Lead frame, lead frame array and packaging body

Abstract

The utility model provides a lead frame, a lead frame array and a packaging body, and belongs to the field of semiconductor packaging. The lead frame comprises a frame body, a base island and a plurality of pins surrounding the base island. A groove is arranged around the base island and / or the plurality of pins, and the groove is arranged on the back face of the lead frame and used for being filled with plastic packaging materials. During plastic packaging, plastic packaging materials can be filled into the grooves. Therefore, after plastic packaging, the connection between the whole plastic packaging layer and the lead frame is firmer, and the plastic packaging layer is not easy to fall off in the subsequent transportation or use process; therefore, the internal structure of the chip can be better protected, and the service life of the chip and the corresponding electronic equipment is prolonged.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor packaging, in particular to a lead frame, a lead frame array and a packaging body. Background Art

[0002] Manufacturing a complete chip product usually requires processes such as chip design, wafer manufacturing, chip packaging and testing. In chip packaging, the wafer is usually bonded to the base island in the middle of the lead frame, and the wafer is connected to the pins through connecting wires to achieve electrical and mechanical connections between the inside of the chip and the outside world. Finally, the lead frame and wafer are coated with plastic packaging materials. After the packaging is completed, there is a layer of plastic packaging material on the outside of the chip to protect the wafer and the pins. Due to the increasing pursuit of small and thin chip products, when using existing packaging technology, the thickness of the chip is getting smaller and smaller, and the thickness of the plastic packaging layer is also getting smaller and smaller, which will cause the plastic packaging material to fall off, resulting in low packaging reliability and stability, affecting product yield and life. Utility Model Content

[0003] The purpose of the utility model is to provide a lead frame and a lead frame array, which can make the connection between the plastic sealing layer and the lead frame more firm and not easy to fall off after plastic sealing, thereby improving the reliability and stability of the package and increasing the product yield and life.

[0004] Another object of the present invention is to provide a package body, which adopts the lead frame.

[0005] The utility model is achieved in this way:

[0006] A lead frame comprises a frame body, a base island and a plurality of pins surrounding the base island;

[0007] The base island is connected to the frame body through connecting ribs at a first side and / or a second side opposite to the first side;

[0008] A groove is arranged around the base island and / or the plurality of pins. The groove is arranged on the back side of the lead frame and is used for filling with a plastic packaging material.

[0009] Further, at least two pins are arranged on a first side where the first side edge of the base island is located and a second side where the second side edge of the base island is located; at least ten pins are arranged on a third side of the base island and a fourth side opposite to the third side.

[0010] Further, the at least two pins located on the first side of the base island are surrounded by the connecting ribs on the first side of the base island; and the at least two pins located on the second side of the base island are surrounded by the connecting ribs on the second side of the base island.

[0011] Furthermore, the plurality of pins are separated from the base island.

[0012] Furthermore, the grooves are arranged on the four edges of the back side of the base island and the back side of the connecting rib; and the grooves are arranged on both sides of the back side of each of the plurality of pins.

[0013] Furthermore, the depth of the groove is half of the thickness of the lead frame.

[0014] Furthermore, the aspect ratio of the lead frame is 3:1.

[0015] Furthermore, the lead frame has a thickness of 0.119 mm-0.135 mm.

[0016] A lead frame array comprises a plurality of the lead frames; the plurality of lead frames are connected into one body.

[0017] A package body, comprising the lead frame, wafer and plastic packaging material as described above;

[0018] The wafer is arranged on the base island; the grooves on the base island and the back of the pins are filled with the plastic packaging material, and other areas on the base island and the back of the pins are exposed outside the plastic packaging material.

[0019] The beneficial effects of the utility model are:

[0020] The lead frame, lead frame array and package body obtained by the utility model through the above design have a groove on the back of the lead frame. When plastic sealing is performed, the hot-melt plastic sealing material can flow into the groove. When the plastic sealing material solidifies, the plastic sealing material in the groove is stuck in the groove. Therefore, after plastic sealing, the connection between the entire plastic sealing layer and the lead frame is more firm, and it is not easy to fall off during the subsequent transportation or use process; thereby, the internal structure of the chip can be better protected and its service life is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a schematic diagram of a lead frame provided by an embodiment of the utility model (wherein the hatched portion represents a groove);

[0023] Figure 2is a schematic diagram of a package provided by an embodiment of the utility model;

[0024] Figure 3 The utility model embodiment provides Figure 1 Middle AA section view (where the hatching represents the lead frame entity);

[0025] Figure 4 The utility model embodiment provides Figure 1 Middle BB cross-sectional view (where the hatching represents the lead frame entity);

[0026] Figure 5 It is a schematic diagram of a frame array provided in an embodiment of the utility model.

[0027] Icon: 1-lead frame; 11-pin; 12-base island; 121-first side; 122-second side; 123-third side; 124-fourth side; 13-groove; 14-connecting rib; 15-package body. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] like Figure 1 This embodiment provides a new type of lead frame 1, which includes a frame body, a base island 12 and a plurality of pins 11 surrounding the base island 12. The frame body is a rectangular thin plate structure, the base island includes a first side and a second side opposite to the first side, and the first side and the second side of the base island are connected to the frame body through connecting ribs. The base island is located in the middle of the frame body, wherein the base island 12 is used to install a wafer, and the wafer is electrically connected to a plurality of pins 11 through a plurality of wires. After the connection is completed, the wires (not shown in the figure), the pins 11 and the wafer are plastic-sealed to form Figure 2 The package structure shown.

[0030] Please continue to refer to Figure 1 The base island is roughly rectangular, and includes a first side and a second side opposite to each other, and a third side and a fourth side opposite to each other. The length of the first side and the second side is less than the length of the third side and the fourth side; the first side and the second side are connected to the frame body through connecting ribs.

[0031] Furthermore, in this embodiment, the aspect ratio of the lead frame 1 is 3:1, that is, the lead frame 1 is a long and narrow thin plate. On the lead frame, at least two pins are arranged on the first side (the side where the first side is located) and the second side (the side where the second side is located) of the base island, and at least 10 pins are arranged at the corresponding positions of the third side (the side where the third side is located) and the fourth side (the side where the fourth side is located) of the base island. In addition, the two pins located on the first side of the base island are surrounded by the connecting ribs on the first side of the base island; the two pins located on the second side of the base island are surrounded by the connecting ribs on the second side of the base island. In addition, in other embodiments, the size and number of pins of the lead frame can be adjusted according to actual conditions.

[0032] As an example, Figure 1 As shown, there are two connecting ribs on each side, and the two connecting ribs and the side edges of the base island together surround the two pins.

[0033] As an example, Figure 1 As shown, a plurality of pins 11 are located on the lead frame body and are separated from the base island 12 .

[0034] The base island and the pins are surrounded by grooves 13, which are arranged on the back of the lead frame for filling plastic packaging materials. The grooves 13 are recesses formed by semi-etching. For the specific etching process, reference can be made to the relevant technology, which is not described in detail in this application. Of course, in other embodiments, other processes can also be used to process the grooves. In addition, the grooves 13 can be continuous grooves or multiple recesses arranged on the back of the lead frame 1.

[0035] During plastic sealing, the hot-melt plastic sealing material can flow into the groove 13. After the plastic sealing material solidifies, the connection between the plastic sealing layer and the lead frame 1 is tighter and firmer, making it difficult for the plastic sealing layer to fall off the lead frame 1, thereby providing long-term protection for the wafer.

[0036] The thickness of the lead frame 1 provided in this embodiment is generally about 0.119 mm-0.135 mm, preferably 0.127 mm. Since the overall thickness of the lead frame 1 is relatively small, if the depth of the groove 13 is too deep, it is inevitable that the strength of the lead frame 1 will be seriously weakened. However, if the depth of the groove 13 is too small, there is less plastic encapsulation material filling the groove 13, and the connection between the plastic encapsulation layer and the lead frame 1 is not strong enough. Based on this, preferably, the depth of the groove 13 is about half of the overall thickness of the lead frame 1; thereby, both the strength of the lead frame 1 board and the connection strength between the plastic encapsulation layer and the lead frame 1 can be taken into account. The specific width of the groove 13 can be determined according to actual conditions.

[0037] Furthermore, if Figure 1As shown, grooves 13 are provided on the edges around the back side of the base island 12 and the back side of the connecting rib 14 ; grooves 13 are provided on both sides of the back side of each of the plurality of pins 11 .

[0038] In this embodiment, the base island 12 is roughly rectangular, and a circle of grooves 13 are arranged around it; grooves 13 are also arranged on both sides of the lead 11; and grooves 13 are arranged on the back of the connecting rib 14. The above design allows the grooves 13 to be distributed in different parts of the lead frame 1, so that the plastic encapsulation material can fill different parts of the frame, making the package more solid.

[0039] Please refer to Figure 3 and Figure 4 In addition, in order to further increase the connection strength between the plastic encapsulation layer and the lead frame 1, the two inner side surfaces of the groove 13 are both concave. When the plastic encapsulation material is filled into the groove 13 and solidified, since the two inner side surfaces of the groove 13 are concave, the two side surfaces of the plastic encapsulation material in the groove 13 are convex, so that the plastic encapsulation material in the groove 13 is stuck in the groove 13, thereby making the connection between the plastic encapsulation layer and the lead frame 1 more secure.

[0040] Since the connection between the plastic encapsulation material and the lead frame 1 adopts a new method, this connection method makes it difficult for the plastic encapsulation layer to fall off even if a relatively thin plastic encapsulation layer is used; thus, it provides conditions for reducing the overall thickness of the chip, making the packaged volume smaller and reducing the requirements for installation space.

[0041] The lead frame 1 provided in this embodiment has the following beneficial effects:

[0042] Since the grooves 13 are distributed around the base island 12 , the plurality of pins 11 and the back of the connecting rib, the lead frame 1 can be stably connected to the lead frame 1 through the plastic packaging material in the grooves 13 , thereby increasing the reliability and stability of the packaging.

[0043] This embodiment also provides a lead frame array, such as Figure 5 The lead frame array comprises a plurality of the aforementioned lead frames; the plurality of lead frames are arranged in an array and connected as a whole. The lead frame array is cut to form the aforementioned lead frame.

[0044] like Figure 2 This embodiment also provides a package, which includes the lead frame, wafer and plastic packaging material; wherein the wafer is arranged on the base island; the groove on the back of the base island and / or the groove on the back of the pin and / or the groove on the back of the rib is filled with plastic packaging material, and other areas on the back of the base island and the pin are exposed outside the plastic packaging material. By exposing part of the area, the chip can be electrically connected to the outside world, while improving the heat dissipation performance.

[0045] As an example, Figure 2 The package thickness shown is preferably 0.45 mm.

[0046] It should be noted that Figure 2 The embodiment shown is described by taking QFN as an example. QFN (Quad Flat No-leads Package) is one of the surface mount packaging processes and is a leadless package. The packaged product is square or rectangular. There is a large exposed pad at the center of the bottom of the package for heat conduction. There are conductive pads around the package periphery for electrical connection. However, the lead frame 1 is not only used for QFN, but also for other types of packages.

[0047] The above description is only the preferred implementation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A lead frame, characterized in that: It includes a frame body, a base island and a plurality of pins surrounding the base island; The first side edge of the base island and / or the second side edge opposite to the first side edge are connected to the frame body via connecting ribs; A groove is arranged around the base island and / or the plurality of pins. The groove is arranged on the back side of the lead frame and is used for filling with a plastic packaging material.

2. The lead frame according to claim 1, characterized in that: At least two pins are arranged on each of the first side where the first side edge of the base island is located and the second side where the second side edge is located; The base island comprises a third side and a fourth side which are arranged opposite to each other, and at least ten pins are arranged on each of the third side and the fourth side of the base island.

3. The lead frame according to claim 2, wherein: The at least two pins located on the first side of the base island are surrounded by the connecting ribs on the first side of the base island; the at least two pins located on the second side of the base island are surrounded by the connecting ribs on the second side of the base island.

4. The lead frame according to any one of claims 1 to 3, characterized in that: The plurality of pins are separated from the base island.

5. The lead frame according to claim 4, characterized in that: The grooves are arranged on the edges around the back side of the base island and the back side of the connecting rib; and the grooves are arranged on both sides of the back side of each of the plurality of pins.

6. The lead frame according to claim 5, characterized in that: The depth of the groove is half of the thickness of the lead frame.

7. The lead frame according to claim 4, characterized in that: The aspect ratio of the lead frame is 3:

1.

8. The lead frame according to claim 7, characterized in that: The lead frame has a thickness of 0.119 mm to 0.135 mm.

9. A lead frame array, characterized in that: It comprises a plurality of lead frames as claimed in any one of claims 1 to 8; the plurality of lead frames are connected into one body.

10. A package, characterized in that: The package body comprises a lead frame, a wafer and a plastic packaging material as described in any one of claims 1 to 8; The wafer is arranged on the base island; the grooves on the base island and the back of the pins are filled with the plastic packaging material, and other areas on the base island and the back of the pins are exposed outside the plastic packaging material.

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