Lead frame wire for high-density chip packaging

Abstract

The utility model relates to the technical field of lead frames, and discloses a lead frame wire for high-density chip packaging, which comprises a side frame, the inner side of the side frame is transversely connected with a weft connecting rib, and the inner side of the side frame is connected with a warp connecting rib at a position perpendicular to the weft connecting rib; the pins are connected to the inner sides of the side frames and the weft connecting ribs, trapezoidal bosses are installed at the positions, corresponding to the pins, of the bottoms of the weft connecting ribs and the side frames, and cutting grooves are formed in the outer sides of the interiors of the pins. According to the lead frame wire for packaging the high-density chip, the cutting grooves are formed in the surfaces of the pins, so that the pins are cut more accurately, the cutting grooves are formed in the surfaces of the pins, the pins are cut off during cutting, the expansion coefficient and the strength are the same during cutting, and the service life of the lead frame wire is prolonged. And leftover materials are not left after the pins are cut.

Description

Technical Field

[0001] The utility model relates to the technical field of lead frames, in particular to a lead frame wire for high-density chip packaging. Background Art

[0002] With the development of semiconductor technology, people's demand for low-cost electronic products with smaller size and more functions continues to grow. The lead frame is used to carry chips and is also a bridge to connect the internal circuit lead ends of the chip with the external PCB board pads. It is an important basic raw material for the electronic information industry.

[0003] A common lead frame has one or more lead frame plastic encapsulation units, which further include a number of device units arranged at equal intervals, with cutting paths between adjacent device units. However, due to the different strengths of the side frames and the cutting paths, the existing cutting process must take into account both the side frames and the cutting paths, which will affect the life of the cutting blade. In addition, since the pins are directly connected to the side frames, tiny scraps are easily unable to be removed during the separation process and are mixed into the product testing process, increasing the number of stuck material failures on the machine and reducing the production accuracy of high-density chips, greatly affecting the efficiency and life of the equipment, and failing to meet the working requirements of the lead frame. Therefore, a lead frame wire for high-density chip packaging is proposed. Utility Model Content

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies of the prior art, the utility model provides a lead frame wire for high-density chip packaging to solve the technical problem that tiny scraps are easily unable to be removed cleanly during the separation process due to the direct connection between the pins and the side frames.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solution: a lead frame wire for high-density chip packaging, comprising:

[0008] A side frame, wherein the inner side of the side frame is laterally connected with a weft connecting rib, and the inner side of the side frame is connected with a warp connecting rib at a position perpendicular to the weft connecting rib;

[0009] Pins are connected to the inner sides of the side frames and the weft connecting ribs, and the bottoms of the weft connecting ribs and the side frames corresponding to the pins are both provided with trapezoidal bosses;

[0010] The chip carrying block is installed at the inner end of the pin, and the inner and outer sides of the pin are provided with cutting grooves. The length of the trapezoidal boss is flush with the left and right end faces of the pin, and the opening position of the cutting groove is flush with the inner end face of the trapezoidal boss.

[0011] Preferably, the number of the weft connecting ribs is 2-3 groups, the number of the warp connecting ribs is 6-9 groups, and the number of the pins is 2-4 groups, thereby improving the strength of the lead frame.

[0012] Preferably, the length of the cutting groove exceeds half of the width of the pin, and the hypotenuse of the trapezoidal boss is arranged toward the pin, thereby improving the smoothness of cutting the pin.

[0013] Preferably, chip pads are installed at positions inside the chip carrying block corresponding to the pins, and feature recognition units are installed at positions inside the side frames between the chip carrying blocks, which facilitates processing and recognition.

[0014] Preferably, positioning holes are provided inside the side frames, the width of the warp connecting ribs is twice that of the weft connecting ribs, and strip grooves are provided in the middle position and upper and lower sides of the warp connecting ribs. The strip grooves allow the warp connecting ribs to be segmented, so that the distance between the middle parts of the lead frame is the same in a point-to-point manner, and the length difference between the middle part and the upper and lower edges is minimized, thereby achieving a balance to adjust the undulation during cutting.

[0015] Preferably, the width of the strip grooves exceeds half of the width of the warp connecting ribs, and the upper and lower sides of the strip grooves are both arc-shaped.

[0016] (III) Beneficial effects

[0017] Compared with the prior art, the utility model provides a lead frame wire for high-density chip packaging, which has the following beneficial effects:

[0018] The lead frame wire for high-density chip packaging has a cutting groove opened on the surface of the pin, which makes the cutting of the pin more accurate. Since the cutting groove is opened on the surface of the pin, the pins are cut off during cutting, so that the expansion coefficient and strength are the same during cutting. Compared with the cutting method in which the pin is directly connected to the side frame, the pin will not have residual scraps after cutting, thereby improving the quality of the lead frame. At the same time, the added trapezoidal boss ensures the smoothness of the pin when cutting and avoids the problem of adhesion or deformation of the incision. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the weft connecting ribs and the warp connecting ribs of the utility model;

[0021] Figure 3 This is a schematic diagram of the pin structure of the utility model.

[0022] In the figure: 1. Side frame; 2. Weft connecting ribs; 3. Warp connecting ribs; 4. Pins; 5. Chip carrying block; 6. Feature recognition unit; 7. Positioning hole; 8. Trapezoidal boss; 9. Cutting groove; 10. Chip pad; 11. Strip groove. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] The utility model provides a technical solution, a lead frame wire for high-density chip packaging, including a side frame 1, a weft connection rib 2, a warp connection rib 3, a pin 4, a chip carrying block 5, a feature recognition unit 6, a positioning hole 7, a trapezoidal boss 8, a cutting groove 9, a chip pad 10 and a strip groove 11:

[0025] See also Figure 1 The inner side of the side frame 1 is laterally connected with a weft connecting rib 2, and the inner side of the side frame 1 is connected with a warp connecting rib 3 at a position perpendicular to the weft connecting rib 2;

[0026] See also Figure 2 , pin 4 is connected to the inner side of the side frame 1 and the weft connecting rib 2, the weft connecting rib 2 and the bottom of the side frame 1 corresponding to the pin 4 are both installed with a trapezoidal boss 8, the number of the weft connecting rib 2 is 2-3 groups, the number of the warp connecting rib 3 is 6-9 groups, and the number of the pin 4 is 2-4 groups;

[0027] The chip carrying block 5 is mounted on the inner end of the pin 4. Figure 3 , the inner and outer sides of the pin 4 are provided with cutting grooves 9, the length of the trapezoidal boss 8 is flush with the left and right end faces of the pin 4, the opening position of the cutting groove 9 is flush with the inner end face of the trapezoidal boss 8, the length of the cutting groove 9 exceeds half of the width of the pin 4, and the hypotenuse of the trapezoidal boss 8 is set toward the pin 4, please refer to Figure 2The chip pads 10 are installed at the positions corresponding to the pins 4 inside the chip carrying block 5, and the positions between the chip carrying blocks 5 on the inner side of the side frame 1 are installed with feature recognition units 6. The cutting grooves 9 opened on the surface of the pins 4 make it more accurate to cut the pins 4. Since the cutting grooves 9 are opened on the surface of the pins 4, the pins 4 are cut off during cutting, so that the expansion coefficient and strength are the same during cutting. Compared with the cutting method in which the pins 4 are directly connected to the side frame 1, the pins 4 will not have residual scraps after cutting, which improves the quality of the lead frame. At the same time, the trapezoidal bosses 8 are added to ensure the smoothness of the pins 4 during cutting and avoid the problem of adhesion or deformation of the incision.

[0028] A positioning hole 7 is provided inside the side frame 1, and the width of the warp connecting rib 3 is twice that of the weft connecting rib 2. Strip grooves 11 are provided in the middle position and upper and lower sides of the warp connecting rib 3. The width of the strip grooves 11 exceeds half of the width of the warp connecting rib 3. The upper and lower sides of the strip grooves 11 are both arc-shaped. The strip grooves 11 are provided so that the warp connecting rib 3 can be segmented, and the distance between the middle part of the lead frame is made the same in a point-to-point manner, so that the length difference between the middle part and the upper and lower edges is minimized, so as to achieve a balance to adjust the undulation during cutting.

[0029] The present solution makes the cutting of the pin 4 more precise by opening the cutting groove 9 on the surface of the pin 4. Since the cutting groove 9 is opened on the surface of the pin 4, the pins 4 are cut off during cutting, so that the expansion coefficient and strength are the same during cutting. Compared with the cutting method in which the pin 4 is directly connected to the side frame 1, no scraps will remain on the pin 4 after cutting, thereby improving the quality of the lead frame. At the same time, the added trapezoidal boss 8 ensures the smoothness of the pin 4 during cutting and avoids the problem of adhesion or deformation of the incision. At the same time, the strip groove 11 opened makes it possible to segment the warp connecting ribs 3, so that the distance between the middle part of the lead frame is the same in a point-to-point manner, so that the length difference between the middle part and the upper and lower edges is minimized, and a balance is achieved to adjust the undulation during cutting.

[0030] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or includes elements inherent to such process, method, article or device.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lead frame wire for high-density chip packaging, characterized in that: include: A side frame (1), wherein the inner side of the side frame (1) is laterally connected to a weft connecting rib (2), and the inner side of the side frame (1) is connected to a warp connecting rib (3) at a position perpendicular to the weft connecting rib (2); A pin (4) is connected to the inner side of the side frame (1) and the weft connecting rib (2), and a trapezoidal boss (8) is installed at a position corresponding to the pin (4) at the bottom of the weft connecting rib (2) and the side frame (1); The chip carrying block (5) is mounted on the inner end of the pin (4), the inner and outer sides of the pin (4) are provided with cutting grooves (9), the length of the trapezoidal boss (8) is flush with the left end face and the right end face of the pin (4), and the opening position of the cutting groove (9) is flush with the inner end face of the trapezoidal boss (8).

2. The lead frame wire for high-density chip packaging according to claim 1, characterized in that: The number of the weft connecting ribs (2) is 2-3 groups, the number of the warp connecting ribs (3) is 6-9 groups, and the number of the pins (4) is 2-4 groups.

3. The lead frame wire for high-density chip packaging according to claim 1, characterized in that: The length of the cutting groove (9) exceeds half the width of the pin (4), and the oblique sides of the trapezoidal boss (8) are arranged toward the pin (4).

4. The lead frame wire for high-density chip packaging according to claim 1, characterized in that: Chip pads (10) are installed at positions inside the chip carrying block (5) corresponding to the pins (4), and feature recognition units (6) are installed at positions inside the side frames (1) located between the chip carrying blocks (5).

5. The lead frame wire for high-density chip packaging according to claim 1, characterized in that: A positioning hole (7) is provided inside the side frame (1); the width of the warp connecting ribs (3) is twice that of the weft connecting ribs (2); and strip grooves (11) are provided in the middle position and on the upper and lower sides of the warp connecting ribs (3).

6. The lead frame wire for high-density chip packaging according to claim 5, characterized in that: The width of the strip grooves (11) exceeds half the width of the warp connecting ribs (3), and the upper and lower sides of the strip grooves (11) are both arranged in an arc shape.

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