JP2002110885A - Frame for resin-sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent solder from being fused by suppressing heat generation in dicing and to eliminate wire peeling in wire bonding as to a frame having an array of lead frames used for batch molding type semiconductors. SOLUTION: The frame is used to obtain the individual resin-sealed type semiconductor devices by molding semiconductor elements together at a time after arraying the semiconductor elements on lead frames 11 and performing wire bonding, and cutting grid leads L with a dicing saw; and the grid leads L is wide enough to cut it twice with the dicing saw. The friction in the dicing is reduced by using a narrow-width dicing saw and the heat generation is suppressed to prevent solder from being fused. A mesh type clamper which presses even the grid leads is usable and the resonance in the wire bonding is suppressed to eliminate the wire peeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a resin-encapsulated semiconductor device in which a semiconductor element is mounted on a lead frame and an outer periphery thereof, particularly, an upper surface side of the semiconductor element is sealed with a mold resin. It is.

[0002]

2. Description of the Related Art In recent years, with the increase in the density of substrate mounting, there has been a demand for smaller and thinner semiconductor products mounted on the substrate. LSIs are also strictly required to reduce the number of chips and reduce the size and weight of packages due to high integration.
(Chip Size Package) is spreading rapidly. In particular, in the development of thin semiconductor products using a lead frame, a single-sided resin-sealed semiconductor device in which a semiconductor element is mounted on a lead frame and the mounting surface is sealed with a mold resin has been developed. I have.

FIG. 1 is a cross-sectional view showing an example of a resin-sealed semiconductor device, and FIG. 2 is a plan view showing the sealing resin as seen through. The resin-encapsulated semiconductor device shown in these figures includes a semiconductor element 4 mounted on a die pad 3 supported by suspension leads 2 of a lead frame 1, an electrode on the upper surface of the semiconductor element 4, and a terminal of the lead frame 1. A thin metal wire 6 electrically connected to the portion 5, and a sealing resin 7 for sealing an area surrounding the semiconductor element 4 including the upper side of the semiconductor element 4 and the lower side of the die pad 3 are provided. This resin-encapsulated semiconductor device is a non-lead type in which a so-called outer lead does not protrude, and both an inner lead and an outer lead are integrated as a terminal portion 5. The lead frame 1 used is half-etched so that the die pad 3 is located above the terminal portion. With such a step, the sealing resin 7 can be present below the die pad 3, and a thin type is realized even if the die pad is not exposed.

In the above-described non-lead type resin-encapsulated semiconductor device, since the size of a semiconductor element is small, a matrix type manufactured by arranging a plurality of rows in the width direction of one frame is mainly used. . And recently,
In response to demands for cost reduction, there has been a shift from the individually molded type as shown in FIG. 3 to the collectively molded type as shown in FIG.

In the individual mold type, as shown in FIG. 3A, small mold cavities C of a small size are provided in one frame F in a divided state.
After the molding, the semiconductor device S shown in FIG. That is, a semiconductor element is mounted on a die pad of a lead frame using silver paste or the like, and after performing wire bonding, individual semiconductor elements are individually molded and then punched out as individual semiconductor devices using a mold.

In the collective mold type, as shown in FIG. 4A, several large-sized mold cavities C are provided in one frame F. After arranging a large number of semiconductor elements in a matrix and molding the semiconductor elements collectively, the portions of the grid leads L of each lead frame are cut with a dicing saw to obtain a semiconductor device S shown in FIG. What you get. That is, a semiconductor element is mounted on a die pad of a lead frame with a silver paste or the like, and after performing wire bonding, a plurality of semiconductor elements are collectively molded with a predetermined cavity size, and then singulated by dicing. You do it.

[0007]

The frame used in the above-mentioned batch-molded semiconductor device usually has a grid lead width of about 0.15 to 0.25 mm, and a width larger than the grid lead width. A dicing saw is used to cut the semiconductor device into individual pieces by one cutting. Since a dicing saw having such a large width is used, the frame becomes 200 ° C. or higher due to frictional heat at the time of dicing, and there is a problem that the exterior solder used at the time of connecting the substrate is melted. Therefore, conventionally, the cutting speed of dicing has been reduced.

On the other hand, in the wire bonding step, the frame is placed on a heater block, the periphery of the lead frame in the frame is held down by a clamper, and pressure and ultrasonic vibration are applied to the thin metal wires in the clamped state for connection. . In this case, the frame can be clamped only for each cavity. That is, a wind clamper having substantially the same size as the mold cavity is used as a clamper for holding the frame during wire bonding.

Therefore, although the batch mold type has an advantage that the manufacturing efficiency is high, when the cavity size becomes large, the inside of the cavity is not sufficiently held down, and the connection strength defect due to the escape of ultrasonic waves during bonding is reduced. Then, a phenomenon occurs in which the terminal portion once connected is separated due to resonance during bonding.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a frame in which lead frames used in a collectively molded type semiconductor device are arranged, and which is used for dicing. A resin-encapsulated semiconductor device frame that suppresses heat generation, prevents solder melting, prevents resin scattering during dicing, and suppresses wire peeling by suppressing resonance during wire bonding. Is to provide.

[0011]

In order to achieve the above object, a resin-encapsulated semiconductor device frame according to the present invention has a plurality of lead frames arranged in a matrix through grid leads. After mounting each semiconductor element on the die pad of the lead frame, performing wire bonding, molding those semiconductor elements collectively, cutting the grid lead with a dicing saw, and individual resin sealing type In a frame used to obtain a semiconductor device, the width of the grid lead is set to a width that can be cut twice by a dicing saw.

In the lead frame having the above structure, it is preferable to form a groove and / or a through hole at the grid lead.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 5 is a plan view showing an essential part of an example of a frame for a resin-sealed semiconductor device according to the present invention, FIG. 6 is a partially enlarged plan view of the frame shown in FIG. 5, and FIG. It is -A sectional drawing.

In FIG. 5, F is a single metal frame for a lead frame, in which 3 × 3 lead frames 11 are arranged in a matrix with grid leads L intersecting each other. The grid leads L are connecting the terminal portions 5 of the adjacent lead frames 11. Usually, a plurality of such matrix lead frames are arranged in a horizontally long frame F. In the frame F of the present invention, as shown in FIG. 5, the width of the grid lead L is designed to be wide, and is 0.15 to 0.25 mm in the related art, but is 0.5 to 1 in the illustrated one. 0.5 mm.

Further, as shown in FIGS. 6 and 7 in an enlarged manner, a linear groove 12 is formed by half etching from the front side of the frame F so as to pass through the dicing line α of the grid lead L. I have. further,
Grooves 12 having the same width are also provided around the entire nine lead frames. The groove 12 may be formed from the back side of the frame F as shown in FIG.

The procedure for manufacturing a resin-encapsulated semiconductor device using the frame F shown in FIG. 5 is as follows. First, a semiconductor element is mounted on the die pad 3 of each lead frame 11 of the frame F using silver paste, and wire bonding is performed between the terminal portion 5 and the electrode on the upper surface of the semiconductor element. After the semiconductor elements are collectively molded with a predetermined cavity size, the dicing line α is cut with a dicing saw so as to leave the terminal portions 5 of the respective lead frames 11, and the semiconductor devices are singulated.

The wire bonding in this case can be performed as follows. That is, while holding the entire periphery of the nine lead frames, the grid leads L
A mesh-shaped clamper having such a shape as to hold the lead frame 11 is produced, and wire bonding is performed while each lead frame 11 is individually pressed by the clamper.
Alternatively, instead of holding down the entire periphery of the nine lead frames, the periphery of three lead frames in a row may be held down, and the wire bonding may be performed with the clamping window size reduced. Thereby, resonance of the frame F due to ultrasonic vibration during wire bonding is suppressed, so that peeling of bonding does not occur.

The dicing uses a dicing saw as thin as possible to cut the frame F, and cuts and removes the portion of the grid lead L by cutting twice to singulate the semiconductor device. That is, at the grid lead L, cutting is performed twice so that the dicing line α becomes a cut surface on one side of the dicing saw.
The entire periphery of each of the lead frames is cut from the frame F by single cutting. The dicing saw actually used is
Practically, the width is about 0.15 mm. Since the friction is reduced by reducing the width of the dicing saw in this manner, the heat generated during dicing is reduced to 100 ° C.
And solder melting can be prevented.

Further, as shown in this example, the dicing line α
When the groove 12 is provided at this point, since the metal at the groove 12 is removed and becomes resin, the generation of heat due to friction is reduced and the generation of metal burrs is also reduced.
Further, since the dicing saw is cut from the front side of the frame F, it is preferable to have the groove 12 on the back side as shown in FIG.

FIG. 9 is a plan view showing a main part of another example of the resin-encapsulated semiconductor device frame according to the present invention, and FIG.
9 is a partially enlarged plan view of the frame shown in FIG.
It is A sectional drawing.

This frame F is substantially the same as that shown in FIGS. 5 to 7, except that a linear groove 12 is provided from the front side of the frame F by half-etching, and a grid lead L Are formed with elongated through holes 13 arranged in two rows. Such a through hole 13 can be formed by double-sided etching. Note that the groove 12 may be formed from the back side of the frame F as shown in FIG.

In the frame F, the metal is removed from the through hole 13 to be a resin, and the metal and the resin are firmly adhered to each other. Therefore, the resin generated during dicing between the dicings falls off and scatters. Less.

[0024]

As described above, according to the present invention, a plurality of lead frames are arranged in a matrix through grid leads, and a semiconductor element is mounted on a die pad of each lead frame, and wire bonding is performed. After performing these steps, the semiconductor elements are collectively molded, and then the grid leads are cut with a dicing saw to obtain individual resin-encapsulated semiconductor devices. Is characterized by having a width that can be cut twice with a dicing saw, so that the use of a dicing saw with a small width reduces friction during dicing, thereby suppressing heat generation during dicing and preventing solder melting. be able to. Further, it is possible to use a mesh-shaped clamper that also holds down the grid leads, thereby suppressing resonance during wire bonding and eliminating wire peeling.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a resin-sealed semiconductor device.

FIG. 2 is a plan view of the resin-sealed semiconductor device shown in FIG.

FIG. 3 is an explanatory diagram of an individual mold type.

FIG. 4 is an explanatory view of a collective mold type.

FIG. 5 is a plan view showing a main part of an example of a resin-encapsulated semiconductor device frame according to the present invention.

6 is a partially enlarged plan view of the frame shown in FIG.

FIG. 7 is a sectional view taken along line AA of FIG. 5;

8 is a sectional view showing a modification of the frame shown in FIG. 5 corresponding to FIG. 7;

FIG. 9 is a plan view showing a main part of another example of the resin-sealed semiconductor device frame according to the present invention.

FIG. 10 is a partially enlarged plan view of the frame shown in FIG. 9;

FIG. 11 is a sectional view taken along line AA of FIG. 9;

12 is a cross-sectional view showing a modification of the frame shown in FIG. 9 corresponding to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead frame 2 Suspended lead 3 Die pad 4 Semiconductor element 5 Terminal part 6 Thin metal wire 7 Sealing resin 11 Lead frame 12 Groove 13 Through hole C Mold cavity F Frame L Grid lead S Semiconductor device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F061 AA01 BA01 CA21 CB13 DD12 5F067 AB03 AB04 BA02 BA03 BA08 BB04 BC13 BD05 BE02 DA16 DF03

Claims (3)

[Claims] 1. A plurality of lead frames are arranged in a matrix through grid leads. Semiconductor elements are mounted on die pads of the respective lead frames, and after performing wire bonding, the semiconductor elements are mounted. In a frame used to obtain individual resin-encapsulated semiconductor devices by cutting the grid leads with a dicing saw after molding all at once, the width of the grid leads can be cut twice with a dicing saw. A resin-encapsulated semiconductor device frame, characterized in that: 2. The grid lead has a width of 0.5 to 1.5 m.
2. The resin-sealed type semiconductor device frame according to claim 1, wherein the width of the dicing saw is about 0.15 mm. 3. The resin-encapsulated semiconductor device frame according to claim 1, wherein a groove and / or a through hole is formed at the grid lead.