JP2001077285A - Lead frame and manufacture of resin-sealed semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead frame, in which an external terminal is arranged in a row at the bottom of a package, the surface of each external electrode is positively exposed, and generation of resin flash can be prevented, and to provide a manufacturing method of resin-sealed semiconductor device using the same, by constituting the semiconductor device using a frame which can be mounted on a substrate at its bottom side. SOLUTION: In a lead frame for an LGA(land grip array), the surface of land lead electrodes 16 in a land lead part 4, whose bottom is to be a land electrode is arranged lower than the land surface of a lead part 5 in advance by a semi-cutting part 24. By doing so, since the land electrodes 16 cuts into and is bonded on a sealing seat in resin-sealing, the sealing resin does not flow into the surfaces of the land electrodes 16. As a result, resin flash is prevented from occurring on the surfaces of the land electrodes 16 of the land lead parts 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame having a lead having land electrodes serving as external terminals in addition to a conventional lead frame having a beam-shaped lead. Land grid array (LGA) mounted with elements and sealed with resin
The present invention relates to a method for manufacturing a mold resin-sealed semiconductor device.

[0002]

2. Description of the Related Art In recent years, in order to cope with miniaturization of electronic equipment, high-density mounting of semiconductor components such as resin-encapsulated semiconductor devices has been required.
Thinning is progressing. In addition, the number of pins has been increased while being small and thin, and a high-density small and thin resin-sealed semiconductor device has been demanded.

Hereinafter, a lead frame used in a conventional resin-encapsulated semiconductor device will be described.

FIG. 20 is a plan view showing the structure of a conventional lead frame. As shown in FIG. 20, a conventional lead frame includes a frame 101 and its frame 10.
1, a rectangular die pad portion 102 on which a semiconductor element is mounted, a suspension lead portion 103 supporting the die pad portion 102, and when a semiconductor element is mounted, the mounted semiconductor element and a thin metal wire or the like. A beam-shaped inner lead portion 104 electrically connected by the connecting means, an outer lead portion 105 provided continuously with the inner lead portion 104 for connection to an external terminal, and an outer lead portion 1
The tie bars 105 are connected and fixed to each other, and the tie bar portions 106 serve as resin stoppers during resin sealing.

The lead frame has a plurality of patterns each having the structure shown in FIG.
They are arranged vertically continuously.

Next, a conventional resin-encapsulated semiconductor device will be described. FIG. 21 is a cross-sectional view showing a resin-sealed semiconductor device using the lead frame shown in FIG.

As shown in FIG. 21, a semiconductor element 107 is mounted on a die pad section 102 of a lead frame, and the semiconductor element 107 and the inner lead section 104 are electrically connected by a thin metal wire 108. The outer periphery of the semiconductor element 107 and the inner lead part 104 on the die pad part 102 is sealed with a sealing resin 109. From the side of the sealing resin 109, the outer lead portion 10
5 is provided so as to protrude, and the tip is bent.

In a conventional method of manufacturing a resin-encapsulated semiconductor device, as shown in FIG. 22, a semiconductor element 107 is bonded to a die pad 102 of a lead frame with an adhesive (die bonding step), The distal end portion of the inner lead portion 104 is connected by a thin metal wire 108 (wire bonding step). After that, the semiconductor element 107
Is sealed, the sealing region is sealed with a sealing resin 109 in the region surrounded by the tie bar portion 106 of the lead frame, and the outer lead portion 105 is sealed by protruding outside (resin). Sealing step). Then, the boundary portion of the sealing resin 109 is cut by the tie bar portion 106, each outer lead portion 105 is separated, the frame 101 is removed, and the tip of the outer lead portion 105 is bent (tie bar cut / bend). Process),
A resin-sealed semiconductor device having the structure shown in FIG. 21 can be manufactured. Here, in FIG. 22, a region indicated by a broken line is a region to be sealed with the sealing resin 109.

[0009]

However, in the conventional lead frame, when the semiconductor element is highly integrated and the number of pins is increased, there is a limit in forming the width of the inner lead portion (outer lead portion). In order to cope with the problem, the number of inner lead portions (outer lead portions) increases, so that the lead frame itself becomes large, and as a result, the size of the resin-encapsulated semiconductor device also increases. There is a problem that a fixed semiconductor device cannot be realized. In addition, when increasing the number of inner leads without changing the size of the lead frame in order to support multiple pins of the semiconductor element, the width of each inner lead must be reduced, and etching of the lead frame may be performed. There are many problems in processing.

Recently, as a semiconductor device of a surface mounting type, a semiconductor element is mounted on a carrier (wiring board) having an external electrode (ball electrode, land electrode) provided on the bottom surface, and after electrical connection is made, the semiconductor element is mounted. Ball grid array (BGA), which is a semiconductor device in which the upper surface of the carrier is resin-sealed
And a land grid array (LGA) type semiconductor device. This type of semiconductor device is a semiconductor device mounted on a motherboard on the bottom side, and such a surface mount type semiconductor device is becoming mainstream in the future. Therefore, in order to cope with such a trend, a big problem that a conventional lead frame and a resin-sealed semiconductor device using the lead frame cannot be dealt with has become apparent.

In a conventional resin-encapsulated semiconductor device, an external lead composed of an outer lead portion is provided to protrude from a side surface of a sealing resin, and the external lead and a substrate electrode are bonded and mounted. Therefore, BGA type, LGA
The reliability of board mounting is lower than that of a semiconductor device of the type. In addition, since BGA type and LGA type semiconductor devices use a wiring board, there is a problem that the cost is high.

The present invention provides a lead frame type resin-encapsulated semiconductor device capable of coping with the above-mentioned conventional problems and future trends in semiconductor devices. It is intended to use and configure. Provided are a lead frame in which external terminals are arranged in a row configuration on the bottom surface of the package, and the surface of each external electrode is reliably exposed to prevent occurrence of resin burrs, and a method of manufacturing a resin-encapsulated semiconductor device using the same. Is what you do.

[0013]

In order to solve the above-mentioned conventional problems, a lead frame according to the present invention comprises a frame main body made of a metal plate and a semiconductor element mounted in a substantially central region of the frame main body. A die pad portion, a suspension lead portion supporting the die pad portion at a distal end portion, and being connected to a frame at the other end portion, at least a distal end portion extending toward the die pad portion, and the other end portion extending from the frame. A first lead portion connected to the frame and having a bottom surface serving as a land electrode; a tip portion extending to a tip portion region of the first lead portion; and a tip portion disposed at the other end portion connected to the frame frame; And a second lead portion having a bottom surface serving as a land electrode, and a land electrode on the bottom surface of the first lead portion and a land electrode on the bottom surface of the second lead portion constitute two rows of land electrodes. At least the second lead A leadframe land electrode portion has a structure which is disposed below the semi-cutting press so as to be positioned below the land electrode surface of the first lead portion.

According to the method of manufacturing a resin-encapsulated semiconductor device using a lead frame of the present invention, a frame main body made of a metal plate and a die pad portion for mounting a semiconductor element disposed in a substantially central region of the frame main body are provided. And a suspension lead portion supporting the die pad portion at the tip end and connected to the frame frame at the other end portion, and at least the tip end portion extends toward the die pad portion, and the other end portion is connected to the frame frame. A first lead portion having a bottom surface serving as a land electrode; a first lead portion extending to a leading end region of the first lead portion; the leading end portion being disposed; the other end portion being connected to the frame frame; A second lead portion serving as an electrode, and a land electrode on the bottom surface of the first lead portion and a land electrode on the bottom surface of the second lead portion constitute two rows of land electrodes; The lead is the land Preparing a lead frame having a configuration in which a pole portion is disposed below by a half-cut press so that the pole portion is positioned below a land electrode surface of the first lead portion; and A step of mounting a semiconductor element on a die pad section, electrode pads on a main surface of the semiconductor element mounted on the die pad section, and upper surfaces of a first lead section and a second lead section of the lead frame. Connecting with a thin metal wire,
A step of adhering a sealing sheet to at least the bottom surfaces of the die pad portion, the first lead portion, and the second lead portion on the back surface side of the lead frame; and at least ends of the first lead portion and the second lead portion. A pressing force is applied to the
In the state where the land electrode surface of the lead portion and the land electrode surface of the second lead portion are pressed against the sealing sheet, the semiconductor element, the die pad portion, and the region of the fine metal wire are sealed as the upper surface side of the lead frame. A method of manufacturing a resin-encapsulated semiconductor device, comprising the steps of resin-encapsulating with a resin, and removing the sealing sheet from the lead frame after resin encapsulation.

Specifically, at least a first lead portion,
A pressing force is applied to the end of the second lead portion, and the land electrode surface of the first lead portion and the land electrode surface of the second lead portion are pressed against a sealing sheet. In the step of resin-sealing the semiconductor element, the die pad portion, and the thin metal wire region with a sealing resin as the upper surface side, the land electrode surface of the first lead portion is pressed against a sealing sheet when the pressing force is applied. Manufacturing method of a resin-encapsulated semiconductor device in which the land electrode surface of the second lead portion is pressed and bitten by the sealing sheet and the sealing resin does not flow around the land electrode surface. It is.

As described above, in the lead frame of the present invention, when a resin-encapsulated semiconductor device is formed, a land electrode serving as an external electrode is provided as a lead body.
When the semiconductor element is mounted, the semiconductor element and each lead are connected by a thin metal wire, and the resin is sealed to form a resin-encapsulated semiconductor device, the bottom surface of the resin-encapsulated semiconductor device, that is, in the package bottom region, The bottom surface of the land portion of the land lead portion is disposed, and the bottom surface of the lead portion is disposed outside the land portion to form external terminals arranged in two rows.
An LGA (land grid array) type package can be configured.

Further, by using the lead frame of the present invention, the land electrode of the second lead portion is disposed below the land electrode surface of the first lead portion by the half cut portion by the half cut press. The pressing force causes the surface of the land electrode to bite into and adhere to the sealing sheet, thereby preventing the second lead portion from floating due to the injection pressure of the resin sealing, and preventing the sealing resin from flowing around the land electrode surface. In addition, it is possible to suppress the occurrence of resin burrs on the surface of the land electrode of the second lead portion.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lead frame, a resin-sealed semiconductor device using the same and a method for manufacturing the same according to the present invention will be described below with reference to the accompanying drawings.

First, the lead frame of this embodiment will be described.

FIG. 1 is a plan view showing a lead frame of the present embodiment. FIG. 2 is an enlarged view showing a lead portion of the lead frame of the present embodiment, and FIG. 2 (a) is a plan view and FIG.
3A is a cross-sectional view taken along a line A-A1 and a line B-B1 in FIG. In FIG. 1, a region indicated by a two-dot chain line indicates a sealing region when a semiconductor element is mounted using the lead frame of the present embodiment and sealed with a resin.

As shown in FIGS. 1 and 2, the lead frame of the present embodiment is made of a copper plate or a metal plate such as a 42-alloy used for a normal lead frame, and has a die pad portion on which a semiconductor element is mounted. 1, a suspension lead 3 connected to the frame 2 at the end thereof and supporting the four corners of the die pad 1 at the tip, a tip facing the die pad 1, and a tip connected to the frame 2. Is a lead frame including a linear land lead portion 4 (second lead portion) and a linear lead portion 5 (first lead portion) which are arranged in a horizontal direction. An external terminal (land portion) is formed on the bottom surface, and the lead portion 5 can be connected to the mounting board as an external terminal on the outer side surface in addition to the bottom surface.

More specifically, the die pad portion 1 is provided with a circular protrusion 6 at a substantially central portion of the surface thereof, and the protrusion 6 is formed by pressing a flat plate constituting the die pad portion 1 by pressing. A half-cut press is applied to project upward. The projecting portion 6 substantially serves as a portion for supporting the semiconductor element, and when the semiconductor element is mounted, a gap is formed between the surface of the die pad portion 1 excluding the projecting portion 6 and the back surface of the semiconductor element. ing. A groove 7 is provided in a region surrounding the protruding portion 6 on the surface of the die pad portion 1 so that a sealing resin enters the groove 7 when a semiconductor element is mounted and sealed with a resin. In this embodiment, the groove 7 has a circular annular groove 7. When the semiconductor element is mounted on the protruding part 6 of the die pad part 1 with an adhesive by the groove part 7 and the resin is sealed, the sealing resin enters the groove part 7. Therefore, the surface of the die pad part 1 is stressed by thermal expansion. Even if resin peeling occurs between the resin and the sealing resin, the peeling itself can be trapped in the groove, and a decrease in reliability can be prevented. Of course, the configuration of the groove portion 7 may be a configuration in which the groove portions are partially connected other than the annular configuration, and the number thereof may be two or more, three, four, or one. And the size of the semiconductor element to be mounted.

Further, the land lead portions 4 and the lead portions 5 of the lead frame of the present embodiment are arranged alternately in parallel when connected to the frame 2, and in the arrangement facing the die pad portion 1, The tips of the land leads 4 extend closer to the die pad 1 than the tips of the leads 5, and the tips are staggered in plan view. In this arrangement, when the semiconductor element is mounted and sealed with resin, two rows of external terminals are arranged in a staggered manner on the bottom surface of the package. The bottom surface of the portion 5 is arranged on the package bottom surface. In particular, as shown in FIG. 2, the land lead portion 4 is a linear lead, and a land portion 8 having a curvature at a tip portion serving as an external terminal is formed on a bottom portion of the tip portion. The portions other than the portion where 8 is formed are thinned by half-etching, and the lands 8 have the original thickness of the leads.

That is, in the land lead portion 4, the land portion 8 has a shape projecting downward, and the land lead portion 4 itself has an upper surface larger than the lower surface. FIG. 1
In FIG. 2, the portion indicated by the broken line on the bottom surface of the tip of the land lead portion 4 indicates the land portion 8, and FIG. 2 shows the portion where the grid-like hatched region is half-etched. Also, as shown in FIG. 2, the outer peripheral portion of the lead portion 5 is thinned by half-etching, and the lead portion 5 has a wide portion 9. A groove portion is formed near the root of the wide portion 9. 10 are provided. In addition, a land portion is formed on the bottom surface of the tip portion so that the tip portion has a curvature. The hatched portions in FIGS. 1 and 2 are the grooves 10. A semiconductor element is mounted using the lead frame of the present embodiment,
When the resin is sealed with resin, the lead portion 5 itself has a single-sided sealing structure in which the bottom and side surfaces are exposed. Therefore, unlike the lead portion of a conventional full-mold package, stress caused by sealing resin, Stress may be applied to the lead. However, even if a stress is applied to the lead portion 5 by the stress of the sealing resin and the stress after mounting the substrate by the groove portion 10, the stress can be absorbed by the groove portion 10.
This prevents breakage of the connection portion of the thin metal wire, and can maintain the reliability of the product after mounting. Here, the surface area of the land part 8 of the land lead part 4 and the wide part 9 of the lead part 5
Is a bonding pad to which a thin metal wire is connected.

In the lead frame of the present embodiment, the land lead portion 4 and the lead portion 5 are linear leads, and the portion constituting the land portion 8 on the bottom surface has a shape having a curvature at the tip. In addition, since they are linear with each other, the lands 8 form a staggered pattern in the package arrangement.

A rectangular annular groove 11 is provided on the bottom surface corresponding to the area surrounding the protrusion 6 of the die pad 1 of the lead frame of the present embodiment. This groove 1
1, when the substrate is mounted on the bottom surface of the die pad portion 1 using a bonding material such as solder, the solder is prevented from spreading excessively, the mounting accuracy is improved, and the die pad portion 1 itself is radiated from the semiconductor element. It can absorb stress. In this embodiment, one groove 11 is used. However, even if an annular groove is formed near the outer peripheral portion of the bottom surface of the die pad 1, further improvement in mounting accuracy can be achieved.
Further, a dummy land portion may be provided on the suspension lead portion 3, or a bent portion may be provided on the suspension lead portion 3.

The numbers of the land lead portions 4 and the lead portions 5 can be appropriately set according to the number of pins of the semiconductor element to be mounted. The lead frame of the present embodiment has a plated surface, and for example, nickel (Ni), palladium (P
d) and a metal such as gold (Au) are laminated and plated appropriately. Further, the lead frame of the present embodiment does not consist of one pattern as shown in FIG. 1, but can be formed continuously in the left, right, up and down directions.

When the semiconductor device is mounted on the lead frame of this embodiment, the semiconductor element and each lead are connected by a thin metal wire, and the resin is sealed to form a resin-sealed semiconductor device. On the bottom surface of the semiconductor device, that is, on the package bottom surface, a bottom surface of a land portion 8 having a curvature at the tip of the land lead portion 4 is arranged. Outside the land portion 8, a tip portion of the lead portion 5 has a curvature. Are arranged to form a staggered two-row arrangement of external terminals.
An LGA (land grid array) type package can be configured. By forming the resin-encapsulated semiconductor device using the lead frame of the present embodiment, the groove 7 is provided on the surface of the die pad portion 1. Since the separation can be trapped in the groove 7, the reliability of the resin-encapsulated semiconductor device can be maintained. In addition, there are other advantages such as improvement of heat radiation characteristics, improvement of accuracy of solder bonding at the time of mounting on a substrate, and mounting of a semiconductor element having a large area.

Next, the resin-sealed semiconductor device of the present invention will be described with reference to the drawings. FIG. 3 is a plan view showing the resin-encapsulated semiconductor device according to the present embodiment, FIG. 4 is a bottom view showing the resin-encapsulated semiconductor device according to this embodiment, and FIGS. FIG. 3 is a cross-sectional view showing a resin-sealed semiconductor device according to an embodiment. The cross-sectional view of FIG. 5 shows a cross-section taken along the line C-C1 in FIG. 3 and the cross-section taken along the line E-E1 in FIG. 4, and the cross-sectional view of FIG.
2 shows a cross section taken along a line FF1 in FIG. The present embodiment is a resin-sealed semiconductor device using the lead frame shown in FIGS. 1 and 2 as an example.

As shown in FIGS. 3, 4, 5 and 6, the resin-encapsulated semiconductor device of this embodiment has a protrusion 6 on the surface and a circular or rectangular shape surrounding the protrusion 6 or And a die pad 1 having an annular groove 11 on the bottom surface, and the die pad 1
A semiconductor element 12 mounted on a protruding portion 6 of the semiconductor device via a conductive adhesive (not shown) such as a silver paste, a lead portion 5 having a groove portion 10 on a surface thereof, and an exposed bottom surface;
And a land lead portion 4 which extends toward the die pad portion 1 side from the tip end region and exposes the bottom surface of the tip end to form a land electrode; and an electrode pad on the main surface of the semiconductor element 12 (not shown). ) And the fine metal wire 1 electrically connecting the land lead portion 4 and the bonding pad portion 13 of the lead portion 5 to each other.
4, a region excluding the bottom surface of the die pad portion 1, a mounted semiconductor element 12, a region excluding the bottom surface of the land lead portion 4, a region excluding the outer side surface and the bottom surface of the lead portion 5, and the metal fine wire 14 are sealed. It is made of a sealing resin 15.
The bottom surface of the tip of the land lead portion 4 exposed from the package portion made of the sealing resin 15 and the outer side surface and the bottom surface of the lead portion 5 constitute external electrodes when mounted on a mounting board such as a printed board. A land electrode 16 is formed, and the bottom surface of the lead portion 5 and the bottom surface of the tip portion of the land lead portion 4 in the tip region are exposed to form a staggered two-row land configuration. The land electrode 16 is exposed from the sealing resin 15 but is projected and exposed with a step of about 20 [μm], and has a standoff at the time of board mounting. is there. Similarly, the bottom surface of the die pad portion 1 is also protruded and exposed, and when mounted on a substrate, the heat radiation efficiency can be improved by solder bonding. Further, a concave portion 1 is provided on the bottom surface of the die pad portion 1.
7 are formed, and the protrusion 6 is formed on the die pad 1.
Is formed in a half-cut state by press working on the upper surface of the substrate, and a concave portion corresponding to the amount of protrusion is formed on the bottom surface correspondingly. In the present embodiment, the thickness of the die pad portion 1 (lead frame thickness) made of a 200 [μm] metal plate is 140 [μm] to 180 [μm] (70 [%] to 90 [90% of the thickness of the metal plate itself]. [%]) Projecting protrusion 6
Is formed.

The area of the bonding pad section 13 in the land lead section 4 and the lead section 5 is 100 μm.
m] or more so that a wire bond of not less than [m] can be achieved, a high-density electrode arrangement is possible, and a small and thin resin-sealed semiconductor device can be realized. Furthermore, with the structure of the present embodiment, it is possible to cope with the increase in the number of pins and to realize a high-density surface-mount type resin-encapsulated semiconductor device.
The thickness of the semiconductor device itself is also 80
An extremely thin resin-encapsulated semiconductor device of about 0 [μm] can be realized.

In the resin-sealed semiconductor device of this embodiment, the area of the top surface of the land lead portion 4 and the top surface of the lead portion 5 sealed by the sealing resin 15 is smaller than that of the sealing resin 15.
It is configured to be larger than the area of the land electrode 16 on the side that is exposed and protruded from the surface, improves the bite with the sealing resin 15, improves the adhesion, and improves the reliability of connection when mounting the substrate. Can be obtained.

As described above, in the resin-encapsulated semiconductor device of this embodiment, the bottom surface of the land electrode 16 of the land lead portion 4 is disposed on the bottom surface of the package.
Land electrodes 16 which are the bottom surfaces of the lead portions 5 are arranged on the outside of the semiconductor device to constitute external terminals arranged in two rows in a staggered manner, and can constitute an LGA (land grid array) type package. . The groove 7 is provided on the surface of the die pad 1, and even if the sealing resin 15 peels off between the back surface of the semiconductor element 12 and the surface of the die pad 1, the peeling can be trapped by the groove 7. For,
The reliability can be maintained as a resin-sealed semiconductor device. In addition, there are other advantages such as improvement of heat radiation characteristics, improvement of accuracy of solder bonding at the time of mounting on a substrate, and mounting of a semiconductor element having a large area.

Further, the resin-encapsulated semiconductor device of this embodiment is different from the conventional one in that an LGA-type resin-encapsulated semiconductor device using a lead frame without using a wiring board or a circuit board is used. This is a resin-encapsulated semiconductor device with improved characteristics. FIG. 7 is a sectional view showing an example of a mounted state of the resin-sealed semiconductor device of the present embodiment shown in FIG.

As shown in FIG. 7, in the resin-encapsulated semiconductor device of this embodiment, the land electrode 16 on the bottom surface of the package and the mounting board 18 such as a printed board are bonded to a bonding agent 19 such as solder.
Is connected and implemented. Here, the land electrode on the bottom surface of the land lead portion is mounted with only the bottom portion in contact with the bonding agent, but the land electrode 16 of the lead portion 5 is mounted with the bottom portion in contact with the bonding agent 19. In addition, since the outer side surface of the lead portion 5 is exposed, the bonding agent 19 is mounted in contact with the side surface of the lead portion 5.

That is, normally, only the bottom portion of the land electrode is bonded to the mounting board via the bonding agent, but in the present embodiment, the outer land electrode in the row-shaped land electrode is a lead electrode. Since the outer portion is exposed from the package portion (sealing resin 15), by providing a bonding agent to the outer side surface, a two-point bonding structure of the bottom surface and the side surface is obtained. ,
The mounting strength of the connection with the mounting board can be improved, and the reliability of the connection can be improved. This is a mounting structure that could not be achieved by a normal lead frame LGA type semiconductor device. In the present embodiment, the land electrode configuration is a two-row configuration of a land electrode and a lead type land electrode. A connection portion can be provided on the outside, and an innovative structure that can improve the reliability of connection by a two-point joint structure of the bottom surface and the side surface is provided.

As described above, the semiconductor element is mounted and sealed with a resin by using the lead frame as shown in the present embodiment, so that the semiconductor element is electrically connected to the bottom of the resin-sealed semiconductor device. The land electrodes thus formed can be arranged in two linear or staggered rows. as a result,
As a result, a semiconductor device of a surface mounting type can be obtained, and the reliability of substrate mounting can be improved as compared with the conventional mounting by lead bonding.

The resin-encapsulated semiconductor device of the present embodiment does not use a substrate such as a circuit board provided with land electrodes unlike a conventional BGA type semiconductor device, but is made of a metal plate called a lead frame. L from frame body
It constitutes a GA-type semiconductor device, and is more advantageous than a conventional BGA-type semiconductor device in terms of mass productivity and cost.

In the resin-encapsulated semiconductor device of the present embodiment, the outer land electrodes in the row-structured land electrodes are:
Since the side portion of the outer portion is exposed from the package portion, a fillet is formed by providing a bonding agent to the outer side surface, and a two-point joint structure of the bottom surface and the side surface is formed. Thus, the mounting strength of the connection with the mounting board can be improved, and the reliability of the connection can be improved. This is a mounting structure that could not be achieved by a normal lead frame LGA type semiconductor device. In the present embodiment, the land electrode configuration is a two-row configuration of a land electrode and a lead type land electrode. A connection portion can also be provided on the outside, and the mounting strength can be improved by a two-point bonding structure of the bottom surface and the side surface.

Next, an embodiment of a method of manufacturing a resin-sealed semiconductor device according to the present invention will be described with reference to the drawings.
8 to 13 are cross-sectional views for each process showing the method for manufacturing the resin-encapsulated semiconductor device of the present embodiment. Note that, in the present embodiment, the lead frame as shown in FIG.
An embodiment of manufacturing a GA-type resin-sealed semiconductor device will be described. Further, in the present embodiment, since the description will be made with reference to the cross-sectional view of the land lead portion 4 for convenience, the lead portion 5 is not shown in the drawing.

First, as shown in FIG. 8, a frame main body made of a metal plate, a projection 6 disposed in an open area of the frame main body, and a circular or rectangular shape surrounding the projection 6 on its surface. Annular groove 7 and annular groove 1 on the bottom surface
1 and a die pad portion 1 for mounting a semiconductor element having a recess 17 and a suspension lead portion (not shown) supporting the die pad portion 1 at the tip end and connected to a frame (not shown) at the other end. Although not shown, the bottom surface becomes a land electrode,
It has a wide bonding pad portion to which a fine metal wire is connected on the front end surface thereof, a groove portion is provided near the bonding pad portion, the grooves are arranged with regularity, and the other end portion is connected to the frame. The lead portion and the bottom surface are the land electrode 1
6, having a wide bonding pad portion 13 to which a thin metal wire is connected on the front end surface, the upper surface is larger in area than the lower surface, and the front end portions are arranged in a staggered manner at the front end portions of the lead portions. Then, a lead frame having a two-row configuration with the lead portions and a land lead portion 4 having the other end connected to the frame is prepared.

Next, as shown in FIG. 9, the semiconductor element 12 is bonded to the projected portion 6 of the die pad portion 1 of the prepared lead frame via a conductive adhesive such as silver paste with its main surface facing up. .

Next, as shown in FIG.
The electrode pads on the main surface of the semiconductor element 12 mounted thereon by bonding are electrically connected to the land lead portions 4 of the lead frame and the bonding pad portions 13 on the respective upper surfaces of the lead portions (not shown) by thin metal wires 14. Connecting. Here, the area of each bonding pad to which the thin metal wire 14 is connected is:
As an example, it is 100 [μm] or more.

Next, as shown in FIG. 11, the lead is brought into close contact with the back side of the lead frame, that is, the bottom surface of the die pad portion 1, the land electrode 16 of the land lead portion 4, and the bottom surface of the lead portion (not shown). The sealing tape or the sealing sheet 20 is brought into close contact with the back side of the frame. The sealing sheet 20 used here is a resin sheet that has no adhesive force to the lead frame and can be easily removed by peeling off after resin, and is sealed to the back side of the lead frame in the resin sealing step. As a result, it is possible to reliably prevent the resin from wrapping around, and as a result, to prevent resin burrs from adhering to the back surfaces of the die pad portion 1, the land lead portion 4, and the lead portion (not shown). Therefore, a water jet process for removing resin burrs after resin sealing can be omitted.

Next, as shown in FIG.
The upper surface side of the lead frame is resin-sealed with a sealing resin 15 in a state in which the semiconductor chip 12 is adhered, and the regions of the semiconductor element 12, the die pad portion 1, and the thin metal wires 14 are resin-sealed. Usually, single-sided sealing is performed by transfer molding using upper and lower sealing dies. That is, a single-sided sealing structure excluding the die pad portion 1, the land lead portion 4, and the bottom portion of the lead portion (not shown) is obtained. In particular, a portion of the land lead portion 4 and the lead portion (not shown) connected to the frame 2, that is, a lead portion that is not resin-sealed, is sealed by the first mold of the upper and lower molds via the sealing sheet 20. By pressing against the mold, the bottom surface of each of the land lead portion 4 and the lead portion (not shown) is pressed against the sealing sheet 20 and resin-sealed in a state of being in close contact therewith. And the bottom surfaces of the land lead portion 4 and the lead portion (not shown) can be arranged with a standoff from the package bottom surface (the sealing resin 15 bottom surface).

The sealing sheet 20 is adhered to and adhered to the back surface of the lead frame by adhering a sealing sheet that has been supplied in advance to the upper and lower molds for resin sealing before resin sealing. Alternatively, the sealing sheet may be adhered to and adhered to the lead frame in a separate step before resin sealing, and then supplied to a sealing mold to seal the resin.

Next, as shown in FIG. 13, after sealing the resin, the sealing sheet is removed by peel-off or the like, and then the suspension lead portion, the land lead portion 4, and the portion of each lead portion connected to the frame of each lead portion. Disconnect. At this stage, cutting is performed so that the end of each lead portion is arranged substantially flush with the side surface of the package sealed with resin. The land lead portion 4 and the bottom surface of the lead portion constitute a land electrode 16, the side surface portion outside the lead portion also constitutes an external electrode, the bottom surface of the die pad portion 1 is also exposed, and has a heat dissipation structure.

As described above, according to the method of manufacturing the resin-encapsulated semiconductor device of the present embodiment, the bottom surface of the land electrode 16 of the land lead portion 4 is arranged in the inner row of the package bottom face, and the outer row of the land electrode 16 is arranged in the outer row. Are land electrodes, which are the bottom surfaces of the lead portions, arranged to form external terminals in a linear or staggered two-row arrangement, and can constitute an LGA (land grid array) type package.
Further, since the configuration of the land electrode is a two-row configuration of a land electrode and a lead-type land electrode, a connection portion can be provided outside the package, and a two-point bonding structure of the bottom surface and the side surface can be used for connection. A resin-encapsulated semiconductor device that can improve reliability can be realized.

Next, in the structure of the lead frame shown in the present embodiment, a new problem has become apparent separately.

Hereinafter, description will be made with reference to the drawings. FIG. 14 is an enlarged view of a part of a normal land lead portion 4 (second-row lead) in the lead frame according to the present embodiment. FIG. 14A is a plan view, and FIG. 14
It is sectional drawing of GG1 location of (a). FIG. 15 is a partial cross-sectional view showing the influence of the injected resin on the land lead portion 4 and the lead portion 5 when resin sealing is performed. FIG. 16 is a partial cross-sectional view showing the influence of the injected resin on the land lead portion 4 and the lead portion 5 as in FIG. FIG. 17 is a sectional view showing a part of the resin-sealed semiconductor device after resin sealing.

As shown in FIG. 14, the land lead portion 4, which is a normal second lead portion, has a land portion 8 at its tip, and the bottom surface is a land electrode 16. However, at the time of resin sealing, as shown in FIG.
Is pressed by the first mold 21 against the second mold 22 via the sealing sheet 20, and the land portion 8 of the land lead portion 4 is pressed from the pressed position.
Are spaced apart from each other, and the force with which the land electrode 16 of the land portion 8 adheres to the sealing sheet 20 is weakened. As a result, the land electrode 16 of the land portion 8 of the land lead portion 4 rises from the sealing sheet 20 due to the injection pressure of the injected sealing resin indicated by the arrow, and is sealed with the resin in a peeled state. In the case of the lead portion 5, which is the first lead portion, since the distance from the pressed portion is short, the bottom surface of the lead portion 5 comes into close contact with the sealing sheet 20 and is separated from the sealing sheet 20 by the pressing force. There is no such thing.

When resin sealing is performed in such a state, FIG.
As shown in FIG. 7, the sealing resin wraps around the bottom surface (land electrode 16) of the land lead portion 4, and a resin burr 23 is formed on the surface of the land electrode 16 of the land lead portion 4, which does not function as an external electrode. Can occur. To deal with such a problem, it is a technically important task to securely adhere the bottom surface of the land lead portion 4 to the sealing sheet 20 and prevent the resin burrs 23.

Hereinafter, an embodiment for solving the problem will be described with reference to the drawings with regard to a lead frame of the present invention and a method of manufacturing a resin-sealed semiconductor device using the same.

Here, an embodiment will be described in which the surface of the land electrode 16 of the land lead portion 4 can be securely brought into close contact with the sealing sheet.

FIG. 18 is a view showing a land lead portion of a lead frame according to the present embodiment. The lead frame has the same basic structure as the lead frame shown in FIG. The configuration and operation of the land lead portion 4 are different. At least in the land lead portion 4, the land lead portion 4 is provided with a configuration that cuts into and adheres to the sealing sheet.
18A is a plan view, and FIG.
FIG. 18B is a cross-sectional view taken along a line H-H1 in FIG.
For comparison of the step on the land electrode surface, the lead portion 5 as the first lead portion is shown by a broken line.

The lead frame of the present embodiment is similarly disposed in a frame main body made of a metal plate, in an open area of the frame main body, and has a projection on the surface and a circular or rectangular shape surrounding the projection. An annular groove portion, a die pad portion for mounting a semiconductor element having an annular groove portion and a concave portion on the bottom surface, a suspension lead portion supporting the die pad portion at the tip end, and connected to the frame at the other end portion, and a bottom surface. Is a land electrode, has a wide bonding pad portion to which a fine metal wire is connected on the surface of the tip portion, a groove portion is provided near the bonding pad portion, and is arranged with regularity, and the other end portion is arranged. A lead portion connected to the frame and a bottom surface serve as a land electrode, and a wide bonding pad portion to which a fine metal wire is connected is provided on the front end surface, and the front end portion of the lead portion is staggered. And a land lead portion connected to the frame and the other end portion is formed in a two-row configuration together with the lead portion, and as shown in FIG. Reference numeral 4 denotes a portion of the land portion 8 other than the portion constituting the land electrode 16 having a small thickness, and a portion constituting the land electrode 16 protruding downward. A semi-cut portion 24 by pressing is provided, the land portion 8 itself is disposed below, and the land electrode 16 surface of the land lead portion 4 is disposed below the land electrode surface of the lead portion as the first lead portion. I have. That is, the surface of the land electrode 16 of the land lead portion 4 is disposed lower than the surface of the land electrode 16 of the lead portion 5 by the half cut portion 24 (space S in the drawing) by the half cut press.

As shown in FIG. 18, a semi-cut portion 24 is provided in a portion near the root of the land electrode 16 of the land lead portion 4,
The land portion 8 itself is disposed below, and the land electrode 16
Is disposed below the surface of the land electrode 16 of the lead portion 5, so that the surface of the land electrode 16 of the land lead portion 4 bites into the sealing sheet by the pressing force of the mold during resin sealing. A close contact state is formed. Therefore, the floating of the land lead portion 4 is prevented, and the surface of the land electrode 16 of the land lead portion 4 is in close contact with the sealing sheet. It is possible to suppress the occurrence of resin burrs on the surface of the land electrode 16 of the lead portion 4.

The half-cut amount of the half-cut portion 24 of the present embodiment is appropriately determined according to the distance from the end of the land lead portion 4 connected to the frame to the front end and the pressing force when pressing with the mold. , But usually the lead thickness is 250
In the case of about [μm], a half or more half-cut press is performed to form a step of about 150 [μm].

Next, the land lead portion 4 shown in this embodiment will be described.
An embodiment for manufacturing a resin-encapsulated semiconductor device using a lead frame having the following features will be described.

The process for manufacturing the resin-encapsulated semiconductor device using the lead frame of this embodiment is also omitted because it is the same as the method shown in FIGS. Here, the operation and effect of the lead frame of the present embodiment, particularly the land lead portion 4, in the resin sealing step will be described with reference to the drawings.

FIG. 19 is a cross-sectional view showing a mechanism for obtaining adhesion between the sealing sheet 20 and the land electrode 16 of the land lead portion 4 when resin sealing is performed using the lead frame of this embodiment.

As shown in FIG. 19, the surface of the land electrode 16 of the land lead portion 4 disposed below the surface of the land electrode 16 of the lead portion 5 is pressed by the sealing sheet 20 to reliably bite and adhere.

That is, in the resin sealing step using the sealing sheet, at least the lead portion 5, which is the first lead portion,
A pressing force is applied to the end of the land lead portion 4 which is the second lead portion with a mold, and the land electrode 16 surface of the lead portion 5 and the land electrode 16 surface of the land lead portion 4 are pressed against the sealing sheet 20. In this state, the semiconductor element, the die pad portion, and the thin metal wire region are sealed with a sealing resin as the upper surface side of the lead frame, but when this pressing force is applied, the surface of the land electrode 16 of the lead portion 5 is sealed. A state in which the land electrode 16 of the lead portion 5 is pressed by the sheet 20 is formed.
The surface of the land electrode 16 of the land lead portion 4 disposed below the surface is pressed by the sealing sheet to form a state in which the land electrode 16 is securely bitten, and the resin sealing is performed in a state where the sealing resin does not flow around the surface of the land electrode 16. Is what you do.

Therefore, floating of the land lead portion 4 is prevented, and the surface of the land electrode 16 of the land lead portion 4 is in close contact with the sealing sheet 20 so that there is no gap, so that the sealing resin flows around the surface of the land electrode 16. As a result, it is possible to suppress the occurrence of resin burrs on the surface of the land electrode 16 of the land lead portion 4. In the drawing, the arrows indicate the adhesion of the land electrodes 16 of the land lead portions 4 due to the injection of the sealing resin.

By manufacturing the resin-encapsulated semiconductor device using the lead frame of the present embodiment, the occurrence of resin burrs on the land electrodes 16 of the land lead portions 4 during resin encapsulation is suppressed, and It is possible to realize a resin-sealed semiconductor device in which a land electrode is reliably exposed from a portion with a standoff.

As described above, in order to prevent the land lead portion 4 from rising due to the injection pressure of the resin sealing as described in the present embodiment, the land portion of the land lead portion 4 is previously replaced with the lead as the first lead portion. The land electrode 16 of the land lead portion 4 is disposed below the land surface of the
Of the land electrode 16
The sealing resin does not wrap around to the surface of the land electrode 16 of the land lead portion 4, thereby suppressing the occurrence of resin burrs.

In this embodiment, a lead frame having a lead portion having a two-row configuration including a first lead portion and a second lead portion has been described as an example. However, the present invention is not limited to a two-row lead frame. It is needless to say that the present invention is also effective for a lead frame having a lead portion forming a plurality of rows such as three rows or four rows.

[0068]

As described above, according to the lead frame of the present invention,
A resin-encapsulated semiconductor device having land electrodes instead of conventional beam-shaped lead electrodes can be realized. According to the present invention, land electrodes on the bottom surface of the resin-encapsulated semiconductor device can be formed from a frame state without using a circuit board or the like. The reliability of mounting can be improved.

In the method of manufacturing a resin-encapsulated semiconductor device, a lead-bend step is not required because a protruding lead is not required unlike the conventional method. The bottom surface of the land electrode of the land lead portion is disposed, and the land electrode which is the bottom surface of the lead portion is disposed on the outer row of the land electrode to form two rows of external terminals in a linear or staggered arrangement. A mold package can be configured. And in the land electrode of the row configuration on the bottom surface of the resin-encapsulated semiconductor device of the present invention,
Since the outer land electrode is formed of a lead portion, and the side end of the outer portion is exposed from the package portion, a fillet portion is formed by providing a bonding agent such as solder to the outer side surface. And a two-point bonding structure of the bottom surface and the side surface, so that the mounting strength of the connection with the mounting board can be improved and the reliability of the connection can be improved.

Further, by the action of the lead frame and the structure of the lead frame according to the present invention, the formation of resin burrs on the land electrode surface on the bottom surface of the formed resin-encapsulated semiconductor device is eliminated, and the resin encapsulation for preventing the failure of external electrodes and the mounting failure is prevented. A semiconductor device having a stop type can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing a lead frame according to an embodiment of the present invention.

FIG. 2 is a view showing a lead frame according to an embodiment of the present invention;

FIG. 3 is a plan view showing a resin-sealed semiconductor device according to one embodiment of the present invention.

FIG. 4 is a bottom view showing the resin-sealed semiconductor device according to one embodiment of the present invention;

FIG. 5 is a sectional view showing a resin-sealed semiconductor device according to one embodiment of the present invention;

FIG. 6 is a sectional view showing a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 7 is a sectional view showing a mounting structure of a resin-sealed semiconductor device according to one embodiment of the present invention;

FIG. 8 is a sectional view showing the method for manufacturing the resin-encapsulated semiconductor device according to one embodiment of the present invention;

FIG. 9 is a sectional view showing the method of manufacturing the resin-sealed semiconductor device according to one embodiment of the present invention;

FIG. 10 is a sectional view showing the method of manufacturing the resin-sealed semiconductor device according to one embodiment of the present invention;

FIG. 11 is a sectional view showing the method of manufacturing the resin-encapsulated semiconductor device according to one embodiment of the present invention;

FIG. 12 is a sectional view showing the method for manufacturing the resin-encapsulated semiconductor device according to one embodiment of the present invention;

FIG. 13 is a sectional view showing the method of manufacturing the resin-encapsulated semiconductor device according to one embodiment of the present invention;

FIG. 14 is a partial view showing a land lead portion according to an embodiment of the present invention.

FIG. 15 is a partial cross-sectional view showing a state of resin sealing according to an embodiment of the present invention.

FIG. 16 is a partial cross-sectional view showing a state of resin sealing according to an embodiment of the present invention.

FIG. 17 is a partial cross-sectional view showing a state after resin sealing according to an embodiment of the present invention.

FIG. 18 is a view showing a land lead portion of a lead frame according to the embodiment for solving the problem of the present invention.

FIG. 19 is a view showing a land lead portion of a lead frame according to an embodiment of the present invention.

FIG. 20 is a plan view showing a conventional lead frame.

FIG. 21 is a sectional view showing a conventional resin-encapsulated semiconductor device.

FIG. 22 is a plan view showing a method for manufacturing a conventional resin-encapsulated semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die pad part 2 Frame frame 3 Suspended lead part 4 Land lead part 5 Lead part 6 Projection part 7 Groove part 8 Land part 9 Wide part 10 Groove part 11 Groove part 12 Semiconductor element 13 Bonding pad part 14 Fine metal wire 15 Sealing resin 16 Land electrode 17 Concave part 18 Mounting substrate 19 Bonding agent 20 Sealing sheet 21 First die 22 Second die 23 Resin burr 24 Half cut part 101 Frame frame 102 Die pad part 103 Suspended lead part 104 Inner lead part 105 Outer lead part 106 Tie bar Part 107 semiconductor element 108 thin metal wire 109 sealing resin

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tetsumasa Maru 1-1 Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 5F067 AA01 AA09 AB04 DE14

Claims (3)

[Claims] 1. A frame main body made of a metal plate, a die pad portion for mounting a semiconductor element disposed in a substantially central region of the frame main body, and the die pad portion is supported at a front end portion, and the frame is supported at the other end portion. Suspended lead portion connected to the frame, at least the tip portion extends toward the die pad portion,
The other end is connected to the frame, the first lead has a bottom surface serving as a land electrode, and the tip extends to the tip region of the first lead, and the tip is disposed. A second lead portion connected to the frame and having a bottom surface serving as a land electrode; two rows of land electrodes on the bottom surface of the first lead portion and land electrodes on the bottom surface of the second lead portion; A land electrode is formed, and at least the second lead portion is configured to be disposed below by the half-cut press so that the land electrode portion is positioned below the land electrode surface of the first lead portion. A lead frame, characterized in that: 2. A frame main body made of a metal plate, a die pad portion for mounting a semiconductor element disposed in a substantially central region of the frame main body, a tip end portion supporting the die pad portion, and the other end portion supporting the frame. Suspended lead portion connected to the frame, at least the tip portion extends toward the die pad portion,
The other end is connected to the frame, the first lead has a bottom surface serving as a land electrode, and the tip extends to the tip region of the first lead, and the tip is disposed. A second lead portion connected to the frame and having a bottom surface serving as a land electrode; two rows of land electrodes on the bottom surface of the first lead portion and land electrodes on the bottom surface of the second lead portion; A land electrode is formed, and at least the second lead portion is configured to be disposed below by the half-cut press so that the land electrode portion is positioned below the land electrode surface of the first lead portion. A step of preparing a lead frame; a step of mounting a semiconductor element on the die pad portion of the prepared lead frame; an electrode pad on a main surface of the semiconductor element mounted on the die pad portion; Connecting the upper surfaces of the first lead portion and the second lead portion to each other by a thin metal wire; and sealing at least the bottom surfaces of the die pad portion, the first lead portion, and the second lead portion on the back surface of the lead frame. A step of bringing a stop sheet into close contact, and applying a pressing force to at least the ends of the first lead portion and the second lead portion, thereby applying a land electrode surface of the first lead portion and a land electrode of the second lead portion. A step of resin-sealing the semiconductor element, the die pad portion, and the region of the fine metal wire with a sealing resin as an upper surface side of the lead frame in a state in which the surface is pressed against the sealing sheet; A method for manufacturing a resin-encapsulated semiconductor device, comprising: removing a sheet from the lead frame. 3. A pressing force is applied to at least ends of the first lead portion and the second lead portion to seal a land electrode surface of the first lead portion and a land electrode surface of the second lead portion. In the step of sealing the area of the semiconductor element, the die pad portion, and the thin metal wire with the sealing resin with the sealing resin as the upper surface side of the lead frame in a state where the first lead is pressed against the first lead, And the land electrode surface of the second lead portion is pressed and bitten by the sealing sheet, and the land electrode surface of the second lead portion is pressed by the sealing sheet. 3. The method for manufacturing a resin-encapsulated semiconductor device according to claim 2, wherein the semiconductor device does not come around.