Lead frame

Abstract

The utility model discloses a lead frame which comprises a frame, a plurality of product units are arranged on the frame in the X-axis direction, a plurality of column unit groups are arranged in the product units, each column unit group comprises a plurality of structural units arranged along the Y-axis, and a connecting rib is arranged between every two adjacent structural units; each structural unit comprises a base island and pins, the pins are installed on the two sides of the base island, the base island sinks in the pins, and connecting bands used for connecting the base island and the pins are arranged between the base island and the pins. The base island is provided with a T-shaped lock catch and a first groove; wherein the X axis is perpendicular to the Y axis. The lead frame has the advantages that the base islands sink to the pins through the connecting bands, the heat dissipation effect and the structural strength of the lead frame can be further improved, the first grooves can improve the installation stability of the base islands and the chips, and the second grooves can improve the combination degree of the pins and plastic package materials. The utility model has the advantages of simple structure, strong stability, high space utilization rate and the like.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging technology, and in particular to a lead frame. Background Technology

[0002] The leadframe, a thin metal frame connecting the contact points of the internal chip of a semiconductor integrated circuit to external wires, is a key component in forming circuit loops. Structural units are typically housed within the leadframe for mounting the chip. Traditional leadframes often feature a single-row structure of these structural units; however, a large number of units reduces the structural strength of the leadframe. Furthermore, a single-row arrangement of structural units cannot effectively utilize the space within the leadframe, easily leading to resource waste.

[0003] Currently, the base island and frame in most leadframes are on the same plane, causing the chip to protrude excessively from the frame. When subjected to external forces, this can lead to delamination of the package structure. Furthermore, under heavy loads, the chip may not be able to dissipate heat effectively, resulting in overheating and chip damage. Therefore, it is necessary to improve the structure of the base island. Utility Model Content

[0004] One objective of this application is to provide a lead frame that can solve at least one of the defects in the aforementioned background art.

[0005] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a lead frame, comprising a frame, wherein the frame is provided with a plurality of product units along the X-axis direction, and a plurality of column unit groups are provided within each product unit, wherein each column unit group includes a plurality of structural units arranged along the Y-axis direction, and a connecting rib is provided between two adjacent structural units; each structural unit includes a base island and a pin, wherein the pin is mounted on both sides of the base island, the base island is recessed below the pin, and a connecting strip for connecting the base island and the pin is provided between the base island and the pin; the base island is provided with a T-shaped latch and a first groove; wherein the X-axis and the Y-axis are perpendicular to each other.

[0006] The above design effectively improves the space utilization of the frame and enhances its bending resistance. The connecting ribs between adjacent structural units effectively improve the stability of the product structure, ensure uniform stress distribution on the structural units, and effectively reduce the risk of glue breakage and delamination during the plasticizing process, thereby further improving the product yield.

[0007] Preferably, the sinking depth of the base island is within the range of 0.900±0.100mm; the connecting strip is inclined, and the inclination angle between the connecting strip and the structural unit is 40°. This configuration can effectively increase the contact area between the base island and the molding material, further improving the heat dissipation effect of the product.

[0008] Preferably, the first groove is V-shaped, and the included angle of the first groove is 90°. With this configuration, the encapsulating material in the first groove can engage and limit the chip in the base island, further improving the stability of the chip and base island bonding and preventing the chip from shifting within the base island.

[0009] Preferably, the pin is provided with a second groove, the second groove being V-shaped and having an included angle of 60°. This arrangement allows the molding compound to enter and engage within the second groove, thereby improving the connection strength between the pin and the frame.

[0010] Preferably, there are 6 product units, and each product unit contains 2 column unit groups, with each column unit group including 2 structural units. This arrangement allows for the grouping of structural units within the lead frame, further improving the space utilization of the frame through reasonable area division.

[0011] Preferably, the length of the frame ranges from 260.000±0.100mm, and the width of the frame ranges from 29.500±0.050mm. This configuration allows the frame to have more structural units per unit area, thereby effectively improving the product's packaging efficiency.

[0012] Preferably, the column unit group has multiple positioning holes at both ends, and the diameter of the positioning holes ranges from 2.000±0.025mm. This configuration allows the processing position of the product to be defined based on the positioning holes, enabling the processing machine to quickly begin work by recognizing the positioning holes.

[0013] Preferably, the step distance between two adjacent product units is 43.330 ± 0.030 mm.

[0014] Preferably, the structural unit has multiple pins, with a step distance of 1.140 ± 0.025 mm between adjacent pins. This configuration further improves the heat dissipation efficiency of the lead frame and the signal transmission rate.

[0015] Preferably, a heat sink is installed on the base island, and the thickness of the heat sink ranges from 0.900±0.010mm. This configuration can further improve the heat dissipation effect of the product and prevent the chip from overheating and being damaged.

[0016] Compared with the prior art, the beneficial effects of this application are as follows:

[0017] This invention incorporates multiple structural units within a column unit group, which effectively improves the space utilization of the frame compared to traditional single-row structures, further enhancing the product's bending resistance. Additionally, the connecting ribs between adjacent structural units further improve the product's structural stability.

[0018] This invention features a recessed base island and an inclined connecting strip between the base island and the pins. This increases the contact area between the base island and the molding compound, improving heat dissipation. It also enhances the product's mechanical strength, making the package structure more stable and reducing the risk of delamination under external forces. The first groove improves the mounting stability of the base island and the chip, while the second groove improves the adhesion between the pins and the molding compound. The T-shaped latch effectively prevents the base island from detaching from the molding compound. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the lead frame in this application.

[0020] Figure 2 This is a schematic diagram of the product unit in this application.

[0021] Figure 3 This is a schematic diagram of the structural unit in this application.

[0022] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure at point AA.

[0023] Figure 5 This is a schematic diagram of the cross-sectional structure of the base island in this application.

[0024] Figure 6 for Figure 5 A magnified structural diagram of local area B in the middle.

[0025] Figure 7 This is a schematic diagram of the connection structure between the base island and the pins in this application.

[0026] Figure 8 for Figure 7 A magnified structural diagram of point C in the middle section.

[0027] In the diagram: 1. Frame; 100. Connecting rib; 2. Product unit; 21. Column unit group; 200. Positioning hole; 3. Structural unit; 31. Base island; 32. Pin; 300. Connecting strip; 310. T-lock; 311. First groove; 320. Second groove; 400. Heat sink. Detailed Implementation

[0028] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0029] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0030] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0032] One aspect of this application provides a lead frame, such as Figure 1 , Figure 2 and Figure 3 As shown, one preferred embodiment includes a frame 1 on which multiple product units 2 are arranged along the X-axis, which can further improve the space utilization of the lead frame. Each product unit 2 contains multiple column unit groups 21, each column unit group 21 including multiple structural units 3 arranged along the Y-axis; a connecting rib 100 is provided between two adjacent structural units 3 to increase the structural strength of the lead frame; the X-axis and Y-axis are perpendicular to each other.

[0033] Specifically, such as Figure 3 and Figure 4 As shown, structural unit 3 includes a base island 31 and pins 32 disposed on both sides of the base island 31. The base island 31 is recessed into the lead frame, and a connecting strip 300 is inclinedly disposed between the base island 31 and the pins 32, which can reduce the difficulty of molding the lead frame, provide a certain degree of fault tolerance for chip installation, and reduce the defect rate during production and processing.

[0034] It should be noted that the connecting strip 300 in this application is integrally formed with the base island 31 and the pin 32 to improve the connection stability between the pin 32 and the base island 31; and the base island 31 can also be recessed into the lead frame through the connecting strip 300.

[0035] In this embodiment, as Figure 5 and Figure 6 As shown, the base island 31 is provided with a T-lock 310 and a first groove 311. The T-lock 310 fixes the frame 1, ensuring that the position of the base island 31 within the frame 1 will not shift, reducing the packaging difficulty of the lead frame. The first groove 311 can further improve the bonding strength between the chip and the base island 31 through the molding compound during the molding process, preventing delamination between the chip and the base island 31.

[0036] Understandably, the lead frame in this application has higher space utilization and bending resistance, effectively reducing the risk of adhesive breakage and delamination during the molding process, and further improving product yield.

[0037] In this embodiment, as Figure 4 As shown, to avoid packaging problems caused by bending of the frame 1, the recessed depth of the base island 31 is set to 0.900±0.100mm. This ensures that the base island 31 can better distribute stress under load, and also avoids thermal stress concentration on the base island 31, further improving the heat dissipation performance of the lead frame. The tilt angle of the connecting strip 300 is 40° to prevent packaging problems caused by bending of the frame 1.

[0038] It should be noted that, without affecting heat dissipation and structural strength, the recessed range of the base island 31 and the tilt angle of the connecting strip 300 in this application can be appropriately adjusted according to actual needs. In this application, the tilt angle of the connecting strip 300 is the angle between the connecting strip 300 and the pin 32.

[0039] In this embodiment, as Figure 6 As shown, the first groove 311 is V-shaped and the included angle of the first groove 311 is 90°. When the lead frame is encapsulated, the encapsulating material can enter the first groove 311 and accumulate. The encapsulating materials in multiple first grooves 311 cooperate with each other to limit the chip and prevent the chip from shifting when subjected to external force impact.

[0040] Furthermore, such as Figure 7 and Figure 8 As shown, a second groove 320 in the shape of a V is provided on the pin 32. The included angle of the second groove 320 is 60°. One function of the second groove 320 is that during the lead frame molding process, the molding material enters the second groove 320 to engage, thereby improving the connection strength between the pin 32 and the frame. Another function is to prevent moisture from directly entering the base island 31 and interfering with the chip.

[0041] In this embodiment, as Figure 1 , Figure 2 and Figure 3As shown, there are 6 product units 2, and each product unit 2 has two column unit groups 21. Each column unit group 21 includes two structural units 3. The structural units 3 in the lead frame are divided into hierarchical sections to more clearly distinguish and define the specific installation points of the structural units 3.

[0042] Specifically, the length of frame 1 ranges from 260.000±0.100mm, and the width of frame 1 ranges from 29.500±0.050mm. Frame 1 contains two rows of 24 structural units 3. Compared to traditional lead frames, the lead frame in this application has more structural units 3 per unit area, thereby effectively improving the product's packaging efficiency.

[0043] Understandably, the number and arrangement of structural units 3 in the lead frame can be adjusted within a certain range according to actual needs.

[0044] In this embodiment, as Figure 2 As shown, positioning holes 200 are provided at both ends of column unit group 21, and the diameter of the positioning holes 200 ranges from 2.000±0.025mm. During the molding process of the lead frame, the processing accuracy can be judged based on the position of multiple positioning holes 200, avoiding product deviations during manufacturing. In practical applications, the processing machine identifies and positions the positioning holes 200 to quickly carry out processing steps, thereby improving the production efficiency of the lead frame.

[0045] Furthermore, such as Figure 1 As shown, the step distance between two adjacent product units 2 is 43.330±0.030mm; here, the distance between the two rightmost positioning holes 200 in two adjacent product units 2 is set as the step distance of product unit 2.

[0046] Specifically, such as Figure 3 As shown, there are multiple pins 32 within the same structural unit 3, and the step distance between two adjacent pins 32 is 1.140±0.025mm; this further improves the signal transmission rate of the lead frame, and setting an appropriate step distance between adjacent pins 32 can also effectively improve the heat dissipation efficiency of the product.

[0047] In this embodiment, as Figure 4 As shown, a heat sink 400 is mounted on the back of the base island 31. The thickness of the heat sink 400 ranges from 0.900±0.010mm, which can further improve the heat dissipation effect of the product and prevent the chip from overheating and being damaged. The size and shape of the heat sink 400 can be adjusted appropriately while meeting the heat dissipation requirements of the lead frame.

[0048] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A lead frame, comprising a frame (1), characterized in that, The frame (1) is provided with multiple product units (2) along the X-axis direction. Each product unit (2) is provided with multiple column unit groups (21). Each column unit group (21) includes multiple structural units (3) arranged along the Y-axis direction. A connecting rib (100) is provided between two adjacent structural units (3). Each structural unit (3) includes a base island (31) and a pin (32). The pin (32) is installed on both sides of the base island (31). The base island (31) is recessed below the pin (32). A connecting strip (300) is provided between the base island (31) and the pin (32) for connecting the base island (31) and the pin (32). A T-shaped lock (310) and a first groove (311) are provided on the base island (31). The X-axis and the Y-axis are perpendicular to each other.

2. The lead frame as described in claim 1, characterized in that, The sinking depth of the base island (31) is 0.900±0.100mm; the connecting strip (300) is inclined, and the inclination angle between the connecting strip (300) and the structural unit (3) is 40°.

3. The lead frame as described in claim 1, characterized in that, The first groove (311) is V-shaped, and the included angle of the first groove (311) is 90°.

4. The lead frame as described in claim 3, characterized in that, The pin (32) is provided with a second groove (320), the second groove (320) is V-shaped, and the included angle of the second groove (320) is 60°.

5. The lead frame as described in claim 1, characterized in that, There are 6 product units (2), and each product unit (2) has 2 column unit groups (21), and each column unit group (21) includes 2 structural units (3).

6. The lead frame as described in claim 5, characterized in that, The length of the frame (1) is 260.000±0.100mm; the width of the frame (1) is 29.500±0.050mm.

7. The lead frame as described in claim 6, characterized in that, The column unit group (21) has multiple positioning holes (200) at both ends, and the diameter of the positioning holes (200) is 2.000±0.025mm.

8. The lead frame as described in claim 6, characterized in that, The step distance between two adjacent product units (2) is 43.330±0.030mm.

9. The lead frame as described in claim 6, characterized in that, The structural unit (3) is provided with multiple pins (32), and the step distance between two adjacent pins (32) is 1.140±0.025mm.

10. The lead frame as described in claim 1, characterized in that, A heat sink (400) is installed on the base island (31), and the thickness of the heat sink (400) is in the range of 0.900±0.010mm.

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