A packaging fixture for limiting CLIP

Abstract

The present invention discloses a packaging jig for limiting CLIP, which relates to the field of semiconductor power device packaging and manufacturing. The present invention includes a limiting cover plate, a limiting base, and a lead frame. The limiting base is installed below the limiting cover plate, and the lead frame is embedded and installed inside the limiting base. A chip block is arranged above the lead frame, a solder paste assembly is arranged between the chip block and the lead frame, and a CLIP is arranged above the solder paste assembly; a cover plate window is opened inside the limiting cover plate, a U-shaped limiting column is fixedly connected to one side of the cover plate window, and four cover plate guide columns with the same diameter are fixedly connected to the top of the limiting cover plate. The present invention realizes that the CLIP maintains a fixed patch position during the chip bonding reflow process through a specific lead frame structure and CLIP frame structure design, and cooperates with the structure of the packaging jig, without causing the CLIP to rotate or deviate.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor power device packaging and manufacturing, and in particular relates to a packaging fixture for limiting CLIP. Background Art

[0002] The continuous advancement of semiconductor power device packaging is placing higher demands on the product's electrical performance and heat dissipation capabilities. To achieve both improved heat dissipation and reduced RDS(ON), a dual-sided heat dissipation plus CLIP (copper bonding) structural process is often employed. The CLIP, which leaks outward onto the top of the product, provides top-side heat dissipation, while working with the bottom lead frame to achieve dual-sided heat dissipation. The CLIP also serves as an internal electrical path, resulting in improved RDS(ON) and higher reliability. However, in actual production applications, the CLIP is attached to the chip. During the reflow process, the bonding material (solder paste) is molten, causing the CLIP to rotate and deflect due to tension and gravity. Uncontrollable CLIP rotation and deflection can lead to poor internal electrical performance, poor package appearance, reduced top heat dissipation area, and low product packaging yield.

[0003] The existing technical solution limits the CLIP by designing a nested snap-fit ​​structure between the CLIP and the lead frame, thereby limiting the CLIP corner deviation. However, with the higher power density requirements for power device packaging, the product packaging volume continues to shrink, or the CLIP structure design is more complex. The smaller product volume results in no space for designing a snap-fit ​​structure in the CLIP frame and lead frame structure. The more complex CLIP structure thus limits the CLIP from being able to implement the design of the snap-fit ​​structure, making it impossible for smaller products to achieve the process capability of limiting the CLIP corner.

[0004] Moreover, the existing technical solution of the snap-fit ​​structure makes the CLIP structure and the lead frame structure more complicated, resulting in larger sizes of the CLIP and lead frame, lower material utilization, and higher precision requirements for the tolerance of multiple matching dimensions, which significantly increases the production and manufacturing costs of the lead frame and CLIP materials. Summary of the Invention

[0005] The purpose of the present invention is to provide a packaging jig for limiting CLIP. During the reflow soldering process, the packaging jig limits the CLIP, thereby achieving limitation during the CLIP reflow soldering process and ensuring the packaging yield. A limiting notch is designed on the CLIP, and a matching limiting column is designed on the packaging jig. During the CLIP patch process, the notch of the CLIP and the limiting column of the packaging jig are matched. The CLIP uses the limiting column as a track and slides into the packaging jig from top to bottom. After the patch, the lead frame, the CLIP copper sheet, and the packaging jig are placed together in a vacuum reflow furnace for reflow soldering. During the reflow process, the packaging jig limits the CLIP copper sheet, ensuring that the CLIP copper sheet is not rotated or offset at the pasting position. After the reflow soldering is completed, the packaging jig is removed to complete the CLIP bonding.

[0006] To solve the above technical problems, the present invention is implemented through the following technical solutions.

[0007] The present invention provides a packaging fixture for a limited CLIP, comprising a limit cover, a limit base and a lead frame, the limit base being installed under the limit cover, the lead frame being embedded in the limit base, a chip block being arranged above the lead frame, a solder paste component being arranged between the chip block and the lead frame, and a CLIP being arranged above the solder paste component; a cover window is provided inside the limit cover, a U-shaped limit column is fixedly connected to one side of the cover window, and four cover guide columns with the same diameter are fixedly connected to the top of the limit cover; four limit seat guide holes with the same diameter are provided in the top of the limit base, a window is provided above the limit base, a limit seat bottom plate is fixedly connected inside the window, limit seat guide columns with the same diameter are fixedly connected on both sides of the top of the limit seat bottom plate, and a limit seat rectangular groove is provided on the limit seat bottom plate; frame guide holes are provided on both sides of the top of the lead frame, and a frame carrier and a frame pin are fixedly installed on the top of the lead frame respectively.

[0008] The present invention is further configured such that the solder paste assembly includes a carrier solder paste, a chip solder paste, and a frame solder paste; the chip block is pasted on top of the frame carrier through the carrier solder paste; the CLIP is pasted on top of the chip block through the chip solder paste; and the bottom side of the CLIP is pasted on top of the frame pin through the frame solder paste.

[0009] The present invention is further configured such that two guide U-grooves are symmetrically provided on both sides of the CLIP, and the guide U-grooves cooperate with the U-shaped limiting columns, and the cooperation clearance is designed to be 0.05 mm.

[0010] The present invention is further configured such that the cover plate guide columns are designed at the center positions of the four borders at the top of the limiting cover plate, and the cover plate windows are designed to be arranged in a rectangular array, which can be multiple rows and columns, and a single cover plate window corresponds to a single unit product of the lead frame.

[0011] The present invention is further configured such that the limit base is a whole rectangular alloy plate, the window depth is designed to be greater than twice the thickness of the lead frame, the length and width of the window are greater than the length and width of the lead frame, so that the lead frame can be completely placed in the window, and the limit seat guide hole cooperates with the cover plate guide column.

[0012] The present invention is further configured such that the number of the limiting seat rectangular grooves is multiple, the length and width of the limiting seat rectangular grooves are designed to be the same as the length and width of the cover window, the position of the limiting seat rectangular grooves is designed to be the same as the cover window, and the depth of the limiting seat rectangular grooves is designed to be 0.2 mm.

[0013] The present invention is further configured such that the frame carrier and the frame pins have the same material thickness and are designed to be on the same plane.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The present invention uses a specific lead frame structure and CLIP frame structure design, combined with the structure of the packaging fixture, to achieve a fixed patch position of the CLIP during the die bonding reflow process, without causing the CLIP to rotate or deviate.

[0016] 2. The present invention can solve the problems of the existing industry's anti-rotation and offset structural design schemes in which the lead frame and the CLIP frame are clipped to each other, which bring about high material costs, difficult material production and manufacturing due to the complex material structure, and large material waste, thereby greatly reducing production costs.

[0017] 3. The present invention uses a specific packaging fixture structure and can limit the CLIP by simply designing a U-shaped or circular notch on the CLIP. This solves the problem in the industry that existing products with extremely small packages cannot be limited by designing a CLIP snap-on structure due to the small size of the CLIP, or that the CLIP snap-on structure cannot be designed for more complex product structures. This enables the CLIP to be limited in position for CLIPs of any size and structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0019] Figure 1 A three-dimensional diagram of the overall structure provided by the present invention;

[0020] Figure 2 A top view of the overall assembly structure provided by the present invention;

[0021] Figure 3 For the present invention Figure 2 A magnified view of middle A;

[0022] Figure 4 A schematic diagram of the structure of the limiting base provided by the present invention;

[0023] Figure 5 For the present invention Figure 4 Enlarged view of middle B;

[0024] Figure 6 A schematic diagram of the connection structure between the lead frame and the limiting base provided by the present invention;

[0025] Figure 7 A schematic diagram of the lead frame structure provided by the present invention;

[0026] Figure 8 A schematic diagram of the solder paste assembly structure provided by the present invention;

[0027] Figure 9 A schematic diagram of the CLIP structure provided by the present invention;

[0028] Figure 10 This is a schematic diagram of the limit cover structure provided by the present invention.

[0029] Description of the drawings: 1. Limiting cover; 11. Cover window; 12. U-shaped limiting column; 13. Cover guide column; 2. Limiting base; 21. Limiting seat guide hole; 22. Limiting seat bottom plate; 23. Limiting seat guide column; 24. Limiting seat rectangular groove; 3. Lead frame; 31. Frame guide hole; 32. Frame carrier; 33. Frame pin; 4. Solder paste assembly; 41. Carrier solder paste; 42. Chip solder paste; 43. Frame solder paste; 5. Chip block; 6. CLIP; 61. Guide U groove. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Example 1

[0032] See also Figures 1-10The present invention is a packaging fixture for limiting CLIP, comprising a limiting cover plate 1, a limiting base 2 and a lead frame 3. The limiting base 2 is installed below the limiting cover plate 1, and the lead frame 3 is embedded and installed inside the limiting base 2. A chip block 5 is arranged above the lead frame 3, a solder paste component 4 is arranged between the chip block 5 and the lead frame 3, and a CLIP 6 is arranged above the solder paste component 4; a cover plate window 11 is opened inside the limiting cover plate 1, a U-shaped limiting column 12 is fixedly connected to one side of the cover plate window 11, and four cover plate guide columns 13 with the same diameter are fixedly connected to the top of the limiting cover plate 1; Four limit seat guide holes 21 with the same diameter are opened at the top of the limit base 2, and a window is opened above the limit base 2. The limit seat base plate 22 is fixedly connected inside the window, and limit seat guide columns 23 with the same diameter are fixedly connected on both sides of the top of the limit seat base plate 22. A limit seat rectangular groove 24 is opened on the limit seat base plate 22; the setting of the limit seat rectangular groove 24 prevents the frame carrier 32 and the frame pin 33 from being scratched or scratched. Frame guide holes 31 are opened on both sides of the top of the lead frame 3, and the frame carrier 32 and the frame pin 33 are fixedly installed on the top of the lead frame 3.

[0033] As a preferred embodiment of the above embodiment: the lead frame 3 is supported by the limiting base 2, the limiting guide column is designed on the base to cooperate with the guide hole of the lead frame 3, the chip block 5 is pasted on the lead frame 3, and the CLIP6 is pasted on the surface of the chip block 5. The limiting cover plate 1 cooperates with the limiting seat guide hole 21 through the cover plate guide column 13, and the limiting cover plate 1 and CLIP6 are designed with U-grooves that cooperate with each other, and the limiting cover plate 1 limits CLIP6.

[0034] Example 2

[0035] See also Figures 1-10On the basis of Example 1, the solder paste assembly 4 includes a carrier solder paste 41, a chip solder paste 42 and a frame solder paste 43. The chip block 5 is pasted on the frame carrier 32 through the carrier solder paste 41, and the CLIP6 is pasted on the chip block 5 through the chip solder paste 42. The bottom side of the CLIP6 is pasted on the frame pin 33 through the frame solder paste 43. Two guide U grooves 61 are symmetrically provided on both sides of the CLIP6. The guide U grooves 61 cooperate with the U-shaped limiting columns 12, and the matching clearance is designed to be 0.05mm. The cover guide columns 13 are designed at the center positions of the four borders on the top of the limiting cover 1. The cover window 11 is designed to be arranged in a rectangular array, which can be multiple rows and columns, and a single cover window 11 corresponds to a single unit product of the lead frame 3. The limit base 2 is a whole rectangular alloy plate. The window depth is designed to be greater than 2 times the thickness of the lead frame 3. The length and width of the window are greater than the length and width of the lead frame 3, so that the lead frame 3 can be completely placed in the window. The limit seat guide hole 21 cooperates with the cover guide column 13. There are multiple limit seat rectangular grooves 24. The length and width of the limit seat rectangular grooves 24 are designed to be the same as the length and width of the cover window 11. The position of the limit seat rectangular groove 24 is designed to be the same as the cover window 11. The depth of the limit seat rectangular groove 24 is designed to be 0.2mm. The frame carrier 32 and the frame pin 33 have the same material thickness and are designed to be on the same plane.

[0036] The working principle of the present invention comprises the following steps:

[0037] Step 1: The limiting base 2 is fixed on the pallet through the equipment clamp. One pallet can carry multiple limiting bases 2. The lead frame 3 is sucked and placed in the limiting base 2 through the suction nozzle of the placement machine equipment. The limiting seat guide column 23 on the limiting base 2 cooperates with the lead frame guide hole 31 on the lead frame 3 to fix the lead frame 3 in the limiting base 2.

[0038] Step 2: The chip mounter smears the carrier solder paste 41 on the frame carrier 32 ; the chip mounter picks up the chip block 5 and sticks it on the carrier solder paste 41 .

[0039] Step 3: The placement machine applies chip solder paste 42 on the chip, and the placement machine applies frame solder paste 43 on the frame pin 33.

[0040] Step 4: The placement machine equipment picks up the limiting cover plate 1, and fixes the limiting cover plate 1 on the limiting base 2 by matching the cover plate guide column 13 with the limiting seat guide hole 21.

[0041] Step 5: The placement machine picks up CLIP6 and sticks it on the chip solder paste 42 and the frame solder paste 43. The U-shaped limiting column 12 and the CLIP guide U groove 61 cooperate with each other to fix the position of CLIP6 and limit the rotation and offset of CLIP6.

[0042] Step 6: Place the entire tray into a vacuum reflow oven for solder paste reflow. During the reflow process, the U-shaped limiting column 12 and the guide U-groove 61 cooperate with each other to fix the position of CLIP 6, limiting the CLIP from turning and deflecting.

[0043] Step 7: After the reflow is completed, the placement machine picks up the limit cover 1, removes the limit cover 1, picks up the lead frame 3, and puts the lead frame 3 with the chip and CLIP into the material box to enter the next process.

[0044] Step 8: Grind the plastic-encapsulated product to expose the CLIP6 on the top surface.

[0045] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A CLIP packaging fixture comprising a limiting cover plate (1), a limiting base (2) and a lead frame (3), characterized in that: The limiting base (2) is installed below the limiting cover (1), the lead frame (3) is embedded and installed inside the limiting base (2), a chip block (5) is arranged above the lead frame (3), a solder paste component (4) is arranged between the chip block (5) and the lead frame (3), and a CLIP (6) is arranged above the solder paste component (4); A cover plate window (11) is provided inside the limiting cover plate (1), a U-shaped limiting column (12) is fixedly connected to one side of the cover plate window (11), and four cover plate guide columns (13) of the same diameter are fixedly connected to the top of the limiting cover plate (1); Four limit seat guide holes (21) of the same diameter are provided on the top of the limit seat (2), a window is provided on the top of the limit seat (2), a limit seat bottom plate (22) is fixedly connected to the inside of the window, limit seat guide columns (23) of the same diameter are fixedly connected to both sides of the top of the limit seat bottom plate (22), and a limit seat rectangular groove (24) is provided on the limit seat bottom plate (22); Frame guide holes (31) are provided on both sides of the top of the lead frame (3), and a frame carrier (32) and a frame pin (33) are fixedly mounted on the top of the lead frame (3).

2. A CLIP packaging fixture for limiting position according to claim 1, characterized in that: The solder paste assembly (4) includes a carrier solder paste (41), a chip solder paste (42) and a frame solder paste (43); the chip block (5) is attached to the frame carrier (32) via the carrier solder paste (41); the CLIP (6) is attached to the chip block (5) via the chip solder paste (42); and the bottom side of the CLIP (6) is attached to the frame pin (33) via the frame solder paste (43).

3. The CLIP packaging fixture according to claim 1, characterized in that: Two guide U-grooves (61) are symmetrically provided on both sides of the CLIP (6). The guide U-grooves (61) cooperate with the U-shaped limiting columns (12), and the cooperation clearance is designed to be 0.05 mm.

4. The CLIP packaging fixture according to claim 1, characterized in that: The cover plate guide columns (13) are designed at the center positions of the four frames on the top of the limiting cover plate (1), and the cover plate windows (11) are designed to be arranged in a rectangular array, which can be multiple rows and columns. A single cover plate window (11) corresponds to a single unit product of the lead frame (3).

5. The CLIP packaging fixture according to claim 1, characterized in that: The limiting base (2) is a whole rectangular alloy plate, the window depth is designed to be greater than twice the thickness of the lead frame (3), and the length and width of the window are greater than the length and width of the lead frame (3), so that the lead frame (3) can be completely placed in the window, and the limiting base guide hole (21) and the cover plate guide column (13) cooperate with each other.

6. The CLIP packaging fixture according to claim 1, characterized in that: The number of the limiting seat rectangular grooves (24) is multiple, the length and width of the limiting seat rectangular grooves (24) are designed to be the same as the length and width of the cover plate window (11), the position of the limiting seat rectangular grooves (24) and the cover plate window (11) are designed to be the same, and the depth of the limiting seat rectangular grooves (24) is designed to be 0.2 mm.

7. The CLIP packaging fixture according to claim 1, characterized in that: The frame carrier (32) and the frame pin (33) have the same material thickness and are designed to be on the same plane.

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