JPH11354664A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an interposer from being warped at the projecting part thereof at low cost without requiring resin sealing through injection molding even when the interposer projects from the circumferential fringe of an IC chip and solder bumps are provided on the rear surface at the projecting part. SOLUTION: An IC chip 2 having surface area smaller than that of an interposer 1 is mounted on the surface of the interposer 1 and a plurality of metal bumps 3 for mounting a mother board are formed on the rear surface of the interposer 1. A reinforcing member 4 for preventing deformation of the interposer 1 is provided on the surface thereof projecting from the circumferential fringe of the IC chip 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device in which an IC chip is packaged in a chip size.

[0002]

2. Description of the Related Art In order to reduce the mounting area of a semiconductor device, various types of chip size packages (CSP) in which IC chips are packaged in substantially the same size.
Has become widely used.

There are various types of CSPs (NIKKEI MICRODEVICES, 50 (1)
998)), and a substrate using a flexible organic substrate (interposer) such as a polyimide film as a substrate on which an IC chip is mounted is widely used in terms of reduction in thickness and weight.

Such a CSP has a structure in which, for example, as shown in FIG. 5, an IC chip 52 provided with solder bumps 51 on the back surface is mounted on the surface of an interposer 54 provided with solder bumps 53 on the back surface. . Then, the underfill (sealing resin) 55 is poured between the IC chip 52 and the interposer 54,
Bonded by curing.

In such a CSP, the solder bumps 53 are provided on the back surface of the interposer 54 so as not to protrude outside the outer edge of the IC chip 52.

[0006]

However, in recent years, CS
As the density of P increases, the number of solder bumps on the back surface of the interposer increases. Therefore, in order to maintain a predetermined interval between adjacent solder bumps, the interposer may protrude from the periphery of the IC chip, and a solder bump may be provided on the back surface of the protruding portion.

However, the interposer 54 made of a flexible organic substrate such as a polyimide film, as shown in FIG. 6, has a portion protruding from the periphery of the IC chip 52 of the interposer 54 due to shrinkage during curing of the underfill 55. There is a problem that the outer bump 53a is displaced from a predetermined position. Therefore, C
It becomes virtually impossible to mount the SP on the motherboard by the reflow method or the like.

Further, in order to prevent such warpage of the interposer, it is conceivable to seal the entire IC chip together with the interposer with a resin by an injection molding method, but an extremely expensive mold is required. This is an obstacle to reducing the manufacturing cost.

An object of the present invention is to solve the problems of the prior art as described above.
Even if a solder bump is provided on the back surface of the protruding portion by protruding from the peripheral edge of the C chip, warpage of the protruding portion of the inner poser is prevented at low cost without resin sealing by the injection molding method. The purpose is to:

[0010]

The present inventors can achieve the above object by providing a reinforcing member for preventing deformation of the interposer on the surface of the interposer protruding from the periphery of the IC chip. Heading,
The present invention has been completed.

That is, according to the present invention, an IC chip having a smaller surface area is mounted on the surface of an interposer,
In a semiconductor device in which a plurality of metal bumps for mounting a motherboard are formed on the back surface of the interposer,
A semiconductor device is provided, wherein a reinforcing member for preventing deformation of the interposer is provided on a surface of the interposer protruding from a peripheral edge of the C chip.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the semiconductor device according to the present invention will be described below in detail with reference to the drawings.

The semiconductor device of the present invention is shown in FIG.
(Plan view; FIG. (B) Cross-sectional view at xx; FIG. (C) Perspective view)
As shown in FIG. 1, an IC chip 2 having a smaller surface area is mounted on the surface of the interposer 1, and a plurality of metal bumps 3 for mounting a motherboard (not shown) are formed on the back surface of the interposer 1. Having a structure. Here, a reinforcing member 4 for preventing deformation of the interposer 1 is provided on the surface of the interposer 1a protruding over the entire periphery of the IC chip 2. For this reason, even when the interposer 1 and the IC chip 2 are bonded by curing the underfill 5 filled therebetween, deformation such as warpage of the interposer 1a can be prevented. Therefore, the semiconductor device of the present invention can be accurately mounted on the motherboard even when the metal bumps 3a such as solder balls are provided on the back surface of the interposer 1a protruding from the periphery of the IC chip 2 as shown in FIG. can do.

The reinforcing member 4 can be formed without using an injection molding method requiring an expensive mold.
Since it can be formed by appropriately processing an organic resin film having good processability such as a polyimide film and attaching the film to the interposer 1, packaging can be performed at low cost.

The semiconductor device shown in FIG. 1 is an example in which the interposer 1 protrudes over the entire periphery of the IC chip 2 and the reinforcing member 4 is provided as an annular frame on the surface of the protruded interposer 1a. , As shown in FIG.
If the interposer 1 protrudes only on one side of the IC chip 2, the protruding interposer 1
For example, a linear reinforcing member 4 can be provided on the surface of a.

As shown in FIG. 3, on the premise that deformation of the interposer 1 can be prevented, a part of the reinforcing member 4 which is an annular frame surrounding the IC chip 2 may be discontinuous. The presence of the discontinuous portion 4a is useful for confirming, for example, the vertical and horizontal directions of the semiconductor device.

The IC chip 2 and the interposer 1
In the case of FIG. 1, the electrical connection is made by bump bonding between a metal bump 2a such as a solder pump provided on the back surface of the IC chip 2 and the surface land 1b of the interposer 1. By wire bonding bonding (not shown) between the lands of the interposer or by anisotropic bonding between the lands provided on the back surface of the IC chip and the front lands of the interposer by an anisotropic conductive bonding film. It can be carried out. In particular, it is preferable to use an anisotropic conductive adhesive film in which the alignment accuracy between the IC chip and the interposer is not relatively strict.

Further, the conduction between the front surface land of the interposer and the metal bump on the rear surface can be connected by a known method such as a through hole.

In the semiconductor device of the present invention, other than the provision of a reinforcing member for preventing deformation of the interposer on the surface of the interposer protruding from the peripheral edge of the IC chip, for example, each constituent element As for the material, shape, size, etc. of the semiconductor device, the same configuration as the corresponding component of the known semiconductor device can be adopted.

The semiconductor device of the present invention can be manufactured, for example, as shown in FIG.

First, an interposer (eg, a polyimide substrate) 41 on which a circuit 41a is formed (FIG. 4A)
An opening 42 corresponding to a portion where an IC chip is mounted.
A reinforcing member sheet 43 (FIG. 4B) made of a polyimide film or the like having a thickness of about 50 to 75 μm provided with
Laminating via an adhesive (for example, SAFW40 (manufactured by Toyobo)) 44 (example of laminating conditions = 120 ° C.,
0.5 m / min) (FIG. 4C).

Next, curing of the adhesive (example of pre-curing conditions = 80 ° C., 2 hours: example of after-curing conditions)
= 150 ° C, 1 hour).

Next, an IC is provided via an anisotropic conductive film or the like.
The chip 45 is mounted on the interposer 41 in the opening 42 of the reinforcing member sheet 43 (FIG. 4D).

Next, metal bumps 46 such as solder balls are formed on the back surface of the interposer 41 protruding from the periphery of the IC chip 45 in accordance with a conventional method (FIG. 4E).

Finally, the individual semiconductor devices are diced and separated according to a conventional method. Thereby, the reinforcing member 47
Can be manufactured in a ring shape around the IC chip 45 (FIG. 4F).

In the semiconductor device of the present invention described above, even if the interposer protrudes from the periphery of the IC chip and a solder bump is provided on the back surface of the protruding portion, the warpage of the protruding portion of the inner poser is reduced.
This can be prevented at low cost without resin sealing by the injection molding method.

[0027]

According to the invention, the interposer is
Even in a semiconductor device that protrudes from the periphery of the C chip and has a solder bump on the back surface of the protruding portion, the warpage of the protruding portion of the inner poser can be prevented at low cost without resin sealing by the injection molding method. can do.

[Brief description of the drawings]

FIG. 1 is a top view (FIG. 1A) of a semiconductor device of the present invention;
xx sectional view (FIG. 2 (b)) and perspective view (FIG. 2 (c))
It is.

FIG. 2 is a perspective view of a semiconductor device of the present invention.

FIG. 3 is a perspective view of a semiconductor device of the present invention.

FIG. 4 is a manufacturing process diagram of the semiconductor device of the present invention.

FIG. 5 is a cross-sectional view of a conventional chip size package.

FIG. 6 is an explanatory diagram of a problem of a conventional chip size package.

[Description of Signs] 1 interposer, 2 IC chip, 3 metal bump, 4 reinforcing member, 5 underfill

Continued on the front page (72) Inventor Akira Tsutsumi 12-3 Satsukicho, Kanuma City, Tochigi Prefecture Sony Chemical Corporation

Claims (8)

[Claims] 1. A semiconductor device in which an IC chip having a smaller surface area is mounted on a surface of an interposer and a plurality of metal bumps for mounting a motherboard are formed on a back surface of the interposer. A semiconductor device, wherein a reinforcing member for preventing deformation of an interposer is provided on a surface of the interposer protruding from the semiconductor device. 2. The semiconductor device according to claim 1, wherein the interposer and the IC chip are bonded by underfill. 3. The semiconductor device according to claim 1, wherein at least a part of the plurality of metal bumps is disposed on a back surface of the interposer protruding from a peripheral edge of the IC chip. 4. The semiconductor device according to claim 1, wherein the interposer protrudes over the entire periphery of the IC chip. 5. The semiconductor device according to claim 1, wherein the reinforcing member is an annular frame surrounding the IC chip. 6. The semiconductor device according to claim 5, wherein a part of the reinforcing member, which is an annular frame surrounding the IC chip, is discontinuous. 7. The semiconductor device according to claim 1, wherein the metal bump is a solder ball. 8. The semiconductor device according to claim 1, wherein the reinforcing member is formed from a polyimide film.