Chip packaging structure and packaging process

Abstract

The chip packaging structure comprises a lead frame, a chip body is soldered at the upper end of the lead frame, and the lower end face of the chip body is attached to the upper end face of the lead frame; comprising colloid, the colloid coats the upper end face of the lead frame and the chip body, the coating height of the colloid is larger than the thickness of the chip body, and the chip body is wrapped by the lead frame and the colloid to form packaging; the upper end of the lead frame is provided with groove bodies I arranged in pairs and groove bodies II arranged in pairs, the two groove bodies I arranged in pairs are parallel to each other, the two groove bodies II arranged in pairs are parallel to each other, the groove bodies II are located between the two groove bodies I arranged in pairs, and the groove bodies II are communicated with the groove bodies I; the first groove body is provided with a first outer side line and a first inner side line, and one pair of side lines of the chip body are located between the first outer side line and the first inner side line. According to the chip packaging structure and the packaging technology, the stability of the packaging structure is improved, and the brittle fracture risk of the packaging colloid is reduced.

Description

Technical Field

[0001] The present invention relates to the field of chip packaging technology, and more particularly, to a chip packaging structure and packaging process. Background Art

[0002] Currently, chips are usually packaged with thermosetting plastics. During packaging, the chip is soldered to the upper end of the lead frame and coated with thermosetting plastic. At the junction of the lead frame and the chip, the thickness of the thermosetting plastic changes, which easily causes stress concentration. In addition, thermosetting plastics are more brittle after heating and curing. Therefore, there is a greater risk of brittle cracking at the junction of the lead frame and the chip. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a chip packaging structure and packaging process to improve the structural stability of the package and reduce the risk of brittle cracking of the packaging colloid.

[0004] In order to achieve the above-mentioned object, the present invention adopts the following technical solutions: a chip packaging structure, comprising a lead frame, wherein a chip body is soldered to the upper end of the lead frame, and the lower end surface of the chip body is in contact with the upper end surface of the lead frame; comprising a colloid, wherein the colloid is coated on the upper end surface of the lead frame and the chip body, and the colloid coating height is greater than the thickness of the chip body, and the chip body is wrapped in the lead frame and the colloid to form a package; a pair of grooves 1 and 2 are provided on the upper end of the lead frame, and the two grooves are parallel to each other. The two paired slot bodies 2 are parallel to each other, the slot body 2 is located between the two paired slot bodies 1, and the slot body 2 is connected to the slot body 1; the slot body 1 is provided with an outer edge line 1 and an inner edge line 1, and one pair of edge lines of the chip body is located between the outer edge line 1 and the inner edge line 1; the slot body 2 is provided with an outer edge line 2 and an inner edge line 2, and the other pair of edge lines of the chip body is located between the outer edge line 2 and the inner edge line 2; the lead frame is provided with channels, and multiple channels are provided along the length direction of the slot body 1 and the length direction of the slot body 2, and the channels pass through the lead frame from top to bottom.

[0005] The present invention is further configured such that the chip body is located between the two paired first trough bodies and between the two paired second trough bodies, and the first trough body and the second trough body are gradually inclined downward in the direction approaching the chip body.

[0006] The present invention is further configured such that the channel is located on a side of the first and second slots close to the chip body.

[0007] The present invention is further configured such that the diameter of the pores is between 0.03 mm and 0.05 mm.

[0008] The present invention is further configured such that one lead frame corresponds to two chip bodies.

[0009] The present invention is further configured such that the chip body is a rectangular sheet structure.

[0010] The present invention also adopts the following technical solution: a chip packaging process for producing a chip packaging structure, comprising the following packaging steps:

[0011] ①Solder the chip body to the upper end of the lead frame;

[0012] ② Coating the upper end of the lead frame with colloid;

[0013] ③ Negative pressure is generated in the channel, and the colloid flows completely into trough body 1 and trough body 2.

[0014] The present invention is further configured such that the colloid is a thermosetting plastic.

[0015] The present invention is further configured such that the chip body is installed on a lower mold body, a boss is provided at the upper end of the lower mold body, the boss is inserted into the bottom of the chip body, an upper mold body is provided above the lower mold body, the upper mold body and the lower mold body can press the chip body up and down, a cavity is formed between the upper mold body and the lower mold body, and the chip body is located in the cavity.

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. By setting the first and second groove bodies, the thickness of the colloid at the connection between the lead frame and the chip body is increased, thereby improving its structural stability and reducing the risk of brittle cracking. At the same time, part of the colloid is located under the chip body, and the colloid packaging is more secure by relying on the soldering effect between the lead frame and the chip body.

[0018] 2. When the colloid flows into the first and second troughs, it tends to stagnate at the inlet. This creates negative pressure within the channel, drawing the colloid downward, allowing it to break through the obstruction at the inlet and flow completely into the first and second troughs, improving sealing efficiency. At the same time, the injection pressure can be kept low, preventing excessive pressure on the chip body and reducing the risk of cracks in the plasticized colloid. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic cross-sectional view of an embodiment;

[0020] Figure 2 A schematic top view of an embodiment;

[0021] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 A schematic cross-sectional view of equipment used in the packaging process in the embodiment;

[0023] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0024] Figure 6 for Figure 5 Another state diagram of .

[0025] Figure numerals: lower mold body 1, boss 11, upper mold body 2, countersunk hole 21, driving component 3, fixing plate 31, piston 32, lead frame 4, groove body one 41, outer edge line one 411, inner edge line one 412, groove body two 42, outer edge line two 421, inner edge line two 422, channel 43, chip body 5, air path pipe 6, convex ring one 61, ring groove 611, convex ring two 62, air hole one 63, air hole two 631, colloid 7, glue injection pipe 8, cavity 9. DETAILED DESCRIPTION

[0026] 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.

[0027] like Figure 1 As shown, this embodiment discloses a chip packaging structure, including a lead frame 4, a chip body 5 soldered to the upper end of the lead frame 4, the chip body 5 is a rectangular sheet structure, and the lower end surface of the chip body 5 is in contact with the upper end surface of the lead frame 4.

[0028] like Figure 2 As shown, the upper end of the lead frame 4 is provided with a pair of slots 1 41 and a pair of slots 2 42. Figure 2 In this orientation, the two left and right paired trough bodies 1 41 are parallel to each other, and the two upper and lower paired trough bodies 2 42 are parallel to each other. The trough body 2 42 is located between the two paired trough bodies 1 41, and the trough body 2 42 is connected to the trough body 1 41. To be precise, the longitudinal ends of the two trough bodies 1 41 are connected through the trough body 2 42.

[0029] like Figure 1 、 Figure 2 As shown, one lead frame 4 corresponds to two chip bodies 5. Figure 2 、 Figure 3 As shown, the chip body 5 is located between the two paired first groove bodies 41 and between the two paired second groove bodies 42. Specifically, the first groove body 41 has an outer edge line 411 and an inner edge line 412, and one pair of edges of the chip body 5 is located between the outer edge line 411 and the inner edge line 412. The second groove body 42 has an outer edge line 421 and an inner edge line 422, and the other pair of edges of the chip body 5 is located between the outer edge line 421 and the inner edge line 422. Figure 2 In the figure, the dotted line shows the installation position of the chip body 5.

[0030] like Figure 1 As shown, the lead frame 4 is provided with a hole 43, and the hole 43 passes through the lead frame 4 from top to bottom. Figure 2 、 3 As shown, multiple channels 43 are provided along the length of both the first and second troughs 41 and 42. Channels 43 have a diameter between 0.03 mm and 0.05 mm and are manufactured using specialized processes, including laser drilling and electric spark drilling. Because the channels 43 are relatively small, and the encapsulating colloid 7 is a thermosetting plastic and relatively viscous when in a fluid state, it is difficult for it to pass through the channels 43. This prevents the colloid 7 from overflowing from the lead frame 4.

[0031] like Figure 1 As shown, the first groove body 41 gradually slopes downward toward the chip body 5, and the channel 43 is located on the side of the first groove body 41 close to the chip body 5. This allows the glue 7 in the first groove body 41 to easily flow toward the channel 43 during glue injection and packaging. A similar arrangement is used for the second groove body 42, which gradually slopes downward toward the chip body 5, and the channel 43 is located on the side of the second groove body 42 close to the chip body 5.

[0032] like Figure 1 As shown, the colloid 7 coats the upper end surface of the lead frame 4 and the chip body 5. The coating height of the colloid 7 is greater than the thickness of the chip body 5. The chip body 5 is wrapped by the lead frame 4 and the colloid 7 to form a package. The colloid 7 is a thermosetting plastic. When applied, it flows to the upper end of the lead frame 4 by extrusion, and the colloid 7 flows into the groove body 1 41 and the groove body 2 42. The colloid 7 is relatively viscous and has a large flow resistance. The groove body 1 41 and the groove body 2 42 are relatively shallow, with a depth between 0.2mm and 0.5mm. In addition, since the edge of the chip body 5 extends out of the inner edge line 1 412 and the inner edge line 2 422 corresponding to the groove body 1 41 and the groove body 2 42, the distance between the edge of the chip body 5 and the outer edge line 1 411 and the outer edge line 2 421 corresponding to the groove body 1 41 and the groove body 2 42 is 0.5mm-1.5mm, so as to form a glue inlet. When the colloid 7 flows into the groove body 1 41 and the groove body 2 42, it is easy to form stagnation at the glue inlet. A negative pressure is formed in the channel 43 to attract the colloid 7 downward, so that the colloid 7 breaks through the obstruction of the glue inlet and flows completely into the groove body 1 41 and the groove body 2 42, thereby improving the sealing efficiency. At the same time, the injection pressure can be kept at a low level to prevent a large injection pressure from being generated on the chip body 5. This is because as the colloid 7 is heated and plasticizes the chip body 5, the pressure of the colloid 7 on the chip body 5 is maintained, which is likely to affect the service life of the chip body 5. After the colloid 7 is plasticized, its properties become brittle, and this pressure will also cause the plasticized colloid 7 to easily crack.

[0033] By providing the groove body 1 41 and the groove body 2 42 , the thickness of the colloid 7 at the connection between the lead frame 4 and the chip body 5 is increased, thereby improving the structural stability and reducing the risk of brittle cracking. At the same time, part of the colloid 7 is located below the chip body 5 , and the packaging of the colloid 7 is more secure by relying on the soldering effect of the lead frame 4 and the chip body 5 .

[0034] A chip packaging process for producing a chip packaging structure includes the following packaging steps:

[0035] ①Solder the chip body 5 to the upper end of the lead frame 4.

[0036] like Figure 4 As shown, the lead frame 4 is mounted on the lower mold body 1 . A boss 11 is provided on the upper end of the lower mold body 1 , and the lead frame 4 is inserted into the upper end of the boss 11 .

[0037] ② The upper mold body 2 moves downward and approaches the lower mold body 1. The upper mold body 2 and the lower mold body 1 press the lead frame 4 up and down. The upper mold body 2 is equipped with a heating wire for heating. Figure 6 As shown, a cavity 9 is formed between the upper mold body 2 and the lower mold body 1 . The cavity 9 is a glue injection space, and the chip body 5 is located in the cavity 9 .

[0038] like Figure 4 As shown, the lower mold body 1 is equipped with a driving component 3, which is a hydraulic cylinder. A fixed plate 31 is installed at the output end of the driving component 3. The fixed plate 31 can move up and down under the drive of the driving component 3. A piston 32 is installed at the upper end of the fixed plate 31. The piston 32 is inserted into the lower mold body 1. The piston 32 is connected to the piston on the inner wall of the lower mold body 1. The piston 32 is located below the lead frame 4. The piston 32 moves upward to push the gas upward along the channel 43.

[0039] ③ Such as Figure 4 As shown, the upper mold body 2 is equipped with an air conduit 6, which is connected to a vacuum generator to evacuate the cavity 9, reducing the air pressure in the cavity 9. This reduces the resistance caused by the compressed gas in the cavity 9 during injection, improves the fluidity of the colloid 7, and improves production efficiency. The air conduit 6 is driven by a cylinder to move up and down.

[0040] like Figure 5 As shown, the gas pipeline 6 includes a second convex ring 62 at the bottom and a first convex ring 61 above the second convex ring 62. Figure 6As shown, the air conduit 6 is provided with a first air hole 63 and a second air hole 631. The first air hole 63 communicates with the second air hole 631, which is then connected to the vacuum generator's exhaust line. The protruding ring 61 is provided with an annular groove 611, which communicates with the second air hole 631. As the air conduit 6 moves downward, the bottom of the air conduit 6 extends downward from the upper wall of the upper mold body 2, and the annular groove 611 communicates with the cavity 9. This draws air from the cavity 9 to reduce its internal pressure, thereby minimizing the localized airflow pressure blockage that would otherwise occur after the colloid 7 is introduced.

[0041] ④ The upper mold body 2 is equipped with a glue injection pipe 8, which injects glue 7 into the cavity 9 to coat the upper end of the lead frame 4 with glue 7. The glue 7 is heated and solidified to form a plastic seal.

[0042] ⑤ The piston 32 moves downward, and the channel 43 generates negative pressure. The negative pressure formed in the channel 43 attracts the colloid 7 downward, so that the colloid 7 breaks through the obstruction of the glue inlet and flows completely into the groove body 1 41 and the groove body 2 42, thereby improving the glue sealing efficiency.

[0043] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A chip packaging structure, characterized in that: It comprises a lead frame (4), the upper end of the lead frame (4) is soldered with a chip body (5), and the lower end surface of the chip body (5) is bonded to the upper end surface of the lead frame (4); The chip body (5) comprises a colloid (7), the colloid (7) being coated on the upper end surface of the lead frame (4) and the chip body (5), the coating height of the colloid (7) being greater than the thickness of the chip body (5), and the chip body (5) being wrapped by the lead frame (4) and the colloid (7) to form a package; The upper end of the lead frame (4) is provided with a pair of groove bodies (41) and a pair of groove bodies (42), the two groove bodies (41) are parallel to each other, the two groove bodies (42) are parallel to each other, the groove body (42) is located between the two groove bodies (41), and the groove body (42) is connected to the groove body (41); The groove body (41) is provided with an outer edge line (411) and an inner edge line (412), and one pair of edge lines of the chip body (5) is located between the outer edge line (411) and the inner edge line (412); The second groove body (42) is provided with a second outer edge line (421) and a second inner edge line (422), and the other pair of edges of the chip body (5) is located between the second outer edge line (421) and the second inner edge line (422); The lead frame (4) is provided with a hole (43), and a plurality of the holes (43) are provided along the length direction of the first slot (41) and the length direction of the second slot (42), and the holes (43) pass through the lead frame (4) from top to bottom.

2. The chip packaging structure according to claim 1, wherein: The chip body (5) is located between the two paired trough bodies (41) and between the two paired trough bodies (42), and the trough bodies (41) and (42) are gradually inclined downward in a direction approaching the chip body (5).

3. The chip packaging structure according to claim 1, wherein: The hole (43) is located on one side of the first groove body (41) and the second groove body (42) close to the chip body (5).

4. The chip packaging structure according to claim 1, wherein: The diameter of the pore (43) is between 0.03 mm and 0.05 mm.

5. The chip packaging structure according to claim 1, wherein: One lead frame (4) corresponds to two chip bodies (5).

6. The chip packaging structure according to claim 1, wherein: The chip body (5) is a rectangular sheet structure.

7. A chip packaging process for producing the chip packaging structure according to claim 1, characterized in that: The packaging steps include the following: ① Soldering the chip body (5) to the upper end of the lead frame (4); ② The upper end of the lead frame (4) is coated with the colloid (7); ③ The channel (43) generates negative pressure, and the colloid (7) completely flows into the first tank (41) and the second tank (42).

8. A chip packaging process according to claim 7, characterized in that: The colloid (7) is thermosetting plastic.

9. The chip packaging process according to claim 7, characterized in that: The chip body (5) is mounted on a lower mold body (1); a boss (11) is provided at the upper end of the lower mold body (1); the boss (11) is inserted into the bottom of the chip body (5); an upper mold body (2) is provided above the lower mold body (1); the upper mold body (2) and the lower mold body (1) can press the chip body (5) together; a cavity (9) is formed between the upper mold body (2) and the lower mold body (1); and the chip body (5) is located in the cavity (9).

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