Semiconductor packaging lead frame

Abstract

The utility model relates to the technical field of integrated circuits, and discloses a semiconductor packaging lead frame which comprises a frame body and a base island, the frame body is provided with an avoiding hole, and the inner wall of the avoiding hole is provided with a plurality of pins; the left end of the base island is connected with the left inner wall of the receding hole through at least one elastic connecting bridge, the right end of the base island is connected with the right inner wall of the receding hole through at least one elastic connecting bridge, the elastic connecting bridges are step-shaped, the frame body is higher than the base island and is mutually planar, the base island corresponds to the receding hole, and the cross section of the base island is smaller than that of the receding hole. The base island is used for bearing a semiconductor chip. The left end and the right end of the base island are connected with the frame body through the elastic connecting bridges, the elastic connecting bridges elastically deform to absorb the pressure of the colloid, the buffering effect is achieved, the base island and the frame body can be kept parallel, the PAD can be kept flat, glue overflowing and the risk of cooling performance reduction caused by glue overflowing are reduced, the risk of chip dark fringes is reduced, and the service life of the chip is prolonged. And the performance and the reliability of the packaging body are improved.

Description

Technical Field

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

[0002] The semiconductor package lead frame is the mounting carrier for integrated circuit chips and is an important basic material in the semiconductor industry. The semiconductor package lead frame provides mechanical support for the chip, connects the chip to the circuit board, and provides an electrical and thermal path from the chip to the circuit board. During the chip packaging process, resin encapsulation glue is usually used to encapsulate the chip on the chip carrier to protect it from the influence of the external environment. The current lead frame has an uneven PAD and glue overflow. The glue overflow refers to the part of the encapsulation glue that may flow out of the chip packaging area and solidify during the packaging process. If the amount of glue overflow is large, it may increase the total thickness of the package, causing the size of the package to exceed the design requirements, thereby affecting its application in electronic devices. The uneven PAD and glue overflow have the risk of causing dark lines on the chip, affecting the performance and reliability of the package. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a semiconductor package lead frame that can reduce the risk of chip dark marks and improve package performance and reliability.

[0004] According to an embodiment of the present invention, a semiconductor packaging lead frame includes a frame body and a base island, the frame body is provided with an avoidance hole, and the inner wall of the avoidance hole is provided with multiple pins; the left end of the base island is connected to the left inner wall of the avoidance hole through at least one elastic connecting bridge, and the right end of the base island is connected to the right inner wall of the avoidance hole through at least one elastic connecting bridge, and the elastic connecting bridge is stepped. The frame body is higher than the base island and is planar with each other. The base island is arranged corresponding to the avoidance hole, and the cross-section of the base island is smaller than the cross-section of the avoidance hole. The base island is used to carry a semiconductor chip.

[0005] It has at least the following beneficial effects:

[0006] The elastic connecting bridge is elastic, and the left and right ends of the base island are connected to the frame through the elastic connecting bridge. During the sealing process, the elastic connecting bridge undergoes elastic deformation to absorb the pressure of the colloid, and then resets, which has a buffering effect. It can keep the base island parallel to the frame and keep the PAD flat, reduce the risk of glue overflow caused by lead frame deformation and the risk of decreased heat dissipation performance caused by glue overflow, avoid affecting the fit between the packaging mold and the PAD, reduce the risk of chip dark lines, and ultimately improve the performance and reliability of the package.

[0007] According to some embodiments of the present invention, the elastic connecting bridge includes a first inclined portion, a transition portion and a second inclined portion connected in sequence, the end of the first inclined portion away from the transition portion is connected to the inner wall of the avoidance hole, and the end of the second inclined portion away from the transition portion is connected to the base island, the first inclined portion and the second inclined portion both have an obtuse angle with the base island, and the transition portion and the base island are parallel to each other.

[0008] According to some embodiments of the present invention, the left and right ends of the front inner wall of the avoidance hole and the left and right ends of the rear inner wall of the avoidance hole are provided with L-shaped pins, and the pins include a fixed end and a connecting end connected to each other, the fixed end is fixedly connected to the inner wall of the avoidance hole, and the connecting end is used to connect to the semiconductor chip, the end face of the connecting end on the left faces right, and the end face of the connecting end on the right faces left.

[0009] According to some embodiments of the present invention, the frame, the pins, the base island and the elastic connecting bridge are processed by an integrated molding method.

[0010] According to some embodiments of the present invention, a widened portion is provided at one end of the pin close to the center of the avoidance hole, and the widened portion is used to increase the connection surface with the wire.

[0011] According to some embodiments of the present invention, the cross-section of the widened portion is square, and the width of the widened portion is greater than the width of the pin.

[0012] According to some embodiments of the present invention, the cross-section of the widened portion is circular, and the outer diameter of the widened portion is greater than the width of the pin.

[0013] According to some embodiments of the present invention, the widened portion is provided with a receiving hole for receiving welding materials.

[0014] According to some embodiments of the present invention, the front end face, rear end face, left end face and right end face of the base island are all provided with groove structures, and the groove structures are used to increase the contact area between the packaging glue and the base island and to accommodate excess packaging glue.

[0015] According to some embodiments of the present invention, the groove structure is wavy or semicircular.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0018] Figure 1 This is a schematic structural diagram of an embodiment of the present utility model;

[0019] Figure 2 This is a side structural diagram of an embodiment of the present utility model;

[0020] Figure Number:

[0021] Frame 100; avoidance hole 110;

[0022] Pin 200;

[0023] Base Island 300;

[0024] Elastic connecting bridge 400 ; first inclined portion 410 ; transition portion 420 ; second inclined portion 430 . DETAILED DESCRIPTION

[0025] The following describes in detail embodiments of the present invention. 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 only to explain the present invention and are not to be construed as limiting the present invention.

[0026] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0027] In the description of this utility model, "a plurality" means more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0028] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0029] Reference Figure 1The utility model discloses a semiconductor package lead frame, including a frame body 100 and a base island 300. The frame body 100 is provided with an avoidance hole 110, and the inner wall of the avoidance hole 110 is provided with a plurality of pins 200; the left end of the base island 300 is connected to the left inner wall of the avoidance hole 110 through at least one elastic connecting bridge 400, and the right end of the base island 300 is connected to the right inner wall of the avoidance hole 110 through at least one elastic connecting bridge 400. The elastic connecting bridge 400 is stepped, the frame body 100 is higher than the base island 300 and they are parallel to each other, the base island 300 is arranged corresponding to the avoidance hole 110, the cross section of the base island 300 is smaller than the cross section of the avoidance hole 110, and the base island 300 is used to carry semiconductor chips.

[0030] The frame 100 is higher than the base island 300 and is flush with the base island 300. The base island 300 is arranged corresponding to the avoidance hole 110. The cross section of the base island 300 is smaller than the cross section of the avoidance hole 110. The semiconductor chip is placed on the base island 300, and a space for accommodating the semiconductor chip is formed between the frame 100 and the base island 300. After the semiconductor chip is placed on the base island 300, the semiconductor chip is prevented from protruding too much above the frame 100.

[0031] The elastic connecting bridge 400 is elastic, and the left and right ends of the base island 300 are connected to the frame 100 through the elastic connecting bridge 400. During the sealing process, the elastic connecting bridge 400 undergoes elastic deformation to absorb the pressure of the colloid, and then resets, having a buffering effect. It can keep the base island 300 parallel to the frame 100 and keep the PAD flat, reducing the risk of glue overflow caused by lead frame deformation and the risk of decreased heat dissipation performance caused by glue overflow, avoiding affecting the fit between the packaging mold and the PAD, reducing the risk of generating chip dark lines, and ultimately improving the performance and reliability of the package.

[0032] See also Figure 1 and Figure 2 In some embodiments, the elastic connecting bridge 400 includes a first inclined portion 410, a transition portion 420 and a second inclined portion 430 connected in sequence, the end of the first inclined portion 410 away from the transition portion 420 is connected to the inner wall of the avoidance hole 110, and the end of the second inclined portion 430 away from the transition portion 420 is connected to the base island 300. The angles between the first inclined portion 410 and the second inclined portion 430 and the base island 300 are obtuse angles, and the transition portion 420 and the base island 300 are parallel to each other.

[0033] The first inclined portion 410, the transition portion 420 and the second inclined portion 430 form an elastic structure, so that the elastic connecting bridge 400 can undergo elastic deformation. The elastic connecting bridge 400 ensures that the frame 100 and the base island 300 are connected together, while allowing relative movement between the base island 300 and the frame 100.

[0034] It is understood that the first inclined portion 410, the transition portion 420, and the second inclined portion 430 are stair-shaped, with smooth transitions between the frame 100 and the first inclined portion 410, between the first inclined portion 410 and the transition portion 420, between the transition portion 420 and the second inclined portion 430, and between the second inclined portion 430 and the base island 300.

[0035] See also Figure 1 In this embodiment, there are four elastic connection bridges 400. The left end of the base island 300 is connected to the left inner wall of the avoidance hole 110 via two elastic connection bridges 400, and the right end of the base island 300 is connected to the right inner wall of the avoidance hole 110 via two other elastic connection bridges 400. The four elastic connection bridges 400 are connected to the base island 300 in a bilaterally symmetrical manner.

[0036] See also Figure 1 In some embodiments, L-shaped pins 200 are provided at the left and right ends of the front inner wall of the avoidance hole 110 and the left and right ends of the rear inner wall of the avoidance hole 110. The pins 200 include a fixed end and a connecting end connected to each other. The fixed end is fixedly connected to the inner wall of the avoidance hole 110, and the connecting end is used to connect to the semiconductor chip. The end face of the connecting end on the left faces right, and the end face of the connecting end on the right faces left.

[0037] The end face of the pin 200 located in the middle of the front inner wall of the avoidance hole 110 faces rearward, and the end face of the pin 200 located in the middle of the rear inner wall of the avoidance hole 110 faces forward, so that there are pins 200 around the avoidance hole 110 to facilitate electrical connection between each port of the semiconductor chip and each pin 200.

[0038] No pins 200 are set on the left inner wall and the right inner wall of the avoidance hole 110, so that the left inner wall and the right inner wall of the avoidance hole 110 have a large enough area to set the elastic connecting bridge 400, ensuring the connection strength between the elastic connecting bridge 400 and the frame 100.

[0039] It is conceivable that the port of the semiconductor chip and the pin 200 are connected via a wire or lead, which is a copper wire, an aluminum wire, or a gold wire. The wire is connected to the port of the semiconductor chip and the pin 200 by welding.

[0040] See also Figure 1 In some embodiments, a widened portion is provided at one end of the pin 200 close to the center of the avoidance hole 110, and the wire is connected to the pin 200 through the widened portion. The widened portion is used to increase the connection surface with the wire to ensure the connection strength between the wire and the pin 200.

[0041] In some embodiments, the cross-section of the widened portion is square, and the width of the widened portion is greater than the width of the pin 200, which facilitates aligning the wire with the widened portion and improves the efficiency and quality of connecting the wire to the pin 200.

[0042] In some embodiments, the cross-section of the widened portion is circular, and the outer diameter of the widened portion is larger than the width of the pin 200, so as to facilitate aligning the wire with the widened portion and improve the efficiency and quality of connecting the wire with the pin 200.

[0043] The wire is connected to the pin 200 and the semiconductor chip by welding, and welding material is used. The widened portion is provided with a receiving hole for receiving the welding material. After the welding material melts, it enters the receiving hole, thereby improving the connection strength and reliability between the wire and the pin 200.

[0044] See also Figure 1 In some embodiments, the frame 100, the pins 200, the base island 300 and the elastic connecting bridge 400 are processed by an integrated molding method.

[0045] In some embodiments, the front, left, rear and right end surfaces of the base island 300 are provided with groove structures, which are used to increase the contact area between the packaging glue and the base island 300 and to accommodate excess packaging glue.

[0046] In some embodiments, the groove structure is wavy or semicircular.

[0047] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] Of course, the present invention is not limited to the above-mentioned embodiments. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A semiconductor package lead frame, characterized in that: include: The frame (100) is provided with an avoidance hole (110), and the inner wall of the avoidance hole (110) is provided with a plurality of pins (200); The base island (300) has a left end connected to the left inner wall of the avoidance hole (110) through at least one elastic connecting bridge (400), and a right end connected to the right inner wall of the avoidance hole (110) through at least one elastic connecting bridge (400), wherein the elastic connecting bridge (400) is stepped, and the frame (100) is higher than the base island (300) and is parallel to each other, and the base island (300) is arranged corresponding to the avoidance hole (110), and the cross section of the base island (300) is smaller than the cross section of the avoidance hole (110), and the base island (300) is used to carry semiconductor chips.

2. The semiconductor package lead frame according to claim 1, wherein: The elastic connecting bridge (400) includes a first inclined portion (410), a transition portion (420) and a second inclined portion (430) connected in sequence, wherein one end of the first inclined portion (410) away from the transition portion (420) is connected to the inner wall of the avoidance hole (110), and one end of the second inclined portion (430) away from the transition portion (420) is connected to the base island (300), and the angles between the first inclined portion (410) and the second inclined portion (430) and the base island (300) are both obtuse angles, and the transition portion (420) and the base island (300) are parallel to each other.

3. A semiconductor package lead frame according to claim 1 or 2, characterized in that: The left and right ends of the front inner wall of the avoidance hole (110) and the left and right ends of the rear inner wall of the avoidance hole (110) are both provided with L-shaped pins (200), and the pins (200) include a fixed end and a connecting end connected to each other, the fixed end being fixedly connected to the inner wall of the avoidance hole (110), and the connecting end being used for connecting to the semiconductor chip, with the end face of the connecting end on the left facing right and the end face of the connecting end on the right facing left.

4. The semiconductor package lead frame according to claim 1, wherein: The frame (100), the pins (200), the base island (300) and the elastic connecting bridge (400) are processed using an integrated molding method.

5. The semiconductor package lead frame according to claim 1, wherein: An end of the pin (200) close to the center of the avoidance hole (110) is provided with a widened portion, and the widened portion is used to increase the connection surface with the wire.

6. The semiconductor package lead frame according to claim 5, wherein: The cross section of the widened portion is square, and the width of the widened portion is greater than the width of the pin (200).

7. The semiconductor package lead frame according to claim 5, wherein: The cross section of the widened portion is circular, and the outer diameter of the widened portion is greater than the width of the pin (200).

8. The semiconductor package lead frame according to any one of claims 5 to 7, characterized in that: The widened portion is provided with a receiving hole for receiving welding materials.

9. The semiconductor package lead frame according to claim 1, wherein: The front end face, the rear end face, the left end face and the right end face of the base island (300) are all provided with groove structures, and the groove structures are used to increase the contact surface between the packaging glue and the base island (300) and to accommodate excess packaging glue.

10. The semiconductor package lead frame according to claim 9, wherein: The groove structure is wavy or semicircular.

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