Quad flat no-lead (QFN) packaging lead frame arranged in array

Abstract

The utility model provides a QFN packaging lead frame arranged in an array. The QFN packaging lead frame comprises a plurality of lead frame units arranged in an array and a frame supporting frame. A cutting channel is arranged between two adjacent lead frame units; each lead frame unit comprises three base islands, a lead supporting frame and a plurality of pins; wherein the two base islands are arranged side by side in the first direction and are directly connected with the lead supporting frame, the third base island is arranged on one side, in the second direction, of the two base islands arranged side by side in the first direction, and the third base island is located in the middle position in the first direction. One side of the third base island is directly connected with the lead supporting frame, the two sides adjacent to the side are connected with the lead supporting frame through connecting ribs, the pins are distributed on the peripheries of the three base islands and connected with the lead supporting frame, and the first direction is perpendicular to the second direction. A plurality of chips can be sealed in one packaging body at the same time, the packaging efficiency is effectively improved, and the packaging cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chip packaging, in particular to a QFN packaging lead frame arranged in an array. Background Art

[0002] Chip packaging refers to the technology of wrapping individual bare chips formed after wafer dicing with insulating plastic packaging materials or ceramic materials, leading out the internal circuits of the integrated circuit, and avoiding the contact between the chip and the outside world. This technology can effectively prevent the integrated circuits on the internal chip from being corroded by impurity particles, bad gases or water vapor in the air, thus avoiding damage to the chip. Chip packaging technology greatly improves the reliability of the chip. Different packaging technologies vary greatly in manufacturing processes and techniques, and also play a crucial role in the performance of the chip itself.

[0003] The existing packaging forms mainly include DIP, SOP, and QFP. Lead frame products are mostly used for the packaging of discrete devices and medium- and low-grade ICs, and the proportion of lead frames used for integrated circuits is relatively small. The lead frame is used as the carrier of the chip after wafer dicing during the packaging manufacturing process. At the same time, it uses bonding materials (gold wire, aluminum wire, copper wire) to connect the internal circuit leads of the chip to the lead frame, realizing the formation of an electrical loop between the internal circuit of the chip and the external pins. It not only plays the role of a bridge connecting to external wires and the mechanical role of fixing the installed chip, but also can play a role in heat conduction to the outside during the operation of the chip. Most semiconductor chips need to use lead frames, which are important basic materials in the semiconductor chip packaging production process.

[0004] With the further improvement of the integration of semiconductor circuits, the medium- and high-grade leadless quad flat package (Quad Flat No-Lead, abbreviated as QFN) packaging has been favored. QFN is one of the surface mount packages. Compared with the traditional pin package, QFN reduces the volume and weight of the package, enabling the chip to integrate more functions under the same size. Since the QFN chip package removes the pins, the connection between the chip and the external circuit is simpler and more reliable, and the market scope is wide. For environments with high heat dissipation requirements, the heat generated during the operation of the product can be conducted out through the exposed base island heat sink. Currently, most QFN packages are mainly based on the QFN frame in the form of 1 block and single base island, with relatively low co-packaging integration, low packaging efficiency, and high cost. Summary of the Utility Model

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide a QFN packaging lead frame arranged in an array, which is used to solve the problems in the prior art that most QFN packages are mainly based on the QFN frame in the form of 1 block and single base island, with relatively low co-packaging integration, low packaging efficiency, high cost, etc.

[0006] To achieve the above object and other related objects, the present utility model provides a QFN package lead frame arranged in an array, and the lead frame includes: a plurality of lead frame units arranged in an array and a frame support border;

[0007] Adjacent two of the lead frame units are connected by pins; the frame support border is directly connected to the adjacent lead frame unit;

[0008] A dicing channel is provided between adjacent two of the lead frame units;

[0009] Each of the lead frame units includes three base islands, a lead support border and a plurality of the pins; wherein, two of the base islands are arranged side by side in a first direction and are directly connected to the lead support border, the third base island is arranged on one side of the two base islands arranged side by side in the first direction in a second direction, and the third base island is located at the middle position in the first direction, one side of the third base island is directly connected to the lead support border and the two sides adjacent to this side are connected to the lead support border through connecting ribs, the pins are distributed on the periphery of the three base islands and are connected to the lead support border, and the first direction is perpendicular to the second direction.

[0010] Optionally, the areas of the two base islands arranged side by side in the first direction are larger than the area of the third base island.

[0011] Further, power MOS transistor chips are mounted on the two base islands arranged side by side in the first direction, and an IC chip is mounted on the third base island.

[0012] Optionally, at least one side of the front periphery of the two base islands arranged side by side in the first direction is provided with a glue-locking groove.

[0013] Further, at least one side of the back periphery of the two base islands arranged side by side in the first direction is provided with a first groove; the glue-locking groove and the first groove are arranged on different sides of the two base islands arranged side by side in the first direction.

[0014] Further, the first groove extends towards the inside of the base island.

[0015] Optionally, the glue-locking groove is arranged on the two sides of the base island close to the lead support border; the first groove is arranged on the two sides of the base island far from the lead support border.

[0016] Optionally, at least one side of the back periphery of the third base island is provided with a second groove; the back of the connecting rib is provided with a third groove, and the second groove is communicated with the third groove.

[0017] Further, the glue-locking groove, the first groove, the second groove and the third groove are all semi-etched.

[0018] Optionally, the width of the first groove is 0.3 mm.

[0019] As described above, the QFN package lead frame arranged in an array of the present utility model is provided with a plurality of lead frame units arranged in an array, and three base islands are arranged in each lead frame unit. Moreover, by making full use of the area of the lead frame unit, the three base islands are arranged such that two of them are arranged side by side, and the third base island is vertically arranged in the middle position on one side of the two base islands, so as to realize co-packaging of multiple chips in one package body, effectively improving the packaging efficiency and reducing the packaging cost. Description of the Drawings

[0020] Figure 1 It shows a schematic structural diagram of the QFN package lead frame arranged in an array of the present utility model.

[0021] Figure 2 It shows a schematic back structure diagram of the lead frame unit in the QFN package lead frame arranged in an array of the present utility model.

[0022] Figure 3 It shows Figure 2 a side view of the cross-section at AA in

[0023] Figure 4 It shows Figure 2 a side view of the cross-section at BB in

[0024] Figure 5 It shows Figure 2 a side view of the cross-section at CC in

[0025] Figure 6 It shows Figure 2 a side view of the cross-section at DD in

[0026] Figure 7 It shows a schematic front structure diagram of the lead frame unit in the QFN package lead frame arranged in an array of the present utility model.

[0027] Figure 8 It shows a schematic partial structure diagram of the QFN package lead frame arranged in an array of the present utility model.

[0028] Figure 9 It shows Figure 8 an enlarged schematic structure diagram at A in

[0029] Description of Component Labels

[0030] 1 Lead Frame Unit

[0031] 10 Base Island

[0032] 11 Lead Support Frame

[0033] 12 Pin

[0034] 13 Connecting Rib

[0035] 14 Glue Locking Groove

[0036] 15 First Groove

[0037] 16 Second Groove

[0038] 17 Third Groove

[0039] 18 Fourth Groove

[0040] 2 Frame Support Border

[0041] 3 Cutting Channel Detailed Implementation Manner

[0042] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

[0043] Please refer to Figures 1 to 9 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present utility model. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the ratio relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the implementation scope of the present utility model. The change or adjustment of their relative relationships, without substantial change of the technical content, should also be regarded as the implementable scope of the present utility model.

[0044] As Figure 1 and Figure 2 shown, the present utility model provides a QFN package lead frame arranged in an array, and the lead frame includes:

[0045] A plurality of lead frame units 1 arranged in an array and a frame support border 2;

[0046] Adjacent two lead frame units 1 are connected by pins 12; the frame support border 2 is directly connected to the adjacent lead frame unit 1;

[0047] A dicing lane 3 is provided between two adjacent lead frame units 1;

[0048] As Figure 2 shown, each lead frame unit 1 includes: three base islands 10, a lead support frame 11, and a plurality of pins 12; wherein, two of the base islands 10 are arranged side by side in a first direction and are directly connected to the lead support frame 11, and the third base island 10 is arranged on one side of the two base islands 10 arranged side by side in the second direction, and the third base island 10 is located at the middle position in the first direction. One side of the third base island 10 is directly connected to the lead support frame 11 and the two adjacent sides on this side are connected to the lead support frame 11 through connecting ribs 13. The pins 12 are distributed around the three base islands 10 and are connected to the lead support frame 11. The first direction and the second direction are perpendicular to each other.

[0049] It should be noted here that the first direction and the second direction only need to be perpendicular to each other, indicating that the shape of the entire lead frame is rectangular. For ease of understanding, Figure 1 the lead frame is placed on the horizontal plane of a two-dimensional direct coordinate system, and the first direction is defined as the X direction of the two-dimensional rectangular coordinate system, and the second direction is defined as the Y direction of the two-dimensional rectangular coordinate system.

[0050] The QFN package lead frame arranged in an array in this embodiment is provided with a plurality of lead frame units arranged in an array, and three base islands are provided in each lead frame unit. And by making full use of the area of the lead frame unit, the three base islands are arranged such that two of them are arranged side by side, and the third base island is vertically arranged in the middle position on one side of the two base islands, so as to realize simultaneous encapsulation of multiple chips in one package body, effectively improving the encapsulation efficiency and reducing the encapsulation cost.

[0051] As Figure 2 and Figure 7 shown, as an example, the areas of the two base islands 10 arranged side by side in the first direction are larger than the area of the third base island 10. This setting method can further improve the utilization rate of each lead frame unit 1. For example, the areas of the two base islands 10 arranged side by side in the first direction are larger, and power MOS transistor chips can be considered to be installed. The area of the third base island 10 is smaller, and IC chips can be considered to be installed.

[0052] As Figure 2 and Figure 7As shown, by way of example, a glue locking groove 14 may also be provided on at least one side of the front periphery of the two base islands 10 arranged side by side along the first direction. During the injection molding process, the glue locking groove 14 can accommodate the encapsulant, so that the upper and lower parts of the encapsulation form an embedded structure, strengthening the bonding force between the encapsulant and the entire lead frame and reducing the probability of delamination; in addition, it can also block the moisture in the external environment from entering the encapsulation body, improving the packaging reliability. The shape and number of the glue locking grooves 14 can be set according to actual needs. For example, the glue locking grooves 14 can be provided on one side, two sides, three sides or four sides of the front periphery of the two base islands 10 arranged side by side along the first direction. In addition, each side of the glue locking groove 14 can be a continuous groove or a discontinuous groove. When it is a discontinuous groove, the number of the glue locking grooves 14 provided on each side is not overly restricted and is selected according to actual needs. As Figure 2 shown, the glue locking grooves 14 are provided on both sides of the front periphery of the two base islands 10 arranged side by side along the first direction, and each side of the glue locking groove 14 is a discontinuous groove. Five glue locking grooves 14 are provided in the second direction and three glue locking grooves 14 are provided in the first direction. In addition, the shape of each glue locking groove 14 is U-shaped. Furthermore, the glue locking groove 14 can be set as a semi-etched glue locking groove.

[0053] As Figure 2 and Figure 7 shown, by way of example, a first groove 15 may also be provided on at least one side of the back periphery of the two base islands 10 arranged side by side along the first direction. During the injection molding process, the first groove 15 can accommodate the encapsulant, so that the upper and lower parts of the encapsulation form an embedded structure, strengthening the bonding force between the edge of the base island and the encapsulant and reducing the risk of delamination. The number of the first grooves 15 provided is not overly restricted. For example, the first grooves 15 can be provided on one side, two sides, three sides or four sides of the back periphery of the two base islands 10 arranged side by side along the first direction.

[0054] Preferably, the glue locking groove 14 and the first groove 15 are provided on different sides of the two base islands 10 arranged side by side along the first direction. Further, the glue locking groove 14 is provided on both front sides of the two base islands 10 arranged side by side along the first direction, and the first groove 15 is provided on the other two complementary back sides of the two base islands 10 arranged side by side along the first direction. As Figure 2 and Figure 7 shown, the glue locking groove 14 is provided on the two sides of the base island 10 close to the lead support frame 11; the first groove 15 is provided on the two sides of the base island 10 far from the lead support frame 11. Furthermore, the first groove 15 can be set as a semi-etched groove.

[0055] As Figure 2 and Figure 5As shown, by way of example, the first groove 15 extends towards the inner side of the base island 10, as Figure 5 shown in, the inner side of the base island 10 is in the first direction extending towards the right, so the first groove 15 extends towards the right.

[0056] As Figure 2 and Figure 7 shown, by way of example, a second groove 16 can also be provided on at least one side of the periphery of the back surface of the third base island 10; a third groove 17 is provided on the back surface of the connecting rib 13, and the second groove 16 is made to communicate with the third groove 17. Similarly, during the injection molding process, the second groove 16 and the third groove 17 can accommodate the encapsulant, so that the upper and lower parts of the encapsulation form an embedded structure, strengthening the bonding force between the edge of the base island and the encapsulant and reducing the risk of delamination. Furthermore, as Figure 3 and Figure 6 shown, the second groove 16 and the third groove 17 can be provided as semi-etched grooves.

[0057] As Figure 2 and Figure 4 shown, by way of example, fourth grooves 18 can also be provided on both sides of the periphery of the back surface of the pins 12. Similarly, the fourth grooves 18 can also be provided as semi-etched grooves. To improve the bonding force between the pins and the encapsulant and reduce the risk of delamination.

[0058] By way of example, the base material of the lead frame is generally made of copper, with a silver plating on the upper surface layer. The chip is fixed on the base island 10 through a conductive adhesive to ensure the conductive performance between the chip and the base island 10.

[0059] As a specific example, as Figure 1 shown, 29 lead frame units 1 are selected to be arranged side by side in the first direction (i.e., the X direction) within the lead frame, 7 lead frame units 1 are arranged in the second direction (i.e., the Y direction), and they are arranged in a 7-row and 29-column matrix within the entire lead frame, with a total of 203 lead frame units 1. The length of the entire lead frame in the first direction is 258 ± 0.1 mm, and the length in the second direction is 78 ± 0.05 mm; as Figure 8 and Figure 9 shown, the pitch L1 between two adjacent lead frame units 1 in the first direction within the entire lead frame is 8.300 ± 0.025 mm, the pitch L2 between them in the second direction is 9.300 ± 0.025 mm, and the width D of the scribe lane is 0.300 ± 0.025 mm; the size of the back surfaces of two base islands 10 arranged side by side in the first direction is 3.5 mm × 4.825 mm, and the size of the back surface of the third base island 10 is 2.522 mm × 1.247 mm; as Figure 2 and Figure 7As shown, among all the pins 12 of the entire lead frame, 13 pins 12 on the outer periphery of the third base island 10 are used as lead-out pin positions, the pitch of the lead-out pin positions is 0.65 ± 0.025 mm, and the length of the lead-out pin positions is 0.55 ± 0.025 mm; as Figure 2 and Figure 7 shown, the width of the connecting rib 13 is 0.25 mm; as Figure 5 shown, the width of the first groove 15 provided on the two base islands 10 arranged side by side in the first direction is 0.3 mm; as Figure 2 and Figure 7 shown, the lead frame unit 1 is provided with the above-mentioned glue-locking groove 14, the first groove 15, the second groove 16, the third groove 17 and the fourth groove 18, and they are all semi-etching grooves. Among them, the glue-locking groove 14 is provided on two sides of the base island 10 close to the lead support frame 11; the first groove 15 is provided on two sides of the base island 10 away from the lead support frame 11; as Figure 2 and Figure 7 shown, each side of the glue-locking groove 14 is a discontinuous groove, 5 glue-locking grooves 14 are provided in the second direction, 3 glue-locking grooves 14 are provided in the first direction, and the shape of each glue-locking groove 14 is U-shaped.

[0060] In summary, the present invention provides a QFN package lead frame arranged in an array. The lead frame is provided with a plurality of lead frame units arranged in an array, and three base islands are provided in each lead frame unit. And by making full use of the area of the lead frame unit, the three base islands are arranged such that two of the base islands are arranged side by side, and the third base island is vertically arranged in the middle position on one side of the two base islands, so as to realize co-packaging of multiple chips in one package, effectively improving the packaging efficiency and reducing the packaging cost. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0061] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A QFN package lead frame arranged in an array, characterized in that: The lead frame comprises: a plurality of lead frame units arranged in an array and a frame support frame; Two adjacent lead frame units are connected via pins; the frame support frame is directly connected to the adjacent lead frame unit; A cutting path is formed between two adjacent lead frame units; Each of the lead frame units includes three base islands, a lead support frame and a plurality of the pins; wherein, two of the base islands are arranged side by side along a first direction and are directly connected to the lead support frame, the third base island is arranged on one side of the two base islands arranged side by side along the first direction along a second direction, and the third base island is located in the middle position along the first direction, one side of the third base island is directly connected to the lead support frame and the two sides adjacent to the side are connected to the lead support frame through connecting ribs, the pins are distributed on the periphery of the three base islands and are connected to the lead support frame, and the first direction and the second direction are perpendicular to each other.

2. The array-arranged QFN package lead frame according to claim 1, characterized in that: The areas of the two base islands arranged side by side along the first direction are larger than the area of ​​the third base island.

3. The array-arranged QFN package lead frame according to claim 2, characterized in that: Power MOS tube chips are installed on two base islands arranged side by side along the first direction, and an IC chip is installed on the third base island.

4. The array-arranged QFN package lead frame according to claim 1, characterized in that: At least one side of the front periphery of the two base islands arranged side by side along the first direction is provided with a glue locking groove.

5. The array-arranged QFN package lead frame according to claim 4, characterized in that: A first groove is provided on at least one side of the back periphery of the two base islands arranged side by side along the first direction; the glue locking groove and the first groove are arranged on different sides of the two base islands arranged side by side along the first direction.

6. The array-arranged QFN package lead frame according to claim 5, characterized in that: The first groove extends toward the inner side of the base island.

7. The array-arranged QFN package lead frame according to claim 5, characterized in that: The glue locking groove is arranged on two side edges of the base island close to the lead support frame; the first groove is arranged on two side edges of the base island away from the lead support frame.

8. The array-arranged QFN package lead frame according to claim 5, characterized in that: A second groove is arranged on at least one side of the back periphery of the third base island; a third groove is arranged on the back side of the connecting rib, and the second groove is connected to the third groove.

9. The array-arranged QFN package lead frame according to claim 8, characterized in that: The glue locking groove, the first groove, the second groove and the third groove are all half-etched.

10. The array-arranged QFN package lead frame according to claim 5, characterized in that: The width of the first groove is 0.3 mm.

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