CN104064485B - The wire solder joint intensifying method of semiconductor device - Google Patents

Abstract

The invention provides a wire welding point strengthening method of a semiconductor device, comprising: opening at least two through holes in the welding area of the lead wire in the frame; welding wires in the welding area, and the welding positions of the wires are located in two adjacent Between the through holes; a locking card is provided in the through holes to tightly clamp the wires and the lead wires in the frame together. In the above scheme provided by the present invention, the wires welded to the lead wires in the frame are firmly clamped on the lead wires in the frame through the locking clip, which effectively avoids the situation that the wires and the lead wires in the frame are peeled off, and strengthens the connection between the wires and the wires in the frame. The electrical connection of the leads improves the reliability of semiconductor devices, especially semiconductor power devices.

Description

Wire solder joint strengthening method for semiconductor devices

technical field

The invention relates to the technical field of semiconductor device packaging, in particular to a method for strengthening solder joints of semiconductor devices.

Background technique

In the packaging process of semiconductor power devices, metal wires such as aluminum wires and aluminum strips are mainly used to achieve effective welding between the chip and the inner leads of the lead frame to meet the high electrical performance requirements such as high voltage and high current when the power device is working. . The schematic diagram of the packaging structure is shown in Figures 1-4, including: a frame carrier 1 for heat dissipation and carrying the chip 2; a frame inner lead 3 for electrical connection; an aluminum alloy for connecting the chip 2 and the frame inner lead 3 wire 4 and/or aluminum tape 5; die-mounting glue 6 for bonding the chip 2 to the frame loading table 1.

Due to the high internal temperature of the device when the power product is working, and sometimes the external working environment is relatively harsh, it is required that the welding reliability between the aluminum wire 4 and/or aluminum strip 5 and the lead wire 3 in the frame is relatively high, but the reliability of the power product During medium and practical applications, the aluminum wire 4, the aluminum strip 5 and the inner lead wire 3 of the frame will still be peeled off due to thermal stress, moisture, fluctuations in process quality control, etc., resulting in failure of the electrical parameters and functions of the product. In response to this failure, although the industry has improved welding reliability through bonding parameters, steel nozzle structure, materials, and process layered control, it has not been able to effectively avoid the gap between the aluminum wire 4, the aluminum strip 5, and the lead wire 3 in the frame. peel off.

Contents of the invention

A brief overview of the invention is given below in order to provide a basic understanding of some aspects of the invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or critical parts of the invention nor to delineate the scope of the invention. Its purpose is merely to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

The invention provides a method for strengthening solder joints of semiconductor devices, comprising:

Open at least two through holes in the soldering area of the lead in the frame;

Welding wires in the welding area, the welding position of the wires is located between two adjacent through holes;

A locking card is provided in the through hole to tightly clamp the wire and the lead wire in the frame together.

In the above scheme provided by the present invention, the wire welded to the lead wire in the frame is firmly clamped on the lead wire in the frame by locking the card, which effectively avoids the situation that the wire and the lead wire in the frame are peeled off, and strengthens the connection between the wire and the lead wire in the frame. The electrical connection of the leads improves the reliability of semiconductor devices, especially semiconductor power devices.

Description of drawings

The above and other objects, features and advantages of the present invention will be more easily understood with reference to the following description of the embodiments of the present invention in conjunction with the accompanying drawings. The components in the drawings are only to illustrate the principles of the invention. In the drawings, the same or similar technical features or components will be denoted by the same or similar reference numerals.

Fig. 1 is the structural representation of prior art;

Fig. 2 is the A-A sectional view of Fig. 1;

Fig. 3 is a structural schematic diagram of another prior art;

Fig. 4 is the B-B sectional view of Fig. 3;

FIG. 5 is a schematic diagram of a strengthened structure of a wire solder joint of a semiconductor device obtained by a method according to an embodiment of the present invention;

Fig. 6 is the C-C sectional view of Fig. 5;

Fig. 7 is a schematic diagram of installing the locking card on the lead wire in the frame in the embodiment of the present invention;

Fig. 8 is a schematic diagram of the lock card installed on the lead wire in the frame in the embodiment of the present invention.

detailed description

Embodiments of the present invention will be described below with reference to the drawings. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that representation and description of components and processes that are not related to the present invention and known to those of ordinary skill in the art are omitted from the drawings and descriptions for the purpose of clarity.

An embodiment of the present invention provides a method for strengthening solder joints of semiconductor devices, including:

Open at least two through holes in the soldering area of the lead in the frame;

Solder the wire in the welding area, and the welding position of the wire is located between two adjacent through holes;

A locking card is provided in the through hole to tightly clamp the wire and the lead wire in the frame together.

Wherein, the number of through holes is determined by the number of wires to be soldered, and at least one through hole is ensured on both sides of each wire. For example, four through holes may be used to reinforce two wires, and independent through holes are provided on both sides of each wire. Of course, three through holes can also be used to reinforce the two wires, that is, a through hole located in the middle can be shared. In the case of sharing a through hole, the shared through hole can use a larger-sized hole or a long hole.

In the above scheme provided by the present invention, the wire welded to the lead wire in the frame is firmly clamped on the lead wire in the frame by locking the card, which effectively avoids the situation that the wire and the lead wire in the frame are peeled off, and strengthens the connection between the wire and the lead wire in the frame. The electrical connection of the leads improves the reliability of semiconductor devices, especially semiconductor power devices.

It should be noted that if the welding area is close to the edge of the lead in the frame, at least one through hole is provided on the edge, and this through hole can be regarded as a groove penetrating the lead in the frame. The shape of the groove is, for example but not limited to, a semicircle.

As shown in Fig. 5 and Fig. 6, the wire solder joint strengthening structure of the semiconductor device obtained by the method of the embodiment of the present invention includes a lead wire 3 in the frame, the surface of the lead wire 3 in the frame has a welding area, and the welding area is welded with a wire. It includes a locking card; both sides of the wire are provided with through holes through the lead wires in the frame; the locking card includes a pressing part, and a locking part is suspended from the pressing part, and the pressing part is pressed on the wire, and the locking part passes through the through hole, and the card The side of the lead facing away from the wire within the frame.

Specifically, the locking portion has an overhanging end far away from the pressing portion, and the overhanging end is bent over the side of the lead wire 3 in the frame that is away from the wire. Wherein, the locking part may be a metal strip or a metal sheet that hangs outward from the pressing part. The end of the metal strip or the metal sheet away from the pressing part is the overhanging end. After the metal strip or metal sheet passes through the through hole, its overhanging end is bent so that it is tightly pressed against one side of the lead wire 3 in the frame. Adopting this structure has high connection reliability, easy realization of the connection process, and low cost.

In actual use, there are two locking parts hanging outwards in the same direction on the pressing part, and the hanging ends of the two locking parts are bent towards each other. Opposite bending takes up little space on the side of the lead in the frame, so the space on the side of the lead in the frame can be utilized as much as possible. As one of the preferred implementation manners, the locking card may adopt a straight-sided C-shaped structure in which each side is generally straight.

In actual use, the wire can be aluminum wire 4 , aluminum strip 5 or a combination of aluminum wire 4 and aluminum strip 5 .

When the wire adopts the aluminum wire 4, the side of the aluminum wire 4 away from the lead wire 3 in the frame has an arc-shaped protrusion, and the pressing part has an arc-shaped arch, and the arc-shaped protrusion matches the arc-shaped arch, so that the locking card 7 and the arc-shaped arch are matched. The wire contact is closer, which improves the stability of the connection between the locking card 7 and the aluminum wire 4 . Taking the straight-edge C-shaped structure of the locking card 7 as an example, the generally linear part facing the opening of the locking card 7 is the pressing part 9, and an arc-shaped arch is provided in the middle of the generally linear part. The two sides extend downwards respectively to form a locking part 10, and the overhanging end of the locking part 10 is bent and stuck on the lower side of the lead wire 3 in the frame.

In the process of clamping the aluminum wire 4 and the lead wire in the frame together through the locking clip 7, referring to Fig. 7 and Fig. 8, a spacer 13 is provided under the lead wire 3 in the frame, and the upper surface of the spacer 13 is provided with a through hole 15 Connected arc groove 14, arc groove 14 is shifted from the bottom of one of two adjacent through holes to the other, and the locking card 7 is pushed down by the pushing mechanism 16, and the overhanging end of the locking part contacts the arc. When the groove 14 is reached, the propulsion mechanism continues to move downwards, so that the overhanging end of the locking card 7 is bent along the arc groove 14 and stuck on the side of the lead wire 3 in the frame, so that the aluminum wire 4 and the lead wire 3 in the frame are tightly clamped. Hoop together.

In addition, the overhanging ends of the two locking parts can also be bent opposite to each other. When this structure is used to implement the method, a spacer is provided under the lead in the frame, and the upper surface of the spacer is provided with an arc-shaped groove communicating with the through hole, and the arc-shaped groove is from the bottom of one of the two adjacent through holes to the other. One deviates from, the locking card is pushed downwards by the pushing mechanism, and when the overhanging end of the locking part touches the arc groove, the pushing mechanism continues to move downward, impelling the overhanging end of the locking card 7 to bend back along the arc groove and Clamp on the side of the frame inner lead to tightly clamp the aluminum wire and the frame inner lead together.

When the wire is adopted as the aluminum strip 5, the side of the pressing portion 11 facing the aluminum strip 5 is a plane, and the plane matches the surface of the aluminum strip 5, so that the locking card 8 is in closer contact with the wire, and the contact between the locking card 8 and the aluminum strip is improved. 5 The stability of the connection. Taking the straight-sided C-shaped structure of the locking card 8 as an example, the straight line facing the opening of the locking card 8 is the pressing portion 11 . On both sides of the pressing part 11 , locking parts 12 are respectively extended downwards, and the overhanging ends of the locking parts 12 are bent and locked on the lower side of the lead wire 3 in the frame. The process of clamping the aluminum strip 5 and the lead wire 3 in the frame through the locking card is the same as the process of clamping the aluminum wire 4 and the lead wire 3 in the frame through the locking card, and will not be repeated here.

In actual use, the wire solder joint strengthening structure of the semiconductor device obtained by the method of the embodiment of the present invention also includes a frame loading table 1, on which the chip 2 is fixedly connected, and the chip 2 can be fixed by using the chip mounting adhesive 6. Adhesive on the frame loading table 1, the end of the wire away from the lead wire 3 in the frame is welded to the chip 2.

In addition, it should be noted that, in implementing this method, the lead wires and the lead wires in the frame can be tightened by locking the clips, and the spacer 13 and the propulsion mechanism 16 can be arranged on the aluminum wire or aluminum ribbon bonding machine, and the aluminum wire or aluminum ribbon can be bonded Then implement the above method directly on the aluminum wire or aluminum strip bonding machine. Of course, the pad 13 and the propulsion mechanism 16 can also be made as separate equipment. After the aluminum wire or the aluminum strip is bonded, the frame is taken off from the aluminum wire or the aluminum strip bonding machine, and then the pad 13 and the propelling mechanism 16 can be used to advance the frame. The above-mentioned method is implemented on the equipment formed by the mechanism 16.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (8)

1. A wire solder joint strengthening method for a semiconductor device, characterized in that it comprises: Open at least two through holes in the soldering area of the lead in the frame; Welding wires in the welding area, the welding position of the wires is located between two adjacent through holes; A locking card is provided in the through hole to tightly clamp the wire and the lead wire in the frame together. The locking card includes a pressing part, and a locking part hangs outward from the pressing part. The pressing part The part is pressed on the wire, the locking part passes through the through hole, and is stuck on the side of the lead wire in the frame away from the wire; A groove is provided at the edge of the lead in the frame, and the locking part passes through the lead in the frame through the groove. 2 . The method for strengthening solder joints of semiconductor devices according to claim 1 , wherein the locking portion has an overhanging end far away from the pressing portion, and the overhanging end is bent over the lead in the frame. The side facing away from the wire. 3. The wire solder joint strengthening method of a semiconductor device according to claim 2, characterized in that two locking parts are suspended outwards in the same direction on the pressing part, and the overhanging ends of the two locking parts are Bend towards each other. 4. The method for strengthening solder joints of semiconductor devices according to claim 3, wherein a spacer is provided under the lead in the frame, and the upper surface of the spacer is provided with an arc that communicates with the through hole. The arc-shaped slot deviates from the bottom of one of the two adjacent through holes to the other, and pushes the locking card downward so that the overhanging end of the locking card bends along the arc-shaped slot. Fold and snap the sides of the leads inside the frame. 5. The wire solder joint strengthening method of a semiconductor device according to claim 2, characterized in that two locking parts are suspended outwards in the same direction on the pressing part, and the overhanging ends of the two locking parts are Bend away from each other. 6. The method for strengthening solder joints of semiconductor devices according to claim 5, characterized in that a spacer is provided under the lead in the frame, and the upper surface of the spacer is provided with an arc that communicates with the through hole. The arc-shaped slot deviates from the bottom of one of the two adjacent through holes to the other, and the locking card is pushed downward so that the overhanging ends of the locking card face away from each other along the arc-shaped slot. Bend and snap the sides of the leads inside the frame. 7. The method for strengthening solder joints of semiconductor devices according to any one of claims 1-4, wherein the wire is an aluminum wire, and the side of the aluminum wire away from the lead in the frame has an arc shape The pressing part has an arc-shaped arch, and the arc-shaped protrusion matches with the arc-shaped arch. 8. The wire solder joint strengthening method of a semiconductor device according to any one of claims 1-4, wherein the wire is an aluminum strip, and the side of the pressing portion facing the aluminum strip is a plane, so Said plane matches the surface of said aluminum strip.