JPH05206201A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To supplement the decrease in finger strength that accompanies the thinning of the inner lead part of the film chip carrier,
To improve the bondability with a semiconductor device chip, enable miniaturization of metal wiring, and realize a highly integrated semiconductor device. In a semiconductor device in which a semiconductor device chip is mounted on a chip carrier in which metal wiring is formed on a flexible film member, a terminal portion of the semiconductor device chip has metal wiring from a metal wiring forming surface side of the chip carrier. Of the inner lead portion, and a through column of a heat conductive material penetrating the flexible film member is provided on the back surface side of the connecting portion of the inner lead portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mounts a semiconductor device chip such as an IC or LSI on a chip carrier used for connecting its terminal portion to an external container (so-called package) or a terminal portion of a circuit board. The present invention relates to a semiconductor device and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a plurality of connection pads (bumps) on a semiconductor device chip are bonded wires,
Alternatively, it is connected to a lead frame or a terminal portion of a circuit board by a lead wire formed on a tape-shaped or batch-type film chip carrier. Here, the use classification of the bonding wire and the film chip carrier depends on the pitch between bumps of the semiconductor device chip, and for example, the pitch is 200 to 300 μm.
In the case of m or less, a film chip carrier is generally used.

In the conventional film chip carrier, a device hole for inserting a semiconductor device chip is bored in an electrically insulating flexible film made of a polyimide film, a polyester film or the like. A large number of metal wirings (lead wires) are formed on the peripheral edge of the device hole opening on one surface so as to radially project inner lead parts into the device opening.

The inner lead portion of this lead wire is
When the semiconductor device chip is inserted into the device hole, the inner lead part and the bump of the semiconductor device chip are pressed (from the inner lead part side). Bonded and connected.

By the way, in recent years, the trend toward higher integration of semiconductor device chips has been remarkable, and the number of input / output connection pads has increased accordingly, and the pitch between bumps is now 100 μm.
Semiconductor device chips of m or less are also in the stage of practical application. However, it is very difficult to produce a film chip carrier having a fine pitch inner lead portion capable of accommodating such a semiconductor device chip having an extremely narrow pitch between bumps.

That is, a general method for forming metal wiring of a chip carrier is to deposit a copper foil of about 35 μm on a flexible film member by vapor deposition or to attach a piece of copper foil, and then use this copper foil. Formed by etching,
Alternatively, the surface of the flexible film member is provided with a catalytically active layer for electroless plating in a predetermined wiring pattern, and then copper plating is performed. The following problems occur.

In the former etching method, for example, when the target inner lead pitch is 70 μm, the conductor width of the inner lead portions is about 35 μm, but when the copper foil layer is 35 μm thick, the conductor width is about 35 μm. / Since the conductor thickness ratio is 1 or less, side etching is remarkable in such a case, and the inner lead portions of the individual wirings become trapezoidal in cross section. In the latter plating method, bumps may stick out from the stacked plating layers in the pitch direction and short-circuit between wirings. For example, when the copper plating thickness is 35 μm, the bumps have a size of 20 μm. It may reach the level.

To solve such a problem,
In any of the above methods, it is desired to reduce the thickness of the metal wiring. In other words, if the copper foil layer is thin by the etching method, side etching does not proceed so much and wiring with a substantially rectangular cross section is obtained, and if the plating thickness is thin, the bumps grow too much even by the plating method. And there is less risk of short circuit.

[0009]

However, since the inner lead portion of the metal wiring in the conventional chip carrier has the overhang structure protruding to the opening portion of the device hole as described above, it is different from the semiconductor device chip. The metal wire alone must withstand the pressure applied during bonding. It is said that the pressure resistance (hereinafter referred to as “finger strength”) at the time of bonding needs to be 5 to 15 g, but the copper foil layer of the inner lead portion is thinned to have a width of 25 μm and a thickness of 18 μm, for example. The finger strength of the copper foil wiring is 12 g. For this reason, such a thin metal wiring may not be able to withstand the bonding of the semiconductor device chip, which has been a factor of reducing the reliability of the product as a semiconductor device.

Here, the flexible film member is left (or newly formed) on the back surface side of the inner lead portion of the metal wiring (the back side of the surface connected to the bump portion of the semiconductor device chip) to form the inner lead portion. Although reinforcement is considered, this method has a problem that the adhesiveness at the time of bonding is lowered. That is, in the conventional bonding process, the heating / pressurizing tool is brought into contact with the back surface side of the inner lead portion to perform the heating / pressurizing work. Since the flexible film member is interposed, heat and pressure from the tool cannot be efficiently transmitted. Therefore, the adhesion failure between the inner lead portion and the bump portion may occur, and if the heating temperature or the pressurizing force is increased in order to avoid this, the flexible film member may be deteriorated or the inner lead portion may be broken (disturbed). ), And a problem such as a failure of the semiconductor device chip itself occurs.

Therefore, the present invention solves these problems, enables finer metal wiring, has sufficient finger strength, and has a semiconductor device using a chip carrier having excellent bonding processability and durability. It is intended to provide a manufacturing method thereof.

[0012]

To achieve the above object, according to the present invention, a semiconductor device chip is mounted on a chip carrier having a plurality of sets of metal wiring formed on one surface side of a flexible film member. In the device, the terminal portion of the semiconductor device chip is connected to the inner lead portion of the metal wiring from the metal wiring formation surface side of the chip carrier, and the flexible film member is provided on the back surface side of the connection portion of the inner lead portion. Provided is a semiconductor device having a through column of a heat conductive material penetrating therethrough.

Here, in a method of manufacturing a semiconductor device in which a semiconductor device chip is mounted on a chip carrier having a plurality of sets of metal wiring formed on one surface side of a flexible film member, the semiconductor device chip When connecting the terminal portion from the metal wiring forming surface side of the chip carrier to the inner lead portion of the metal wiring, a thermal conductive material penetrating the flexible film member on the back surface side of the connecting portion of the inner lead portion. By using a chip carrier provided with a through pillar, a pressing tool of a bonding apparatus is applied to the through pillar, and the inner lead portion is pressed against the protruding terminal portion of the semiconductor device chip by the pressure applied through the through pillar. Manufacture semiconductor devices.

[0014]

According to the present invention, as the chip carrier constituting the semiconductor device as described above, the through column of the heat conductive material penetrating the flexible film member is provided on the back surface side of the connecting portion of the inner lead portion of the metal wiring. I am using what is being used.
Then, when the semiconductor device is bonded to the semiconductor device chip by using this chip carrier, the pressing tool of the bonding device is applied to the through pillar of the chip carrier, and the chip is inserted through the through pillar of the inner lead part. The terminals are joined to each other by applying pressure or heating at the same time.

Here, at the time of bonding, since the through column of the heat conductive material is interposed between the pressure tool of the joining device and the inner lead portion, the joining portion between the inner lead portion and the terminal portion of the semiconductor device chip is formed. In this case, the pressure and heat from the pressure tool are efficiently conducted through the through columns, and the bondability between them is extremely good. Therefore, the heating and pressing work by the pressing tool of the joining device at the time of bonding can be performed at a low pressure, at a low temperature, and in a short time, and the semiconductor device can be manufactured within a range that does not damage the semiconductor device chip. It has become a thing.

Furthermore, in the chip carrier used for this semiconductor device, the inner lead portion does not have an overhang structure as in the conventional case, and a flexible film member is provided on the back surface side of the joint portion with the semiconductor device chip. Is provided. Therefore, as compared with a metal wiring alone, the finger strength of the inner lead portion is improved by the amount of being supported and fixed by the flexible film member, and even if the thickness of the metal wiring is extremely thinner than the conventional one, It is possible to sufficiently withstand the heating pressure applied in the bonding process applied from the pressure tool of the ordinary bonding apparatus.

In addition, since the inner lead portion is reinforced in this way, the inner lead portion is not deformed or disturbed due to contact with any object or the like, and good bondability with the semiconductor device chip is obtained. As a result, the yield of products when completed as a semiconductor device is improved.

Here, in the case of forming the above through pillars on the chip carrier, for example, the flexible film member in the region including the inner lead portion is ground in advance from the back side of the inner lead portion to reduce the wall thickness. By making it thin, it is possible to easily form a small-diameter through column at this location. As a method for forming such a small diameter through column, an example thereof is described in Japanese Patent Application No. 1-35029 (JP-A-2-215145) filed by the present applicant, but the method is not limited to this method. Absent. A specific example of the method of forming the chip carrier will be described below. Here, a method of forming a so-called tape carrier in which the film chip carrier is formed in a tape shape will be described, but the same applies to a batch type film chip carrier.

First, a flexible tape having a thickness of about 10 to 200 μm, which is excellent in heat resistance and is made of polyimide, polyphenylene sulfide, polyethylene terephthalate, liquid crystal polymer, etc., is used. Metal coating (copper, chromium, nickel, etc.)
To form. Then, if necessary, copper plating is further applied to form a metal foil layer mainly composed of copper having a thickness of 1 to 50 μm,
A composite tape consisting of a flexible tape and a metal foil layer is formed.

Then, if necessary, the peripheral region including the inner lead portion group forming region of the flexible film member is thinned by etching from the back side of the metal foil layer by etching. Further, the flexible film member at the place of joining to the terminal portion of the semiconductor device chip (the back surface portion of the joining portion) near the tip of the inner lead portion is removed by etching until it reaches the metal foil of the inner lead portion.

The cutting shape at this time does not extend beyond the width of the inner lead portion, and it is desirable that the opening area is as large as possible as long as the flexible film member can support and fix the inner lead portion. A rectangular through hole having the width of the inner lead portion as one side and the other side of about 0.5 mm is sufficient.

Then, the through hole is filled with a heat conductive material such as metal by electrolytic plating or the like to provide a through column. Generally, copper plating is easy. Further, at this time, electroless metal plating, metal vapor deposition, etc. are performed in advance, and after conducting the conductive treatment on the wall surface of the through hole of the flexible film member, it is more preferable to perform the above-mentioned electrolytic plating because the through column formed here is It is securely fixed to the flexible film member and is stable against bonding pressure.

Thereafter, the metal foil layer is etched by lithography to form metal wiring. The lithography for forming the metal wiring can be performed before the etching of the flexible film member, but at this time, the metal wiring surface must be protected with a resist from the etching solution of the flexible film member. I won't.

As a method for etching a flexible tape made of a polymer film, a solution for dissolving and decomposing the polymer film is used. For example, when the flexible tape is made of a polyimide film, preferable results can be obtained with an etching solution such as a mixed solution of hydrazine and ethylenediamine, a solution of an alkaline chemical such as potassium hydroxide mixed with ethanol or water. Also, ECR
Dry etching such as plasma and excimer laser processing can also be used.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. Although the following examples describe the case where the tape carrier is used as the chip carrier, the same applies to the case of a single batch type. 1 is a partial plan view of a tape carrier of a semiconductor device according to a first embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a partial sectional view of a semiconductor device using this tape carrier. It is a figure.

First, a method for manufacturing the tape carrier in this embodiment will be described. In this example, a thickness of 50
A 0.2 μm copper film is attached to one surface of a flexible tape 2 made of a polyimide film of μm by a sputter deposition method, and electrolytic copper plating is further applied to form a copper foil layer having a thickness of 10 μm. Make a tape.

Then, the copper foil layer was etched using an aqueous solution of ferric chloride to form a plurality of sets of metal wirings 1 having a conductor width d = 25 μm and a conductor pitch p = 50 μm at predetermined intervals in the longitudinal direction. .. At this time, the outer portions of all the outer leads 1b of the metal wiring 1 are connected to the electrodes 1c for electrolytic plating. In FIG. 1, the number of wirings of the four sets of metal wirings is partially omitted.

Further, the metal wiring 1 in the present embodiment has an inner lead portion 1a to be bonded to the bump 7 of the semiconductor device chip 6 inside, and an outer lead portion connected to a terminal portion of a lead frame or an external circuit board. 1
With b as the outside, they are arranged radially in four directions as shown in FIG. Here, in the present embodiment, each metal wiring 1 is provided with an outer lead portion 1b corresponding to the inner lead portion 1a in a one-to-one correspondence, and each outer lead portion 1b is connected to the outside of a lead frame, a circuit board, or the like. Although it is connected to the terminal portion of the circuit device, it is not limited to this type.

That is, the metal wiring formed on the tape carrier according to the present invention is only when the wiring having the inner lead portion at one end and the outer lead portion at the other end is arranged at a predetermined pitch as shown in FIG. Instead, the outer lead portion and the inner lead portion may correspond to one to plural, or the inner lead portion may be connected to a predetermined circuit formed on the outer side thereof. Further, in the present embodiment, only one inner lead portion to which the semiconductor device chip is bonded is formed on one metal wiring, but a plurality of inner lead portions may be formed on one metal wiring in some cases. It may be done.

Next, cyclized isoprene rubber is applied to both surfaces of the metal wiring 1 forming surface and the flexible tape 2 surface of the composite tape having the metal wiring 1 formed thereon, and the entire surface of the metal wiring 1 forming surface is exposed. In addition, the flexible tape 2 side is the inner lead 1
Exposure is performed except for the peripheral portion 3 of the group a (where the device hole is conventionally opened), the sprocket hole 5, and the outer lead hole 1b. Then, this is developed with 1,1,1 trichloroethane to form a resist layer having openings in the peripheral portion 3 and the like of the inner lead 1a group.

Further, this was immersed in a 5N potassium hydroxide aqueous solution at 50 ° C. for 1 hour to remove a part of the flexible film member at the opening, and then washed with water. Then, the cyclized isoprene rubber of the resist was immersed in toluene to remove the resist. As a result, the flexible tape 2 on the peripheral portion 3 of the inner lead 1a group was thinned to a thickness of 11 μm.

Then, again, cyclized isoprene rubber is applied to the surface of the flexible tape 2 side, and both ends of the width of the inner lead 1a and the inner lead are formed on the back side of the inner lead 1a on the surface where the flexible tape 2 is formed. The area surrounded by the metal wiring from the position 0.5 mm from the tip of the part to the position 0.5 mm further inside, the sprocket hole 5, and the outer lead hole 1b.
Except for the above, it was exposed and developed to form a resist layer.

This is immersed in a 5N aqueous potassium hydroxide solution at 50 ° C. for 20 minutes and then washed with water to form a through hole extending from the back side of the inner lead 1a to the surface of the flexible tape 2 and a sprocket hole. 5, outer lead hole 1b
And were formed.

Then, cyclized isoprene rubber is applied to the sprocket hole 5 and the outer lead hole 1b and exposed to form a resist layer on these parts. In this state, a copper film having a thickness of 0.2 μm was deposited by a sputter deposition method, then immersed in toluene to remove the resist, and the wall surface of the through hole was subjected to a conductive treatment.

Then, cyclized isoprene rubber is applied to the surface on which the metal wiring 1 is formed, exposed except the electrode portion 1c, and developed. In this state, the electrode portion 1c is energized to perform electrolytic plating, so that the through holes are filled and the through columns 8 are formed (see FIG. 2). Finally, the unnecessary resist was peeled off to complete the tape carrier.

The tape carrier formed in this manner is mounted in a carrier having a sprocket hole, is sent to an inner lead bonder, and is bonded to a semiconductor device chip. At this time, approximate feed alignment is performed by the sprocket holes of the tape carrier, and precise relative alignment between the bonding tool of the inner lead bonder, the inner lead portion of the tape carrier, and the bunff of the semiconductor device chip is a separate position detection. Means (not shown)
By.

At the time of this bonding, the semiconductor device chip (the bunff of) is the inner lead 1 of the metal wiring 1.
The bonding tool is arranged on a (on the side of the tape carrier where the metal wiring is formed), and the bonding tool is arranged below the through column 8 (on the side of the flexible tape of the tape carrier). Then, a heating and pressurizing operation is performed with the bonding tool in contact with the through-holes 8 to bond the bunches of the semiconductor device chips and the inner leads 1a of the metal wirings 1. This bonding work could be performed with a bonding tool at a heating temperature of 450 ° C. and a pressure of 30 g / cm ² for about 1 second.

As described above, the semiconductor device according to the present embodiment is formed. The tape carrier and the semiconductor device chip of the products of these embodiments have a very good bonding state, and compared with the conventional product. There is no comparison. Furthermore, the inner lead portion was not damaged at all in the tape carrier alone and the completed semiconductor device.

[0039]

As described above, according to the present invention, since the metal wiring can be thinned without lowering the finger strength of the inner lead portion, it is possible to miniaturize the metal wiring of the chip carrier, which has been impossible in the past. Therefore, a highly integrated semiconductor device can be realized.

Although the inner lead portion of the chip carrier is reinforced by the flexible film member, it penetrates from the surface on the flexible film member side to the portion of the inner lead portion which is joined to the terminal portion of the semiconductor device chip. Since the pillars are made of a heat conductive material, at the time of bonding the chip carrier and the semiconductor device chip, heat is quickly transferred to the joint through the through pillars made of this heat conductive material, and the pressure is low and the temperature is low. Moreover, there is an advantage that the bonding can be performed in a short time and the semiconductor device chip is not damaged.

In addition, since the inner lead portion is reinforced in this way, the inner lead portion is not deformed or disturbed due to contact with some object, so that the bondability with the semiconductor device chip is improved. There is also an advantage that the yield is improved when the semiconductor device is completed.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a tape carrier used in a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a partial enlarged view showing the vicinity of an inner lead portion 1a of the tape carrier shown in FIG.

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal wiring, 1a ... Inner lead part, 1b ... Outer lead part, 1c ... Electrode for plating, 2 ... Flexible tape, 3 ... Inner lead part peripheral region (thin film flexible tape part) 4 ... Outer lead holes, 5 ... Sprocket holes, 6 ... Semiconductor device chips 7 ... Bumps, 8 ... Through holes

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kenichi Otani 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (2)

[Claims] 1. A semiconductor device in which a semiconductor device chip is mounted on a chip carrier having a plurality of sets of metal wiring formed on one surface side of a flexible film member, wherein the terminal portion of the semiconductor device chip is The metal wire forming surface side of the chip carrier is connected to the inner lead portion of the metal wire, and the through column of the heat conductive material penetrating the flexible film member is provided on the back surface side of the connecting portion of the inner lead portion. A semiconductor device, which is provided. 2. A method of manufacturing a semiconductor device, comprising: mounting a semiconductor device chip on a chip carrier having a plurality of sets of metal wiring formed on one surface side of a flexible film member; When connecting from the metal wiring formation surface side of the chip carrier to the inner lead portion of the metal wiring, on the back surface side of the connection portion of the inner lead portion, of the heat conductive material penetrating the flexible film member. Using a chip carrier provided with a through pillar, a pressing tool of a bonding apparatus is applied to the through pillar, and the inner lead portion is pressed against the protruding terminal portion of the semiconductor device chip by the pressing force through the through pillar. A method of manufacturing a semiconductor device, which is characterized.