JP2003347504A - Semiconductor device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To widen a range of combinations of mountable chip sizes in a semiconductor device wherein two chips are mounted in a stacked state. <P>SOLUTION: A die pad 2 of a lead frame is held between first and second LSI chips 3 and 6. By making the height of a bonding wire 5, which connects an electrode 4 of the first LSI chip 3 and an inner lead 1, lower than the thickness of the die pad 2, assembly can be made regardless of the size of the second LSI chip 6, leading to the formation of a thin package having a body thickness of 1 mm or less. Due to this structure, restrictions on sizes of the two LSI chips 3 and 6 can be reduced and a range of combinations of sizes of the two LSI chips 3 and 6 can be widened, resulting in realizing a thin device. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which semiconductor chips are stacked and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in order to reduce the cost and size of LSI semiconductor devices, LSIs having different functions have been developed.
There has been proposed a multi-chip package in which an LSI chip formed by I or different processes is three-dimensionally mounted.

A conventional example will be described below with reference to Japanese Patent Application Laid-Open No. 1-2353 / 1990.
The multi-chip package disclosed in Japanese Patent Publication No. 63 will be described with reference to FIG.

[0004] First, as shown in FIG.
A chip 53 is die-bonded to a die pad 51 of a lead frame, and an inner lead 52 and an electrode 55 are connected by a bonding wire 57. A second LSI chip 54 is die-bonded to the surface of the first LSI chip 53 with an insulating resin or the like, and external electrodes 56 and inner leads 5 are formed.
2 are connected by bonding wires 58 and packaged by transfer molding.

[0005] A method of manufacturing the conventional multi-chip package will be described. First, a first LSI chip 5 such as a logic or a memory is mounted on a die pad 51 of a lead frame.
3 is die-bonded with a die-bond resin 61 such as a conductive resin. Next, the second LSI chip 54 is die-bonded to the surface of the first LSI chip 53 with a die bond resin 62 such as an insulating resin. Next, the first and second LSI chips 53,
The external electrodes 55 and 56 of 54 are electrically connected to the inner leads 52 by wire bonding. Next, a sealing resin 59 is formed by transfer molding or the like and packaged.

According to this conventional configuration and manufacturing method,
After the first and second LSI chips 53 and 54 are die-bonded, the first LS
In order to enable the wire bonding of the I chip 53, the size of the second LSI chip 54 does not cover the external electrodes 55 of the first LSI chip 53 at the time of die bonding.
The die bond resin 62 protrudes and the first LSI chip 5
It is necessary not to cover the third electrode 55, and the second LS
The I chip 54 is limited to one that is sufficiently smaller than the first LSI chip 53.

[0007]

According to the above-described conventional multi-chip package with three-dimensional mounting, the size of the second LSI chip 54 located three-dimensionally on the upper side is smaller than that of the first LSI chip 53 on the lower side. Since it is necessary to be sufficiently smaller than the size, the applicable range in which the combination of the two chips can be applied is narrow. In particular, when a memory chip is applied to one chip, a normal memory chip is a rectangle having a large aspect ratio, and two sides (long side and short side) of a quadrangle are two sides of the other chip. In contrast, the long side is large and the short side is small,
In many cases, application to three-dimensional mounting is impossible, and the configuration has a narrow application range.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device in which two chips are stacked and mounted, and which can be applied to a wide range of combinations of mountable chip sizes, and a method of manufacturing the same.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor device using a lead frame having leads serving as inner leads and outer leads and a die pad, wherein a second semiconductor chip is provided above the first semiconductor chip. A mounted semiconductor device, wherein the surface of the first semiconductor chip is fixed to the lower surface of the die pad, the electrode on the surface of the first semiconductor chip and the inner lead are connected by a thin metal wire, The back surface faces the surface of the first semiconductor chip via the die pad, and the second semiconductor chip is arranged so as to overlap at least a part of the metal wiring, and the back surface of the second semiconductor chip is fixed to the upper surface of the die pad. And the second
Electrically connecting the electrodes on the surface of the semiconductor chip with the inner leads, covering the first semiconductor chip and the second semiconductor chip with a sealing resin, and exposing the outer leads outside the sealing resin. And

According to the first aspect of the present invention, since the second semiconductor chip is provided on the first semiconductor chip via the die pad, the thin metal wire connected to the electrode of the lower first semiconductor chip. Is made lower than the thickness of the die pad, the second semiconductor chip does not come into contact with the thin metal wires connected to the electrodes of the first semiconductor chip, and the first and second semiconductor chips are not contacted. And the applicable range of chip size combinations that can be mounted can be widened.

According to a second aspect of the present invention, in the semiconductor device according to the first aspect, the die pad includes a first chip fixing portion for fixing a first semiconductor chip on a lower surface, and a second semiconductor chip on an upper surface. A second chip fixing portion to be fixed,
It is characterized by having a connecting portion connecting the first chip fixing portion and the second chip fixing portion such that the first chip fixing portion is located below the second chip fixing portion.

According to the second aspect of the invention, in addition to the effect of the first aspect, by forming the die pad three-dimensionally, the thickness of the die pad can be increased, and the die pad can be connected to the electrode of the first semiconductor chip. The restriction on the height of the thin metal wire is relaxed, and the applicable range of the chip size is further expanded.

According to a third aspect of the present invention, there is provided a semiconductor device in which a second semiconductor chip is mounted on a first semiconductor chip using a lead frame having leads serving as inner leads and outer leads. An inner lead arranged so as to overlap the peripheral portion of the surface of the first semiconductor chip is fixed to the surface of the first semiconductor chip via an insulating tape, and the electrode on the surface of the first semiconductor chip and the inner lead are connected. The connection is made with a thin metal wire, the surface of the first semiconductor chip and the thin metal wire are covered with an insulating resin, the second semiconductor chip is placed on the insulating resin, and the electrodes and inner leads on the surface of the second semiconductor chip are connected to each other. Is electrically connected to the first
The semiconductor chip and the second semiconductor chip are covered with a sealing resin, and the outer leads are exposed outside the sealing resin.

According to the third aspect of the present invention, the surface of the first semiconductor chip and the fine metal wires connected to the electrodes on the surface of the first semiconductor chip are covered with the insulating resin, and the second metal is placed on the insulating resin. The second semiconductor chip does not come into contact with the fine metal wires connected to the electrodes of the first semiconductor chip, thereby eliminating the restrictions on the chip size of the first and second semiconductor chips. Thus, the applicable range of the combination of chip sizes that can be mounted can be widened.

According to a fourth aspect of the present invention, the semiconductor device includes an outer lead, a first inner lead continuous with the outer lead, a die pad set down from the first inner lead, and a die pad and the first inner lead. A lead frame having a second inner lead that is disposed between the first inner lead and the die pad so as to be located on the same plane or above the same plane as the die pad. The back surface is fixed on the die pad, and the electrode on the front surface of the first semiconductor chip and the second
And the inner lead of the
The inner lead and the second inner lead are connected by a thin metal wire, the second semiconductor chip is fixed to the surface of the first semiconductor chip with an insulating adhesive, and the electrode on the surface of the second semiconductor chip is The first inner lead is connected to the first semiconductor chip by a metal wiring, the first semiconductor chip and the second semiconductor chip are covered with a sealing resin, and the outer leads are exposed outside the sealing resin.

According to the fourth aspect of the present invention, the first semiconductor chip and the second semiconductor chip are formed by using the above-described lead frame.
Metal wires connected to the semiconductor chip do not intersect. Further, by forming the electrodes of the first semiconductor chip only on one pair of two opposing sides of the chip shape (square), the applicable range of the combination of the sizes of the two chips can be widened.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a semiconductor device.
5. The method of manufacturing a semiconductor device according to claim 4, wherein, when manufacturing the lead frame, the die pad held by the suspension lead, the outer lead, the first inner lead continuous with the outer lead, the die pad and the first pad. Forming a work-in-process of a lead frame provided with a second inner lead disposed between the inner lead and the die pad, and connecting the second inner lead to a suspension lead holding the die pad at an end. A step of fixing with a sticking tape, a step of separating a connection portion between the second inner lead and the die pad, and a step of downsetting the separated die pad portion and the second inner lead from the first inner lead. It is characterized by including.

According to the invention of claim 5, a lead frame used for the semiconductor device of claim 4 can be manufactured.

A semiconductor device according to a sixth aspect of the present invention has an outer lead, an inner lead continuous with the outer lead and having a tip set down, and a die pad set down from the inner lead excluding the tip. Using a lead frame that is down-set so that the tip of the inner lead is on the same plane or above the same plane as the die pad, the back surface of the first semiconductor chip is fixed on the die pad, The electrode on the surface of the chip and the downset end of the inner lead are connected by a thin metal wire, and the second semiconductor chip is fixed to the surface of the first semiconductor chip with an insulating adhesive. The electrode on the surface of the chip and the portion outside the downset end of the inner lead are connected by metal wiring, and the first semiconductor chip and It covers the second semiconductor chip with a sealing resin, characterized in that the exposed outer leads to the outside of the sealing resin.

According to the sixth aspect of the present invention, the first semiconductor chip and the second semiconductor chip are formed by using the above-described lead frame.
Metal wires connected to the semiconductor chip do not intersect. Further, by forming the electrodes of the first semiconductor chip only on one pair of two opposing sides of the chip shape (square), the applicable range of the combination of the sizes of the two chips can be widened.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multi-chip package (hereinafter referred to as MC) which is a semiconductor device according to an embodiment of the present invention.
P) will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
10A to 10C are cross-sectional views in the order of steps of a method for manufacturing an MCP according to the embodiment. In FIG. 1, reference numeral 1 denotes an inner lead (electrode portion, internal electrode portion) of a lead frame (support),
2 is a die pad of a lead frame (element mounting portion), 3 is a first LSI chip (first semiconductor chip), 4 is a first LSI chip.
5 is a bonding wire (metal thin wire) connecting the electrode 4 of the first LSI chip and the inner lead 1, 6 is a second LSI chip (second semiconductor chip), and 7 is a second Electrodes of the LSI chip, 8 is an insulating resin (insulating adhesive), 9 is a bonding wire for connecting the electrode 7 of the second LSI chip and the inner lead 1,
Reference numeral 10 denotes a sealing resin, and 11 denotes outer leads (external electrode portions) of a lead frame. FIG. 4 shows the first
FIG. 4 is a plan view showing an example of the configuration (size) of the LSI chip 3 and the second LSI chip 6 of FIG.

In the method of manufacturing an MCP according to the present embodiment, first, as shown in FIG. 1A, a first LSI chip 3 is die-bonded to a die pad 2 of a lead frame. The material of the lead frame is 42 alloy, Cu or the like, and the thickness is about 0.15 mm. The die pad 2
For the purpose of improving the flow of the resin in the transfer molding process to be performed later and reducing the thickness of the package, press working is performed in advance so that the position is lower than the position of the inner lead 1 of the lead frame. deep. In the die bonding step, although not shown, the resin is cured by heating using a conductive or insulating epoxy or polyimide resin, and the first LSI chip 3 is fixed. Then, the electrodes 4 of the first LSI chip 3 and the inner leads 1 are connected by bonding wires 5. The diameter and material of the bonding wire 5 and the method of wire bonding are the same as those of the bonding wire 9 described later.

Next, as shown in FIG. 1B, the second L
The back surface of the SI chip 6 is fixed to the front surface of the first LSI chip 2 using an insulating resin 8. At this time, the insulating resin 8
The thickness of the first LSI chip 6 is such that the back surface of the second LSI chip 6 is
The position is set to be higher than the uppermost part of the bonding wire 5 of the chip 3. Usually, the loop height of the bonding wire 5 is set to about 50 μm to 200 μm, and the thickness of the insulating resin 8 is set to about 55 μm to 300 μm. The material of the insulating resin 8 is liquid epoxy, polyimide, acrylic, or the like. After being formed on the surface of the first LSI chip 3 by a dispensing method, a stamping method, or the like, the second LSI
The chip 6 is set and cured by heating. The properties of the insulating resin 8 include not only a liquid but also a solid formed by a B stage, an insulating film, a film having an adhesive material formed on both sides, or a thermoplastic film. The formation region of the insulating resin 8 here is the first region.
In this case, since the insulating resin 8 can be a film type, the workability can be improved and the cost can be reduced.

Next, as shown in FIG. 1C, the second L
The electrodes 7 of the SI chip 6 and the inner leads 1 are electrically connected by connecting the bonding wires 9 by wire bonding. The bonding wire 9 is usually 1
The diameter is about 8 μm to 30 μm, and the material is Au, C
u, Al, or the like, in which an insulating film is formed on the surface of the bonding wire 9 can also be used. As a method of wire bonding, ball bonding by ultrasonic thermocompression bonding or wedge bonding is used. At this time, the portion of the back surface where the electrode 7 of the second LSI chip 6 is located is not fixed with the insulating resin 8, but bonding is performed from the end of the non-fixed portion of the insulating resin 8 forming region. If the distance to the position where the wire 9 is connected is up to about 2 mm, the second LSI chip 6
With this rigidity, it can sufficiently withstand the load during wire bonding, and the wire bonding property can be sufficiently ensured.
Further, by adopting the configuration shown in FIGS. 2 and 3 described later, wire bonding of the second LSI chip 6 can be easily performed.

Next, as shown in FIG. 1D, a sealing resin 10 is formed by transfer molding, and then the outer leads 11 are formed to complete the MCP.

As shown in FIG. 1D, in the MCP of the present embodiment, a thick insulating resin 8 is provided on the surface of the first LSI chip 2 and the back surface of the second LSI chip 6 is
Bonding wire 5 for connecting first LSI chip 3
, The second LSI chip 6 does not come into contact with the bonding wires 5 connected to the first LSI chip 3. Conventionally, the size of two LSI chips to be stacked needs to be smaller for the upper LSI chip than for the lower LSI chip.
In the present embodiment, as is apparent from FIG. 1, the insulating resin 8 is provided so as to be thicker than the loop height (uppermost portion) of the bonding wires 5 of the first LSI chip 3. As shown in FIG. 4, even if at least one of the two orthogonal sides of the planar shape of the upper second LSI chip 6 is larger than the two orthogonal sides of the planar shape of the first LSI chip 3, The bonding wires 5 can be stacked without being damaged. Therefore, the size restriction of the two LSI chips 3 and 6 is reduced, the application range of the combination of the sizes of the two LSI chips 3 and 6 is wide, and the versatility is high.

In the present embodiment, the first and second L
Since the size (planar shape) of the SI chips 3 and 6 is shown in FIG. 4, a part of the bonding wire 5 in which the upper second LSI chip 6 is connected to the lower first LSI chip 3 And the second LS
When the size of the I chip 6 is small and is arranged inside the electrode 4 of the first LSI chip 3, the second LS
It goes without saying that the I chip 6 does not overlap with the bonding wires 5 connected to the first LSI chip 3.

[Second Embodiment] FIG. 2 shows a second embodiment of the present invention.
FIG. 3 is a cross-sectional view of the MCP according to the embodiment, and portions corresponding to those in FIG.

In the second embodiment shown in FIG. 2, the region where the insulating resin 8 is formed is the entire surface of the first LSI chip 3. Other configurations and manufacturing methods are the same as in the first embodiment. According to the second embodiment, the first
Compared with the embodiment, the area where the second LSI chip 6 is fixed with the insulating resin 8 is expanded, and the second LSI chip 6 to be stacked is stacked.
Even if the size of the chip 6 is larger than that of the first embodiment, wire bonding to the second LSI chip 6 can be easily performed.

In the case of the second embodiment, since the insulating resin 8 is formed over the entire surface of the first LSI chip 3,
The insulating resin 8 is formed in at least the entire region where the first LSI chip 3 and the second LSI chip 6 overlap.

[Third Embodiment] FIG. 3 shows a third embodiment of the present invention.
FIG. 3 is a cross-sectional view of the MCP according to the embodiment, and portions corresponding to those in FIG.

In the third embodiment shown in FIG. 3, the size (planar shape) of the die pad 2 of the lead frame is made substantially equal to the size (planar shape) of the second LSI chip 6, and the second The region where the insulating resin 8 for fixing the LSI chip 6 is formed is a region extending from the entire back surface of the second LSI chip 6 to the surface of the first LSI chip 4 and the die pad 2. Are the same as in the first embodiment. With this configuration, the second LSI
The back surface corresponding to the position of the electrode 7 of the chip 6 is an insulating resin 8
, The wire bonding property to the second LSI chip 6 is improved, and the first LSI chip 3 and the second LSI chip are further improved as compared with the first and second embodiments. The size difference between the chips 6 can be increased, and the applicable range can be further expanded.

In the case of the third embodiment, since the insulating resin 8 is formed under the entire back surface of the second LSI chip 6, the first LSI chip 3 and the second LSI chip 6 are separated. Needless to say, the insulating resin 8 is formed in all of the overlapping regions, as shown in FIG.
The insulating resin 8 is also formed on at least a part of the side surface of the I chip 3.

In the above-described first to third embodiments, the case of packaging is a QFP or SOP by resin sealing, but a CSP or BGA package using a carrier may be used. FIG. 5 shows the case of the CSP or BGA package. (A), (b), (c) of FIG.
Respectively correspond to the first, second and third embodiments. In FIG. 5, reference numeral 31 denotes a wiring board (support) called a carrier. The wiring board 31 is generally formed by wiring a plurality of layers of insulating substrates made of ceramic or epoxy resin with copper, and usually has a carrier (package size). This is the size of the wiring board 31). Reference numerals 32 and 33 denote electrode portions of the wiring board 31. The electrode portion 32 is connected to the electrode 4 of the first LSI chip 3, and the electrode portion 33 is connected to the electrode 7 of the second LSI chip 6. Note that the element mounting portion of the support is the wiring substrate 31 in the case of FIGS.
5C, the portion where the first LSI chip 3 is mounted and the insulating resin 8 are formed on the wiring board 31 in the case of FIG. That is the part that is.

[Fourth Embodiment] FIG. 6 shows a fourth embodiment of the present invention.
FIG. 3 is a cross-sectional view of the MCP according to the embodiment, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

The MCP according to the present embodiment comprises a first LSI chip 3 and a second LSI chip as in the first to third embodiments.
Instead of fixing the chip 6 with the thick insulating resin 8,
The die pad 2 of the lead frame is sandwiched between the first and second LSI chips 3 and 6, the surface of the first LSI chip 3 is fixed to the lower surface of the die pad 2, and the back surface of the second LSI chip 6 is Is fixed to the upper surface of. The height of the bonding wire 5 connecting the electrode 4 of the first LSI chip 3 and the inner lead 1 is smaller than the thickness of the die pad 2.

In the method of manufacturing the MCP according to the fourth embodiment, first, the first LSI chip 3 is die-bonded to the lower surface of the die pad 2 of the lead frame. At this time, the area to be die-bonded and the die pad size are the first LS
It is inside the electrode 4 part of the I chip 3. Although not shown, the resin is cured by heating using an insulating epoxy or polyimide resin, and the first LSI chip 3 is fixed. Next, the electrodes 4 of the first LSI chip 3 and the inner leads 1 are connected by bonding wires 5 which are thin metal wires. At this time, the loop height of the bonding wire 5 must be lower than the thickness (about 80 μm to 200 μm) of the die pad 2, and the loop height is 50 μm to 100 μm.
m. Thereafter, the back surface of the second LSI chip 6 is die-bonded to the upper surface of the die pad 2, and the electrodes 7 of the second LSI chip 6 and the inner leads 1 are connected by bonding wires 9 which are thin metal wires. Finally, molding is performed with the sealing resin 10 so that only the outer leads 11 as the external electrodes are exposed.

According to the present embodiment, the first and second LS
The first LS is sandwiched between the die pads 2 by the I chips 3 and 6.
By making the height of the bonding wire 5 connecting the electrode 4 of the I chip 3 and the inner lead 1 lower than the thickness of the die pad 2, the bonding can be performed irrespective of the size of the second LSI chip 6, and the body thickness can be reduced. A thin package of 1 mm or less can be formed. Therefore, the restriction on the size of the two LSI chips 3 and 6 can be reduced, the applicable range of the combination of the sizes of the two LSI chips 3 and 6 can be widened, and a thin device can be realized.

[Fifth Embodiment] FIG. 7A is a sectional view of an MCP according to a fifth embodiment of the present invention.
A is a three-dimensional die pad, and other portions corresponding to those in FIG. 1 are denoted by the same reference numerals. FIG. 7B is a plan view of the three-dimensional die pad 2A.

The MCP of the present embodiment has a configuration using a three-dimensional die pad 2A in place of the die pad 2 of FIG. 6, and is otherwise the same as FIG. The three-dimensional die pad 2A is
A first chip fixing portion 2a to which the first LSI chip 3 is fixed on the lower surface, a second chip fixing portion 2b to which the second LSI chip 6 is fixed on the upper surface, and a first chip fixing portion 2a
Is located below the second chip fixing portion 2b.
The lead frame is machined and formed so as to include a connecting portion 2c for connecting the chip fixing portion 2a and the second chip fixing portion 2b.

In the method of manufacturing the MCP according to the present embodiment, first, the first LSI chip 3 is die-bonded to the lower surface of the first chip fixing portion 2a of the three-dimensional die pad 2A of the lead frame. At this time, the size of the region to be die-bonded and the size of the first chip fixing portion 2a are equal to those of the first LSI chip 3.
Inside the electrode 4 part. Although not shown, the resin is cured by heating using an insulating epoxy or polyimide resin, and the first LSI chip 3 is fixed. next,
The electrodes 4 of the first LSI chip 3 and the inner leads 1 are connected by bonding wires 5 which are thin metal wires. At this time, the loop height of the bonding wire 5 must be lower than the height (about 300 μm) of the three-dimensional die pad 2A, and the loop height is about 250 μm. After that, the back surface of the second LSI chip 6 is
A is die-bonded to the upper surface of the second chip fixing portion 2b of A, and the electrodes 7 of the second LSI chip 6 and the inner leads 1 are connected by bonding wires 9 which are thin metal wires. Finally, molding is performed with the sealing resin 10 so that only the outer leads 11 as the external electrodes are exposed.

According to the present embodiment, the electrodes 4 of the first LSI chip 3 are different from those of the fourth embodiment shown in FIG.
The restriction on the height of the bonding wire 5 which is a thin metal wire to be connected to the wire is relaxed, and the wiring of a thin metal wire having a diameter of φ25 μm to 30 μm and a wire length of about 6 mm becomes possible, and the applicable range of the chip size is dramatically improved.

[Sixth Embodiment] FIG. 8 shows a sixth embodiment of the present invention.
It is sectional drawing of the MCP in embodiment. In FIG. 8, reference numeral 12 denotes a double-sided adhesive tape made of an insulating resin. Other parts corresponding to those in FIG. 1 are denoted by the same reference numerals.

In the MCP of the present embodiment, the inner lead 1 overlaps the surface of the first LSI chip 3 and the inner lead 1 in the overlapping portion is the first L chip.
An insulating resin 8 is fixed to the surface of the SI chip 3 with an insulating tape 12 so as to cover the surface of the first LSI chip 3 and the bonding wires 5 connected to the first LSI chip 3.
Is formed, and the second LSI chip 6 is formed on the insulating resin 8.
Is fixed.

In the method of manufacturing the MCP according to the present embodiment, first, the first LSI chip 3 is fixed to the lower surface of the inner lead 1 of the lead frame via the insulating tape 12, and the electrode 4 of the first LSI chip 3 is fixed. And inner lead 1
Are connected by a bonding wire 5 which is a thin metal wire. After that, the surface of the first LSI chip 3 is covered with the insulating resin 8. At this time, the bonding wires 5, the electrodes 4 of the first LSI chip 3, and a part of the inner leads 1 are covered. The second LSI chip 6 is die-bonded on the insulating resin 8, and the electrodes 7 of the second LSI chip 6 and the inner leads 1 are bonded.
Are connected by a bonding wire 9 which is a thin metal wire. Finally, molding is performed with the sealing resin 10 so that only the outer leads 11 as the external electrodes are exposed.

According to the present embodiment, the insulating resin 8 is formed so as to cover the surface of the first LSI chip 3 and the bonding wires 5 connected to the first LSI chip 3,
By fixing the second LSI chip 6 on the insulating resin 8, the second LSI chip 6 does not come into contact with the bonding wires 5 connected to the first LSI chip 3, so that the first and second LSI chips 6 The restriction on the chip size of the two LSI chips 3 and 6 can be eliminated, and the applicable range of the combination of chip sizes that can be mounted can be widened.

[Seventh Embodiment] FIG. 9A is a plan view of a MCP according to a seventh embodiment of the present invention before resin sealing, and FIG. -A 'sectional view,
FIG. 9C is a sectional view taken along the line BB 'in FIG. 9A. FIG. 10 is a process order plan view showing a manufacturing process of a lead frame used for the MCP according to the seventh embodiment of the present invention.

9 and 10, reference numeral 13 denotes a first inner lead of a lead frame, 14 denotes a die pad of the lead frame, 15 denotes a second LSI chip (second semiconductor chip), and 16 denotes a second LSI chip. 15 electrodes, 17
Is a bonding wire for connecting the second LSI chip 15, 18 is a first LSI chip (first semiconductor chip), 19 is an electrode of the first LSI chip 18, and 21 is a connection for the first LSI chip 18. Bonding wire,
22 is a bonding wire connecting the first and second inner leads 13 and 24a, 23 is an insulating adhesive tape, 24a is the second inner lead of the lead frame,
24b is a small die pad, and 25 is an IC chip.

The MCP of this embodiment includes an outer lead (not shown), a first inner lead 13 continuous with the outer lead, a die pad 14 set down from the first inner lead 13, and a die pad 14. And the first inner lead 13 and the die pad 1
4, the second inner lead 24a and the small die pad 24b which are set down so as to be located on the same plane as
And a lead frame having the following. Other configurations will be described in place of the following manufacturing method.

In the method of manufacturing the MCP according to the present embodiment, the first LSI chip 18 is die-bonded to the down-set die pad 14 and then the second LSI chip 1
5 is mounted and fixed on the first LSI chip 18. At this time, although not shown, the resin is cured and fixed by heating through an insulating epoxy or polyimide resin between the second LSI chip 15 and the first LSI chip 18. Before or after this, the IC chip 25 is also die-bonded to the small die pad 24b. Next, the electrode 19 of the first LSI chip 18 and the second inner lead 24a of the lead frame are connected to the bonding wire 2 which is a thin metal wire.
1 and the second inner lead 24a and the first inner lead 24a.
Of the first inner lead 13 and the electrode 19 of the first LSI chip 18 are connected by a bonding wire which is a thin metal wire. After that, the electrodes 16 of the second LSI chip 15 and the first inner leads 13 are connected by bonding wires 17. Finally, a sealing resin (not shown) is formed so that only the outer leads as the external electrodes are exposed.

According to the configuration of FIG. 9, the bonding wires of the first LSI chip 18 and the second LSI chip 15 do not intersect by using the above-described lead frame. Further, since the electrodes 19 of the first LSI chip 18 are formed only on one pair of two opposite sides of the chip shape (square), the electrodes 19 are 2
The range of application of a combination of one chip size can be widened. Further, the height of the die pad 14 can be made higher than that of FIG. 9 so that the second LSI chip 15 can be overlapped on the inner lead 13.

As shown in FIG. 10A, the lead frame used in this embodiment is provided with a die pad 14 at the center, a first inner lead 13 around the center, and a die pad. A lead frame (work in process) is provided between the first inner lead 13 and the second inner lead 13 and the second inner lead 24a and the small die pad 24b connected from the die pad 14 are provided. Next, FIG.
As shown in FIG. 0 (b), an insulating adhesive tape 23 is attached to the lower surfaces of the second inner leads 24a and the small die pads 24b so as to overlap the support leads (suspension leads) holding the die pads 14. Next, FIG.
As shown in (c), the second inner lead 24a and the small die pad 24b are separated from the die pad 14 (C in FIG. 10A indicates a part to be separated), and thereafter, the die pad 14 and the second inner lead 24a and The downset portion 26 is provided on the support lead so that the small die pad 24b is located below the first inner lead 13.

As described above, the second inner leads 24a
Is located on the same plane as the die pad 14 set down from the first inner lead 13 so that the MCP
Wiring can be easily done. Further, by providing the small die pad 24b in the area of the second inner lead 24a, the IC chip 25 (FIG. 9) can be mounted.

In the present embodiment, the second inner lead 24a and the small die pad 24b are located on the same plane as the die pad 14, but the down-set is performed so that the second inner lead 24a and the small die pad 24b are located below the first inner lead 13. If this is done, the same effect can be obtained even if it is positioned above the same plane as the die pad 14. In this case, for example, FIG.
By providing a downset portion between the adhesive tape 23 of the support lead and the die pad 14 in addition to the downset portion 26 of 0, the second lower portion is provided above the die pad 14 and below the first inner lead 13. Inner lead 24a and small die pad 24b can be located.

When it is not necessary to mount the IC chip 25, it goes without saying that the small die pad 24b need not be provided.

[Eighth Embodiment] FIG. 11A is a plan view of an MCP according to an eighth embodiment of the present invention before resin sealing, and FIG. 11A is a sectional view, and FIG. 11C is a sectional view taken along the line BB ′ in FIG. In FIG. 11, reference numeral 13a denotes a downset portion for lowering the tip portion 13b of the inner lead 13, and other portions corresponding to those in FIG. 9 are denoted by the same reference numerals.

The lead frame used in the MCP of the present embodiment includes an outer lead (not shown), an inner lead 13 which is continuous with the outer lead, and has a tip 13b downset, and a tip 13b of the inner lead 13.
And a die pad 14 which is set down from a portion except for the die pad 14. The inner lead tip 13b is set down on the same plane as the die pad 14 or above the same plane, and the down set height is 100 to 40.
The range is 0 μm. Other configurations of the MCP will be described instead of the following manufacturing method.

In the method of manufacturing the MCP according to the present embodiment, the first LSI chip 18 is die-bonded to the down-set die pad 14, and then the second LSI chip 1
5 is mounted and fixed on the first LSI chip 18. At this time, although not shown, the resin is cured and fixed by heating through an insulating epoxy or polyimide resin between the second LSI chip 15 and the first LSI chip 18. Next, the electrodes 19 of the first LSI chip 18
And the down-set inner lead tip 13b are connected by a bonding wire 21 which is a thin metal wire. Further, the outside of the electrode 16 of the second LSI chip 15 and the downset portion of the inner lead 13 is connected by a bonding wire 17 which is a thin metal wire. The bonding wires 21 and 17 connected to the first and second LSI chips 18 and 15 do not contact each other in the height direction. Finally, a sealing resin (not shown) is formed so that only the outer leads as the external electrodes are exposed.

According to the structure of FIG. 11, the first LSI chip 18
And the bonding wires of the second LSI chip 15 do not intersect. In addition, since the electrodes 19 of the first LSI chip 18 are formed only on one pair of two opposing sides of the chip shape (square shape), two electrodes 19 are formed in the cross-sectional direction BB ′ in FIG. The applicable range of combinations of chip sizes can be widened. Further, the height of the die pad 14 can be made higher than that of FIG. 11 so that the second LSI chip 15 can be overlapped on the inner lead 13. Further, it is possible to perform wiring at a lower height of the bonding wire (a portion intersecting the upper and lower chips), and the present invention can be applied to a thin package having a package body thickness of 1 mm or less.

[0061]

As described above, according to the present invention, the back surface of the upper second semiconductor chip to be stacked is positioned higher than the metal wires connected to the electrodes on the lower first semiconductor chip. Because of the structure, there is no limitation on the size of the two semiconductor chips to be stacked, the application range of the MCP is wide, the cost is low, and a small-sized, high-density, and high-performance stacked semiconductor device can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in a process order of a method for manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor device according to a third embodiment of the present invention.

FIG. 4 is a plan view showing an example of a combination of a first LSI chip and a second LSI chip according to an embodiment of the present invention.

FIG. 5 is a sectional view of a semiconductor device showing another example of the first, second, and third embodiments of the present invention.

FIG. 6 is a sectional view of a semiconductor device according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a semiconductor device according to a fifth embodiment of the present invention and a plan view of a three-dimensional die pad used for the semiconductor device.

FIG. 8 is a sectional view of a semiconductor device according to a sixth embodiment of the present invention.

FIG. 9 is a plan view and a cross-sectional view of a semiconductor device according to a seventh embodiment of the present invention.

FIG. 10 is an essential part plan view showing a method of manufacturing a lead frame used in a semiconductor device according to a seventh embodiment of the present invention in the order of steps;

FIG. 11 is a plan view and a cross-sectional view of a semiconductor device according to an eighth embodiment of the present invention.

FIG. 12 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Inner lead of lead frame 2 Die pad of lead frame 2A Three-dimensional die pad 2a First chip fixing part 2b of three-dimensional die pad Second chip fixing part 2c of three-dimensional die pad Connecting part 3 of three-dimensional die pad 3 First LSI chip 4 First LSI Chip Electrode 5 Bonding Wire Connecting First LSI Chip 6 Second LSI Chip 7 Second LSI Chip Electrode 8 Insulating Resin 9 Bonding Wire 10 Connecting Second LSI Chip Stop resin 11 Outer lead 12 of lead frame 12 Insulating tape 13 (First) inner lead 13a of lead frame Down set part 13b of inner lead 14 Tip of inner lead 14 Die pad 15 Second LSI chip 16 Second LSI chip Electrode 17 Connects the second LSI chip Bonding wire 18 first LSI chip 19 electrode 21 of first LSI chip bonding wire 22 connecting first LSI chip bonding wire 23 connecting first and second inner leads 23 insulating bonding tape 24a lead frame Second inner lead 24b small die pad 25 IC chip

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Toshiyuki Fukuda             Matsushita Electric, 1006 Kadoma, Kazuma, Osaka             Sangyo Co., Ltd.

Claims (6)

[Claims] 1. A semiconductor device having a second semiconductor chip mounted on a first semiconductor chip using a lead frame having leads serving as inner leads and outer leads and a die pad, wherein the first semiconductor chip is mounted on a first semiconductor chip. The front surface of the semiconductor chip is fixed to the lower surface of the die pad, the electrode on the front surface of the first semiconductor chip and the inner lead are connected by a thin metal wire, and the rear surface of the second semiconductor chip is connected via the die pad. Facing the front surface of the first semiconductor chip, and arranging the second semiconductor chip so as to overlap at least a part of the metal wiring, and fixing the back surface of the second semiconductor chip to the upper surface of the die pad; An electrode on the surface of the second semiconductor chip is electrically connected to the inner lead, and the first semiconductor chip and the second semiconductor chip are electrically connected. Covering the flop with a sealing resin, the semiconductor device being characterized in that to expose the outer lead to the outside of the sealing resin. 2. The die pad has a first chip fixing portion for fixing a first semiconductor chip on a lower surface, a second chip fixing portion for fixing a second semiconductor chip on an upper surface, and the first chip fixing portion. 2. A connecting part which connects the first chip fixing part and the second chip fixing part such that the part is located below the second chip fixing part. Semiconductor device. 3. A semiconductor device in which a second semiconductor chip is mounted on a first semiconductor chip using a lead frame having leads serving as inner leads and outer leads. An inner lead arranged so as to overlap the peripheral portion of the surface is fixed to the surface of the first semiconductor chip via an insulating tape, and the electrode on the surface of the first semiconductor chip and the inner lead are connected by a thin metal wire. Connecting, covering the surface of the first semiconductor chip and the fine metal wire with an insulating resin, placing the second semiconductor chip on the insulating resin, and connecting the electrode on the surface of the second semiconductor chip with the electrode. An inner lead is electrically connected, the first semiconductor chip and the second semiconductor chip are covered with a sealing resin, and the outer lead is provided outside the sealing resin. Wherein a the out was. 4. An outer lead, a first inner lead continuous with the outer lead, a die pad set down from the first inner lead, and a die pad disposed between the die pad and the first inner lead. Using a lead frame having a second inner lead that is down-set from the first inner lead so as to be on the same plane as the die pad or above the same plane; A back surface is fixed on the die pad, and an electrode on the front surface of the first semiconductor chip is connected to the second semiconductor chip.
And the first inner lead and the second inner lead are connected by a thin metal wire, and the surface of the first semiconductor chip is connected to the second inner lead by an insulating adhesive. Fix the semiconductor chip of
An electrode on the surface of the second semiconductor chip and the first inner lead are connected by metal wiring, and the first semiconductor chip and the second semiconductor chip are covered with a sealing resin. A semiconductor device wherein the outer leads are exposed to the outside. 5. The method of manufacturing a semiconductor device according to claim 4, wherein, when manufacturing a lead frame, a die pad held by a suspension lead, an outer lead, and a first inner lead connected to the outer lead. Forming a work-in-process of the lead frame provided with a second inner lead disposed between the die pad and the first inner lead and connected to the die pad; and Fixing a lead with an adhesive tape with a suspension lead holding the die pad as an end, separating a connection portion between the second inner lead and the die pad, and removing the die pad portion and the second Downsetting the inner lead from the first inner lead. The method of production. 6. An outer lead, an inner lead that is continuous with the outer lead and has a tip set down, and a die pad that is set down from the inner lead excluding the tip and includes a die pad. Using a lead frame that is down-set so that a tip portion is on the same plane or above the same plane as the die pad, the back surface of the first semiconductor chip is fixed on the die pad, Connecting the electrode on the surface of the semiconductor chip and the downset end of the inner lead with a thin metal wire, fixing the second semiconductor chip to the surface of the first semiconductor chip with an insulating adhesive; An electrode on the surface of the second semiconductor chip and a portion outside the downset end of the inner lead are connected by metal wiring A semiconductor device, characterized in that said first semiconductor chip and the second semiconductor chip is covered with a sealing resin to expose the outer lead to the outside of the sealing resin.