JPH1187562A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which is excellent in reflow- resistant and high volume production properties by a method wherein an adhesive film material used for bonding a reinforcing material to a wiring tape is formed of thermosetting and low-elasticity resin. SOLUTION: Balls serving as an electrical connection terminal to a mounting board are provided outside a semiconductor device or outside and inside the semiconductor device. A wiring tape outside the semiconductor device is required to be lined with a reinforcing material so as to be flat. An adhesive film composed of a thermosetting resin component and a low-elasticity resin component is used to paste the reinforcing material to the wiring tape. A semiconductor device which is excellent both in reflow-resistant and in connection reliability can be obtained by using an adhesive film composed of a thermosetting resin component and a low-elasticity resin component as adhesive material to bond a wiring tape and a reinforcing material together. A manufacturing method which is excellent in high volume production can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-density, multi-pin, high-speed transmission-compatible semiconductor device excellent in electrical characteristics, mounting reliability, and assemblability, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for higher integration and higher density of semiconductor devices along with higher performance of electric and electronic components. Therefore, semiconductor elements are LSI, VLSI, ULSI
Higher integration, higher functionality, larger elements, more pins,
Higher speed and higher power consumption have been advanced. In response, the package structure of a multi-pin semiconductor device has changed from a structure having connection terminals on two sides of an element to a structure having terminals on all four sides. Further, a grid array structure in which connection terminals are arranged on a grid on the entire mounting surface using a multilayer carrier substrate has been put to practical use to cope with the increase in the number of pins.

In this grid array structure, a ball grid array structure (BGA) in which connection terminal length is shortened in order to enable high-speed signal transmission is applied. The ball-type structure as the connection terminal also has a large conductor width, and is thus effective in reducing inductance. Further, recently, organic materials having a relatively low dielectric constant have been studied for a multilayer carrier substrate to cope with a higher speed. In addition, in addition to the carrier substrate, a TAB (Tape Automated
A BGA using a tape has also been developed (IEICE Technical Report, Vol. 96, No. 414, 1996).

However, since a wiring tape such as a TAB tape does not have a rigid structure like a carrier substrate, in order to mount a ball as an external terminal, it is often lined with some reinforcing material to ensure flatness. In general, the thermal expansion coefficients of the reinforcing material, the wiring tape, and the real-layer substrate are different from each other, so that a thermal stress is generated, which may cause a problem in connection reliability of the external terminals such as a ball.

[0005]

SUMMARY OF THE INVENTION The present invention discloses a technique of using a film material comprising a thermosetting resin component and a low elastic modulus resin component to reduce thermal stress in a semiconductor device, thereby achieving excellent flatness. Another object of the present invention is to provide a semiconductor device which is excellent in mass productivity.

[0006]

In order to achieve the above object, the present invention provides the following means. The means is that the tape material having the wiring layer and the semiconductor element are electrically connected,
In a semiconductor device having external terminals for electrically connecting to a mounting substrate on the wiring tape and having a reinforcing material for flattening the wiring tape, a film material for bonding the reinforcing material and the wiring tape is heated. This is achieved by providing a semiconductor device comprising a curable resin component and a low elastic modulus resin component.

As a film material, a step of forming external terminals using solder balls or the like for connecting to a mounting board in a manufacturing process of a semiconductor device, or a solder reflow step for mounting a semiconductor element of the present invention on a mounting board is used. Pass. Since the reflow temperature is generally processed at a high temperature of 200 to 250 ° C., the semiconductor device which has absorbed moisture evaporates and swells with the vapor pressure and swells with the film material. And defects such as peeling.

Therefore, it is required that the film material used has as low a moisture absorption rate as possible. In the present invention, as a result of examining various film materials, it has been found that a material composed of a thermosetting resin component and a low elastic modulus resin component has excellent reflow characteristics as compared with a thermoplastic material.

Further, since the film material functions as a stress relieving layer, it is desirable that the film material is formed of a low elastic modulus resin having an elastic modulus at room temperature of 4000 MPa or less. Therefore, it becomes possible to achieve desired properties by including a low elastic modulus resin component. From the viewpoint of reflow characteristics, the film material desirably has a moisture absorption rate of 3% or less at 85 ° C./85% RH for 168 hours.

[0010] The film material may have a three-layer structure having an adhesive layer on both sides of a support, in addition to a uniform structure consisting of only an adhesive component. In this case, a polyimide material is often used as the central support. In some cases, a porous support is impregnated with an adhesive.

As the film shape, there are various punched shapes, mesh shapes and the like. The mesh shape can reduce the sticking area and is more effective in improving the reflow resistance during moisture absorption. In the case of a multilayer structure typified by a three-layer structure, the adhesive layers are on both sides of the support, but may be made of different materials. The thickness of the adhesive layers on both sides may be the same or different.

The method of manufacturing a semiconductor device according to the present invention is basically formed by the following steps. That is, the tape material on which the wiring layer is formed and the connection pads of the semiconductor element are electrically connected. As a connection method, a method of connecting to a semiconductor element using a connection lead formed in advance on a wiring tape by a circuit, in this case, a single point bonding, a collective gang bonding method, or the like is used. As another connection technique, a method of connecting the both by wire bonding or the like is used.

Next, the connection portion is sealed with an insulating material,
A reinforcing material is stuck on the wiring tape using an adhesive film comprising a thermosetting resin component and a low elastic modulus resin component to achieve flatness. Finally, external terminals as electrical connection terminals with the mounting board are formed on the wiring tape. Generally, when using solder balls as external terminals,
A ball forming method by plating is often used. In the case of plating, examples of metals include gold, nickel, copper, and solder.

In order to increase the mass productivity in the manufacturing process, it is possible to take a step of integrating the reinforcing material with the wiring tape in advance via an adhesive film. As a general manufacturing method in this case, a method in which the tape on which the wiring layer is formed is transported in a long reel process and a reinforcing material having an adhesive film is continuously attached is effective for mass productivity.
In this case, the outermost adhesive layer of the film affixed to the reinforcing material can be adhered to the wiring tape in an uncured A stage or a semi-cured B stage. In the step of bonding to the wiring tape using the obtained reinforcing material with an adhesive film, the resin further hardens and finally reaches the C stage.

The adhesive film can be attached to the wiring tape in advance. In this case, a reinforcing material is attached using a wiring tape with an adhesive film. The method of pasting the reinforcing material before connecting these semiconductor elements to the wiring tape can confirm the pasting state of the reinforcing material in advance, and it is possible to remove defects before connecting the semiconductor elements, and waste semiconductor elements. This is advantageous in terms of cost and yield.

Typical thermosetting resin components constituting the adhesive component of the film material include epoxy resin, polyimide resin, polyamide resin, cyanate resin, isocyanate resin, fluorine-containing resin, silicon-containing resin, urethane resin, and the like.
Examples include styrene resin, maleimide resin, phenol resin, unsaturated polyester resin, diallyl phthalate resin, cyanamide resin, polybutadiene resin, various other polymer blends, and polymer alloys.

Representative low elastic modulus resin components constituting the adhesive component of the film material include acrylic rubber, polybutadiene rubber, acrylonitrile butadiene rubber, fluorine rubber, silicone rubber and the like.

The elastic modulus of the adhesive film material is preferably high in a high temperature range from the viewpoint of reflow characteristics, but is preferably as low as possible in a room temperature range.
Since the semiconductor element, the mounting board, the wiring tape, and the reinforcing material have different coefficients of thermal expansion, thermal stress is generated in external terminals formed of solder balls and the like during mounting, and connection reliability becomes an important issue. If the elasticity of the adhesive film existing between the reinforcing material and the wiring tape is low, this portion becomes a stress buffer layer, which is advantageous from the viewpoint of connection reliability. It is desirable that the elastic modulus at room temperature be 4000 MPa or less.

Further, hopefully, the entire temperature cycle test (-
The elastic modulus at 55 ° C to 150 ° C) is desirably 2000 MPa or less. While maintaining the elastic modulus at such high temperatures,
As a material having a relatively low elastic modulus in a low temperature region including room temperature, a silicone material is often used. A film material made of a silicone-based material is one of extremely important materials in a semiconductor device having the same structure as the present invention.

However, the film material of the present invention has the following advantages as compared with the silicone material. That is, since silicone has low cohesive energy, the cyclic low-molecular compound is gradually thermally decomposed due to the heat history of the manufacturing process, and its volatile components may be contaminated to cause a failure such as poor connection. Further, even in a long-term heat treatment such as high-temperature storage (for example, 150 ° C. or more), the same thermal decomposition product may cause contamination to the surroundings.

The film material of the present invention is not only composed of a uniform structure consisting of only an adhesive component, but also, for example, of a three-layer structure having an adhesive layer on both sides of a support. May be impregnated with an adhesive. Examples of the support for the film material include a film or a porous material such as polyimide, epoxy, polyethylene terephthalate, cellulose, acetate, or a fluorine-containing polymer.

As the film shape, there are various punched shapes, mesh shapes and the like. The mesh shape can reduce the sticking area and is effective in improving the reflow resistance during moisture absorption. In the case of a three-layer structure, the thickness of the adhesive layer on both sides,
The type can be arbitrarily controlled, and the fluidity at the time of sticking can be easily controlled.

85 ° C./85% RH of adhesive film material
By using a material having a saturated moisture absorption of 3% or less, the value of vapor pressure due to moisture absorption during reflow can be suppressed, and good reflow characteristics can be obtained.

A tape having a wiring layer is generally composed of a flexible circuit board. That is, a polyimide material is used as the insulating layer, an epoxy material is used as the adhesive layer with the conductor,
Polyimide-based materials, phenol-based materials, polyamide-based materials, and the like are used. Copper is often used as the conductor layer. The wiring circuit may be coated on copper with nickel, gold plating, or the like. In some flexible circuit boards, a material in which copper is directly formed on a polyimide insulating layer that does not use an adhesive layer with a conductor may be used. The tape having a wiring layer may have a multilayer wiring structure. In this case, a power supply layer, a ground layer, and the like can be formed in the wiring tape in addition to the signal wiring layer, and a semiconductor device having excellent electric characteristics can be provided.

FIG. 1 shows a typical example of the semiconductor device of the present invention. The ball, which is an electrical connection terminal with the real substrate, may be outside the periphery of the semiconductor element, or may be both inside and outside. The wiring tape outside the semiconductor element needs to be lined with a reinforcing material to ensure flatness. In order to attach this reinforcing material to the wiring tape, an adhesive film composed of a thermosetting resin component and a low elastic modulus resin component is used.

It is also possible to mount a heat conductive material such as a heat spreader on the upper part of the back surface of the semiconductor element in consideration of heat dissipation. At this time, the reinforcing material and the heat spreader may be configured separately or may be integrated. Regarding the adhesion of the heat spreader, an adhesive film composed of a thermosetting resin component and a low elastic modulus resin component in the present invention or an adhesive film obtained by adding a heat conductive component such as a metal piece to this component can be used.

In the present invention, the semiconductor element is Si, Ga
Memory, logic,
I for gate array, custom, power transistor, etc.
This is an element that forms terminals such as C and LSI and has terminals that are connected to leads, bumps, and the like.

That is, the present invention relates to a semiconductor device using a tape having a wiring layer as an intermediate material for electrical connection between a semiconductor element and a mounting board, and a thermosetting resin component as a bonding material between the wiring tape and a reinforcing material, and a low elasticity. By using a film composed of a high-resin component, it has become possible to provide a semiconductor device having excellent reflow resistance and connection reliability. By using a film material composed of a thermosetting resin component and a low elastic modulus resin component, it becomes possible to provide a production method excellent in mass productivity.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

Example 1 An adhesive film (Hitachi Chemical, prototype, 50 μm thick) composed of an epoxy resin and an acrylic rubber (20% by weight of the whole) was reinforced with a reinforcing material (MF).
202, 0.2 mm thick, Hitachi Cable) at 100 ° C for 2 seconds, position this on the wiring tape, and
After 5 seconds, the post-curing was heated in a thermostat at 170 ° C. for 60 minutes. The semiconductor elements were electrically connected to the wiring tape having the reinforcing material by collective gang bonding, and the connection portions were sealed with an epoxy-based sealing material (Hitachi Chemical, RCO21C). Finally, solder balls, which are connection terminals with the mounting substrate, were mounted on the wiring tape to obtain the semiconductor device shown in FIG.

The obtained semiconductor device was heated at 85 ° C./85% RH.
After absorbing moisture for 168 hours with a constant temperature and humidity layer, the adhesive layer was subjected to infrared reflow at a maximum temperature of 245 ° C.
It was confirmed that defects such as voids did not occur. Furthermore, the connection reliability of the leads and solder bumps of the obtained semiconductor device was confirmed. At this time, a glass cloth substrate epoxy resin copper-clad laminate FR-4 (Hitachi Chemical, MCL-E-
67) was used. The reliability test was performed using a temperature cycle (-55 ° C).
← → 125 ° C., 1000 times). (Example 2) Polyimide film (Ube Industries, SGA,
Adhesive layers composed of the same epoxy resin and acrylic rubber (25% by weight of the entire adhesive component) as in Example 1 were applied on both surfaces of a thickness of 25 μm) to a thickness of 20 μm to form a three-layer film material. The obtained film material was positioned and attached to a wiring tape. At this time, the bonding conditions are 100 ° C, 3
Seconds. Next, an aluminum reinforcing material was attached to the wiring tape. The bonding conditions were 150 ° C. and 10 seconds. Further, post-curing was performed in a thermostat at 170 ° C. for 60 minutes.

Next, the pads were electrically connected to the pads of the semiconductor element by collective gang bonding using the connection leads on the wiring tape. The connection was sealed with an epoxy-based sealing material (Hitachi Chemical, RC021C). Finally, solder balls, which are connection terminals with the mounting substrate, were mounted on the wiring tape to obtain the semiconductor device shown in FIG.

The reflow characteristics and the connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed in the same manner as in Example 1.

Embodiment 3 A semiconductor element and a wiring tape are electrically connected in advance by wire bonding.
The connection portion was sealed with an epoxy-based sealing material (Hokuriku paint, chip coat 8107). Next, a composition composed of YX4000 (oiled shell) and E-180 (oiled shell) (equivalent ratio) as epoxy resin on the wiring tape, and XER91 (Nippon Synthetic Rubber) (30 in total) as butadiene rubber. Weight%), a 42-alloy heat spreader-integrated reinforcing material with an adhesive film attached thereto was attached at 130 ° C. for 5 seconds, and finally, a solder ball as a connection terminal with a mounting substrate was attached on the wiring tape as shown in FIG. -3 was obtained. Thereafter, the adhesive film was heated in a thermostat at 170 ° C. for 60 minutes as final curing conditions.

The reflow characteristics and the connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed in the same manner as in Example 1.

(Example 4) Epoxy as thermosetting resin
EPICLON N-665 (Dainippon Ink and Chemicals) and XL-
Composition comprising 225-2L (Mitsui Toatsu Chemicals) (equivalent ratio),
It is composed of polytetrafluoroethylene rubber particles (Daikin Industries) (15% by weight in total) as a low elastic modulus component,
In order to further improve the film forming property, polyimide (bisphenol A bistrimellitate dianhydride and bis- (4
-(Reactant with 2-aminophenoxyphenyl) ether (20% by weight of total) was added to form a film.

This was adhered to a wiring tape while punching out the shape, and a copper heat spreader-integrated reinforcing material was further adhered. The bonding was performed at 120 ° C. for 5 seconds. Next, the wiring tape with the reinforcing material was insulatively bonded to the semiconductor element using the same adhesive film, and the wiring tape and the pad of the semiconductor element were electrically connected by single point bonding while applying ultrasonic waves. The connection was sealed with an epoxy-based sealing material (Hitachi Chemical, RC021C). Finally, solder balls as connection terminals with the mounting board were attached on the wiring tape to obtain the semiconductor device shown in FIGS.

The reflow characteristics and the connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed by the same method as in Example 1.

Example 5 A semiconductor element was electrically connected to a wiring tape by a wire bonding method, and the connection portion was sealed with an epoxy-based sealing material (Hitachi Chemical, RC021C). Next, YX4000 (oiled shell) as epoxy resin and E
PX-GE2 (Nippon Shokubai) as a composition acrylic rubber composed of -180 (oiled shell) (equivalent ratio)
(0% by weight). At this time, the bonding condition is 1
30 ° C., 5 seconds. Further, a heat spreader was stuck at 130 ° C. for 5 seconds with an adhesive film containing 50% by weight of silver filler in the resin composition. Finally, solder balls, which are connection terminals with the mounting substrate, were mounted on the wiring tape to obtain the semiconductor device shown in FIG. 1-5.

The reflow characteristics and connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed in the same manner as in Example 1.

(Embodiment 6) After electrically connecting a semiconductor element to a wiring tape by single point bonding using ultrasonic waves, a thermosetting resin, liquid cyanate AroCy L-10 (Asahi Chiba) was used as an adhesive film in naphthene. A composition using manganese oxide as a catalyst (0.2 parts by weight with respect to cyanate), aluminum having a low elastic modulus component bonded with a material composed of silicone rubber E601 (Toray Dow Corning) (30% by weight of the whole). The reinforcing material was attached to the wiring tape at 120 ° C. for 2 seconds.

Thereafter, the portion where the semiconductor element and the wiring tape were electrically connected was sealed with an epoxy-based sealing material (Hokuriku paint, chip coat 8107). Furthermore, an aluminum metal plate is used as a heat spreader with the same adhesive film.
It was affixed at 0 ° C. for 2 seconds. Finally, solder balls, which are connection terminals with the mounting board, are mounted on the wiring tape, and FIG.
Was obtained.

The reflow characteristics and connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed in the same manner as in Example 1.

(Comparative Example 1) A silicone resin (Toray Dow Corning, JCR6126) was positioned on a wiring tape, and an elastomer having a thickness of 50 μm was formed by printing using a metal mask. Next, a copper reinforcing material was attached, and a curing reaction was performed at 150 ° C. for 60 minutes. The semiconductor element was electrically connected to the wiring tape having the reinforcing material by gang bonding.

The connection portion was sealed with a silicone-based sealing material (Toshiba Silicone, TSJ3150). Finally, solder balls, which are connection terminals with the mounting substrate, were mounted on the wiring tape to obtain the semiconductor device shown in FIG.

The reflow characteristics and the connection reliability of the leads and the solder bumps of the obtained semiconductor device were confirmed in the same manner as in Example 1.

Comparative Example 2 Epoxy film containing no low modulus component, YX4000 (oiled shell) and E-180
Using a film composed of (oiled shell) (equivalent ratio), a semiconductor device was fabricated in the same manner as in Example 1 at a bonding condition of 150 ° C. and 10 seconds, and the reflow characteristics and the connection reliability of the leads and solder bumps were prepared. Was confirmed in the same manner as in Example 1.

[0048]

[Table 1]

[0049]

The tape material having the wiring layer and the semiconductor element are electrically connected, and the wiring tape has external terminals for electrically connecting to the mounting substrate, and the wiring tape and the reinforcing material are bonded. In a semiconductor device using a film as a material, a semiconductor device having excellent reflow resistance can be provided by using a material in which an adhesive film includes a thermosetting resin component and a low elastic modulus resin component. By using a film material in a portion where the thermal stress generated due to a difference in thermal expansion coefficient between the wiring tape, the reinforcing material, the semiconductor element, and the mounting substrate is reduced, a manufacturing method excellent in mass productivity can be provided.

The film material is excellent in flatness,
A manufacturing process with excellent workability can be provided. Due to the stress relaxation effect of the film material, the connection reliability of both the lead part that electrically connects the wiring tape and the semiconductor element and the bump that electrically connects the semiconductor device and the mounting board in the temperature cycle test are simultaneously improved. It is possible to be satisfied.

[Brief description of the drawings]

FIG. 1 is a view illustrating each process of mounting each component on a semiconductor device.

[Explanation of symbols]

1.1.1, 1.2.1, 1.3.1, 1.4.1, 1.5.1,
1.6.1 Semiconductor device, 1.1.2, 1.2.2, 1.3.
2, 1.4.2, 1.5.2, 1.6.2 ... wiring tape, 1.
1.3, 1.2.3, 1.3.3, 1.4.3, 1.5.3, 1.
6.3: Ball-shaped terminal, 1.1.4, 1.2.4, 1.3.
4, 1.4.4, 1.5.4, 1.6.4 ... sealing material, 1.1.
5, 1.2.5, 1.3.5, 1.4.5, 1.5.5, 1.6.
5 ... Inner lead, 1.1.6, 1.2.6, 1.3.6,
1.4.6, 1.5.6, 1.5.8, 1.6.6, 1.6.8 ...
Adhesive film 1.1.7, 1.2.7, 1.5.7, 1.6.
7. Reinforcing material 1.3.7, 1.4.7 ... Heat spreader-integrated reinforcing material, 1.5.9, 1.6.9 ... Heat spreader.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masanori Segawa 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Takumi Ueno 7-1, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi Research Laboratory, Hitachi Ltd. 5-2-1, Kamimizu Honcho Semiconductor Division, Hitachi, Ltd.

Claims (7)

[Claims] A tape material having a wiring layer and a semiconductor element are electrically connected to each other. The wiring tape has external terminals for electrically connecting to a mounting substrate. A semiconductor device having a reinforcing material, wherein a film material for bonding the reinforcing material and the wiring tape comprises a thermosetting resin component and a low elastic modulus resin component. 2. A semiconductor device according to claim 1, wherein the thermosetting resin component of the film material is an epoxy resin. 3. The semiconductor device according to claim 1, wherein the low elastic modulus resin component of the film material is acrylic rubber. 4. A semiconductor device according to claim 1, wherein the low elastic modulus resin component of the film material is 10 to 50% by weight of the whole composition. 5. The semiconductor device according to claim 1, wherein the film material has a three-layer structure having an adhesive layer on both surfaces of a support. 6. A semiconductor device according to claim 4, wherein the support of the film material is made of polyimide. 7. A tape material having a wiring layer and a semiconductor element are electrically connected to each other, and the wiring tape has external terminals for electrically connecting to a mounting substrate. A method of manufacturing a semiconductor device having a reinforcing material, wherein a film material for bonding the reinforcing material and the wiring tape comprises a thermosetting resin component and a low elastic modulus resin component.