Lead frame for chip packaging

Abstract

The utility model discloses a lead frame for chip packaging, and belongs to the technical field of chip packaging. The lead frame comprises a base, a placing groove, a cover plate, clamping grooves and pins, wherein the placing groove is formed in the base and used for placing a chip; the cover plate is arranged at the position, corresponding to the upper portion of the placing groove, of the base; the clamping grooves are formed in the base, located on the periphery of the placing groove and distributed in a linear array; according to the lead frame for chip packaging, through the arrangement of the bonding parts, the welding positions of the gold wires and the pins can be positioned, the welding contact area of the gold wires and the pins is increased, the risk that welding spots fall off is reduced, meanwhile, through the arrangement of the buffer connecting pieces, stress generated by thermal expansion or machinery can be buffered in the welding process, and the welding quality is improved. The problem of deformation or welding spot cracking caused by stress concentration of the pins is reduced, and the reliability of the lead frame in complex environments of high temperature, vibration and the like is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of chip packaging, and particularly relates to a lead frame for chip packaging. BACKGROUND

[0002] With the rapid development of electronic technology, chip packaging technology, as an important link of integrated circuit manufacturing, has been widely applied to various electronic products. Traditional chip packaging technology mainly relies on a lead frame as a bridge for connecting a chip and an external circuit.

[0003] A lead frame for chip packaging is disclosed in Chinese Utility Model Patent No. CN216354184U. The lead frame is provided with a heat dissipation groove, a heat dissipation plate, a heat conduction sheet, a mounting edge, a protruding edge, and a fixed clamping groove. The lead frame not only realizes convenient and rapid chip packaging, but also improves the heat dissipation performance of the chip. However, when the chip and the pin are welded by gold wires, the gold wires are directly introduced into the plane of the pin for welding. The welding area of this contact mode is limited, and the welding point is easily affected by external forces, temperature changes and other factors, resulting in falling off, which affects the performance and reliability of the chip.

[0004] Therefore, the application provides a lead frame for chip packaging to solve the above problems. CONTENT OF THE UTILITY MODEL

[0005] The application provides a lead frame for chip packaging, which aims to solve the problems of limited gold wire welding area of the existing chip packaging lead frame, and the welding point being easily affected by external forces and temperature stress and falling off.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme: a lead frame for chip packaging, comprising a base, a placing groove for placing a chip arranged on the base, a cover plate arranged on the base at a position above the placing groove, a clamping groove arranged on the base and located around the placing groove and arranged in a linear array, and a pin clamped in the clamping groove.

[0007] The lead frame further comprises a bonding portion arranged at an end of the pin away from the clamping groove for changing the gold wire welding contact area, and a buffer connecting piece arranged on the base and corresponding to a position below the bonding portion of the pin for buffering the welding of the pin; the design of the bonding portion not only positions the welding position of the gold wire and the pin, but also increases the welding contact area of the gold wire and the pin, reducing the risk of welding point falling off, and the design of the buffer connecting piece can buffer the stress caused by thermal expansion or machinery during the welding process, reducing the problems of deformation or cracking of the welding point caused by stress concentration of the pin, and improving the reliability of the lead frame in complex environments such as high temperature and vibration.

[0008] Preferably, in order to realize the soldering of the gold wire and the pin, the bonding part comprises a positioning hole provided at the end of the pin away from the card slot for gold wire connection and a plurality of protrusions arranged in the positioning hole; the positioning hole provides a clear position for gold wire connection, can accurately position the soldering position, and improves the accuracy and consistency of soldering; the plurality of protrusions increase the soldering contact area of the gold wire and the pin, and the larger contact area can disperse the stress borne by the soldering point, reduce the risk of soldering point falling off caused by excessive local stress, and improve the stability and reliability of electrical connection.

[0009] Preferably, in order to ensure the contact area of the protrusions and the gold wire, the protrusions are semispherical or conical; the design of the semispherical or conical protrusions can provide more contact points when the gold wire contacts the pin, further increase the soldering contact area of the gold wire and the pin, make the combination between the gold wire and the pin more compact during soldering, disperse the stress borne by the soldering point, and effectively reduce the risk of soldering point falling off caused by excessive local stress.

[0010] Preferably, in order to further ensure the effect of soldering, the inner wall of the positioning hole is coated with a molten material for covering the connection between the gold wire and the positioning hole; the design of the molten material can melt under the influence of high temperature during soldering, and after cooling and solidification after soldering, the molten material will tightly cover the connection between the gold wire and the positioning hole, fill the tiny gap, form a tight connection, further reduce the possibility of soldering point falling off, improve the soldering quality and stability, and ensure the stability of electrical connection.

[0011] Preferably, in order to realize buffering, the buffer connecting piece comprises a positioning column arranged at a position below the pin corresponding to the positioning hole, a positioning jack provided on the base for inserting the positioning column, and an elastic piece sleeved on the positioning column and fixedly connected with the positioning column and the pin at both ends; the cooperation of the positioning column and the positioning jack further accurately positions the pin, ensures the installation accuracy of the pin on the base, provides a basis for subsequent stable soldering and electrical connection, and at the same time, the design of the elastic piece can elastically deform to absorb and buffer stress, reduce the deformation of the pin caused by stress concentration, and reduce the risk of soldering point cracking.

[0012] Preferably, in order to ensure buffering, the elastic piece is a spiral spring or a wave spring; the spiral spring and the wave spring have good elastic performance, and when the pin is subjected to thermal expansion or mechanical stress, the spiral spring and the wave spring can effectively absorb and buffer these stresses, reduce the deformation of the pin caused by stress concentration, and reduce the risk of soldering point cracking.

[0013] The lead frame for chip packaging can not only position the soldering position of the gold wire and the pin, but also increase the soldering contact area of the gold wire and the pin, and reduce the risk of soldering point falling off through the arrangement of the bonding part.

[0014] The lead frame for chip packaging can buffer thermal expansion or mechanical stress generated during welding process through the buffer connecting piece, reduce deformation or cracking of the solder joint caused by stress concentration of the pin, and improve the reliability of the lead frame in complex environments such as high temperature and vibration.

[0015] The lead frame for chip packaging is provided with a molten material in the positioning hole, which can melt during welding, and after cooling and solidification after welding, it is tightly covered at the connection between the gold wire and the positioning hole, fills the small gap, forms a tight connection, further reduces the possibility of solder joint falling off, improves the welding quality and stability, and ensures the stability of electrical connection. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 It is a structural schematic diagram of a lead frame for chip packaging.

[0017] Fig. 2 It is a structural schematic diagram of a base in a lead frame for chip packaging.

[0018] Fig. 3 It is an exploded view of a buffer connecting piece in a lead frame for chip packaging.

[0019] In the figure:

[0020] 1, base;

[0021] 2, cover plate;

[0022] 3, placing groove;

[0023] 4, clamping groove;

[0024] 5, pin;

[0025] 6, bonding part; 61, positioning hole; 62, protrusion;

[0026] 7, buffer connecting piece; 71, positioning column; 72, positioning jack; 73, elastic piece. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Embodiment 1

[0029] The present embodiment provides a lead frame for chip packaging, as shown in Figs. 1-3As shown, the lead frame comprises a base 1, a placement groove 3 arranged on the base 1 for placing a chip, a cover plate 2 arranged on the base 1 at a position corresponding to above the placement groove 3, a clamping groove 4 arranged on the base 1 and located around the placement groove 3 and arranged in a linear array, a pin 5 clamped in the clamping groove 4, a bonding part 6 arranged on the pin 5 away from the clamping groove 4 for changing the contact area of gold wire welding, and a buffer connecting piece 7 arranged on the pin 5 at a position corresponding to below the bonding part 6 and on the base 1 for welding buffering of the pin 5.

[0030] In use, first, the chip is placed in the placement groove 3 of the base 1, and the placement groove 3 provides accurate positioning and stable support for the chip. Then, the pin 5 is clamped in the clamping groove 4 arranged in a linear array around the placement groove 3, so that the pin 5 is arranged in order around the chip, which prepares for the connection between the chip and the external circuit. Subsequently, when welding, the design of the bonding part 6 enables manual operation or automatic equipment to accurately place the gold wire at the predetermined position according to the positioning of the bonding part 6, ensuring the accuracy and consistency of each welding position, while also increasing the welding contact area with the gold wire, reducing the risk of weld point falling off due to excessive local stress. In addition, during the welding process, when the pin 5 is subjected to high temperature and material thermal expansion stress or mechanical external force, the buffer connecting piece 7 will elastically deform to absorb and buffer the stress, reducing the deformation of the pin 5 caused by stress concentration and reducing the risk of weld cracking. After the gold wire and the pin 5 are welded, the cover plate 2 is covered, and the cover plate 2, the base 1, the pin 5 and other components together form a relatively closed and stable packaging environment.

[0031] Specifically, the bonding part 6 comprises a positioning hole 61 opened at the end of the pin 5 away from the clamping groove 4 for gold wire connection, and a plurality of protrusions 62 arranged in the positioning hole 61.

[0032] The design of the positioning hole 61 provides a clear connection position for the gold wire during the gold wire welding process. During welding, the operator or automatic equipment can accurately place the gold wire at the predetermined position according to the positioning hole 61, which greatly improves the accuracy and consistency of welding and reduces the problem of poor connection caused by welding position deviation. In addition, the design of the plurality of protrusions 62 can increase the welding contact area of the gold wire with the pin 5. Compared with the traditional planar welding method with limited contact area, the protrusions 62 provide more contact points, making the combination between the gold wire and the pin 5 more compact, further improving the stability and reliability of electrical connection.

[0033] In order to ensure the contact area of the protrusion 62 and the gold wire, the protrusion 62 is hemispherical or conical; the design of the hemispherical or conical protrusion 62 can provide more contact points when the gold wire contacts the pin 5, further increasing the welding contact area of the gold wire and the pin 5, making the combination between the gold wire and the pin 5 more compact during welding, dispersing the stress borne by the welding point, and effectively reducing the risk of welding point falling off caused by excessive local stress.

[0034] Further, the buffer connecting piece 7 includes a positioning column 71 arranged at a position below the positioning hole 61 of the pin 5, a positioning insertion hole 72 opened on the base 1 for inserting the positioning column 71, and an elastic piece 73 sleeved on the positioning column 71 and fixedly connected with the positioning column 71 and the pin 5 at both ends;

[0035] When the pin 5 is subjected to high temperature to cause material thermal expansion stress or mechanical external force, the elastic piece 73 will elastically deform, and the elastic deformation of the elastic piece 73 can absorb and buffer these stresses, so that the stress borne by the pin 5 is dispersed and relieved, thereby reducing the deformation of the pin 5 caused by stress concentration and the risk of welding point cracking.

[0036] In addition, in order to ensure buffering, the elastic piece 73 is a spiral spring or a wave spring; the spiral spring and the wave spring have good elastic properties, and when the pin 5 is subjected to thermal expansion or mechanical stress, the spiral spring and the wave spring can effectively absorb and buffer these stresses, reduce the deformation of the pin 5 caused by stress concentration, and reduce the risk of welding point cracking.

[0037] Embodiment 2

[0038] Different from embodiment 1, in order to further ensure the welding effect, the inner wall of the positioning hole 61 is coated with a molten material for covering the connection between the gold wire and the positioning hole 61; during welding, heat melts the molten material, and then the molten material flows and fills the small gap between the gold wire and the positioning hole 61; when the welding is completed and solidified, the molten material tightly covers the connection to form a stable bonding layer, reduces the entry of air and impurities, avoids oxidation and corrosion, reduces the risk of welding point falling off, ensures the stability of electrical connection, and in addition, the molten material can be a solder alloy or a low-melting-point alloy.

[0039] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A lead frame for chip packaging, comprising a base (1), a placement slot (3) arranged on the base (1) for placing a chip, a cover plate (2) arranged on the base (1) at a position above the placement slot (3), a clamping slot (4) arranged on the base (1) and located around the placement slot (3) and distributed in a linear array, and a lead pin (5) clamped in the clamping slot (4). characterized in that The lead frame further comprises a bonding portion (6) arranged on the lead pin (5) at an end away from the clamping slot (4) for changing the contact area of gold wire welding, and a buffer connecting piece (7) arranged on the lead pin (5) at a position below the bonding portion (6) and on the base (1) for welding buffering of the lead pin (5).

2. The lead frame for a chip package of claim 1, wherein: The bonding portion (6) comprises a positioning hole (61) arranged on the lead pin (5) at an end away from the clamping slot (4) for gold wire connection, and a plurality of protrusions (62) arranged in the positioning hole (61).

3. The leadframe for a chip package of claim 2, wherein: The protrusions (62) are hemispherical or conical.

4. The leadframe for a chip package of claim 2, wherein: The inner wall of the positioning hole (61) is coated with a molten material for coating the connection between the gold wire and the positioning hole (61).

5. The leadframe for a chip package of claim 2, wherein: The buffer connecting piece (7) comprises a positioning column (71) arranged on the lead pin (5) at a position below the positioning hole (61), a positioning jack (72) arranged on the base (1) for plug-in connection of the positioning column (71), and an elastic member (73) sleeved on the positioning column (71) and fixedly connected with the positioning column (71) and the lead pin (5) at both ends.

6. The leadframe for a chip package of claim 5, wherein: The elastic member (73) is a spiral spring or a wave spring.

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