TO-94 lead frame

Abstract

The utility model relates to a TO-94 lead frame, which comprises a frame and a plurality of installation units arranged on the frame, each installation unit comprises a first base island, a second base island, a first pin, a second pin, a third pin and a fourth pin, the first pin, the second pin, the third pin and the fourth pin are sequentially arranged from left to right, the first base island is connected with the first pin, and the second base island is connected with the fourth pin. A first channel is arranged between the first base island and the second base island, a second channel is arranged between the first base island and the second pin, and at least part of the first channel and the second channel are located on the same straight line. The TO-94 lead frame obtained by the utility model has the following advantages that the first channel and the second channel are located on the same straight line, during packaging, resin can flow downwards to the second channel along the first channel, the blocking in the middle is less, the resin is located on the straight line, the flowing is smooth, and the packaging effect is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to integrated circuit technical field especially relates to a TO-94 lead frame. BACKGROUND

[0002] In prior art, such as the TO-94 power integrated circuit package structure of Chinese utility model patent announcement No.CN 204809213 U discloses a plurality of independent packaging units, the packaging unit includes first frame carrier wafer table, second frame carrier wa wafer table, inner lead welding part and lead pin assembly;The lead pin assembly includes first pin, second pin, third pin and fourth pin, the first frame carrier wafer table is connected with the first pin, the second frame carrier wafer table is connected with the fourth pin, the second pin and the third pin are arranged in the avoidance area formed between the first frame carrier wafer table and the second frame carrier wafer table, and are fixedly connected with the inner lead welding part.But when the packaging unit is packaged, the channel between the first frame carrier wafer table and the second frame carrier wafer table is directly opposite to the inner lead welding part, and the resin flows inwardly and collides with the inner lead welding part, so that the resin flows unsmoothly, and the packaging effect is affected. SUMMARY

[0003] The purpose of the present application is to provide a TO-94 lead frame that allows resin to flow more smoothly.

[0004] The technical scheme adopted by the present application is as follows: a TO-94 lead frame, comprising a frame and a plurality of mounting units arranged on the frame, the mounting unit comprising a first base island, a second base island, and a first pin, a second pin, a third pin and a fourth pin arranged in order from left to right, the first base island being connected with the first pin, the second base island being connected with the fourth pin, a first channel being provided between the first base island and the second base island, a second channel being provided between the first base island and the second pin, at least part of the first channel and the second channel being on the same straight line.

[0005] Compared with the prior art, the first channel and the second channel are on the same straight line, and when packaging, the resin can flow downward along the first channel onto the second channel, the obstruction in the middle is less, and the flow is smooth on the straight line, ensuring the packaging effect.

[0006] In some embodiments of the present application, the first base island is in the form of a straight strip, and has a small area, which is convenient for adapting to small chips;A step is provided on the first base island away from the second base island, at least one side of the step facing the second base island, which can maintain the distance between the first base island and the second base island without reducing the area of the second base island;The corner of the step is smoothly transitioned, and the resin flow can be more smooth.

[0007] In some embodiments of the present application, the first base island is provided with a first electroplated area, and the first electroplated area extends from the connecting end of the first pin to the other end. The design of the first electroplated area can improve the conductivity of the contact part with the chip, and balance the cost and the performance of the device.

[0008] In some embodiments of the present application, the second base island is L-shaped, and one end of the L-shaped second base island is connected with the fourth pin. The width of the vertical edge of the L-shaped second base island is greater than the width of the horizontal edge of the L-shaped second base island, so that the area of the second base island is large and suitable for large chips.

[0009] In some embodiments of the present application, the second base island is provided with a second electroplated area, and the second electroplated area is L-shaped. The second electroplated area extends from the connecting end of the fourth pin to the other end. The design of the second electroplated area can improve the conductivity of the contact part with the chip, and balance the cost and the performance of the device.

[0010] In some embodiments of the present application, the side of the second base island away from the fourth pin is beyond the side of the first base island away from the first pin. The area of the second base island is increased, and at the same time, the entrance of the first channel is clear, which is beneficial to the entering of the resin. The width of the first channel is smaller than the width of the second channel, so that the resin can stably flow into the second channel.

[0011] In some embodiments of the present application, the top of the second pin is T-shaped, so that the area of the top of the second pin is large and beneficial to the contact with the chip. The third electroplated area is provided on the second pin, the initial end of the third electroplated area is in the same straight line with the connecting end of the first base island and the first pin, and the third electroplated area extends to the top end of the second pin. The design of the third electroplated area can improve the conductivity of the contact part with the chip, and balance the cost and the performance of the device.

[0012] In some embodiments of the present application, the top of the third pin is T-shaped, so that the area of the top of the third pin is large and beneficial to the contact with the chip. The fourth electroplated area is provided on the third pin, the initial end of the fourth electroplated area is in the same straight line with the connecting end of the second base island and the fourth pin, and the fourth electroplated area extends to the top end of the third pin. The design of the fourth electroplated area can improve the conductivity of the contact part with the chip, and balance the cost and the performance of the device.

[0013] In some embodiments of the present application, the third channel is provided between the third pin and the second base island, the fourth channel is provided between the second pin and the third pin, and the fifth channel is provided between the second pin and the third pin and the second base island.

[0014] In some embodiments of the present application, the end of the first pin, the end of the second pin, the end of the third pin and the end of the fourth pin are connected with the frame. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the embodiment 1 of the utility model, and

[0016] Figure 2 is a structural schematic diagram of the mounting unit of the embodiment 1 of the utility model.

[0017] In the drawing: 1, frame; 2, first base island; 3, second base island; 4, first pin; 5, second pin; 6, third pin; 7, fourth pin; 8, first channel; 9, second channel; 10, step; 11, first electroplating area; 12, second electroplating area; 13, third electroplating area; 14, fourth electroplating area; 15, third channel; 16, fourth channel; 17, fifth channel. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the utility model to achieve the predetermined utility model purposes, the specific embodiments, structures, features and effects according to the utility model are described in detail as follows in combination with the drawings and preferred embodiments.

[0019] Embodiment 1:

[0020] The TO-94 lead frame provided in the embodiment includes a frame 1 and a plurality of mounting units arranged on the frame 1, as shown in Figure 1 , Figure 2 The mounting unit includes a first base island 2, a second base island 3 and a first pin 4, a second pin 5, a third pin 6 and a fourth pin 7 arranged in sequence from left to right, the bottom of the first base island 2 is connected with the top of the first pin 4, the bottom of the second base island 3 is connected with the top of the fourth pin 7, a first channel 8 is arranged between the first base island 2 and the second base island 3, a second channel 9 is arranged between the first base island 2 and the second pin 5, and at least part of the first channel 8 and the second channel 9 are on the same straight line.

[0021] The first channel 8 and the second channel 9 are on the same straight line, during packaging, the resin can flow downward along the first channel 8 to the second channel 9, the resistance in the middle is small, it is on the straight line, the flow is smooth, and the packaging effect is guaranteed.

[0022] In order to ensure the reliability of the first base island 2, the first base island 2 is in the form of a straight strip, a step 10 is arranged on the first base island 2 and away from the second base island 3, at least one side of the step 10 faces the second base island 3, and the corner of the step 10 is smoothly transitioned. The first base island 2 is in the form of a straight strip, the area is small, and it is convenient to adapt to small chips; the design of the step 10 can maintain the distance between the first base island 2 and the second base island 3 without reducing the area of the second base island 3.

[0023] In order to improve the conductivity, the first island 2 is provided with a first plating area 11; the first plating area 11 extends from the connecting end of the first pin 4 to the other end. In the embodiment, the first plating area 11 is plated with silver. The design of the first plating area 11 can improve the conductivity of the contact part with the chip, and the cost and the device performance are considered.

[0024] In order to make the second island 3 reliable, the second island 3 is in the shape of L after being rotated by 180°, the vertical edge of the L-shaped second island 3 is wider than the horizontal edge of the L-shaped second island 3. The second island 3 is in the shape of L, which is convenient for connecting with the fourth pin 7 at one end, and the vertical edge of the L-shaped second island 3 is wide, so that the area of the second island 3 is large and suitable for large chips.

[0025] In order to improve the conductivity, the second island 3 is provided with a second plating area 12, the second plating area 12 is in the shape of L after being rotated by 180°, and the second plating area 12 extends from the connecting end of the fourth pin 7 to the other end. In the embodiment, the second plating area 12 is plated with silver. The design of the second plating area 12 can improve the conductivity of the contact part with the chip, and the cost and the device performance are considered.

[0026] In the embodiment, the second plating area 12 extends along the adjacent two edges of the outer side of the second island 3; the second plating area 12 completely covers the vertical edge of the L-shaped second island 3 after being rotated by 180°, and the second plating area 12 at least partially covers the horizontal edge of the L-shaped second island 3 after being rotated by 180°.

[0027] In order to make the area of the second island 3 large, the side of the second island 3 away from the fourth pin 7 is beyond the side of the first island 2 away from the first pin 4, which increases the area of the second island 3 and makes the entrance of the first channel 8 clear, which is beneficial for the resin to enter; the width of the first channel 8 is smaller than the width of the second channel 9, so that the resin can stably flow into the second channel 9.

[0028] In order to make the second pin 5 reliable, the top of the second pin 5 is in the shape of T, so that the area of the top is large and beneficial for contacting with the chip; the second pin 5 is provided with a third plating area 13, the initial end of the third plating area 13 is in the same straight line with the connecting end of the first island 2 and the first pin 4, and the third plating area 13 extends to the top end of the second pin 5.

[0029] The side of the second pin 5 facing the second island 3 is the top end. In the embodiment, the third plating area 13 is plated with silver.

[0030] The design of the third plating area 13 can improve the conductivity of the contact part with the chip, and the cost and the device performance are considered.

[0031] In order to make the third pin 6 reliable, the top of the third pin 6 is T-shaped, so that the area of the top is large, facilitating contact with the chip; the third pin 6 is provided with a fourth plating area 14, the initial end of the fourth plating area 14 is in the same straight line with the connecting end of the second base island 3 and the fourth pin 7, and the fourth plating area 14 extends to the top end of the third pin 6.

[0032] The side of the third pin 6 facing the second base island 3 is a top end. In the embodiment, the fourth plating area 14 is plated with silver.

[0033] The design of the fourth plating area 14 can improve the conductivity of the contact part with the chip, and the cost and device performance are considered.

[0034] In order to make the resin flow reliable, the third channel 15 is arranged between the third pin 6 and the second base island 3; the fourth channel 16 is arranged between the second pin 5 and the third pin 6; the fifth channel 17 is arranged between the second pin 5 and the third pin 6 and the second base island 3. The third channel 15 and the fifth channel 17 are communicated, the fourth channel 16 and the fifth channel 17 are communicated, and the second channel 9 and the fifth channel 17 are communicated, so as to ensure that the resin can flow inside and ensure the packaging effect.

[0035] In order to make the mounting unit and the frame 1 connected reliably, the ends of the first pin 4, the second pin 5, the third pin 6 and the fourth pin 7 are connected with the frame 1. The outer side of the first pin 4 and the outer side of the fourth pin 7 are connected with the frame 1 or the adjacent mounting unit.

[0036] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the technical solution of the present application, and any equivalent embodiments with equivalent changes are equivalent to the above embodiments. Any modification, equivalent change and modification of the above embodiments according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A TO-94 lead frame comprising a frame (1) and a plurality of mounting units provided on the frame (1), characterized in that, The mounting unit comprises a first base island (2), a second base island (3), a first pin (4), a second pin (5), a third pin (6) and a fourth pin (7) arranged in sequence from left to right, the first base island (2) is connected with the first pin (4), the second base island (3) is connected with the fourth pin (7), a first channel (8) is arranged between the first base island (2) and the second base island (3), a second channel (9) is arranged between the first base island (2) and the second pin (5), at least part of the first channel (8) and the second channel (9) are on the same straight line.

2. A TO-94 lead frame according to claim 1, characterized in that: The first base island (2) is in the shape of a straight strip; a step (10) is arranged on the first base island (2) away from the second base island (3), at least one side of the step (10) faces the second base island (3); the corner of the step (10) is smoothly transitioned.

3. The TO-94 lead frame of claim 1 wherein: A first electroplating area (11) is arranged on the first base island (2); the first electroplating area (11) extends from the connecting end of the first pin (4) to the other end.

4. The TO-94 lead frame of claim 1 wherein: The second base island (3) is in the shape of L, the width of the vertical edge of the L-shaped second base island (3) is greater than the width of the horizontal edge of the L-shaped second base island (3).

5. The TO-94 lead frame of claim 1 wherein: A second electroplating area (12) is arranged on the second base island (3), the second electroplating area (12) is in the shape of L, and the second electroplating area (12) extends from the connecting end of the fourth pin (7) to the other end.

6. The TO-94 lead frame of claim 1 wherein: The side of the second base island (3) away from the fourth pin (7) exceeds the side of the first base island (2) away from the first pin (4); the width of the first channel (8) is smaller than the width of the second channel (9).

7. The TO-94 lead frame of claim 1 wherein: The top of the second pin (5) is in the shape of T; a third electroplating area (13) is arranged on the second pin (5), the initial end of the third electroplating area (13) is on the same straight line with the connecting end of the first base island (2) and the first pin (4), and the third electroplating area (13) extends to the top end of the second pin (5).

8. The TO-94 lead frame of claim 1 wherein: The top of the third pin (6) is in the shape of T; a fourth electroplating area (14) is arranged on the third pin (6), the initial end of the fourth electroplating area (14) is on the same straight line with the connecting end of the second base island (3) and the fourth pin (7), and the fourth electroplating area (14) extends to the top end of the third pin (6).

9. The TO-94 lead frame of claim 1 wherein: A third channel (15) is arranged between the third pin (6) and the second base island (3); a fourth channel (16) is arranged between the second pin (5) and the third pin (6); a fifth channel (17) is arranged between the second pin (5) and the third pin (6) and the second base island (3).

10. The TO-94 lead frame of claim 1 wherein: The end of the first pin (4), the end of the second pin (5), the end of the third pin (6) and the end of the fourth pin (7) are connected with the frame (1).

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