JP4427535B2 - Mounting method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device capable of achieving a low-profile size and low stiffness as well as reducing a warpage of the package, while assuring flatness as an element semiconductor device product. <P>SOLUTION: The semiconductor device incorporates an organic substrate which has metallic traces on its top surface, a low-profile silicon chip connected with the metallic traces on this organic substrate using a flip chip structure, and sealing materials encapsulated between the organic substrate and the silicon chip for protection of the top surface on the silicon chip. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention relates to a method for mounting a semiconductor device for a semiconductor integrated circuit such as an LSI, VLSI, ULSI, or GI.

FIG. 1 shows a semiconductor package (BGA: Ball Grid Arr) currently used.
It is a cross-sectional perspective view which shows one structural example of ay). In this semiconductor package, a silicon chip 102 having a thickness of 300 μm to 450 μm or more is mounted on a substrate 101 which is an interposer. Bonding pad (electrode) of silicon chip 102
Are connected to the electrodes on the surface of the substrate 101 by bonding wires 103. Further, from the electrode on the surface side of the substrate 101, through the through hole formed in the substrate 101, the substrate 101
Is electrically connected to a solder ball (substrate mounting terminal) 104 disposed on the back surface side.
The package is molded in such a shape that the silicon chip 102 is encapsulated with the mold resin 105. Then, it is connected to a mounting substrate via solder balls (substrate mounting terminals) 104 to constitute a mounting body.

However, the thickness of the semiconductor package shown in FIG. 1 is about 1.2 mm even if it is thin, and the package is sufficiently satisfactory to meet the recent demand for thinner packages due to the downsizing and weight reduction of portable devices and the like. It was not thick.

Therefore, in order to further reduce the thickness of the semiconductor package, it is conceivable to reduce the thickness of each constituent material of the package (see, for example, Patent Document 1). However, if the thickness of each constituent material is simply reduced, the warpage of the package increases, and there is a problem that flatness as a single product cannot be secured. For example, in the case of realizing a 0.12 mm package, each component material to be used, for example, a mold resin is used as it is.
When used at a Young's modulus of about 12 to 25 GPa, a large warp of about 1.5 mm occurs for a length of 20 mm. In addition, since the rigidity of each constituent material itself is high, a resin crack occurs even with a slight displacement, and the reliability as a product cannot be secured.

From such a point, conventionally, even if the package thickness is extremely thin, it has not been realized as a semiconductor package.
JP-A-9-232503

  The present invention provides a method for mounting a semiconductor device having low rigidity and high mounting reliability.

According to one embodiment of the present invention, there is provided a method for mounting a semiconductor device, including a step of thinning a semiconductor chip to a thickness of 10 μm to 150 μm, and sealing above the main surface of a flexible substrate having a plurality of metal wirings formed on the main surface. The step of mounting the semiconductor chip via a member , the plurality of mounting wirings of the mounting substrate on which a plurality of mounting wirings are formed on the main surface, and the plurality of metal wirings are respectively aligned and electrically connected to each other A step of electrically connecting the plurality of mounting wirings and the plurality of metal wirings with each other, wherein a first adhesive layer is provided on an exposed portion of the flexible substrate between the plurality of metal wirings. Providing the second adhesive layer at an exposed portion of the mounting substrate between the plurality of mounting wirings, aligning the plurality of metal wirings and the plurality of mounting wirings; A step of applying a predetermined pressure between the substrate and the mounting substrate to bond the first and second adhesive layers to each other, and to connect the plurality of mounting wirings and the plurality of metal wirings to each other to connect each other. It is characterized by that.

According to the present invention, it is possible to provide a method for mounting a semiconductor device having low rigidity and high mounting reliability.

According to one embodiment of the present invention, it is an object of the present invention to provide a semiconductor package that can be thinned to achieve low rigidity, and can have flatness as a single product with small warpage of the package.

Another aspect of the present invention is to provide a mounting body having a small overall thickness and high mounting reliability.

According to still another aspect of the present invention, there is provided a mounting body having low rigidity and high mounting reliability that can be mounted on a curved surface such as a side wall of a pipe.

Another aspect of the present invention is to provide a mounting body in which a plurality of semiconductor chips are stacked in the thickness direction and the overall thickness is thin and mounting reliability is high.

According to still another aspect of the present invention, there is provided a method for manufacturing a mounting body that allows the mounting body to be easily assembled.

One embodiment of the present invention includes a low-rigidity board (hereinafter referred to as a “flexible board”) on which a plurality of metal wirings are formed on a main surface, and a plurality of connection pads disposed above the flexible board. Connecting metal for electrically connecting a low-rigidity semiconductor chip (hereinafter referred to as “flexible semiconductor chip”), a plurality of connection pads on the semiconductor chip, and a plurality of metal wirings on the flexible substrate. And a flexible package comprising a sealing member sealed between a flexible substrate and a flexible semiconductor chip.

A flexible package according to another embodiment of the present invention is characterized in that a flexible semiconductor chip having a reduced rigidity is mounted on a semiconductor chip that is thinner than a commonly used thickness. Semiconductor chips include silicon (Si) and germanium (Ge) elemental semiconductors, gallium arsenide (GaAs), gallium phosphide (GaP), and indium phosphide (InP).
Alternatively, a compound semiconductor chip such as silicon carbide (SiC) may be used. Further, the rigidity of the entire package is reduced by reducing the thickness of each component of the package such as a flexible substrate. For this reason, generation | occurrence | production of the package crack by displacement can be avoided. Further, since the sealing member is enclosed between the flexible substrate and the flexible semiconductor chip, the warpage of the package can be extremely reduced. For this reason, it becomes possible to ensure sufficient flatness as a single product of the flexible package. In particular, if the sealing member is made of a material having a low linear expansion coefficient, it is possible to further ensure flatness during normal times and a low-rigidity structure, so that it can be mounted on a curved surface. Further, it can be applied to an IC card or the like by utilizing the feature of being thin and having low rigidity.

Still another aspect of the present invention is a flexible substrate having a main surface having a plurality of mounting wirings formed on the main surface, a plurality of mounting wirings and a plurality of metal wirings electrically connected to each other. And a flexible semiconductor chip disposed above the main surface of the flexible substrate,
A semiconductor device, i.e., a module, comprising a plurality of connection pads, a connection metal for electrically connecting a plurality of metal wirings, and a sealing member sealed between the flexible substrate and the flexible semiconductor chip. ).

In a mounting module according to still another aspect of the present invention, a flexible semiconductor chip that is formed thinner than a commonly used thickness is mounted so as to reduce rigidity. In addition, since the thickness of each component such as a flexible substrate is reduced, the entire mounting body is reduced in rigidity. Therefore, even when a stress due to a difference in expansion coefficient occurs due to a temperature history during assembly work or a temperature change as an operating environment, the stress can be relaxed. For example, since the linear expansion coefficients of the mounting substrate and the semiconductor chip are greatly different from each other, due to temperature changes, the mounting substrate extends relative to the semiconductor chip on the high temperature side, and the mounting substrate relative to the semiconductor chip on the low temperature side. Shrinks.

However, in the mounting body according to still another aspect of the present invention, since the thickness of the semiconductor chip is thin, the degree of freedom of displacement in the direction perpendicular to the surface of the semiconductor chip is large. That is, since the semiconductor chip can be freely displaced in the direction perpendicular to the surface thereof, the stress is relieved. Therefore, the internal structure is not easily broken due to the temperature change, and the mounting reliability is improved. As a result, it is possible to ensure the reliability of the mounted body as a product. In addition, since the sealing member is enclosed between the flexible substrate and the flexible semiconductor chip, the warping of the mounting body can be made extremely small, and the flatness as a single product can be sufficiently secured. become.

Since the mounting body according to another aspect of the present invention has a low rigidity structure, a configuration in which the mounting substrate is configured by a curved surface can be realized. Accordingly, as an application example, mounting on a curved surface such as a pipe is possible. Further, it can be applied to an IC card or the like by utilizing the feature of being thin and flexible.

According to still another aspect of the present invention, the main surface includes a mounting substrate having a plurality of mounting wirings formed on the main surface, a plurality of first wirings electrically connected to each of the plurality of mounting wirings. Having first
A flexible substrate, a plurality of first connection pads on the surface, a first flexible semiconductor chip disposed above the main surface of the first flexible substrate, and a plurality of first connection pads , A first connection metal that electrically connects the plurality of first metal wirings, and a first
A first sealing member sealed between the flexible substrate and the first flexible semiconductor chip, a plurality of first metal wirings, and a plurality of second metal wirings electrically connected to each other. A second flexible substrate having a main surface; a second flexible semiconductor chip having a plurality of second connection pads on the surface; and disposed above the main surface of the second flexible substrate;
A second for electrically connecting the plurality of second connection pads and the plurality of second metal wirings, respectively.
Device, ie, a multi chip mod, comprising a connecting metal and a second sealing member sealed between the second flexible substrate and the second flexible semiconductor chip.
ule).

According to still another aspect of the present invention, a thin flexible semiconductor chip is mounted and the thickness of each constituent material such as a flexible substrate is reduced, so that the thickness required for each semiconductor chip is extremely reduced. I can do it. Therefore, a plurality of flexible semiconductor chips are stacked,
When the stack structure is configured, it is possible to reduce the thickness of the entire mounted chip (multi chip module). In addition, since each semiconductor chip has low rigidity, package cracking due to displacement due to differences in the expansion coefficient of components and damage to internal structures can be avoided, and the mounting reliability of the product remains high. It becomes possible to do.

Still another embodiment of the present invention includes a step of thinning a semiconductor chip to a thickness of 10 μm to 150 μm, a step of forming a plurality of mounting wirings on the main surface of the mounting substrate, and a plurality of metals on the main surface of the flexible substrate. From the step of forming the wiring, the step of mounting the semiconductor chip above the main surface of the flexible substrate, and the step of aligning and electrically connecting the plurality of mounting wirings and the plurality of metal wirings, respectively. Mounting method of semiconductor device, ie, mounting module
It is that it is a manufacturing method.

According to the method for manufacturing a mounting body according to still another aspect of the present invention, it is possible to easily manufacture a mounting body with a low overall thickness and low rigidity and high mounting reliability.

(First embodiment)
As shown in FIG. 2 (a), the flexible package according to the first embodiment of the present invention has a plurality of metal wirings 12a,..., 12j,. A flexible substrate 11 and a flexible semiconductor chip 14 disposed above the flexible substrate 11 and having a plurality of connection pads; a connection metal 15a for electrically connecting the plurality of connection pads and the plurality of metal wirings, respectively; .., 15j,..., And a sealing member 16 sealed between the flexible substrate 11 and the flexible semiconductor chip 14.

The metal wiring is a plurality of radially extending aluminum (Al) on the flexible substrate 11.
The wirings 12a,..., 12j,. Al wiring 12a,
.., 12j,... Has a thickness of 9 .mu.m, for example. The flexible substrate 11 is preferably an organic substrate, and in the first embodiment of the present invention, a polyethylene terephthalate (PET) material is used. The thickness of the flexible substrate (PET substrate) 11 is 10-50.
μm is preferred. In FIG. 2A, for example, it is set to 38 μm. Flexible substrate (
By reducing the thickness of the (PET substrate) 11, the rigidity is reduced.

As the flexible semiconductor chip 14, a silicon chip 14 is used. The thickness of the silicon chip 14 is as thin as 10 μm to 150 μm, for example, 50 μm (a manufacturing method will be described later). And this flexible substrate (PET substrate) 1
On the Al wiring 12a formed on the main surface 1, a bump 15a using gold (Au) which is a highly conductive material as a connection metal is formed on the Al wiring 12j. Gold (Au) bumps 15j are arranged. Although not shown, aluminum (Al) or the like is provided at a position corresponding to the gold (Au) bumps 15a,..., 15j,. A connection pad made of a metal thin film is disposed. Then, the corresponding connection pads on the Al wiring 12a and the silicon chip 14 are made of gold (A
u) Connected via bumps 15a,... Al wiring 12j and silicon chip 14
The corresponding upper connection pads are connected via gold (Au) bumps 15j to constitute a flip chip structure. The thicknesses of the gold (Au) bumps 15a,..., 15j,.

In order to protect the surface of the silicon chip 14 including the bump connection portion, the surface of the silicon chip 14 is sealed with an underfill 16 made of a material having a linear expansion coefficient α = 0.01 to 30 ppm / ° C. . Specifically, as the sealing member, for example, an underfill 16 made of an ACF resin or the like having a linear expansion coefficient α of about 0.1 to 15 ppm / ° C. is used.

FIG. 2B is a cross-sectional structure diagram of a mounting body according to the first embodiment of the present invention configured by mounting the flexible package shown in FIG. 2A on a mounting board. A cavity 13 in which the silicon chip 14 is accommodated is formed in the central portion of the flexible substrate (PET substrate) 11. PWB (printed wiring board), FPC
Mounting board 2 such as (flexible printed circuit board)
1, a plurality of radially extending mounting wirings 22a having a thickness of 18 μm to 22 μm,.
..., 22j, ... are arranged. The Al wiring 12a on the main surface of the flexible substrate (PET substrate) 11 and the mounting wiring 22a of the mounting substrate 21 are electrically conductive adhesive 2
3, the Al wiring 12j and the mounting wiring 22j are connected to each other via the conductive adhesive 23 to constitute the mounting body according to the first embodiment of the present invention.
In the mounting body according to the first embodiment of the present invention having such a structure, as shown in FIG.
Since the thickness is about 0 μm, a mounting body having thinness and mounting reliability that is not available in currently used packages is realized.

And Al wiring 12a, ..., 12j of flexible substrate (PET substrate) 11
,..., A very thin silicon film 14 is made of Au bumps 15a.
,..., 15j,... Are connected in a flip chip structure, so that the warpage of the package can be made extremely small. A resin 16 may be sealed between the silicon chip 14 and the flexible substrate (PET substrate) 11. Further, a resin such as a solder resist may be sealed between the silicon chip 14 and the main surface of the mounting substrate 21. Specifically, in the mounting body shown in FIG. 1, as described above, a large warpage of about 1.5 mm occurs for a length of 20 mm, but the warping of the mounting body according to the first embodiment of the present invention is as follows. Warpage can be suppressed to around 0.15 mm for a length of 17 mm.

The thickness of a normal commercially available wafer depends on the wafer size, but is about 450 μm to 1 mm. For example, a 6-inch wafer has a thickness of about 600 μm to 650 μm. As the wafer size increases, the thickness of the wafer also increases. It is desirable that the thickness of the silicon chip 14 used in the mounting body according to the first embodiment of the present invention be as thin as possible than the thickness of such a normal commercially available wafer. Silicon chip 14 by making it extremely thin
It is possible to increase the amount of deflection of the silicon chip 14 until it breaks. That is, by making the thickness of the silicon chip 14 extremely thin and flexible, it becomes possible to reduce the curvature of the silicon chip 14 until the silicon chip 14 is broken.

The graph of the experimental result which shows this effect is shown to Fig.3 (a) and FIG.3 (b). FIG. 3 (a)
FIG. 5 is a graph showing the relationship between the thickness of a silicon chip and the amount of deflection when a fracture experiment is performed using a sample 30 made of a strip-shaped silicon chip as shown in FIGS. 4B and 4C. FIG.
The sample 30 has a predetermined length with a width of 5 mm. On the other hand, for this fracture experiment, a measuring jig having two fulcrum edges is prepared. The distance between the two fulcrums is 5 mm. And
The longitudinal direction of the strip-shaped silicon chip 30 is selected and placed so as to lie between the two fulcrum edges, and a bending pressure is applied to the central part of the two fulcrums to measure the deflection.

When the silicon wafer 31 is thinned by grinding, as shown in FIG. 4A, a circular arc “grind pattern” 39 is generated on the entire surface of the back surface of the silicon wafer 31. As shown in FIG. 4A, the grinding is performed after the silicon wafer 31 is affixed to the surface protection tape 36 and fixed. The surface protection tape 36 is affixed to the flat ring 35, and the silicon wafer 31 is affixed and fixed in a state where wrinkles and the like of the surface protection tape 36 are removed.

In a limited area of a strip-shaped silicon chip having a width of 5 mm as shown in FIG. 4B and FIG. 4C, the grinding pattern 39, more precisely, the tangent line of each grinding pattern 39 is shown. Is
It can be approximated as a pattern of almost parallel lines. Therefore, in the present invention, an angle formed by the direction of the tangent line of the grinding pattern 39 near the long side of the sample with respect to the long side of the sample is defined as “grinding pattern angle θ”. A curve P1 in FIG. 3A shows a result for a sample made of a silicon chip having a grinding pattern angle θ ≦ 10 ° as shown in FIG. 4B. Further, the curve P2 in FIG.
The results for a sample with a grinding pattern angle θ ≧ 80 ° as shown in FIG. A sample cut out in a direction such that the grinding pattern angle θ ≦ 10 ° shown in FIG. 4B is cut out in a direction such that the grinding pattern angle θ ≧ 80 ° shown in FIG. 4C. It can be seen that the amount of deflection is greater than that and is strong against breakage.

Therefore, in the first embodiment of the present invention, it is preferable to use as the flexible semiconductor chip 14 a silicon chip cut out in a direction such that the grinding pattern angle θ ≦ 10 °.

The silicon chip of the curve P1 and the silicon chip of the curve P2 in FIG. As is apparent from FIG. 3A, the amount of deflection until breakage increases as the wafer thickness decreases.

FIG. 3B is a graph showing the relationship between the thickness of the silicon chip and the half-curvature of curvature. FIG.
The measurement result when the width of the silicon chip is 5 mm is shown in the same manner as in FIG. A curve W1 in FIG. 3B shows the result of the sample having a grinding pattern angle θ ≦ 10 ° shown in FIG. 4B, and a curve W2 shows the result in FIG.
The result of the sample with the grinding pattern angle θ ≧ 80 ° shown in FIG.

As is clear from FIG. 3B, it can be seen that the thinner the thickness of the silicon chip is, the smaller the curvature half of the bending (warping) of the silicon chip until the breaking of the silicon chip is, and the more flexible the silicon chip is. Then, the sample chip W1 cut out in the direction so that the grinding pattern angle θ ≦ 10 ° has half the bending curvature of the silicon chip than the sample W2 cut out in the direction so that the grinding pattern angle θ ≧ 80 °. It can be seen that the amount is small and strong against breakage. 3B also shows that in the first embodiment of the present invention, it is preferable to use as the flexible semiconductor chip 14 a silicon chip cut out in a direction such that the grinding pattern angle θ ≦ 10 °. .

In the first embodiment of the present invention, a silicon chip 14 having a thickness of 50 μm is applied as an example. However, if the silicon chip 14 has a thickness of about 10 μm to 150 μm, the same effect can be obtained. In particular, a thickness of about 30 μm to 100 μm is preferable. If it becomes 30 μm or less, handling of the silicon chip 14 becomes difficult.
Industrially, the thickness is not very reasonable.

FIG. 5A is a cross-sectional structure diagram at room temperature of a flexible package according to a modification of the first embodiment of the present invention and a mounting body using the flexible package. As shown in FIG. 5A, a flexible package according to a modification of the first embodiment of the present invention includes a plurality of radially extending aluminum (Al) wirings 12a,..., 12j,. The silicon chip 14 is arranged on the flexible substrate 11 arranged on the main surface. On the Al wiring 12a formed on the main surface of the flexible substrate 11, gold (Au
) Bumps 15a... On the Al wiring 12j are gold (Au) bumps 15j.
... are arranged. A connection pad made of a metal thin film such as aluminum (Al) is provided at a position corresponding to the gold (Au) bumps 15a,..., 15j,. Is arranged. Then, the corresponding connection pads on the Al wiring 12a and the silicon chip 14 are connected via the gold (Au) bumps 15a.
..., the Al wiring 12j and the corresponding connection pad on the silicon chip 14 are connected via a gold (Au) bump 15j to form a flip chip structure. The thickness of the silicon chip 14 is 150 μm or less. In order to protect the surface of the silicon chip 14 including the bump connection portion, the surface of the silicon chip 14 is sealed with an underfill 16. A through hole penetrating the flexible substrate 11 is provided in the periphery of the flexible substrate 11, and embedded metal 19a,..., 19j,. ing. Embedded metal for connection 19a,..., 19j,.
The main surface of the PET substrate 11 is connected to Al wirings 12a,..., 12j,.

On the other hand, on the main surface of the mounting substrate 21, mounting wirings 22a, ..., 22d, 22e, 2
2f, 22g,..., 22j,. And the embedded metal 19a, ..., 19j, ... for connection embedded in the flexible substrate 11,
Mounting wiring 22a, ..., 22d, 22e, 22f, 22g, ..., 22j,
... Are solder balls 104a,..., 104d, 104e, 104f, 1
04g,..., 104j,.

5 (b) and 5 (C) are cross-sectional views for explaining the bending due to temperature change of the mounting body according to the modification of the first embodiment of the present invention shown in FIG. 5 (a). FIG. 5C schematically shows the bending of the silicon chip 14, the flexible substrate 11, the mounting substrate 21, and the like when the temperature is 125 ° C. and FIG. 5C is the low temperature at −55 ° C. The mounting substrate 21 has a linear expansion coefficient α _MB = 15 to 1
It is about 8 ppm / ° C., which is greatly different from the linear expansion coefficient α _{SI of} silicon = 3.5 ppm / ° C. However, in the mounting body according to the modification of the first embodiment of the present invention, since the silicon chip 14 is thin, the degree of freedom of displacement in the direction perpendicular to the surface of the silicon chip 14 is large. That is, since the silicon chip 14 can be freely displaced in the direction perpendicular to the surface thereof, the mounting substrate 21 extends (125 ° C.) or contracts (−55 ° C.) relative to the silicon chip 14 due to a temperature change. Solder balls 104a,..., 104d, 10
4e, 104f, 104g,..., 104j,. Therefore, the solder balls 104a,..., 104d, 104e, 1 due to temperature changes.
04f, 104g,..., 104j,... Are less likely to be destroyed, and mounting reliability is improved.

On the other hand, FIG. 6A is a cross-sectional view for explaining a schematic structure of a comparative example of the mounting body according to the modification of the first embodiment shown in FIG. This comparative example is different from the mounting body shown in FIG. 5A in that a thick silicon chip having a thickness of 300 μm is used, but other structures are common. 6 (b) and 6 (C) are cross-sectional views for explaining bending due to temperature change of the mounting body according to the comparative example shown in FIG. 6 (a). That is, FIG. 6B shows a high temperature of 125 ° C.
FIG. 6C shows the silicon chip 14 and the flexible substrate 11 when the temperature is low at −55 ° C.
And the bending of mounting board | substrate 21 grade | etc., Is shown typically. In the mounting body according to this comparative example, since the silicon chip 14 is thick, the degree of freedom of displacement in the direction perpendicular to the surface of the silicon chip 14 is small and rigid. For this reason, unlike the case of FIG. 5B and FIG. 5C, the silicon chip 14 can hardly be displaced in the direction perpendicular to the surface thereof.
The mounting substrate 21 extends relative to the silicon chip 14 (125 ° C.) or shrinks (−
55 ° C), the solder balls 104a, ..., 104d, 104e, 1
04f, 104g,..., 104j,..., Embedded metal 19a for connection,.
..., 19j, ... or between solder balls 104a, ..., 104d,
104e, 104f, 104g,..., 104j,.
..., 22d, 22e, 22f, 22g,..., 22j,. Also, the solder balls 104a, 104d, 104e, 1
04f, 104g,..., 104j,... Themselves are subjected to a large stress, and the solder balls are broken.

FIG. 7 is a graph for explaining the relationship between the thickness of the silicon chip and the TCT reliability. It can be seen that TCT reliability increases as the thickness of the silicon chip decreases. And
The slope indicating the proportional relationship between the thickness of the silicon chip and the TCT reliability is the thickness 1 of the silicon chip.
It can be seen that the change greatly occurs at 50 μm. That is, the thickness of the silicon chip is 150 μm
Above m, the TCT reliability does not change significantly even if the thickness of the silicon chip changes. However, when the silicon chip thickness is 150 μm or less, the TCT reliability decreases even if the thickness of the silicon chip decreases. It can be seen that the property is remarkably improved. That is, FIG. 7 shows that the thickness of the silicon chip of 150 μm is the inflection point in the relationship between the thickness of the silicon chip and the TCT reliability.

Next, a method for manufacturing a mount module according to the first embodiment of the present invention will be described.
(A) First, a predetermined pattern of a semiconductor integrated circuit is formed on the surface of the silicon wafer 31 by a predetermined photolithography process, a CVD process, an oxidation process, an ion implantation process, an etching process, and the like. Then, a passivation film such as a PSG film, a BPSG film, or a silicon nitride film (Si ₃ N ₄ film) is deposited on the surface of the silicon wafer 31. That is, the silicon wafer 3
A pattern of a semiconductor integrated circuit is periodically formed on the surface of 1 by a step-and-repeat method. There is a dicing line between patterns. And
As shown in FIG. 8A, the silicon wafer 31 on which the pattern of the semiconductor integrated circuit is formed, the work table 3 of the dicing apparatus with the pattern forming surface 41 side of the semiconductor integrated circuit facing upward.
3 is fixed by a predetermined method. For example, the silicon wafer 31 is sucked and fixed by a vacuum chuck. Then, the dicing blade 34 is rotated so that the chip thickness (for example, 50 μm) for the flexible package according to the first embodiment of the present invention is at least 5 times.
A groove 32 having a depth of about μm is formed along the dicing line.

(B) Next, as shown in FIG. 8B, the flat ring 35 is attached to the surface protection tape 36. Then, with the flat ring 35 removing wrinkles and the like of the surface protection tape 36, the pattern form surface 41 of the silicon wafer 31 having the grooves 32 formed on the adhesive side of the surface protection tape 36 in FIG. Paste and fix.

(C) Then, the back surface of the silicon wafer 31 is shaved using, for example, an infeed grinding method. That is, as shown in FIG. 8C, the silicon wafer 31 held by the flat ring 35 and the surface protection tape 36 is sucked and fixed to the work table 37 of the grinding apparatus. Then, the back surface of the silicon wafer 31 is ground while pressing the grindstone 38. At this time, the work table 37
Then, grinding is performed until the back surface (grinding surface) of the silicon wafer 31 reaches the groove 32 while rotating the grindstone 38. When the grinding surface reaches the groove 32, the silicon wafer 31 is divided into individual chips. The depth of this grinding is the thickness of the silicon chip 31 at the time of completion (for example, 50 μm).
).
(D) Then, as shown in FIG. 8D, the flat ring 35 on which the divided individual silicon chips 14 are attracted and fixed is installed in the die bonding apparatus. Then, using a tool 40 such as a pick-up needle, the pattern forming surface 32 is passed over the surface protective tape 36.
In contrast, pressure is applied downward. Then, the silicon chip 14 is peeled from the surface protection tape 36. In this way, for example, a thin flexible silicon chip 14 having a thickness of 50 μm is completed.

(E) Next, a thin continuous tape-like PET substrate 11 having a thickness of, for example, about 38 μm is prepared as a flexible substrate. The main surface of the continuous tape-like PET substrate 11 has a thickness of 9
An Al thin film of about μm is deposited on the entire surface. Then, patterning is performed by an etching method, and a plurality of radially extending Al wirings 12a, ..., 12j,... Are formed on the main surface of the continuous tape-like flexible substrate 11 as shown in FIG. ... pattern is formed. The patterning of the Al wirings 12a, ..., 12j, ... may be performed using a screen printing method. This Al wiring 12a,..., 21j,.
Through the patterning, openings 10 where the PET substrate 11 is exposed are periodically formed at predetermined positions on the main surface of the continuous tape-shaped flexible substrate 11. The opening 10 is a rectangular window for mounting a chip.

(F) Next, as shown in FIG. 8 (f), ACF resin 16 (or ACP resin) which is a continuous resin is applied to each opening 10 for chip mounting by a potting method or the like.

(G) Subsequently, as shown in FIG. 8G, the Al wiring 12a on the PET substrate 11 side,.
.., 12j,... And Au bump 15a on the silicon chip 14 side,.
5j,... Is aligned, and the silicon chip 14 is mounted on the PET substrate 11. After that, by heating to about 120 ° C., melting the continuous resin, and further curing,
The silicon chip 14 is fixed on the PET substrate 11. At this stage, continuous tape PE
A silicon chip 14 is mounted on each of the openings 10 periodically arranged on the T substrate 11, and a plurality of packages are continuously formed. Therefore, next, as shown in FIG. 8 (h), it is cut into individual flexible packages. In FIG. 8H, 16 Al wirings 12a, 12b, 12c,..., 12j,.
12o and 12p patterns are shown.

(H) On the other hand, a separate mounting substrate 21 is prepared, and a plurality of mounting wirings 22a extending radially on the main surface of the mounting substrate 21 by an etching method, a screen printing method, or the like.
., 22j, ... are patterned. And mounting wiring 22a, ..., 2
2j,... A conductive adhesive 23 is applied thereon. As the conductive adhesive 23, for example, an ACF resin or an ACP resin containing a conductive particle layer such as nickel (Ni) particles can be used. Next, the Al wirings 12a,..., 12j,.
A,..., 22j,... are aligned with each other, and the flexible package is mounted on the mounting substrate 21. In this state, the conductive adhesive 23 is heated to a predetermined temperature, the conductive adhesive 23 is melted, and further cured to fix the flexible package on the mounting substrate 21. Thereby, the thin mounting body according to the first embodiment of the present invention shown in FIG. 2B is completed.

Further, the flexible package according to the first embodiment of the present invention can be mounted on the mounting substrate 21 by other methods. For example, instead of the method using the conductive adhesive 23 as described above, an “inter-lead bonding method” may be used.

(I) That is, as shown in FIG. 9A, the Al wirings 12d, 12e,
The first adhesive 50a is applied to the portion where the PET substrate 11 between 12f is exposed.

(Ii) Similarly, as shown in FIG. 9B, the mounting wirings 22d and 22e on the mounting substrate 21 side.
, 22f, the second adhesive 50b is applied to the portion where the mounting substrate 21 is exposed. The second adhesive 50b may be the same type of adhesive as the first adhesive 50a.

(Iii) Then, as shown in FIG. 9C, the Al wirings 12d, 12 on the PET substrate 11 side.
e, 12f and the mounting wirings 22d, 22e, 22f on the mounting substrate 21 side are aligned so that the Al wirings 12d, 12e, 12f and the mounting wirings 22d, 22e, 22f are connected. Add As a result, the first adhesive 50a on the PET substrate 11 side and the second adhesive 50b on the mounting substrate 21 side adhere to each other, and the Al wirings 12d, 12e, 12f and the mounting wirings 22d, 22e, 22f are The metals are in strong contact with each other. On the other hand, the PET substrate 11 and the mounting wirings 22d, 22e, 2 between the Al wirings 12d, 12e, 12f.
The mounting substrate 21 between 2f is strongly bonded by the adhesive 50. Here, the adhesive 50 is
The first adhesive 50a and the second adhesive 50b are combined and integrated.

In the inter-lead bonding method, the first adhesive 50a and the second adhesive 50b do not need to be conductive adhesives, and various adhesives having strong adhesive strength can be selected. If a low-temperature curable adhesive is used, the flexible package can be mounted on the mounting substrate 21 at room temperature.

  The first embodiment of the present invention has the following advantages.

(1) The silicon chip 14 is made extremely thin to reduce the rigidity of the silicon chip.
Since the thickness of each constituent material such as the interposer 11 is also made thin and flexible, the whole package can be reduced in rigidity. Thereby, the occurrence of package cracking due to displacement can be avoided, and the reliability as a product can be ensured.

(2) ACF having a low linear expansion coefficient α between the interposer 11 and the silicon chip 14
In this structure, a sealing member 16 such as resin is enclosed. Accordingly, the warpage of the mounting body due to the temperature history at the time of assembling the mounting body (module) can be made extremely small, and the flatness of the mounting body as a single product can be sufficiently secured. .

(Second embodiment)
The second embodiment of the present invention is a multi-chip module having a stack structure in which flexible packages are stacked in two stages. That is, as shown in FIG. 10, a mounting substrate 21 having a plurality of mounting wirings 22a,..., 22j,.
On the top, two first and second flexible packages similar to those shown in FIG. 2B are stacked face-up in the vertical direction. The mounting substrate 21 is made of, for example, PWB, FPC, or the like. A plurality of radially extending mounting wirings 22 a,..., 22 j,... Having a thickness of 18 μm to 22 μm are arranged on the main surface of the mounting substrate 21.

The first flexible package includes a first flexible substrate 112, a first flexible semiconductor chip 142 disposed above a main surface of the first flexible substrate 112, a first flexible semiconductor chip 142, and a plurality of flexible packages. First metal wiring 122a,...
, 122j,... Are electrically connected to the first connection metal 152a,.
.., 152j,..., And a first sealing member 162 sealed between the first flexible substrate 112 and the first flexible semiconductor chip 142. Here, the first flexible substrate 112 is made of a PET material. A plurality of radially extending aluminum (Al) wires 122a,..., 122j are used as the first metal wires.
,... Are provided on the main surface of the first flexible substrate 112. The first flexible semiconductor chip is a silicon chip 142, which is not shown, but has a plurality of first connection pads on the periphery of the surface of the chip. Gold as the first connecting metal (Au
) The bumps 152a,..., 152j,.
.., 122j,... are electrically connected to the plurality of first connection pads on the first flexible semiconductor chip 142, respectively. That is, the first Al wiring 1
A first gold (Au) bump 152a is formed on the first Al wiring 122j.
Is arranged with a first gold (Au) bump 152j. 1st A
The corresponding connection pads on the l wiring 122a and the first silicon chip 142 are connected to the first gold (A
u) Connected via the bump 152a, and the first Al wiring 122j and the corresponding connection pad on the first silicon chip 142 are connected via the first gold (Au) bump 152j. Thus, the first flip chip structure is formed.

In order to protect the surface of the first silicon chip 142 including the bump connection portion, the surface of the first silicon 142 is sealed with a first sealing member (underfill) 162.

Similarly, the second flexible package is a second flexible substrate (PET substrate).
111, a second flexible semiconductor chip 141 disposed above the main surface of the second flexible substrate 111, a second flexible semiconductor chip 141, and a plurality of second metal wirings 121a,. , 121j,..., And 151j,..., 151j,.
And a second sealing member 161 sealed between the second flexible semiconductor chip 141 and the second flexible semiconductor chip 141. On the main surface of the second flexible substrate 111, a plurality of second metal wirings 121a, ..., 121j, ... are formed. The plurality of second metal wirings 121a,..., 121j,... Are a plurality of first metal wirings 122a,. · · · Electrically connected to each of The second flexible semiconductor chip is a silicon chip 141 having a plurality of second connection pads on the surface. The gold (Au) bumps 151a,..., 151j,... As the second connection metal include a plurality of second connection pads on the second flexible semiconductor chip 141 and a plurality of connection pads. Second metal wiring 121a,...
121j,... Are electrically connected to form a second flip chip structure.

The second flexible package includes second Al wirings 121a,.
The second flexible substrate 111 on which 121j,... Are formed is folded downward so that the second Al wiring is located outside. Similarly, the first flexible package includes the first flexible substrate 111 on which the first Al wirings 122a,..., 122j,. It is folded down so that it is located at the bottom. Then, the first Al wiring 122a and the second Al wiring 121a are bonded to each other with a conductive material (conductive adhesive) 60, and the first Al wiring 122j and the second Al wiring 121j are electrically connected to each other. It is adhered by a material (conductive adhesive) 60. As a result, the first and second
In this flexible package, the corresponding Al wirings can be connected to each other, so that multiple layers of the flexible package can be stacked.

The first Al wiring 122a at the bent portion of the main surface of the first flexible substrate 112 and the mounting wiring 22a of the mounting substrate 21 are connected to each other via a conductive material (conductive adhesive) 60. The first Al wiring 122j and the mounting wiring 22j are connected to each other via a conductive material (conductive adhesive) 60. In the second embodiment of the present invention, A stack structure mounting body of such a stack structure is configured.

(Third embodiment)
The flexible package according to the third embodiment of the present invention is a type of flexible package having a beam lead (mounting lead) as shown in the cross-sectional structure diagram of FIG.

Specifically, in the flexible package structure shown in FIG. 2B, a flexible substrate (polyimide substrate) 70 made of a polyimide material is used instead of the PET substrate 11 as an interposer. Beam leads (copper foils) 71a, ..., 71j, ... are formed on the main surface of the polyimide substrate 70. The thickness of the polyimide substrate 70 is 40 μm, for example, and the beam leads 71a,..., 71j,.
The thickness of is, for example, 15 μm.

Also, one end of the beam leads 71a,..., 71j,.
In order to protect the surface of the silicon chip 14 including the connecting portions, the silicon chip 14 is connected to the Au bumps 15a,..., 15j,. 14 is sealed with an underfill 16 such as an ACF resin. The thickness of this connection portion is 20 μm, for example. And the beam lead 71a, ...
.., 71j,..., Lead terminals 77a,..., 77j,.
As shown in FIG. 11 (a), the mounting wiring 22a on the main surface of the mounting substrate 21...
.., 22j,..., For example, solder 79a made of tin-silver-copper,.
It is joined by.

The manufacturing method of the flexible package having such a structure is shown in FIG.
) To 8 (g), a substrate in which a plurality of polyimide substrates 70 are periodically connected in a tape shape is used instead of the tape-like PET substrate 11. A
Replacing with l wirings 12a,..., 12j,.
,..., 71j,. But,
In other processes, the silicon chip 14 is mounted on the interposer by the same process.

In the process of cutting into individual packages from the continuous tape to which the polyimide substrate 70 is periodically connected, as shown in FIG. 11B, the polyimide substrate 70 and the copper foil (beam lead).
71a,..., 71j,..., In the region where the polyimide substrate 70 does not exist, the beam leads 71a,.
・ Cut off. By this cutting, the individual polyimide substrates 70 are separated, and the flexible package is cut off from the continuous tape. The ends of the beam leads 71a,..., 71j,... Cut at the same time are bent at a predetermined angle for mounting, and lead terminals 77a,. ... is formed. As a result, the shape of the flexible package cut into individual pieces is such that the beam leads 71a,..., 71j,.

Lead terminals 7 which are ends of the beam leads 71a,..., 71j,.
7a,..., 77j,.
a, ..., 22j, ... and solder 79a, ..., 79j, ...
If solder mounting (OLB: outer lead bonding) is used, a thin mounting module having the structure shown in FIG. 11A is completed.

In the flexible package according to the third embodiment of the present invention, since the polyimide having a relatively high heat resistance temperature is used for the interposer 70, the high temperature mounting process on the premise of solder reflow (heat treatment) is the same as that of the first embodiment. This is possible with the package structure. If only the OLB mounting process is used, a PET substrate having a heat-resistant temperature of 150 ° C. or lower can be used.

FIG. 12 shows an example of a stack structure in which the flexible packages according to the third embodiment of the present invention are stacked in multiple stages. That is, a plurality of mounting wirings 22a,.
,... Are stacked in a vertical direction with four face-up first to fourth flexible packages similar to those shown in FIG. 11B. The mounting substrate 21 is made of, for example, PWB, FPC, or the like. Mounting wiring 22a, ...
, 22j,... Are formed as a plurality of radial patterns having a thickness of 18 μm to 22 μm.

The first flexible package includes a first flexible substrate 704, a first flexible semiconductor chip 144 disposed above the main surface of the first flexible substrate 704, a first flexible semiconductor chip 144, and a plurality of First metal wiring 714a,...
, 714j,... Are electrically connected to the first connection metal 154a,.
, 154j,..., And a first sealing member 164 enclosed between the first flexible substrate 704 and the first flexible semiconductor chip 144. Here, the first flexible substrate 704 is made of a polyimide material. As a first metal wiring, a plurality of radially extending 15 μm-thick beam leads (copper foil) 714a,...
.., 714j,... Are provided on the main surface of the first flexible substrate 704.
The first flexible semiconductor chip is a silicon chip 144, which is not shown, but has a plurality of first connection pads on the periphery of the surface of the chip 144. The gold (Au) bumps 154a,..., 154j,... As the first connection metal are a plurality of first metal wirings 714a,. And the plurality of first connection pads on the first flexible semiconductor chip 144 are electrically connected to each other. That is, the first gold (Au) bump 154a is formed on the first beam lead (copper foil) 714a.
... on the first beam lead (copper foil) 714j, the first gold (Au) bump 15 is formed.
4j is arranged. The beam lead (copper foil) 714a and the corresponding connection pad on the first silicon chip 144 are connected through the first gold (Au) bump 154a, and the first beam lead (copper). Foil) 714j and the first silicon chip 144
The corresponding connection pads on the upper side are connected through the first gold (Au) bump 154j to constitute the first flip chip structure. In order to protect the surface of the first silicon chip 144 including the bump connection portion, the surface of the first silicon chip 144 is sealed with a first sealing member (underfill) 164.

At the same time, the second flexible package includes a second flexible substrate (polyimide substrate) 703, a second flexible semiconductor chip 143 disposed above the main surface of the second flexible substrate 703, and a second flexible package. Second connection metal 153a for electrically connecting the semiconductor chip 143 and a plurality of second metal wires, ie, beam leads (copper foil) 713a,..., 713j,. , 153j,... And a second sealing member 163 sealed between the second flexible substrate 703 and the second flexible semiconductor chip 143. On the main surface of the second flexible substrate 703, a plurality of second metal wirings 713a,. The plurality of second beam leads (copper foils) 713a,..., 713j,.
... Are a plurality of first beam leads (copper foil) 71 of the first flexible package.
4a,..., 714j,. The second flexible semiconductor chip is a silicon chip 143 and has a plurality of second connection pads on the surface. Gold (Au) bump 153a as a second connecting metal,...
153j,... Are a plurality of second connection pads on the second flexible semiconductor chip 143, and a plurality of second beam leads (copper foils) 713a,.・
Are electrically connected to each other to constitute a second flip chip structure.

Similarly, the third flexible package includes third beam leads 712a,.
.., 712j,... Are arranged on a third flexible substrate (polyimide substrate) 702 on the main surface. And on the 3rd beam lead 712a formed in the main surface of this 3rd flexible substrate (polyimide substrate) 702, the 3rd gold (Au) bump 152a is... A third gold (Au) bump 152j is arranged on the beam lead 712j. The third beam lead 712a and the corresponding connection pad on the third silicon chip 142 are connected via the third gold (Au) bump 152a,..., The third Al wiring 1
22j and a corresponding connection pad on the third silicon chip 142 are connected via a third gold (Au) bump 152j to constitute a third flip chip structure. In order to protect the surface of the third silicon chip 142 including the bump connection portion, the surface of the third silicon chip 142 is sealed with a third underfill 162.

The fourth flexible package has a plurality of radially extending beam leads 121a,.
.., 121j,... Are configured by disposing a fourth silicon chip 141 on a fourth flexible substrate 701 made of a polyimide material disposed on the main surface. A fourth gold (Au) bump 151a is formed on the fourth beam lead 711a formed on the main surface of the fourth flexible substrate (polyimide substrate) 701,. A fourth gold (Au) bump 151j is arranged on the beam lead 711j. The fourth beam lead 711a and the corresponding connection pad on the fourth silicon chip 141 are connected via the fourth gold (Au) bump 151a, and the fourth beam lead 711j and the fourth silicon chip are connected. 141, the corresponding connection pad on the fourth gold (A
u) Connected via bumps 151j to form a fourth flip chip structure. In order to protect the surface of the fourth silicon chip 141 including the bump connection portion, the surface is sealed with a fourth underfill 161.

Then, the beam lead 711 of the first, second, third and fourth flexible packages.
a, 712a, 713a, and 714a are guided to gather on the mounting wiring 22a, and the solder 7
It is fixed by 9a. Similarly, the beam leads 711j, 712j, 713j, and 714j of the first, second, third, and fourth flexible packages are guided to be assembled to the mounting wiring 22j, fixed by the solder 79j, and stacked in four layers. Structure implementation (multit
i chip module).

(Fourth embodiment)
FIG. 13 is a sectional structural view of a flexible package and a mounting module using the same according to a fourth embodiment of the present invention. A flexible package according to a fourth embodiment of the present invention includes a plurality of radially extending aluminum (Al) wirings 12a, ..., 12j,
.. Is made of a PET material disposed on the main surface, and is configured by disposing a curved silicon chip 14 on a curved flexible substrate 11 having a predetermined curvature. A gold (Au) bump 15a is formed on the Al wiring 12a formed on the main surface of the curved flexible substrate (PET substrate) 11, and a gold (Au) bump 15a is formed on the Al wiring 12j. (Au) bumps 15j are arranged. The Al wirings 12a and 12j and the corresponding connection pads on the silicon chip 14 are connected via gold (Au) bumps 15a and 15j, respectively, to form a flip chip structure. Gold (Au) bump 15a, ...
, 15j,... Is, for example, 20 μm. In order for this bump to protect the surface of the silicon chip 14 including the connecting portion, the surface of the silicon chip 14 is sealed with an underfill 16. The underfill 16 has a low linear expansion coefficient α (α =
0.1-15 ppm / ° C.) Sealing adhesive (ACF resin) is used.

A plurality of radially extending mounting wirings 22a,..., 22j,... Are arranged on the main surface of the mounting substrate 21 such as a curved PWB or FPC. Then, the Al wirings 12a and 12j on the main surface of the curved flexible substrate 11 and the mounting wirings 22a and 22j on the curved mounting substrate 21 are connected to each other via a conductive adhesive,... Al wiring 12
j and the mounting wiring 22j are connected to each other via a conductive adhesive, and a mounting module according to the fourth embodiment of the present invention is configured.

The mounting module according to the fourth embodiment of the present invention shown in FIG. 13 can be interpreted as an example in which the flexible package according to the first embodiment is mounted on the curved mounting board 21, for example. . That is, since the thickness of each component material of the package including the silicon chip 14 is extremely thin, the rigidity is low, and the package can be positively bent and the substrate can be mounted on a curved surface. For example, a mounting body containing a silicon chip 14 in which a pressure sensor, a temperature sensor, and the like are integrated can be attached to a curved surface 81 of a pipe or an electric motor. Alternatively, it is possible to attach a mounting body including a silicon chip 14 in which a fingerprint recognition circuit is integrated on a pen shaft portion such as a ballpoint pen. Furthermore, since the mounting body according to the fourth embodiment of the present invention is extremely thin and has low rigidity as a whole, if applied to an IC card or the like, it will not break even if the IC card is curved. It is very effective in practical use.

That is, it should be construed that the curved mounting board 21 shown in FIG. 13 can exist not only as a steady shape but also as a transitional form.

For example, in the flexible package according to the first to fourth embodiments of the present invention,
The silicon chips 14, 141 to 144 are flexible substrates 11, 111, 112, 70.
, 701 to 704 are mounted in a flip chip structure on the main surface. However, the silicon chip is not necessarily mounted on the main surface of the flexible substrate in a flip chip structure.

FIG. 14A is a sectional view of a flexible package according to another embodiment of the present invention. A flexible package according to another embodiment of the present invention includes a flexible substrate 11 having a plurality of radially extending aluminum (Al) wires 12a,..., 12j,. The silicon chip 14 is arranged in a so-called face-up state with the surface on which the semiconductor integrated circuit is formed facing upward. Silicon chip 14
On the surface of the metal wiring and connection pads 91a, ..., 91j, ..., 91k,
..., 91m, ... are formed. Further, a via hole is provided through the silicon chip 14, and the embedded buried metal 92a,...
.., 92j,... Are embedded. Embedded metal for connection 92a, 9
2j, ..., tungsten (W), titanium (Ti), molybdenum (Mo)
Refractory metals such as these, silicides thereof (WSi ₂ , TiSi ₂ , MoSi ₂ ), etc. can be used. The via hole can be easily opened because the silicon chip 14 is thin. For example,
If a recess (trench) deeper than the final thickness of the silicon chip 14 is formed by the RIE method or the like before the grinding process shown in FIGS. 8A to 8C, the grinding process is automatically completed. In addition,
A via hole opens. On the other hand, Al wirings 12a and 12 on the main surface of the flexible substrate 11 are used.
Similar to the first embodiment, gold (Au) bumps 15a and 15j are arranged on j. Thus, the gold (Au) bumps 15a and 15j and the connection pads 91 on the surface of the silicon chip 14 are obtained.
a and 91j are connected to each other by connecting embedded metals 92a and 92j, respectively.

14A, embedded metal for connection 92a,..., 92j,... And gold (Au) bumps 15a,. However, it functions as the connecting metal of the present invention. In order to protect the surface of the silicon chip 14 including the bump connection portion, the surface of the silicon chip 14 is sealed with an underfill 16. Since the silicon chip 14 is thin, the embedded metal 92a for connection that embeds the inside of the via hole,.
..., 92j,... Can also use solder.

As shown in FIG. 14 (b), the flexible package according to another embodiment of the present invention has the silicon chip 14 disposed on the flexible substrate 11 in the face-up state as in FIG. 14 (a). is doing. On the surface of the silicon chip 14, metal wiring and connection pads 9 are provided.
1a, ..., 91j, ..., 91k, ..., 91m, ... are formed. The Al wirings 12a and 12j on the main surface of the flexible substrate 11 and the connection pads 91a and 91j are respectively soldered on the side surface of the silicon chip 14 by solder 95a.
, 95j are connected to each other. In FIG. 14B, the solders 95a and 95j function as the connection metal of the present invention. Since the silicon chip 14 is thin, connection by such solders 95a and 95j is possible.

In the flexible package according to the first to fourth embodiments of the present invention, the silicon chips 14 and 141 to 144 are exemplified. However, other semiconductor substrates such as a gallium arsenide (GaAs) chip may of course be used. It is.

As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the following claims that are reasonable from the above description.

A flexible substrate having a plurality of metal wirings formed on the main surface, a flexible semiconductor chip disposed above the flexible substrate and having a plurality of connection pads, a plurality of connection pads on the semiconductor chip, and a flexible substrate This is a flexible package comprising a connection metal for electrically connecting the plurality of upper metal wirings, and a sealing member sealed between the flexible substrate and the flexible semiconductor chip. The semiconductor chip is mounted on a flexible semiconductor chip in which the semiconductor chip is made thinner than a commonly used thickness and the rigidity is lowered. Further, the rigidity of the entire package is reduced by reducing the thickness of each component of the package such as a flexible substrate. For this reason, generation | occurrence | production of the package crack by displacement can be avoided. Further, since the sealing member is enclosed between the flexible substrate and the flexible semiconductor chip, the warpage of the package can be extremely reduced. For this reason, it becomes possible to ensure sufficient flatness as a single product of the flexible package. Furthermore, if a mounting substrate having a plurality of mounting wirings formed on the main surface is prepared and each of the plurality of mounting wirings is electrically connected to a plurality of metal wirings, a mounting body with high mounting reliability can be configured. . Furthermore, if a plurality of flexible packages are stacked, a multi-chip module having a thin overall thickness can be configured.

It is a cross-sectional perspective view which shows one structural example of the semiconductor package currently used. It is sectional drawing for demonstrating the schematic structure of the flexible package which concerns on 1st Example of this invention, and the mounting structure (module) which concerns on 1st Example of this invention. The graph which shows the relationship between the thickness of a silicon chip and the amount of bending, and the graph which shows the relationship between the thickness of a silicon chip, and a curvature radius are shown. It is a figure which shows the grinding crest formed on the back surface of a silicon chip, a figure explaining a sample with a grinding crest angle θ ≦ 10 °, and a figure explaining a sample with a grinding crest angle θ ≧ 80 °. FIG. 4 is a cross-sectional view for explaining a schematic structure of a mounting body according to a modification of the first embodiment of the present invention, and a temperature change of the mounting body according to the modification of the first embodiment of the present invention. Sectional drawing for demonstrating bending is shown. As a comparative example, a cross-sectional view for explaining a schematic structure of a mounting body using a thick silicon chip and a cross-sectional view for explaining a bending due to a temperature change of the mounting body (module) are shown. It is a graph explaining the relationship between the thickness of a silicon chip, and TCT reliability. It is process drawing which shows the manufacturing method of the mounting body (module) which concerns on 1st Example of this invention. It is process sectional drawing explaining the adhesion method between the leads of a flexible package as a modification of the manufacturing method of the mounting body which concerns on 1st Example of this invention. It is sectional drawing of the mounting body (multichip module) of the stack structure which concerns on 2nd Example of this invention. Sectional drawing of the flexible package which concerns on 3rd Example of this invention and a mounting body (module) using the same, and sectional drawing which shows the cutting-off process of the flexible package which concerns on 3rd Example of this invention are shown. It is sectional structure drawing of the mounting body (multichip module) which concerns on 3rd Example of this invention. It is a cross-sectional structure figure of the flexible package which concerns on 4th Example of this invention, and the mounting body (module) using the same. The cross-section figure of the flexible package which concerns on the other Example of this invention and the cross-section figure of the flexible package which concerns on the other Example of this invention are shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... PET material 12 ... AL wiring 14 ... Silicon chip 15 ... Au bump 16 ... Underfill 21 ... Mounting substrate 22 ... Mounting wiring 23, 60 ... Conductive adhesive 50 ... Adhesive 70 ... Polyimide material 71 ... Beam lead

Claims (5)

Thinning the semiconductor chip to a thickness of 10 μm to 150 μm;
Mounting the semiconductor chip via a sealing member above the main surface of the flexible substrate having a plurality of metal wirings formed on the main surface;
A step of aligning and electrically connecting the plurality of mounting wirings of the mounting substrate having a plurality of mounting wirings formed on the main surface and the plurality of metal wirings;
The step of electrically connecting the plurality of mounting wirings and the plurality of metal wirings to each other,
Providing a first adhesive layer on the exposed portion of the flexible substrate between the plurality of metal wirings;
Providing a second adhesive layer on an exposed portion of the mounting substrate between the plurality of mounting wirings;
Aligns with the plurality of metal wires and the plurality of mounting wiring, together with the application of a predetermined pressure between the flexible substrate and the mounting substrate are joined together said first and second adhesive layer, A method for mounting a semiconductor device, comprising: connecting the plurality of mounting wirings and the plurality of metal wirings in contact with each other . The semiconductor device mounting method according to claim 1 , wherein the semiconductor chip includes any one of semiconductor materials selected from silicon, germanium, gallium arsenide, gallium phosphide, indium phosphide, and silicon carbide. 3. The method of mounting a semiconductor device according to claim 1, wherein the sealing member is made of ACF or ACP having a linear expansion coefficient α of 0.1 to 15 ppm / ° C. 4. The semiconductor device mounting method according to claim 1, wherein the first and second adhesives are low-temperature curing adhesives. The method of mounting a semiconductor device according to claim 1, wherein the plurality of mounting wirings and the plurality of metal wirings are in contact with each other.

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