Base island of lead frame

Abstract

The utility model discloses a base island of a lead frame, the base island is sequentially provided with an upper half area used for bearing a chip and a lower half area used for heat dissipation along the height direction of the base island, and the upper half area is fixedly connected with the lower half area. The junction of the upper half area and the lower half area on the side wall of the base island is recessed inwards to form a glue locking groove, the glue locking groove is provided with a first side face and a second side face which are oppositely arranged, the first side face is located in the upper half area, and the second side face is located in the lower half area. According to the utility model, the side wall of the base island is provided with the glue locking groove, the plastic packaging material can enter the glue locking groove, the combination strength of the plastic packaging material and the base island is enhanced, the phenomenon of layering of a packaged product caused by separation of the base island and the plastic packaging material is avoided, the original scheme that steps are etched at the two ends of the lower half area is replaced, and the heat dissipation effect is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging products, in particular to a base island of a lead frame. Background Art

[0002] Semiconductor packaging refers to the process of attaching the cut wafer to the corresponding substrate (lead frame) island with glue, and then using ultra-fine metal (gold, tin, copper, aluminum) wires or conductive resins to connect the wafer's bonding pads to the corresponding pins of the substrate to form the required circuit. Among them, the failure phenomenon that often occurs in packaged products is delamination, that is, the lead frame is easily separated from the glue and other plastic packaging materials.

[0003] like Figure 1 As shown, the upper area 110 of the base island 100 is used to carry the chip 300, and the lower area 120 is used for heat dissipation. In order to prevent the plastic encapsulation material 200 from detaching from the base island 100 and causing stratification of the packaged product, the existing solutions are to etch a space at the end of the lower area 120, and the width of the lower area 120 used for heat dissipation is smaller than the width of the upper area 110, so that a step 130 that can hold the plastic encapsulation material 200 can be formed between the upper area 110 and the lower area 120 to prevent the plastic encapsulation material 200 from detaching from the base island 100.

[0004] However, although the etched steps can hold the plastic encapsulation material and prevent the packaged product from being delaminated, they also reduce the area of ​​the lower half area for heat dissipation. The area of ​​the lower half area is smaller than that of the upper half area, which reduces its heat dissipation effect. For some packaged products, they have strict heat dissipation requirements. If the heat cannot be dissipated in time, the heat will easily melt the plastic encapsulation material, resulting in separation of the plastic encapsulation material from the base island and causing delamination. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to propose a base island of a lead frame, which is used to solve the problem that the upper and lower parts of the base island in the prior art have unequal areas, resulting in reduced heat dissipation effect.

[0006] The technical solution adopted by the utility model to solve its technical problem is a base island of a lead frame, and the base island has an upper half area for carrying a chip and a lower half area for heat dissipation in sequence along its height direction, the upper half area is fixedly connected to the lower half area, and the side wall of the base island is recessed inward at the junction of the upper half area and the lower half area to form a glue locking groove, and the glue locking groove has a first side surface and a second side surface arranged opposite to each other, the first side surface is in the upper half area, and the second side surface is in the lower half area.

[0007] Further, the upper half region has a first end surface away from the lower half region, the lower half region has a second end surface away from the upper half region, and the first end surface and the second end surface have the same area.

[0008] Furthermore, the upper half region and the lower half region are symmetrical about a boundary between the upper half region and the lower half region.

[0009] Furthermore, the distance from the first side surface to the second side surface gradually increases from the bottom of the glue locking groove toward the outside.

[0010] Furthermore, the first side surface and the second side surface are both plane surfaces or curved surfaces, and the first side surface and the second side surface are connected at the junction of the upper half area and the lower half area.

[0011] Furthermore, the first side surface and the second side surface are symmetrical about a junction between the upper half area and the lower half area.

[0012] Furthermore, the cross-section of the glue locking groove is semicircular or triangular.

[0013] Furthermore, the glue locking groove also has a bottom surface, and two ends of the bottom surface are respectively connected to the first side surface and the second side surface.

[0014] Furthermore, the first side surface and the second side surface are both planes, and the first side surface and the second side surface are parallel.

[0015] Furthermore, the cross-section of the glue locking groove is arranged in a rectangular shape.

[0016] Compared with the prior art, the utility model has at least the following beneficial effects:

[0017] A glue locking groove is provided on the side wall of the base island, and the plastic encapsulation material can enter the glue locking groove, thereby enhancing the bonding strength between the plastic encapsulation material and the base island, and avoiding the separation of the base island and the plastic encapsulation material, which leads to the delamination of the packaged product, thereby replacing the original solution of etching steps at both ends of the lower half area. At the same time, since the glue locking groove is located at the junction of the upper half area and the lower half area, the first side surface is located in the upper half area, and the second side surface is located in the lower half area, the volume of the lower half area is closer to that of the lower half area, and the heat dissipation effect is better than the original solution of etching steps in the lower half area, thereby avoiding the delamination of the packaged product due to the failure to dissipate heat in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of a packaged product in the background technology;

[0019] Figure 2 Schematic diagram of the structure of the base island and the plastic packaging material in the embodiment;

[0020] Figure 3 It is a cross-sectional view of the base island when the cross section of the glue locking groove in the embodiment is semicircular;

[0021] Figure 4 It is a cross-sectional view of the base island when the cross section of the glue locking groove in the embodiment is triangular;

[0022] Figure 5 It is a cross-sectional view of the base island when the cross section of the glue locking groove in the embodiment is rectangular;

[0023] In the figure:

[0024] 100, base island; 110, upper area; 120, lower area; 130, step; 140, glue locking groove; 141, first side surface; 142, second side surface; 143, bottom surface; 200, plastic encapsulation material; 300, chip. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0026] Please refer to Figure 2-Figure 5 The utility model discloses a base island of a lead frame, wherein the base island 100 has an upper area 110 for carrying a chip 300 and a lower area 120 for heat dissipation in sequence along its height direction, wherein the upper area 110 is fixedly connected to the lower area 120, and a side wall of the base island 100 is inwardly recessed at the junction of the upper area 110 and the lower area 120 to form a glue locking groove 140, wherein the glue locking groove 140 has a first side surface 141 and a second side surface 142 which are arranged opposite to each other, wherein the first side surface 141 is located in the upper area 110, and the second side surface 142 is located in the lower area 120.

[0027] Specifically, the present application provides a glue locking groove 140 on the side wall of the base island 100, and the plastic encapsulation material 200 can enter the glue locking groove 140, thereby enhancing the bonding strength between the plastic encapsulation material 200 and the base island 100, and avoiding the separation of the base island 100 and the plastic encapsulation material 200, which leads to the stratification of the packaged product, so as to replace the original solution of etching steps 130 at both ends of the lower half area 120. At the same time, since the glue locking groove 140 is located at the junction of the upper half area 110 and the lower half area 120, the first side surface 141 is located in the upper half area 110, and the second side surface 142 is located in the lower half area 120, the volume of the lower half area 120 is closer to that of the lower half area 120, and the heat dissipation effect is better than the original solution of etching the steps 130 in the lower half area 120, thereby avoiding the stratification of the packaged product due to the failure to dissipate heat in time.

[0028] The glue locking grooves 140 may be simultaneously opened on all side walls of the base island 100 , or may be opened on one or more side walls.

[0029] It should be noted that the base island 100 is not formed by connecting two different plates, the upper area 110 and the lower area 120. On the contrary, the base island 100 is actually made of one plate, and dividing it into the upper area 110 and the lower area 120 is only for the convenience of description and distinction.

[0030] Further, the upper region 110 has a first end surface away from the lower region 120 , the lower region 120 has a second end surface away from the upper region 110 , and the first end surface and the second end surface have the same area.

[0031] Specifically, the heat of the chip 300 is transferred downward to the second end surface via the first end surface. The first end surface and the second end surface have equal areas, so that the second end surface has sufficient heat dissipation area to dissipate the heat in time.

[0032] Further, the upper region 110 and the lower region 120 are symmetrical about a boundary between the upper region 110 and the lower region 120 .

[0033] The upper area 110 is symmetrical to the lower area 120 , so that the volumes of the upper area 110 and the lower area 120 are equal. When heat is transferred from the upper area 110 to the lower area 120 , the lower area 120 can dissipate heat in time.

[0034] Furthermore, the distance from the first side surface 141 to the second side surface 142 gradually increases from the bottom of the glue locking groove 140 toward the outside.

[0035] Specifically, the glue locking groove 140 in the present application does not need to be etched by an etching solution, and the processing of the glue locking groove 140 can be achieved by rotating a tool. Among them, the distance from the first side surface 141 to the second side surface 142 is the width of the glue locking groove 140. The width of the bottom of the glue locking groove 140 is small, and the width of the opening is large, so that the head of the corresponding cutting tool is small, so as to cut the side wall of the base island 100 at the beginning of cutting.

[0036] Furthermore, the first side surface 141 and the second side surface 142 are both plane surfaces or curved surfaces, and the first side surface 141 and the second side surface 142 are connected at the junction of the upper half area 110 and the lower half area 120 .

[0037] Further, the first side surface 141 and the second side surface 142 are symmetrical about the boundary between the upper half area 110 and the lower half area 120 .

[0038] Furthermore, the cross section of the glue locking groove 140 is semicircular or triangular.

[0039] Specifically, when the cross section of the glue locking groove 140 is semicircular, the cross section of the corresponding cutting tool is circular. When the cross section of the glue locking groove 140 is triangular, the cross section of the corresponding cutting tool is a parallelogram.

[0040] Furthermore, the glue locking groove 140 further has a bottom surface 143 , and two ends of the bottom surface 143 are respectively connected to the first side surface 141 and the second side surface 142 .

[0041] Furthermore, the first side surface 141 and the second side surface 142 are both planes, and the first side surface 141 and the second side surface 142 are parallel.

[0042] Specifically, the first side surface 141 and the second side surface 142 are symmetrical about the center of the bottom surface 143 , so that the force of the plastic encapsulation material 200 in the upper and lower parts of the plastic locking groove 140 is more uniform, thereby enhancing the bonding strength between the plastic encapsulation material 200 and the base island 100 .

[0043] Furthermore, the cross-section of the glue locking groove 140 is configured to be rectangular.

[0044] Specifically, when the cross section of the glue locking groove 140 is a rectangle, the cross section of the corresponding cutting tool is also a rectangle.

[0045] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A base island of a lead frame, wherein the base island has an upper half area for carrying a chip and a lower half area for heat dissipation in sequence along its height direction, wherein the upper half area is fixedly connected to the lower half area, and characterized in that: The side wall of the base island is recessed inward at the junction of the upper area and the lower area to form a glue locking groove, and the glue locking groove has a first side surface and a second side surface arranged opposite to each other, the first side surface is in the upper area, and the second side surface is in the lower area.

2. The base island of a lead frame according to claim 1, characterized in that: The upper half region has a first end surface away from the lower half region, the lower half region has a second end surface away from the upper half region, and the first end surface and the second end surface have the same area.

3. The base island of a lead frame according to claim 1, characterized in that: The upper half area and the lower half area are symmetrical about a boundary between the upper half area and the lower half area.

4. The base island of a lead frame according to claim 1, characterized in that: The distance from the first side surface to the second side surface gradually increases from the bottom of the glue locking groove toward the outside.

5. The base island of a lead frame according to claim 4, characterized in that: The first side surface and the second side surface are both plane surfaces or curved surfaces, and the first side surface and the second side surface are connected at the junction of the upper half area and the lower half area.

6. The base island of a lead frame according to claim 5, characterized in that: The first side surface and the second side surface are symmetrical about a boundary between the upper half area and the lower half area.

7. The base island of a lead frame according to claim 5, characterized in that: The cross section of the glue locking groove is semicircular or triangular.

8. The base island of a lead frame according to claim 1, characterized in that: The glue locking groove also has a bottom surface, and two ends of the bottom surface are respectively connected to the first side surface and the second side surface.

9. The base island of a lead frame according to claim 8, characterized in that: The first side surface and the second side surface are both planes, and the first side surface and the second side surface are parallel.

10. The base island of a lead frame according to claim 9, characterized in that: The cross section of the glue locking groove is arranged in a rectangular shape.

Images