted in contact with the lower surface of the chip structure 4. The pins 3 are embedded in the pin mounting groove 6, and the pins 3 are electrically connected to the chip structure 4.

[0019] The packaging structure body 1 is positioned on the main board 7 during actual installation. A heat conducting plate 8 and a pin docking seat 9 are embedded and installed on the main board 7. The heat conducting plate 8 is aligned with the heat sink 2, and the heat conducting plate 8 and the heat sink 2 are fitted together during actual installation. By setting a QFN packaging structure composed of the packaging structure body 1, the heat sink 2 and the pins 3, the heat sink 2 is set, and the upper surface of the heat sink 2 is fitted together with the lower surface of the chip structure 4. The heat conducting plate 8 is set on the main board 7 where the packaging structure body 1 is installed. By fitting the heat conducting plate 8 and the heat sink 2 together, the operating heat of the chip structure 4 is directed to the heat conducting plate 8 through the heat sink 2, thereby effectively controlling the operating temperature of the chip structure 4 and effectively ensuring the operating effect of the chip structure 4.

[0020] The pins 3 are hooked to improve the connection strength between the pins 3 and the package structure body 1 .

[0021] The pin docking seat 9 is arranged corresponding to the pin 3. When the packaging structure body 1 is actually installed, the pin docking seat 9 and the pin 3 are arranged in contact with each other, and the lower end surface of the pin 3 and the pin docking seat 9 are connected by soldering.

[0022] Embodiment 2, based on embodiment 1, an alignment groove 10 is provided on the upper surface of the pin docking seat 9, the width value of the alignment groove 10 matches the width value of the pin 3, the lower side of the pin 3 protrudes from the lower side of the packaging structure body 1, and when the packaging structure body 1 is actually installed, the pin 3 is cooperated and arranged in the alignment groove 10. By providing the alignment groove 10 on the upper surface of the pin docking seat 9, it is convenient to align the pin 3 with the pin docking seat 9, and the alignment groove 10 can effectively avoid position offset when the pin 3 and the pin docking seat 9 are soldered, thereby improving the welding convenience of the pin 3 and the pin docking seat 9.

[0023] A primary drainage groove 11 is provided at the bottom of the alignment groove 10, and a secondary drainage groove 12 is provided on the lower surface of the pin 3. The primary drainage groove 11 and the secondary drainage groove 12 are arranged correspondingly. When the pin 3 is connected to the pin docking seat 9 by soldering, the liquefied soldering liquid flows into the gap between the primary drainage groove 11 and the secondary drainage groove 12. By providing a primary drainage groove 11 at the bottom of the alignment groove 10 and a secondary drainage groove 12 on the lower surface of the pin 3, when the pin 3 is connected to the pin docking seat 9 by soldering, the soldering liquid can flow into the primary drainage groove 11 and the secondary drainage groove 12, thereby effectively ensuring the soldering area, thereby effectively improving the soldering strength of the pin 3 and the pin docking seat 9.

[0024] The bottom of the first-level drainage groove 11 is tilted downward toward the heat conduction plate 8, and the bottom of the second-level drainage groove 12 is parallel to the bottom of the first-level drainage groove 11, so that the soldering liquid can flow into the first-level drainage groove 11 and the second-level drainage groove 12, thereby further improving the soldering strength between the pin 3 and the pin docking seat 9.

[0025] Example 3, based on Example 2, a thermal grease storage groove 13 is opened at the center position of the lower surface of the heat sink 2, and a thermal grease block 15 is arranged in the thermal grease storage groove 13. The heat generated by the soldering process is used to melt the thermal grease block 15 and flow into the gap between the heat sink 2 and the heat conducting plate 8, thereby ensuring the heat transfer effect between the heat sink 2 and the heat conducting plate 8.

[0026] A three-level drainage groove 14 is provided on the side of the thermal grease storage tank 13. The three-level drainage groove 14 is arranged in a circle around the circumference of the thermal grease storage tank 13. The three-level drainage groove 14 does not completely penetrate the edge of the heat sink 2, so that the melted thermal grease block 15 can fully fill the gap between the heat sink 2 and the heat conducting plate 8.

[0027] The manufacturing method of the QFN packaging structure is used to manufacture the above-mentioned QFN packaging structure. The manufacturing method is to encapsulate the heat sink 2, pins 3, and chip structure 4 in one piece on the packaging structure body 1, and fill the thermal grease storage groove 13 on the lower surface of the heat sink 2 with thermal grease, and allow the thermal grease to solidify into a thermal grease block 15.

[0028] Although the above describes the illustrative specific embodiments of the present application so that those skilled in the art can understand the present application, the present application is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the attached claims, all application creations based on the concept of the present application are protected.

Claims

1. QFN package structure, characterized by: include: A packaging structure body (1), the packaging structure body (1) is used to package a chip structure (4), a heat sink mounting groove (5) is reserved on the lower side of the packaging structure body (1), and pin mounting grooves (6) are reserved on the side and edge of the lower side of the packaging structure body (1); A heat sink (2), wherein the heat sink (2) is embedded in the heat sink mounting groove (5), and the upper surface of the heat sink (2) is mounted in contact with the lower surface of the chip structure (4); A pin (3), wherein the pin (3) is embedded in the pin installation groove (6), and the pin (3) is electrically connected to the chip structure (4).

2. The QFN package structure according to claim 1, wherein: The package structure main body (1) is positioned on the main board (7) during actual installation. A heat conducting plate (8) and a pin docking seat (9) are embedded and installed on the main board (7). The heat conducting plate (8) is aligned with the heat sink (2). When the package structure main body (1) is actually installed, the heat conducting plate (8) and the heat sink (2) are fitted together.

3. The QFN package structure according to claim 2, wherein: The pin (3) is arranged in a hook-type manner.

4. The QFN package structure according to claim 3, wherein: The pin docking seat (9) is arranged corresponding to the pin (3); when the package structure body (1) is actually installed, the pin docking seat (9) and the pin (3) are arranged in contact with each other, and the lower end surface of the pin (3) and the pin docking seat (9) are connected by soldering.

5. The QFN package structure according to claim 4, wherein: An alignment groove (10) is provided on the upper surface of the pin docking seat (9), the width of the alignment groove (10) matches the width of the pin (3), the lower side of the pin (3) protrudes from the lower side of the packaging structure body (1), and when the packaging structure body (1) is actually installed, the pin (3) is arranged in the alignment groove (10).

6. The QFN package structure according to claim 5, wherein: A primary drainage groove (11) is provided at the bottom of the alignment groove (10), and a secondary drainage groove (12) is provided on the lower surface of the pin (3). The primary drainage groove (11) and the secondary drainage groove (12) are arranged correspondingly. When the pin (3) is connected to the pin docking seat (9) by soldering, the liquefied soldering liquid flows into the gap between the primary drainage groove (11) and the secondary drainage groove (12).

7. The QFN package structure according to claim 6, wherein: The bottom of the first-level drainage groove (11) is tilted downward in the direction toward the heat transfer plate (8), and the bottom of the second-level drainage groove (12) is parallel to the bottom of the first-level drainage groove (11).

8. The QFN package structure according to claim 7, wherein: A thermal grease storage groove (13) is provided at a central position on the lower surface of the heat sink (2), and a thermal grease block (15) is provided in the thermal grease storage groove (13).

9. The QFN package structure according to claim 8, wherein: A three-stage drainage groove (14) is provided on the side of the thermal grease storage tank (13), and the three-stage drainage groove (14) is provided in a circle around the circumference of the thermal grease storage tank (13). The three-stage drainage groove (14) does not completely penetrate the edge of the heat sink (2).

10. A method for manufacturing a QFN package structure, characterized in that: The manufacturing method of the QFN packaging structure is used to manufacture any one of the QFN packaging structures of claims 8-9 above, and the manufacturing method comprises the following steps: integrally packaging a heat sink (2), pins (3), and a chip structure (4) on a packaging structure body (1), filling a thermal grease storage groove (13) on the lower surface of the heat sink (2) with thermal grease, and allowing the thermal grease to solidify into a thermal grease block (15).

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