Die flow control structure for reducing wire punching risk

Abstract

The invention discloses a mold flow control structure capable of reducing line punching risk, which comprises a flow guide arc body arranged on the surface of a substrate between a melt glue outlet and a chip and used for guiding and thinning a mold flow, the flow guide arc body reversely protrudes along the mold flow direction, one part of the mold flow can climb over the flow guide arc body to continue descending, and the other part of the mold flow can climb over the chip. And the other part is guided out of the two ends of the flow guide arc body by the flow guide arc body. The flow guide arc body comprises a flow guide arc body I arranged between the upper end head of each row of chips and the melt glue outlet; and one part of the mold flow is guided to a spacing interval between two adjacent rows of chips by the flow guide arc body I. The flow guide arc body further comprises a second flow guide arc body arranged in the interval between the two columns of chips, and a part of die flow entering the interval is guided to the two columns of chips on the two sides through the second flow guide arc body. The method has the advantages that the mold flow flowing to the electrical conductor is thinned, and the impact kinetic energy is weakened, so that the electrical conductor is not easy to bend and deform by impact.

Description

Technical Field

[0001] The invention relates to a mold flow control structure for reducing the risk of wire punching, and belongs to the technical field of chip packaging. Background Art

[0002] After the chip on the substrate is wired with the pins (electrical wires), it needs to be packaged. Chip packaging is to place the wire-bonded chip in a special high-temperature mold, inject molten glue, and then cool it to form a package that covers the chip and all electrical wires.

[0003] Chip packaging is carried out on a large rectangular substrate, with multiple chips arranged vertically and horizontally on the substrate. On the inner wall of one side of the mold used for packaging, there are multiple glue injection holes at equal intervals along the length direction of the rectangular substrate. The glue flowing out of the glue injection holes forms a mold flow on the substrate that flows from one side of the substrate to the other side of the substrate.

[0004] The chip and the pin on the substrate are far apart, and the wire (electrical conductor) between them is long and arches upward. During the chip packaging process, it is sometimes impacted by strong mold flow of molten glue, especially when the mold flow direction is at a large angle of nearly 90 degrees to the length direction of the electrical conductor. The electrical conductor between the chip and the pin is easily bent to the adjacent side of the electrical conductor, causing a short circuit and making the entire chip scrapped. Summary of the invention

[0005] The technical problem to be solved by the present invention is: how to prevent the electric wire from being impacted by strong mold flow and large angle during chip packaging.

[0006] In view of the above problems, the technical solution proposed by the present invention is: A mold flow control structure for reducing the risk of line punching, including a guide arc body arranged on the surface of a substrate between a melt outlet and a chip for diverting and thinning the mold flow, wherein the guide arc body protrudes in the opposite direction of the mold flow, a part of the mold flow can go over the guide arc body and continue to descend, and the other part is diverted by the guide arc body to the outside of the two ends of the guide arc body.

[0007] The guide arc body comprises a guide arc body 1 arranged between the upper end of each column of chips and the melt outlet, and a part of the mold flow is guided by the guide arc body 1 to the interval between two adjacent columns of chips.

[0008] Both ends of the guide arc body 1 are provided with inner guide lead bodies, and the two inner guide lead bodies are respectively parallel to the bonding directions of the electric wires on both sides of all the electric wires above the first chip at the upper end of a corresponding row of chips.

[0009] Below the first diversion arc body, there is a flat peak arc body that blocks and diverts the excessively high part of the mold flow crossing the first diversion arc body. There is a flow-through gap between it and the substrate that allows the molten glue with a set depth to pass through, and the convex direction of its arc is opposite to the direction of the mold flow.

[0010] The flat peak arc body is welded to the inner guiding lead body.

[0011] The diversion arc body further includes a second diversion arc body provided in the interval between two columns of chips. A part of the mold flow entering the interval is respectively diverted by the second diversion arc body to the two columns of chips on both sides.

[0012] At both ends of the second diversion arc body, there are outer guiding lead bodies for making the flow direction of a part of the mold flow guiding to the chips on both sides consistent with the wire bonding direction of the electrical leads on the left or right side of the chip 25.

[0013] On both sides of the second diversion arc body, there are flat peak straight bodies respectively. There is a flow-through gap between the flat peak straight bodies and the substrate that allows the molten glue with a set depth to pass through.

[0014] The flat peak straight body is welded to the outer guiding lead body.

[0015] Below the flat peak arc body between the two inner guiding lead bodies, there is a pillow wire for padding the flat peak arc body. Beneficial effects

[0016] 1. The mold flow flowing towards the electrical leads is thinned, and the impact kinetic energy is weakened, making the electrical leads not easily bent and deformed. 2. The flow direction of the mold flow flowing towards the electrical leads is changed, and it can be as parallel as possible to the wire bonding direction of the electrical leads, avoiding the electrical leads being impacted at a large angle by the mold flow and making the electrical leads easy to deform. Description of the drawings

[0017] Figure 1 It is a top view schematic diagram of the substrate described in the first embodiment; Figure 2 For Figure 1 Partial schematic diagram; Figure 3 It is a three-dimensional schematic diagram of the first diversion arc body and the inner guiding lead body described in the first embodiment; Figure 4 It is a partial top view schematic diagram of the substrate described in the second embodiment; Figure 5 It is a three-dimensional schematic diagram of the first diversion arc body and the flat peak arc body described in the second embodiment; Figure 6 It is a partial top view schematic diagram of the substrate described in the second embodiment, showing a pillow wire added under the flat peak arc body; Figure 7This is a three-dimensional schematic diagram of the guide arc body 1 and the flat peak arc body described in Example 2, and the figure shows that a pillow line is added under the flat peak arc body; Figure 8 It is a partial top view schematic diagram of the substrate described in Example 3; Figure 9 It is a three-dimensional schematic diagram of the guide arc wire body 2 and the outer guide lead wire body described in the third embodiment; Figure 10 It is a partial top view schematic diagram of the substrate described in Example 4; Figure 11 It is a three-dimensional schematic diagram of the guide arc body 2, the outer guide lead body and the flat peak straight body described in Example 4.

[0018] The straight arrows in the above figures indicate the mold flow direction.

[0019] In the figure: 1. Guide arc body 1; 2. Guide arc body 2; 3. Inner guide lead body; 4. Flat-peak arc body; 5. Pillow line; 6. Outer guide lead body; 7. Flat-peak straight body; 8. Substrate; 9. Spacer area; 10. Chip; 11. Electrical conductor; 12. Glue outlet. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with embodiments and drawings: It should be noted here that the directional words "up", "down", "left" and "right" that appear in this article only refer to the viewing orientation. Embodiment 1

[0021] like Figure 1 —3 shows a mold flow control structure for reducing the risk of wire punching, including a guide arc body for diverting and thinning the mold flow, which is arranged on the surface of the substrate 8 between the melt outlet 12 and the chip 10. The guide arc body protrudes in the opposite direction of the mold flow, so that a part of the mold flow is diverted by the guide arc body to the two ends of the guide arc body, and the other part can go over the guide arc body and continue to go down. In this way, the mold flow is blocked by the guide arc body, which first reduces a part of the flow kinetic energy, and can reduce the impact force on the electrical conductor 11 between the chip 10 and the pin, and more importantly, it can guide and separate a part of the mold flow that has not yet dispersed, and only a part of it goes over the guide arc body and continues to move forward in the mold flow direction, so that the mold flow flowing to the chip 10 is diluted, the direction is changed, and the impact force on the electrical conductor 11 is reduced, thereby preventing the electrical conductor 11 from being deformed by punching and short-circuiting with the adjacent electrical conductor 11.

[0022] The above-mentioned guiding arc body includes a guiding arc body 1 provided between the upper end of each column of chips 10 and the melt outlet 12, and a part of the mold flow is guided by the guiding arc body 1 to the interval 9 between two adjacent columns of chips 10. This arrangement is to reduce the impact of the glue liquid just gushing out from the melt outlet 12 on the electrical conductor 11 of the first chip 10 at the upper end of each column of chips, so that more glue liquid enters the interval 9 between two adjacent columns of chips 10, and then the glue liquid entering the interval 9 flows into from both sides of each column of chips 10, so that the front impact of the mold flow on the upper chip 10 in each column of chips can be greatly reduced.

[0023] Both ends of the guide arc body 1 have inner guide lead bodies 3, and the two inner guide lead bodies 3 are parallel to the wire bonding directions of the electric wires 11 on both sides of all the electric wires 11 above the first chip 10 at the upper end of the corresponding row of chips 10 (see Figure 2 As shown), in this way, the direction of the mold flow that crosses the guide arc body 1 to the electric wire 11 above the first chip 10 at the upper end of a row of chips 10 can be basically consistent with the bonding direction of the electric wire 11, thereby preventing the electric wire 11 from being impacted by the mold flow at too large an angle, thereby causing a lateral impact on the electric wire 11.

[0024] The guide arc body is disposed on the base plate 8 by welding. Embodiment 2

[0025] like Figure 4 —7, which is a further improvement of the first embodiment. Below the guide arc body 1, there is a flat peak arc body 4 for blocking and diverting the excessively high part of the mold flow that crosses the guide arc body 1. There is a flow gap between it and the substrate 8 that allows the melt to pass through at a set depth, and the protruding direction of the arc is in the opposite direction of the mold flow. In this way, it can further ensure that the mold flow flowing in from the upper end of a row of chips 10 is controlled at a set depth, and the mold flow above the set depth is guided into the interval 9 between two adjacent rows of chips 10.

[0026] The flat-peak arc body 4 is welded on the inner guide lead body 3, so that the flat-peak arc body 4, the inner guide lead body 3 and the guide arc body 1 can be connected as a whole, so that they can be welded on the substrate 8 at one time, thereby improving work efficiency.

[0027] Below the flat-peaked arc body 4 between the two inner guide wire bodies 3, a pillow line 5 is provided for cushioning the flat-peaked arc body 4. At the same time, the pillow line 5 can also be set as a guide line. Embodiment 3

[0028] like Figure 8 , 9As shown, the difference from the above embodiment is that the diversion arc body further includes a second diversion arc body 2 provided in the interval 9 between two columns of chips 10. A part of the mold flow entering the interval 9 is respectively guided by the second diversion arc body 2 to the two columns of chips 10 on both sides, while the other part of the mold flow entering the interval 9 continues to flow downward. Outer guiding lead bodies 6 are provided at both ends of the second diversion arc body 2 for making the flow direction of a part of the mold flow guided to the chips 10 on both sides consistent with the wire bonding direction of the electrical leads 11 on the left or right side of the chips 25, so as to avoid the electrical leads 11 on both sides of the chips 10 from being impacted by the mold flow at a large angle. Embodiment Four

[0029] As Figure 10 , 11 shown, it is a further improvement of Embodiment Three. On both sides of the second diversion arc body 2, flat peak straight bodies 7 are respectively provided. There is an overflow gap between the flat peak straight bodies 7 and the substrate 8 that allows the set-depth molten glue to pass through, so as to further ensure that the depth of the glue liquid entering the chips 10 from both sides is within the set range.

[0030] The flat peak straight bodies 7 are welded to the outer guiding lead bodies 6, thereby connecting all the second diversion arc bodies 2, their outer guiding lead bodies 6, and the flat peak straight bodies 7 in the interval 9 into one body, so as to improve their welding efficiency on the substrate 8.

[0031] The above embodiments are only used to describe the present invention more clearly and should not be regarded as limiting the protection scope covered by the present invention. Any modification in an equivalent form should be regarded as falling within the protection scope covered by the present invention.

Claims

1. A mold flow control structure for reducing the risk of crossing the finish line, characterized in that: The invention comprises a flow guiding arc body arranged on the surface of a substrate (8) between a melt outlet (12) and a chip (10) for diverting and thinning the mold flow, wherein the flow guiding arc body protrudes in the opposite direction of the mold flow, so that a part of the mold flow can go over the flow guiding arc body and continue to go downward, while the other part is diverted by the flow guiding arc body to the outside of the two ends of the flow guiding arc body.

2. The mold flow control structure for reducing the risk of crossing the finish line according to claim 1, characterized in that: The guide arc body comprises a guide arc body 1 (1) disposed between the upper end of each row of chips (10) and the melt outlet (12), and a portion of the mold flow is guided by the guide arc body 1 (1) to the interval (9) between two adjacent rows of chips (10).

3. The mold flow control structure for reducing the risk of crossing the finish line according to claim 2, characterized in that: Both ends of the guide arc body (1) are provided with inner guide lead bodies (3), and the two inner guide lead bodies (3) are respectively parallel to the bonding directions of the electrical conductors (11) on both sides of all the electrical conductors (11) above the first chip (10) at the upper end in the corresponding row of chips (10).

4. The mold flow control structure for reducing the risk of crossing the finish line according to claim 3, characterized in that: Below the guide arc body 1 (1), a flat peak arc body (4) is provided for blocking and diverting the excessively high portion of the mold flow that passes over the guide arc body 1 (1), and a flow gap is provided between the guide arc body (4) and the base plate (8) to allow the melt glue of a set depth to pass through, and the protruding direction of the arc is opposite to the mold flow.

5. The mold flow control structure for reducing the risk of crossing the finish line according to claim 4, wherein: The flat peak arc body (4) is welded on the inner guide wire body (3).

6. The mold flow control structure for reducing the risk of crossing the finish line according to claim 1, characterized in that: The guide arc body also includes a guide arc body 2 (2) arranged in the spacing area (9) between the two rows of chips (10), and a portion of the mold flow entering the spacing area (9) is guided by the guide arc body 2 (2) to the two rows of chips (10) on both sides.

7. The mold flow control structure for reducing the risk of crossing the finish line according to claim 6, characterized in that: External guide leads (6) are provided at both ends of the second guide arc body (2) for aligning the flow direction of a portion of the mold flow directed to the chips (10) on both sides with the bonding direction of the electrical conductors (11) on the left or right side of the chip 25.

8. The mold flow control structure for reducing the risk of crossing the finish line according to claim 7, characterized in that: Flat-peaked straight bodies (7) are respectively provided on both sides of the second guide arc body (2), and a flow gap is provided between the flat-peaked straight body (7) and the base plate (8) to allow melt glue of a set depth to pass through.

9. The mold flow control structure for reducing the risk of crossing the finish line according to claim 8, characterized in that: The flat-peaked straight body (7) is welded to the outer guide wire body (6).

10. The mold flow control structure for reducing the risk of crossing the finish line according to claim 5, characterized in that: A pillow line (5) for cushioning the flat-peaked arc body (4) is provided below the flat-peaked arc body (4) between the two inner guide wire bodies (3).

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