JP2004101850A - Photosensitive organic and inorganic composite material and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive organic/inorganic composite material having superior temperature cycle characteristics and a semiconductor device. <P>SOLUTION: In the photosensitive organic inorganic composite material made of a photosensitive resin and an inorganic filler, the content of the inorganic filler is at least 30 vol.% to less than 75 vol.%, the inorganic filler preferably has a scale or plate shape, the maximum grain size is 50 μm or less, and an aspect ratio is 4 or more and 50 or less. The photosensitive organic inorganic composite material is dispersed in the resin while being accumulated in a laminar shape in the resin without generating any secondary condensation. The semiconductor using the photosensitive organic inorganic composite material is provided. <P>COPYRIGHT: (C)2004,JPO

Description

【００２３】
【発明の効果】
本発明によれば、温度サイクル試験において絶縁樹脂層クラックの発生の問題がない、信頼性に優れた感光性有機無機複合材料および半導体装置を提供できる。
【図面の簡単な説明】
【図１】温度サイクル信頼性評価用半導体装置の断面概略図である。
【符号の説明】
半導体ウエハー　１
絶縁樹脂層　２
ソルダーレジスト層　３
印刷封止樹脂　４
再配線回路　５
ニッケル／金メッキ層　６
半田ボール　７
金ワイヤー　８[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic-inorganic composite material that is highly reinforced by a highly filled inorganic filler and has photoresolution.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration and high-density mounting of electronic components have been advanced. Semiconductor packages used in these electronic devices have become smaller and have more pins, and mounting substrates for mounting electronic components including the semiconductor packages have also become smaller. Furthermore, in order to enhance the storage in electronic devices, a rigid-flex board, in which a rigid board and a flexible board are laminated and integrated to be bent, has been used as a mounting board.
[0003]
As the size of a semiconductor package has been reduced, the size of a conventional package using a lead frame has reached its limit in miniaturization. Recently, a BGA (Ball Grid) has been used as a package mounted on a circuit board. A new area-mounting type packaging system such as an array (Array) or a CSP (Chip Scale Package) has been proposed. In these semiconductor packages, the electrical connection between the electrodes of the semiconductor chip and the terminals of the substrate made of various materials such as plastics and ceramics, which are called semiconductor package substrates and have the function of the lead frame of the conventional semiconductor package. As a typical connection method, a wire bonding method, a TAB (Tape Automated Bonding) method, and an FC (Flip Chip) method are known. Recently, BGA and CSP structures using an FC connection method that is advantageous for miniaturization of semiconductor packages have been actively proposed, and as represented by wafer level CSP (WLCSP), for further miniaturization, A real chip size package (RCSP) in which the CSP is reduced to the size of a semiconductor chip has been proposed.
[0004]
As such packages have become smaller and thinner, the amount of insulating resin constituting one package has become smaller, and there has been a further demand for improved resin performance with respect to reliability. The problem common to BGA, CSP, and WLPKG is that the photosensitive resin has a structure in which the thermal expansion coefficient is extremely small and is in close contact with silicon or a wafer, or the thermal expansion coefficient is in close contact with an organic material that is constrained by the wafer. Due to the structure, when a temperature cycle test (TC test) is performed on the above semiconductor package to accelerate and evaluate the performance of the package, the resin becomes excessively large due to a mismatch in the thermal expansion coefficient between the photosensitive resin and silicon. Stress is applied and cracks occur. Reliability in the TC test, that is, crack resistance, is indispensable as a material for a semiconductor package.
[0005]
However, in particular, an insulating resin produced by photocrosslinking from a photopolymerizable compound represented by a compound having a methacryloyl group or an acryloyl group, or a thermosetting resin represented by an epoxy resin and a curing agent thereof. The insulating resin produced by crosslinking has poor toughness and poor TC reliability. For this reason, for the purpose of improving the reliability in the TC test, a method of reducing the thermal stress of the insulating resin by rubber modification and a method of reducing the thermal stress of the insulating resin by processing conditions have been studied. In fact, it is not possible to obtain such an effect.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of such problems, and has as its object to provide a highly reliable photosensitive organic-inorganic composite material having excellent crack resistance in a TC test, and a semiconductor device using the same. And
[0007]
[Means for Solving the Problems]
That is, the present invention
(1) a photosensitive organic-inorganic composite material comprising a photosensitive resin and an inorganic filler, wherein the content of the inorganic filler is 30% by volume or more and less than 75% by volume;
(2) The photosensitive organic-inorganic composite material according to (1), wherein the inorganic filler has a flaky or plate-like shape, a maximum particle size of 50 μm or less, and an aspect ratio of 4 to 50.
(2) The photosensitive organic-inorganic composite material according to (1), wherein the inorganic filler has a flaky or plate-like shape, a maximum particle size of 40 μm or less, and an aspect ratio of 4 to 40.
(4) The photosensitive organic-inorganic composite material according to any one of (1) to (3), wherein the inorganic filler is dispersed in the resin so as to be stacked in layers without causing secondary aggregation.
(5) A semiconductor device using the photosensitive organic-inorganic composite material according to any one of (1) to (4),
It is.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The inorganic filler used in the present invention is in the form of a scale or a plate, and preferably has a maximum particle size of 50 μm or less and an aspect ratio of 4 or more and 50 or less, and further has a maximum particle size of 40 μm or less and an aspect ratio of 4 or more and 40 or less. It is more preferred that: When the maximum particle size exceeds 50 μm, the resolution of the photosensitive resin is significantly reduced. Further, when the aspect ratio is less than 4 and the shape approaches a sphere, the effect of stacking the fillers in layers decreases, and the effect of reinforcing the resin with the fillers decreases. It is not preferable to use an acicular filler because anisotropy is exhibited in physical properties in a plane. Further, when the aspect ratio exceeds 50, although the effect of stacking the filler in a layered form is improved, the filler particles become thinner, so that the resistance to cracks extending in the thickness direction of the filler decreases, and the effect of reinforcing the resin with the filler decreases. I do.
[0009]
The addition amount of the inorganic filler is preferably 30% by volume or more and less than 75% by volume, and more preferably 35% by volume or more and less than 70% by volume. If it is less than 30% by volume, the distance between the filler particles becomes long, and the effect of reinforcing the resin with the filler is not sufficient. On the other hand, when the content is 75% by volume or more, the resolution is reduced and the function as a photosensitive resin is not exerted.
[0010]
Further, the present invention is a photosensitive organic-inorganic composite material characterized in that the shape, size, aspect ratio, filling amount and filler of the inorganic filler are dispersed for stacking in a layered form, and the photosensitive material used in the present invention The base resin is not limited at all, but the following are examples. In particular, the effect of improving the crack resistance of the negative photosensitive resin is great.
[0011]
Examples of the negative photosensitive resin include: 1) one or more compounds having a functional group that causes radical polymerization, such as an acryloyl group, a methacryloyl group, or a vinyl group; benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone; Hydroxybenzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, ethylanthraquinone And one or more kinds of photopolymerization initiators typified by butylanthraquinone, etc., and 2) epoxy resin and its curing in the above 1) , Maleimide, Funoru resins include those obtained by adding a thermosetting resin such as cyanate resin.
[0012]
Examples of the positive photosensitive resin include a resin obtained by adding a naphthoquinonediazide compound to a polyimide resin, a polybenzoxazole resin, or the like.
[0013]
In addition to the inorganic filler and the photosensitive resin, an antifoaming agent, a leveling agent, an ultraviolet absorber, and a plasticizer may be added. In addition, rubber particles or irregular or spherical inorganic fillers may be added as long as the inorganic fillers do not hinder stacking in layers. Needle-like fillers may also be added as long as they do not hinder stacking of plate-like or flake-like fillers in layers, and do not cause anisotropy in in-plane physical properties.
[0014]
The organic-inorganic composite material of the present invention is applied to various semiconductor devices. . The semiconductor device of the present invention may have any shape, and any other material may be used as long as the organic-inorganic composite material is used. The photosensitive organic-inorganic composite material can be used, for example, as a solder resist for a circuit called an interposer in a semiconductor device. On the other hand, in a semiconductor device of a type in which a rewiring layer is formed on a wafer, it can be used as a photosensitive insulating resin layer existing between the rewiring layer and the wafer in order to hold the rewiring layer. Further, it can be used as a photosensitive solder resist for covering the rewiring layer. More preferably, it is used for both the photosensitive insulating resin layer and the photosensitive solder resist to increase the composition ratio of the organic-inorganic composite material in the semiconductor device constituting material.
[0015]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.
[Examples and Comparative Examples]
<Photosensitive resin component>
Epoxy resin * 1; EPICLON-N865 (manufactured by Dainippon Ink and Chemicals, Inc.)
Phenol resin * 2; Aronix TO-1496 (manufactured by Toagosei Co., Ltd.)
Photopolymerizable monomer * 3; Neomer PM201 (manufactured by Sanyo Chemical Co., Ltd.)
Photoreaction initiator * 4: Benzyl dimethyl ketal (manufactured by Ciba Specialty Chemicals)
<Inorganic filler component>
Scale silica; scale, maximum particle size 40 μm, aspect ratio 10
Synthetic mica; scaly, maximum particle size 30 μm, aspect ratio 40
Spherical silica; spherical, maximum particle size 5 μm, aspect ratio 1
Mica; scale-like, maximum particle size 40 μm, aspect ratio 30
[0016]
<Preparation of resin solution>
Each resin composition component except the inorganic filler was added to 300 g of methyl ethyl ketone according to the compounding amount shown in Table 1, and the mixture was stirred and dissolved with a disperser (4000 rpm) for about 1 hour. Thereafter, an inorganic filler having the compounding amount shown in Table 1 was added, and the resin solution was passed through a Gaulin-type stirring device (pressure 600 kg / cm ² ) for 15 minutes with a disperser (8000 rpm) while cooling the periphery of the resin solution with ice water. In addition, a solution of a photosensitive organic-inorganic composite material was obtained by performing treatment with an ultimateizer (pressure 200 MPa).
[0017]
<Preparation of copper foil with resin>
The resin solution obtained above was cast and applied on a 5 μm-thick electrolytic copper foil with a bar coater, and dried at 60 ° C. for 10 minutes and at 80 ° C. for 10 minutes to obtain a resin-coated copper foil (RCC) having a resin thickness of 70 μm. ) Got.
<Production of dry film solder resist>
The resin solution obtained above is cast on a 25 μm-thick PET (polyethylene terephthalate) film by a bar coater, and dried at 60 ° C. for 10 minutes and at 80 ° C. for 10 minutes to form a dry film solder having a resin thickness of 18 μm. A resist was obtained.
[0018]
<Production of semiconductor device>
FIG. 1 is a schematic sectional view of a semiconductor device for evaluating temperature cycle reliability.
The RCC was attached to the surface of an 8-inch semiconductor wafer 1 by a roll laminator to obtain a structure in which the semiconductor wafer 1, the insulating resin layer 2, and a copper foil were laminated. Next, a dry film plating resist is stuck on this structure by a roll laminator to form a plating resist layer, and a wire bond finger, a solder ball pad, and a portion to be a circuit connecting them are opened by photolithography. After that, a copper layer having a thickness of 10 μm, a nickel layer having a thickness of 5 μm, and a gold layer 6 having a thickness of 1 μm were formed on the portions by electrolytic plating. Thereafter, the plating resist was peeled off with a 3% aqueous sodium hydroxide solution, and then the RCC copper foil was flash-etched using the gold plating layer as a resist to form a rewiring circuit 5 immediately below the gold plating layer.
[0019]
Further, the surface of the resin layer from which the copper foil has been removed by the etching is exposed using a parallel light exposure machine so that a portion on the wire bond pad can be developed and opened, and is exposed to a 2.38% tetramethylammonium hydroxide aqueous solution. Then, the resin at a predetermined position is dissolved and removed, the surface is irradiated with ultraviolet rays at 500 mJ, and then heated at 180 ° C. for 1 hour, thereby forming a resin opening for wire bonding on the wafer and a wire having a surface coated with gold plating. A fully cured insulating resin layer 2 having a bond finger, a solder ball pad, and a rewiring circuit connecting them was obtained.
[0020]
Next, the above dry film solder resist is stuck on the rewiring circuit 5 by a roll laminator heated to 70 ° C., and a photomask is formed on the opening of the insulating resin layer for wire bonding fingers, solder ball pads and wire bonding. Is exposed at 250 mJ using a parallel light exposure machine, the insulating resin layer at a predetermined position is dissolved and removed with a 2.38% aqueous solution of tetramethylammonium hydroxide, and the surface is irradiated with 500 mJ of ultraviolet light. The solder resist layer 3 was cured by heating at 1 ° C. for 1 hour. Next, after the semiconductor wafer 1 and the redistribution circuit 5 on the insulating resin are joined by the gold wire 8 via the resin opening, the opening of the insulating resin layer and the periphery of the wire bond finger are printed with a sealing resin (CRP5300). (Manufactured by Sumitomo Bakelite) 4 and cured at 180 ° C. for 1 hour. Then, the solder balls 7 were mounted, and finally dicing was performed to obtain a semiconductor device for evaluating TC reliability (FIG. 1). The size is 10 mm × 10 mm × 1.3 mm.
[0021]
The semiconductor device obtained in this manner was subjected to a TC test under the conditions of −65 ° C./30 minutes to 150 ° C./30 minutes while changing the number of cycles to 50, 100, 200, 300, 400, and 500 cycles. Then, the number of occurrences of cracks in the resin layer in the TC test was measured by microscopic observation (n = 10 each). Table 1 shows the results.
From the results shown in Table 1, it is understood that the evaluation results of the TC test of the examples are better than those of the comparative examples.
[0022]
[Table 1]

[0023]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the photosensitive organic-inorganic composite material excellent in reliability which does not have the problem of generation | occurrence | production of an insulating resin layer crack in a temperature cycle test and a semiconductor device can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a semiconductor device for evaluating temperature cycle reliability.
[Explanation of symbols]
Semiconductor wafer 1
Insulating resin layer 2
Solder resist layer 3
Printing sealing resin 4
Rewiring circuit 5
Nickel / gold plating layer 6
Solder ball 7
Gold wire 8

Claims (5)

A photosensitive organic-inorganic composite material comprising a photosensitive resin and an inorganic filler, wherein the content of the inorganic filler is 30% by volume or more and less than 75% by volume. The photosensitive organic-inorganic composite material according to claim 1, wherein the inorganic filler has a flaky or plate-like shape, a maximum particle diameter of 50 µm or less, and an aspect ratio of 4 to 50. The photosensitive organic-inorganic composite material according to claim 1, wherein the inorganic filler has a flaky or plate-like shape, a maximum particle size of 40 µm or less, and an aspect ratio of 4 or more and 40 or less. The photosensitive organic-inorganic composite material according to any one of claims 1 to 3, wherein the inorganic filler is dispersed in the resin so as to be layered without causing secondary aggregation. A semiconductor device using the photosensitive organic-inorganic composite material according to claim 1.

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