JPH08306850A - Resin dam type lead frame - Google Patents

Abstract

(57) [Abstract] [Purpose] In a resin dam type lead frame, leakage of sealing resin is prevented in a resin sealing step during an assembly process of a resin sealing type semiconductor device. A protrusion 3 supported on a side surface of the one lead 2 and a protrusion 3 supported on a side surface of the other lead 2 are provided in a resin dam forming region between the one lead 2 and the other lead 2. Resin dam type lead frame 1 with each of them arranged
In, the width W1 of each of the two protrusions 3 is configured to be wider than the coating width W2 of the resin (4A) applied to the resin dam forming region. The gap length L between the two protrusions 3 is made narrower than the width W1 of these protrusions 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin dam type lead frame, and more particularly, to a resin dam forming region between one lead and the other lead, and a protrusion supported on the side surface of the one lead. The present invention relates to a technique effectively applied to a lead frame of a resin dam type in which protrusions supported on the side surfaces of the other lead are arranged.

[0002]

2. Description of the Related Art A lead frame used in a process for assembling a resin-sealed semiconductor device has a dam bar (tie bar) integrated with one lead and the other lead between the leads. The one lead and the other lead are connected to each other via a dam bar. The dam bar is arranged for the purpose of blocking the sealing resin flowing out between the one lead and the other lead in the resin sealing process during the assembly process of the resin sealing type semiconductor device, and is performed in the cutting process after the resin sealing process. It is cut and removed from the lead.

The leads of the lead frame tend to have a fine pitch as the number of pins of the resin-sealed type semiconductor device increases, and the dam bar arranged between one lead and the other lead is extremely cut. It's getting harder. Therefore, for the purpose of eliminating the dam bar cutting process, a resin dam type lead frame in which one lead and the other lead are connected by a resin dam has been developed. Resin dam
It is formed of an insulative resin applied to a resin dam forming region between one lead and the other lead.

Further, in the resin dam type lead frame, for the purpose of preventing film breakage (separation) of the resin applied to the resin dam forming region between one lead and the other lead, for example, Japanese Patent Laid-Open No. Hei 2 As described in JP-A-310955, in a resin dam forming region between one lead and the other lead, a protrusion supported by the side surface of the one lead and a side surface of the other lead are supported. A resin dam type lead frame has been developed in which each of the protrusions is arranged.

[0005]

The present inventor has found the following problems as a result of studying a resin dam type lead frame having the above-mentioned projections.

In the resin dam type lead frame, the width of each of the two protrusions arranged in the resin dam forming region (width in the same direction as the extending direction of the leads) is equal to that of one lead and the other. Since the width of the resin applied between the lead and the lead is smaller than that of the resin applied to the lead, the resin applied to the resin dam forming region adheres to the respective side surfaces of the one lead and the other lead. The resin attached to the side surface of the lead is
Due to the adhesive force (interfacial tension), it flows along the side surface of the lead in the extending direction. For this reason, the width of the resin dam is considerably expanded compared to the coating width of the resin when it is applied, and the film thickness of the resin dam is correspondingly thinner than the plate thickness of the lead, and In the resin encapsulation process, there occurs a problem that the encapsulation resin leaks from between one lead and the other lead.

Further, the width of the central region of the resin when applied is narrowed, and the mechanical strength of the resin dam in this central region is lower than that of the other regions. Therefore, in the resin encapsulation process during the assembly process, a crack occurs in the central region of the resin dam due to the inflow pressure of the encapsulation resin, and the encapsulation resin leaks from between one lead and the other lead. appear.

It is an object of the present invention to provide a resin dam type lead frame capable of preventing leakage of sealing resin in a resin sealing step during an assembly process of a resin sealing type semiconductor device.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

A resin dam in which a protrusion supported by the side surface of the one lead and a protrusion supported by the side surface of the other lead are arranged in a resin dam forming region between the one lead and the other lead. In the lead frame of the method, the width of each of the two protrusions is configured to be wider than the application width of the resin applied to the resin dam formation region.

[0012]

According to the above-mentioned means, the resin applied to the resin dam forming region between the one lead and the other lead is transmitted by the interfacial tension on the respective side surfaces of the one lead and the other lead and spreads there. Since it is possible to prevent the resin dam from flowing in the existing direction, it is possible to prevent the film thickness of the resin dam made of the resin applied to the resin dam formation region from being reduced, and to reduce the mechanical strength of the central region of the resin dam. Can be prevented. As a result, in the resin encapsulation process during the assembly process of the resin encapsulation type semiconductor device, it is possible to prevent leakage of the encapsulation resin due to the reduction in the film thickness of the resin dam, and to reduce the mechanical stress in the central region of the resin dam. It is possible to prevent the sealing resin from leaking due to a decrease in the mechanical strength.

[0013]

EXAMPLES The structure of the present invention will be described below together with examples in which the present invention is applied to a resin dam type lead frame. In addition, in all the drawings for explaining the embodiment,
Those having the same function are designated by the same reference numeral, and the repeated description thereof will be omitted.

(Embodiment 1) FIG. 1 (plan view) shows a schematic structure of a resin dam type lead frame which is Embodiment 1 of the present invention.

As shown in FIG. 1, a resin dam type lead frame 1 has a plurality of leads 2, tabs 5, four tab suspension leads 5A, etc. arranged in a region defined by a frame 6. To do. The resin dam type lead frame 1 is used in an assembly process of a resin-sealed semiconductor device.

The tab 5 is formed, for example, in a square shape in a plan view, and is supported by the frame body 6 via four tab suspension leads 5A integrated with each of the four corners. Semiconductor pellets are mounted on the pellet mounting surface of the tab 5 in the die bonding step during the assembly process.

Each of the plurality of leads 2 is arranged along each side of the outer periphery of the tab 5 and is supported by the frame body 6.
Each of the plurality of leads 2 includes an inner portion 2A which is sealed with a resin sealing body in a resin sealing step in the assembly process and an outer portion 2B which is molded into a predetermined shape in the molding step in the assembly process. Composed. A bonding wire is connected to each of the plurality of leads 2 in a wire bonding step in the assembly process, and is electrically connected to an external terminal (bonding pad) of a semiconductor pellet mounted on the pellet mounting surface of the tab 5. Connected to.

In the lead frame 1, in the resin dam forming region between the one lead 2 and the other lead 2, the protrusion 3 supported on the side surface of the one lead 2 and the side surface of the other lead 2 are supported. Each of the formed protrusions 3 is arranged. The two protrusions 3 are connected to each other by a resin dam 4. The two protrusions 3 and the resin dam 4 block the sealing resin flowing out between the one lead 2 and the other lead 2 in the resin sealing step during the assembly process. The resin dam 4 is formed of an insulating resin (4A) applied to the resin dam forming region between the one lead 2 and the other lead 2. The insulating resin is formed of, for example, a thermoplastic resin added with a solvent.

As shown in FIG. 2 (enlarged plan view of the main part of FIG. 1), the width (width in the same direction as the extending direction of the lead 2) W1 of the protrusion 3 is one lead 2 and the other. Lead 2
It is configured to be wider than the coating width W2 of the resin (4A) applied to the resin dam forming region between and. For example, the width W of the protrusion 3
1 is set to about 0.8 to 1.0 [mm], and the resin (4
The coating width W2 of A) is set to about 0.5 to 0.7 [mm]. In addition, the gap length L between the protrusion 3 supported by one lead 2 and the protrusion 3 supported by the other lead 2 is
The width W2 of the protrusions 3 is narrower than the width W2. For example, the gap length L is set to about 0.1 to 0.2 [mm].

Next, a method of manufacturing the resin dam type lead frame 1 will be described.

First, a lead frame material is prepared. The lead frame material is, for example, an Fe-Ni alloy (for example, Ni
The content is 42 [%] or 50 [%]), Cu, Cu alloy or the like, and is formed with a plate thickness of about 100 to 150 [μm].

Next, the lead frame material is subjected to an etching process using a photolithography technique or a punching process using a pressing device to form the lead 2 having the protrusion 3, the tab 5, and the tab suspension lead 5A. . The lead 2 is supported by the frame body 6, and the tab 5 is supported by the frame body 6 via the tab suspension lead 5A.

Next, based on the coating width W2, the resin is formed in the resin dam forming region between the one lead 2 and the other lead 2.
Apply (4A). The resin (4A) is continuously applied, for example, along the lead arrangement direction in which a plurality of leads 2 are arranged. At this time, 2 which is arranged in the resin dam forming region
Since the width W1 of each of the three protrusions 3 is made wider than the coating width W2 of the resin (4A), the resin (4A) applied to the resin dam forming region has one lead 2 and the other lead 2
It is possible to prevent the resin (4A) from flowing along the side surface of the lead 2 and flowing out in the extending direction thereof due to the interfacial tension without adhering to the respective side surfaces. Further, since the gap length L between the protrusion 3 supported by one lead 2 and the protrusion 3 supported by the other lead 2 is configured to be narrower than the width W1 of these protrusions 3, the resin ( The coating amount of 4A) can be reduced. Since the applied resin (4A) has fluidity, the width of the applied resin (4A) is slightly expanded as compared with the application width W2. The width of the resin (4A) defines the width of the resin dam 4.

Next, in the resin dam forming region, the lead 2 is clamped from above and below with a mold.

Next, heat treatment is performed to vaporize the solvent contained in the resin (4A), and then the resin (4A) is cooled to be cured. By this step, the resin dam 4 that connects the protrusion 3 supported by the one lead 2 and the protrusion 3 supported by the other lead 2 to each other is formed, and the resin dam type lead frame 1 is almost completed. To do.

The lead frame 1 of the thus configured resin dam scheme, for example, QFP (Q uad F lat P ackag
e) Used in the assembly process of resin-sealed semiconductor devices that employ the structure. A schematic structure of a resin-encapsulated semiconductor device adopting the QFP structure is shown in FIG. 3 (a plan view in which the upper part of the resin encapsulant is removed) and FIG. 4 (a perspective view of a main part). In the figure, 2 is a lead, 2A is an inner part of the lead,
2B is an outer part of the lead, 3 is a protrusion, 4 is a resin dam,
5 is a tab, 5A is a tab suspension lead, 7 is a semiconductor pellet, 8 is a bonding wire, and 9 is a resin sealing body.

In this way, the one lead 2 is formed in the resin dam forming region between the one lead 2 and the other lead 2.
In the lead frame 1 of the resin dam method in which the protrusion 3 supported on the side surface of the other lead and the protrusion 3 supported on the side surface of the other lead 2 are arranged, the width W1 of each of the two protrusions 3 is set to The resin (4
By making the width wider than the coating width W2 in A), the resin (4A) applied to the resin dam forming region between the one lead 2 and the other lead 2 has one lead 2, the other due to the interfacial tension. Since it is possible to prevent the leads 2 from flowing along the respective side surfaces and flowing out in the extending direction thereof, it is possible to prevent the film thickness of the resin dam 4 made of the resin (4A) applied to the resin dam forming region from being reduced. Resin dam 4
It is possible to prevent a decrease in mechanical strength of the central region of the. As a result, it is possible to prevent the sealing resin from leaking due to the reduction in the film thickness of the resin dam 4 in the resin sealing step during the assembly process of the resin sealed semiconductor device.
It is possible to prevent the sealing resin from leaking due to a decrease in the mechanical strength of the central region of the resin dam 4.

Further, the protrusion 3 supported by one lead 2
And the gap length L between the protrusion 3 supported by the other lead 2
Since the width of the protrusions 3 is narrower than the width W1 of the protrusions 3, the coating amount of the resin 4A can be reduced.
Corresponding to this, the manufacturing cost of the resin dam type lead frame 1 can be reduced.

(Embodiment 2) FIG. 5 (plan view of a main portion) shows a schematic structure of a resin dam type lead frame which is Embodiment 2 of the present invention.

As shown in FIG. 5, the resin dam type lead frame 1 has a plurality of leads 2 and tabs 5 arranged in an area defined by a frame 6. This resin dam type lead frame 1 is used in an assembly process of a resin-sealed semiconductor device adopting a QFP structure.

Each of the plurality of leads 2 is supported by the frame body 6, and the inner portion 2A sealed by the resin sealing body in the resin sealing step in the assembly process and the gull wing in the molding step in the assembly process. The outer portion 2B is formed into a shape. Outer part 2 of this lead 2
Since B is formed into a gull wing shape in the forming step during the assembly process, the outer bent portion 2B has the first bent portion 2B1 and the second bent portion 2B2, respectively.

In the lead frame 1, in the resin dam forming region between the one lead 2 and the other lead 2, the protrusion 3 supported by the side surface of the one lead 2 and the side surface of the other lead 2 are supported. Each of the formed protrusions 3 is arranged. The two protrusions 3 are connected to each other by a resin dam 4. The two protrusions 3 and the resin dam 4 block the sealing resin flowing out between the one lead 2 and the other lead 2 in the resin sealing step during the assembly process. The resin dam 4 is formed of an insulating resin (4A) applied to the resin dam forming region between the one lead 2 and the other lead 2. The insulating resin (4A) is formed of, for example, a thermoplastic resin added with a solvent.

The width (width in the same direction as the extending direction of the lead 2) W1 of the protrusion 3 is the resin applied to the resin dam forming region between the one lead 2 and the other lead 2.
It is configured to be wider than the coating width W2 of (4A). The gap length L between the protrusion 3 supported by one lead 2 and the protrusion 3 supported by the other lead 2 is narrower than the width W2 of these protrusions 3.

A protrusion 3 supported by the one lead 2;
Each of the projections 3 supported by the other lead 2 includes a first bent portion 2B1 and a second bent portion 2B1 of the inner portion 2A of the one lead 2 and the outer portion 2B of the other lead 2.
It is extended to a region between the bent portion 2B2. The resin dam type lead frame 1 of this embodiment is used.
A resin-sealed semiconductor device having a QFP structure using is shown in FIG. 6 (perspective view of main part).

In this way, the protrusion 3 supported by one lead 2 and the protrusion 3 supported by the other lead 2 are respectively
Inner portions 2 of one lead 2 and the other lead 2 respectively
The first bent portion 2B of each outer portion 2B from A
Since the mechanical strength of the outer portion 2B of the lead 2 can be increased by extending it to the region between the first bent portion 2B2 and the first bent portion 2B2, it is possible to improve the mechanical strength of the resin-sealed semiconductor device using the QFP structure. After the lead 2 is separated from the frame body 6 in the cutting step, the outer portion 2B of the lead 2 can be prevented from being deformed due to contact with other things, and the outer portion 2B of the lead 2 can be formed into a gull wing shape. In the process, defective molding of the outer portion 2B of the lead 2 can be reduced.

As described above, the inventions made by the present inventor are
Although the present invention has been specifically described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention.

[0037] For example, the present invention is not limited to the lead frame of the resin dam scheme used in the manufacturing process of the resin-sealed semiconductor device of the QFP structure, SOJ (S mall O ut- l
ine J -type lead Package) structure, TSOP (T hin S ma
ll O ut-line P ackage) structure, DIP (D ual I n- line
The present invention can be applied to all resin dam type lead frames used in the manufacturing process of resin-sealed semiconductor devices such as package structures.

[0038]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

It is possible to provide a resin dam type lead frame capable of preventing the sealing resin from leaking in the resin sealing step during the assembly process of the resin sealing type semiconductor device.

[Brief description of drawings]

FIG. 1 is a plan view of a resin dam type lead frame that is Embodiment 1 of the present invention.

FIG. 2 is an enlarged plan view of a main part of FIG.

[Fig. 3] Q using the resin dam type lead frame
The top view which removed the upper part of the resin sealing body of the resin sealing type semiconductor device of FP structure.

FIG. 4 is a perspective view of a main part of the resin-sealed semiconductor device having the QFP structure.

FIG. 5 is a plan view of a main portion of a resin dam type lead frame that is Embodiment 2 of the present invention.

[Fig. 6] Q using the resin dam type lead frame
FIG. 3 is a perspective view of a main part of a resin-encapsulated semiconductor device having an FP structure.

[Explanation of symbols]

1 ... Lead frame of resin dam method, 2 ... Lead, 2A
… Lead inner part, 2B… Lead outer part, 3
... protrusions, 4 ... resin dam, 5 ... tab, 5A ... tab suspension lead, 6 ... frame body, 7 ... semiconductor pellet, 8 ... bonding wire, 9 ... resin encapsulant.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Nakamura 5-20-1 Kamimizuhoncho, Kodaira-shi, Tokyo Hitachi Ltd. Semiconductor Division (72) Inventor Yoshihiko Yamaguchi Yonebashi, Yanazawa, Yonezawa, Yamagata Prefecture 3274 Hitachi Yonezawa Electronics Co., Ltd. in East 3

Claims (4)

[Claims] 1. A protrusion supported by a side surface of the one lead and a protrusion supported by a side surface of the other lead are arranged in a resin dam forming region between the one lead and the other lead. In resin dam type lead frame,
A resin dam-type lead frame, wherein the width of each of the two protrusions is wider than the width of the resin applied to the resin dam forming region. 2. The lead frame of the resin dam method according to claim 1, wherein the gap length between the two protrusions is narrower than the width of these protrusions. 3. The resin dam method according to claim 1, wherein each of the two protrusions is connected to each other by a resin dam made of a resin applied to the resin dam forming region. Lead frame. 4. Each of the two leads includes an inner portion sealed with a resin sealing body and an outer portion molded in a gull wing shape, and each of the two protrusions includes:
4. The extension of each of the two leads from the inner portion to the region between the first bent portion and the second bent portion of the outer portion of each of the two leads. The lead frame of the resin dam method according to any one of the items.