CN105938826A - Lead frame for improving layering of frame surface and plastic package body and package body - Google Patents

Abstract

The invention provides a lead frame and a package body that improve the delamination of the frame surface and the plastic package, and are used in the field of semiconductor packaging technology. The lead frame includes at least one base island, and the base island includes a film-locking area and is used for setting chips In the chip area, a plurality of grooves recessed toward the lead frame are arranged on the surface of the locking film area, and the plurality of grooves form a closed figure. The advantage of the present invention is that a groove is provided in the film-locking area, which increases the contact area of the film-locking film between the surface of the lead frame and the molding compound, and the groove forms a closed structure, which "catches" in the form of a claw The molding compound further enhances the grasping force of the grooves on the molding compound in the subsequent packaging, strengthens the bonding strength between the molding compound and the lead frame, improves the strength of the locking film in the locking area, solves the problem of delamination, and improves reliability.

Description

Lead frame and package with improved frame surface and plastic package delamination

technical field

The invention relates to the field of semiconductor packaging, in particular to a lead frame and a packaging body which improve the delamination of the frame surface and the plastic packaging body.

Background technique

As the chip carrier of integrated circuits, the lead frame is a key structural part that realizes the electrical connection between the lead-out end of the chip's internal circuit and the outer lead by means of a bonding gold wire, forming an electrical circuit. It acts as a bridge connecting the external wire. Most of the semiconductor integrated blocks need to use lead frames, which are important basic materials in the electronic information industry.

Fig. 1 is a structural schematic diagram of an existing lead frame, referring to Fig. 1 and Fig. 2, a chip 3 can be welded on the base island 2 of the lead frame 1, and after the chip 3 is welded and wire-bonded, it is plastic-sealed with mold glue, and the package Lines are marked with dotted lines in the figure. Insufficient binding force between the lead frame and the molding compound will cause the separation of the molding compound and the surface of the lead frame on which no chip is placed, resulting in delamination, which will affect the reliability of the product.

Contents of the invention

The technical problem to be solved by the present invention is to provide a lead frame and a package that improve the delamination between the surface of the frame and the plastic package.

In order to solve the above problems, the present invention provides a lead frame that improves the delamination of the frame surface and the plastic package, including at least one base island, and the base island includes a locking film area and a chip area for setting chips. The surface of the film region is provided with a plurality of grooves which are sunken toward the lead frame, and the plurality of grooves form a closed figure.

Further, a plurality of said grooves enclose one or more back-shaped closed figures.

Further, the cross section of the groove is V-shaped, rectangular or dovetail-shaped.

Further, when the groove has a V-shaped cross section, the V-shaped opening angle is 30°-120°.

Further, when the cross section of the groove is V-shaped, the depth of the groove is 0.01-0.038 mm.

Further, when the cross section of the groove is rectangular or dovetail, the depth of the groove is 30%-80% of the thickness of the lead frame.

Further, a plurality of the grooves are arranged at intervals and form a closed figure.

Further, the distance between two adjacent grooves is 0.1-0.5 mm.

Further, the mold locking area is arranged around the chip area or on two adjacent sides of the chip area.

The present invention also provides a package body, including a plastic package body and a lead frame packaged in the plastic package body, and the lead frame is the above-mentioned lead frame.

The advantage of the present invention is that a groove is provided in the film-locking area, which increases the contact area of the film-locking film between the surface of the lead frame and the molding compound, and the groove forms a closed structure, which "catches" in the form of a claw The molding compound further enhances the grasping force of the grooves on the molding compound in the subsequent packaging, strengthens the bonding strength between the molding compound and the lead frame, improves the strength of the locking film in the locking area, solves the problem of delamination, and improves reliability.

Description of drawings

FIG. 1 is a schematic structural view of an existing lead frame;

Fig. 2 is a structural schematic diagram of a first embodiment of a lead frame that improves the delamination of the frame surface and the plastic package in the present invention;

Fig. 3 is a schematic cross-sectional view of the A-A portion in Fig. 2;

4 and 5 are schematic cross-sectional views of the grooves in the second embodiment of the lead frame that improves the delamination of the frame surface and the plastic package according to the present invention;

Fig. 6 is a schematic structural view of a second embodiment of a lead frame that improves the delamination of the frame surface and the plastic package in the present invention;

FIG. 7 is a schematic structural view of a third embodiment of a lead frame that improves the delamination of the frame surface and the plastic package according to the present invention;

Fig. 8 is a schematic structural view of the package of the present invention.

detailed description

The specific implementation of the lead frame and the package provided by the present invention to improve the delamination of the frame surface and the plastic package will be described in detail below with reference to the accompanying drawings. In the present invention, in order to illustrate the structure of the lead frame of the present invention more clearly, only the structure schematic diagram of the base island is schematically marked in the drawings, and the structure of other parts of the lead frame is the same as that of the existing lead frame.

Referring to FIG. 2 and FIG. 3 , in the first embodiment of the present invention to improve the delamination of the frame surface and the plastic package, the lead frame includes at least one base island 30 , and the base island 30 includes a film-locking area 31 And a chip area 32 for setting chips. The membrane-locking area 31 refers to the surface area of the base island 30 except the chip area 32 , and the membrane-locking area 31 and the chip area 32 are schematically marked with dotted lines in FIG. 3 . Further, the mold locking area 31 is arranged around the chip area 32 or on both sides adjacent to the chip area 32. In this specific embodiment, the mold locking area 31 is arranged adjacent to the chip area 32. See FIG. 8 , in the third specific embodiment of the present invention, the film-locking area 31 is arranged around the chip area 32 .

A plurality of grooves 33 recessed toward the lead frame are provided on the surface of the film-locking area 31, and the plurality of grooves 33 form a closed figure. In this specific embodiment, the plurality of grooves 33 are formed end to end. a closed shape. Forming the closed figure can improve the grasping force of the groove 33 on the mold compound in the subsequent packaging, strengthen the bonding strength of the mold compound and the lead frame, improve the film locking strength of the mold locking area 31, solve the problem of delamination, and improve reliability. Moreover, there is a surface of the lead frame without grooves 33 in the center of the closed figure, so as to prevent all the lead frames in the mold locking area from being formed with grooves 33 and maintain the stability of the lead frame. Preferably, a plurality of the grooves 33 enclose one or more back-shaped closed figures.

Referring to FIG. 3 , in this specific embodiment, the cross section of the groove 33 is V-shaped. Preferably, the V-shaped opening angle θ is 30° to 120°, specifically 30°, 40°, 50°, 60°, 70°, 80°, 50°, 100°, 110°, 120° , the depth of the groove is 0.01-0.038mm, specifically 0.01mm, 0.015mm, 0.020mm, 0.025mm, 0.030mm, 0.035mm, 0.038mm. The V-shaped groove 33 can be formed by half-etching or stamping.

Referring to FIG. 4 and FIG. 5 , in the second specific embodiment of the present invention, the cross section of the groove 33 is rectangular (see FIG. 5 ) or dovetail (see FIG. 6 ). Rectangular grooves or dovetail-shaped grooves can be formed by stamping to strengthen the bonding strength between the mold compound and the lead frame, solve the problem of film locking, and achieve better reliability. Preferably, in this specific embodiment, the depth of the groove 33 is 30%-80% of the thickness of the lead frame, so as to maintain the stability of the lead frame while improving the strength of the locking film. Referring to FIG. 6 , a plurality of the grooves 33 are arranged at intervals and form a closed figure. The distance between two adjacent grooves 33 is 0.1-0.5 mm, that is, the distance from the center of one groove 33 to the center of another adjacent groove 33 is 0.1-0.5 mm, specifically 0.1 mm , 0.2mm, 0.3mm, 0.4mm, 0.5mm.

Preferably, the groove 33 with a V-shaped cross-section and the groove 33 with a rectangular or dovetail-shaped cross-section can be mixed and matched. Referring to Fig. 7, in the third specific embodiment of the present invention, in the clamping area 31, the groove 33 of the rectangular or dovetail-shaped cross-section is arranged on the periphery of the groove 33 of the V-shaped cross-section, further strengthening Lock membrane strength. In this specific embodiment, all the grooves 33 enclose a closed figure, instead of the grooves with the same cross-section enclosing a closed figure. In other specific implementation manners of the present invention, the grooves with the same cross section may form a closed figure.

Referring to FIG. 8 , the present invention also provides a package, which includes a plastic package 100 , a lead frame 101 packaged in the plastic package 100 , and a chip 102 arranged on the base island 30 of the lead frame 101 . In the drawing, the plastic package body 100 is marked with dotted lines, and the structure of the lead frame 101 is the same as that of the above-mentioned lead frame. In the present invention, the lead frame 101 is encapsulated by molding glue, and the molding glue is cured to form the plastic package body 100 . Since the mold locking area 31 of the lead frame 101 is provided with the groove 33, the bonding strength between the mold compound and the lead frame 101 is enhanced, the delamination problem is solved, and the package body has better reliability.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be considered Be the protection scope of the present invention.

Claims (10)

1. A lead frame for improving the delamination of the frame surface and the plastic package, comprising at least one base island, characterized in that the base island includes a film-locking area and a chip area for setting a chip, on the surface of the film-locking area A plurality of grooves recessed toward the lead frame are provided, and the plurality of grooves form a closed figure. 2. The lead frame according to claim 1, characterized in that, a plurality of said grooves surround one or more loop-shaped closed figures. 3 . The lead frame according to claim 1 , wherein the cross section of the groove is V-shaped, rectangular or dovetail-shaped. 4 . 4 . The lead frame according to claim 3 , wherein when the cross section of the groove is V-shaped, the opening angle of the V-shaped is 30°-120°. 5 . The lead frame according to claim 3 , wherein when the cross section of the groove is V-shaped, the depth of the groove is 0.01-0.038 mm. 6 . The lead frame according to claim 3 , wherein when the cross section of the groove is rectangular or dovetail, the depth of the groove is 30%-80% of the thickness of the lead frame. 7. The lead frame according to claim 1, wherein a plurality of said grooves are arranged at intervals and form a closed figure. 8 . The lead frame according to claim 7 , wherein the distance between two adjacent grooves is 0.1-0.5 mm. 9 . The lead frame according to claim 1 , wherein the mold locking area is arranged around the chip area or on two adjacent sides of the chip area. 10. A package, comprising a plastic package and a lead frame packaged in the plastic package, characterized in that the lead frame is the lead frame according to any one of claims 1-9.