JPH09129796A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable semiconductor device with a package which can eliminate any non-resin-filled part resulting from interruption of resin flow even when vertical parts of leads are present when a semiconductor chip is clamped from its upper and lower sides. SOLUTION: In the semiconductor device, tip ends 2a and 3a of leads of a lead frame are connected to respective electrode terminals of upper and lower faces of a semiconductor chip 1 directly or through wide intermediate leads, and vicinities of the connected parts are molded with resin for a package 4. A lead 3 or a vertical part 3b of the intermediate lead bent in a direction of cussing the top of the semiconductor chip is provided with a through hole 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called wipe-onless type semiconductor device in which lead terminals directly sandwich a semiconductor chip from above and below without wire bonding with a gold wire or the like. More specifically, in a so-called Wybonless type semiconductor device, which often occurs when the semiconductor chip is formed by sandwiching the semiconductor chip from the upper and lower surfaces, a lead frame surface of one of the leads is formed in a direction intersecting the frame surface. The present invention relates to a semiconductor device in which a bent vertical portion prevents a resin flow from being interrupted at the time of molding and eliminates an unfilled portion of resin to improve quality and reliability.

[0002]

2. Description of the Related Art Recently, in a semiconductor device having a small number of electrode terminals such as a diode and a transistor, a bump electrode is formed on the electrode terminal by forming a bump electrode without connecting the electrode terminal of the semiconductor chip to the lead by wire bonding. There is adopted a method of connecting the tips of the electrodes directly or by soldering through a wide intermediary lead.

FIG. 4 shows a cross sectional explanatory view of an example of such a semiconductor device. In FIG. 4, reference numeral 1 is a semiconductor chip having a diode formed therein, 2 is one lead having a die pad 2a formed at the tip thereof, and 3 is the tip portion 3a of which is higher than the surface A of the lead frame and is subjected to a forming process. , Another lead having a vertical portion 3b bent in a direction perpendicular to the surface A of the lead frame. Reference numeral 4 denotes a package that covers and protects the semiconductor chip 1 and the tip portions 2a, 3a of the leads, and is formed by pouring resin in a molding die.

The semiconductor chip 1 is die-bonded onto the die pad 2a of the lead frame with a conductive adhesive such as solder paste (cream solder), and the electrode terminals on the upper surface of the semiconductor chip 1 are formed on the electrode terminals with silver or the like. It is connected to the lead 3 by being directly soldered to the tip portion 3a of the lead 3 via the formed bump electrode (not shown). To solder the lead 3 to the tip 3a, the tip 3a of the lead 3 is processed to be higher than the surface A of the frame by a roller mechanism or the like, and then that portion is laid horizontally on the upper surface of the semiconductor chip 1 so that the bump electrode and the tip are formed. It is carried out by bringing the part 3a into contact with it and passing it through a heating furnace.

The package 4 is formed after each electrode terminal and the tip of the lead are connected by soldering or the like.
This is done by placing each semiconductor chip in the cavity of the molding die in the state of the lead frame, and pouring the resin into each cavity to harden it. In many cases, the resin is injected into the cavity at the portion indicated by arrow B in FIG.

[0006]

When the semiconductor chip 1 is, for example, a two-terminal diode, the size of the package is as small as length L × width W × height H of about 5 mm × 3 mm × 2 mm, and it is formed. The width of the lead 3 is 1.5
About 2 mm. Therefore, the width of the lead 3 occupies about 50 to 66% with respect to the lateral length of the cavity of about 3 mm. Therefore, when the resin is injected into the cavity from the direction of the arrow B, the resin is insufficiently injected into the portion on the back side D of the vertical portion 3b of the lead 3, and there is a case where the resin is not completely filled. As a result, package 4
There is a problem that the adhesion between the lead 2 and the lead 2 is poor, and moisture penetrates to lower the reliability.

The present invention solves such a problem, and a vertical portion of a lead (a portion bent so as to have a component perpendicular to the surface of the lead frame) when the semiconductor chip is sandwiched from both upper and lower surfaces. It is an object of the present invention to provide a semiconductor device capable of obtaining a highly reliable package in which the resin flow is blocked and the unfilled portion of the resin does not exist even in the presence of the above.

[0008]

According to the present invention, there is provided a semiconductor device comprising:
A semiconductor device in which a tip portion of a lead of a lead frame is directly or via an intermediary lead having a width connected to each of the electrode portions on the upper and lower surfaces of a semiconductor chip, and the periphery thereof is molded with a packaging resin. A through hole is provided in a vertical portion of the lead or the intermediate lead, which is a portion where the lead or the intermediate lead is bent in a direction intersecting with the upper surface of the semiconductor chip.

When the leads formed from the package formed of the resin are provided on the same plane substantially parallel to the bottom surface of the package, vertical portions of the leads are likely to occur in the package. Therefore, the effect is particularly large.

Here, the same plane substantially parallel to the bottom surface of the package 4 means that the left and right leads led out from both sides of the package are at substantially the same height from the bottom surface of the package, and the semiconductor device is mounted on a printed circuit board or the like. In this case, if the leads are not formed at all, or if they are symmetrically formed, it means that they are derived at the same height from the bottom surface where they can be mounted without any special forming process.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a semiconductor device of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of an embodiment of a semiconductor device of the present invention, FIG. 2 is a sectional explanatory view thereof, a view in which a resin injection port is on the opposite side, and FIG. 3 is a sectional explanatory view of another structure. is there. FIG.
In order to make the characteristic part of the present invention easy to understand,
The package is removed and only the outline is shown by the dash-dotted line.

The example shown in FIG. 1 is an example of a two-terminal diode in which one electrode terminal is formed on each of the upper and lower surfaces of the semiconductor chip as in FIG. 1-2,
The same parts as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

In the present invention, in order to connect to the electrode portion (electrode terminal) on the upper surface of the semiconductor chip 1, the tip portion 3a of the lead 3 is formed upward by a forming process so that it is perpendicular to the surface of the lead frame (right-angle component). Is characterized in that the through hole 5 is provided in the vertical portion 3b that is bent in the direction having the direction (that is, the direction intersecting the upper surface of the semiconductor chip).

As a result, after connecting the respective electrode terminals of the semiconductor chip 1 and the leads to each other, when the semiconductor chip 1 and its periphery are molded with resin to form the package 4, the inside of each cavity of the molding die is molded. Even if the semiconductor chip 1 portion of the lead frame is set and the resin is injected from the direction of arrow B in FIG. 1 or the direction of arrow C in FIG. 2 (the resin injection port is opposite to that in FIG. 1), the lead 3 is vertically The resin flows into the cavity through the through hole 5 provided in the portion 3b. Therefore, the resin does not flow into the back side D of the vertical portion 3b of the lead 3 with respect to the resin injection port of each cavity of the molding die, and there is no unfilled portion of the resin.

Especially in the structure shown in FIG. 2, the back side D
Although the resin is apt to be insufficiently flowed into the resin, such a defective flow is prevented according to the present invention. Therefore, the adhesion at the boundary between the resin and the lead 2 or 3 on the side opposite to the resin injection port is improved, moisture can be prevented from entering, and the reliability of the semiconductor device can be improved.

Conventionally, in order to prevent the lead of the lead frame and the resin for packaging from being separated, as shown in FIG. 4, the lead 2 on the surface A of the lead frame has a through hole 11.
Is provided, and the lead 2 is sandwiched by the resin penetrating the through hole 11 from both sides of the lead 2 to sandwich the lead 2, thereby preventing peeling due to a difference in thermal expansion due to a heat cycle. However, as shown in FIG. 1, in order to improve the flow of the resin, the idea of providing the through hole 5 in the vertical portion 3b of the lead 3 which is bent in a direction perpendicular to the surface of the lead frame is not considered.

As in the present invention, since the through hole 5 is provided in the vertical portion 3b of the lead, which is a portion bent in the direction perpendicular to the surface of the lead frame, the through hole 5 is provided so that the resin is molded into the cavity. The position of the resin injection port is not restricted, the degree of freedom in designing the molding die is improved, and the quality and reliability of the manufactured semiconductor device are significantly improved.

In the example shown in FIG. 1 or 2, the leads 2 and 3 led out from the package 4 are bent toward the bottom surface of the package, and the tips of the leads are substantially flush with the bottom surface of the package 4. The shape of the surface mount is such that it is bent, and is mounted on a printed circuit board or the like and soldered, but the shape of the external lead is not limited to this example. That is, it may be a so-called gull wing shape in which it is bent downward so that it can be inserted into a through hole of a printed circuit board or the like and soldered, or it is bent downward and then further bent outward. However, it is preferable in terms of mounting work that the leads 2 and 3 led out of the package are formed so as to protrude from the same plane that is substantially parallel to the bottom surface of the package 4. In such a case, and in the semiconductor chip 1 In the case of a structure in which the leads are sandwiched from both the upper and lower sides, the effect of the present invention is likely to appear because there is a vertical portion that is a portion that is bent in a direction perpendicular to the lead frame surface by the forming process of the leads.

Further, in the structure shown in FIGS. 1 and 2, the leads 2 and 3 are led out from substantially the center of the package 4. However, as shown in FIG. The structure in which 3 is led out from the bottom surface of the package 4 may be used. With such a structure, the leads 2 and 3 led out of the package 4 after molding can be surface-mounted without forming.
It is efficient. In the structure shown in FIG. 3, the same parts as those in FIGS. In FIG. 3, the die pad 2a is lifted up from the surface A of the lead frame, but this is to cover the lower side of the die pad 2a with resin. In addition, 1a is a bump electrode provided on the electrode terminal, 6 is a conductive adhesive, and 7 is a bump electrode 1a and the tip 3a of the lead 3.
It is a solder that electrically connects with.

In each of the above-mentioned examples, a diode having two terminals was used as the semiconductor chip 1. However, the semiconductor chip 1 is not limited to this, and a multi-terminal diode having two or more diodes formed in one chip. The same applies to the case of, and the case of transistors and ICs.

Further, although the through hole 5 is shown as a circular example, the shape and size are not limited to this, and may be set freely according to the width and length of the lead.

Further, the tip end 3a of the lead 3 of the lead frame was directly processed and connected to the bump electrode of the semiconductor chip, but an intervening lead having a bent width is interposed between the bump electrode and the lead 3. Even if
A similar through hole may be provided in the vertical portion of the intermediary lead.

[0024]

As described above, according to the present invention,
In a semiconductor device in which the tips of the leads are connected to the upper and lower surfaces of the semiconductor chip, and the periphery of the leads is molded with resin, in the vertical part that is the part that is bent in the direction perpendicular to the surface of the lead frame by the forming process of the leads in the package. Since the through holes are provided, the resin is not blocked by the vertical portions of the leads regardless of the direction in which the resin is injected during molding, and the problem of resin unfilling does not occur.

As a result, the degree of freedom in designing the molding die is improved, defective filling of resin is eliminated, yield is improved, and cost is reduced. Further, since the resin is completely filled, the adhesion between the resin and the lead is improved, it is possible to prevent water from entering, and the quality and reliability are greatly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional explanatory view of a semiconductor device having the same structure as FIG. 1 but different resin injection ports.

FIG. 3 is a cross-sectional explanatory view of another structure of the semiconductor device of the present invention.

FIG. 4 is an explanatory diagram of an example of a conventional semiconductor device.

[Explanation of symbols]

 1 Semiconductor Chip 2, 3 Leads 3a Tip 3b Vertical 4 Package 5 Through Hole

Claims (2)

[Claims] 1. A semiconductor device in which tip portions of leads of a lead frame are directly or via intermediate leads having a width connected to respective electrode portions on the upper and lower surfaces of a semiconductor chip, and the periphery thereof is molded with a packaging resin. And
A semiconductor device in which a through hole is provided in a vertical portion of the lead or the intermediary lead, which is a portion where the lead or the intermediary lead is bent in a direction intersecting with an upper surface of the semiconductor chip. 2. The semiconductor device according to claim 1, wherein each lead led out from the package formed of the resin is provided so as to be flush with the bottom surface of the package.