JPH10242441A - Plastic lid member for solid-state image pickup element package and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid member whose specific gravity is small, which is excellent in molding property, transparency and dimension stability and which has a visibility correction function by copolymerizing a monomer containing a specified phosphate group and mixed monomer with a monomer which can be copolymerized with the monomer and containing an ionic metal component in it. SOLUTION: The monomer containing phosphate group represented by a formula I is copolymerized with the monomer which can be copolymerized with the monomer. Then, an acrylic copolymer whose hygroscopic property is small and which is superior in heat resistance, dimension stability and adhesive strength against a package is obtained. Here, the group R of the formula I is polymerized functional group shown by a formula II and (n) becomes '1' or '2'. Then, X in the formula II shows a hydrogen atom or a methyl group, and (m) is the integer of 0-5. The ionic metal group whose main component is set to be copper ions is contained in the acrylic copolymer which is thus obtained at an appropriate rate. Consequently, the lid member absorbing the liquid of a near-infrared area at high efficiency and having a satisfactory visibility correction function is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a plastic lid material for a solid-state imaging device (CCD) package having a visibility correction function.

[0002]

2. Description of the Related Art Conventionally, glass has been used as a lid material for a solid-state imaging device (CCD) package. Here, the lid material for the solid-state imaging device (CCD) package is a closed state of the solid-state imaging device (CCD) for the purpose of preventing the solid-state imaging device (CCD) from malfunctioning and being deteriorated by dust. This is a transparent lid material used together with a package for the purpose. However, the glass material has a large specific gravity and is brittle against impact. Also, when manufacturing a lid material made of glass, it may be damaged when handling the glass material or when performing a cutting process, and a high yield cannot be obtained,
In addition, chipping is apt to occur in the cutting process, so that post-processing is necessary, and these are factors that increase the manufacturing cost. Some glass materials emit radiation such as α-rays.In order to prevent such radiation from causing malfunction of the element memory, special glass materials are used for the lid material. Must be used. Therefore, there is a strong demand for the development of a plastic lid material having a low specific gravity, high strength, easy molding, and excellent dimensional stability and durability.

On the other hand, a solid-state imaging device (CCD) has a wavelength dependence of light-receiving sensitivity having a peak in the near infrared region. Uses a visibility correction filter for a part of the optical system. Thus, if a visibility correction function can be provided to the lid material, it becomes unnecessary to use a visibility correction filter in the optical system of the solid-state imaging device. This is advantageous in that cost and size can be reduced.

[0004]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and the first aspect of the present invention has been made.
The purpose of is to have low specific gravity, excellent moldability, and
Transparency, adhesive toughness to package, dimensional stability,
An object of the present invention is to provide a plastic lid material for a solid-state imaging device (CCD) package having excellent solvent resistance, heat resistance, and mechanical properties, and also having a visibility correction function. A second object of the present invention is to provide a method capable of advantageously producing the above-mentioned plastic lid material for a solid-state imaging device (CCD) package.

[0005]

The plastic lid material for a solid-state imaging device (CCD) package of the present invention is obtained by copolymerizing a mixed monomer comprising the following components (A) and (B). A plastic lid material for a solid-state imaging device (CCD) package, characterized in that the copolymer contains an ionic metal component containing copper ions as a main component. (A) Component: Phosphoric acid group-containing monomer represented by the following formula (1) (B) Component: Monomer copolymerizable with (A) component

[0006]

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In the plastic lid material for a solid-state imaging device (CCD) package according to the present invention, a hydroxyl group in a phosphate group derived from a phosphate group-containing monomer constituting the component (A) and the ionic metal The molar ratio with the components is
It is preferably in the range of 0.5: 1 to 5: 1. Further, it is preferable to use an acrylate compound or a methacrylate compound having a glycidyl group as a part or all of the component (B).

Further, in the plastic lid material for a solid-state imaging device (CCD) package of the present invention, a diffraction grating having an optical low-pass function may be formed on the surface.

According to a method of manufacturing a plastic lid material for a solid-state image pickup device (CCD) package of the present invention, a pair of mold plates having a negative pattern of a diffraction grating formed on one surface of at least one of the mold plates is provided. Are arranged so as to face each other to form a cavity. In the cavity, the metal compound containing a copper compound as a main component, the component (A) and the component (B) are formed.
It is characterized by including a step of obtaining a molded article of the copolymer by copolymerizing the monomer composition containing the components.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The plastic lid material for a solid-state imaging device (CCD) package of the present invention comprises a specific acrylic copolymer containing an ionic metal component containing copper ions as a main component. Then, the specific acrylic copolymer is obtained by copolymerizing a mixed monomer composed of the component (A) and the component (B).

The component (A) used to obtain the specific acrylic copolymer is a phosphate group-containing monomer represented by the above formula (1) (hereinafter referred to as a “specific phosphate group-containing monomer”). The body is also called.) Here, in the present invention, the “phosphate group” means PO (OH) _n- [n is 1 or 2. ) Means a group represented by

As shown in the above formula (1), the specific phosphate group-containing monomer has a phosphate group capable of forming an ionic bond or a coordination bond with an ionic metal component described later in a molecular structure. Have inside. The copolymer holding copper ions via the phosphate group has a characteristic light absorption characteristic in the near infrared region. Further, since the ionic metal component is ionic or coordinated with the phosphate group of the copolymer, the ionic metal component is contained in a state of being uniformly dispersed in the copolymer. The resulting lid material has very little light diffusion and good transparency.

In the formula (1) showing the molecular structure of a specific phosphoric acid group-containing monomer, the group R is, as shown in the formula (2), an acryloyloxy group to which an ethylene oxide group is bonded (X is a hydrogen atom). An atom) or a methacryloyloxy group (when X is a methyl group). Thus, in the molecular structure of the specific phosphate group-containing monomer, by having a radically polymerizable functional group acryloyloxy group or methacryloyloxy group, the specific phosphate group-containing monomer is It is very copolymerizable and can be copolymerized with various monomers. Here, the number m of repeating ethylene oxide groups is 0 to 5, preferably 1 to 5.
Is an integer. If the value of m exceeds 5, the resulting copolymer will have a drastically reduced hardness, and will lack practicality as a lid material.

In the formula (1), the number n of hydroxyl groups is 1
Or 2. The specific phosphoric acid group-containing monomer having a value of n of 1 has two radically polymerizable ethylenically unsaturated bonds bonded to a phosphorus atom and has crosslinkable polymerizability. The specific phosphate group-containing monomer having a value of 2 has the number of ethylenically unsaturated bonds of 1,
It becomes monofunctional. And in the present invention, n
When one or both of the specific phosphate group-containing monomer having a value of 1 and the specific phosphate group-containing monomer having a value of n of 2 can be used, or when both are used The mixing ratio can be selected, but a specific phosphate group-containing monomer having a value of n of 1 and a specific phosphate group-containing monomer having a value of n of 2 , Each having a substantially equimolar amount, for example, a molar ratio of 45 to 55:55
The use of a ratio of 45 is preferable because the solubility of the metal compound described below in the mixed monomer is improved.

The component (B) used together with the component (A) to obtain a specific acrylic copolymer is a monomer copolymerizable with the specific phosphate group-containing monomer used as the component (A). (Hereinafter, also referred to as “copolymerizable monomer”). Then, the copolymer obtained by copolymerizing the specific phosphate group-containing monomer and the copolymerizable monomer has a higher moisture absorption compared to the polymer containing only the specific phosphate group-containing monomer. Low heat resistance, excellent heat resistance, dimensional stability, and adhesive toughness to package. Therefore, according to such a copolymer, the performance as a lid material can be improved.

As the copolymerizable monomer used as the component (B), [1] a specific phosphate group-containing monomer used as the component (A) is uniformly dissolved and mixed, and [2]
(3) good radical copolymerizability with the specific phosphoric acid group-containing monomer used as the component, [3] (A)
The copolymer is not particularly limited as long as it satisfies, for example, obtaining an optically transparent copolymer by copolymerizing with a specific phosphate group-containing monomer used as a component.

Specific examples of the copolymerizable monomer include carbons of alkyl groups such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl methacrylate and cyclohexyl methacrylate. A lower alkyl acrylate compound or a lower alkyl methacrylate compound having a number of 1 to 8, benzyl acrylate, benzyl methacrylate, phenoxy acrylate, an acrylate or methacrylate compound containing an aromatic group such as phenoxy methacrylate, methoxyethyl acrylate, butoxyethyl methacrylate, An act having a lower alkyl group via an ethylene oxide group such as diethylene glycol monomethacrylate Acrylate compounds or methacrylate compounds having an isobornyl group such as a acrylate compound or a methacrylate compound, isobornyl acrylate, etc. Methacrylate compounds can be mentioned.

Also, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,4
-Butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,9-nonanediacrylate, 1,9-nonanedimethacrylate, 2,2-bis [4-acryloxyethoxyphenyl] propane, 2,
Polyfunctional acrylate compounds or polyfunctional methacrylate compounds such as 2-bis [4-methacryloxyethoxyphenyl] propane, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, and pentaerythritol tetramethacrylate , Styrene, α-methylstyrene,
Aromatic monomers such as divinylbenzene and p-tert-butylstyrene, and others can also be used. These compounds increase the heat resistance of the resulting acrylic copolymer, lower the water absorption of the acrylic copolymer,
The component (B) is selected as appropriate for the purpose of imparting properties such as hydrophobicity or hydrophilicity and special reactivity to the surface of the acrylic copolymer, alone or in combination of two or more. Used.

In the present invention, from the viewpoint of improving the adhesiveness to a package, it is preferable to use an acrylate or methacrylate compound having a glycidyl group as a part or all of the component (B).
The use ratio is preferably 1 to 30% by mass of the total amount of the component (A) and the component (B).

By copolymerizing the mixed monomer comprising the above components (A) and (B), a specific acrylic copolymer constituting the lid material of the present invention can be obtained. The ratio of the component (A) to the component (B) in the mixed monomer is such that the weight ratio of the component (A) to the component (B) is 3:97 to 7:
The ratio is preferably 0:30, particularly 10:90 to 50:50. When the proportion of the component (A) in the mixed monomer is less than 3% by mass, an ionic metal component to be described later may be contained in the obtained acrylic copolymer in a sufficiently dispersed state. Becomes difficult, the thickness is small, and
A lid material having a necessary visibility correction function may not be obtained. On the other hand, when the proportion of the component (A) in the mixed monomer exceeds 70% by mass, the obtained acrylic copolymer may have low properties such as moisture resistance and hardness.

The plastic lid material for a solid-state imaging device (CCD) package of the present invention comprises the above acrylic copolymer containing an ionic metal component containing copper ions as a main component. In the present invention, "mainly containing copper ions" means that the proportion of copper ions in all ionic metal components is 50% by mass or more.

Such an ionic metal component containing copper ions as a main component is a metal compound containing a copper compound as a main component.
It can be contained in the acrylic copolymer by adding it to the above-mentioned acrylic copolymer or by adding it to a mixed monomer for obtaining the acrylic copolymer and subjecting it to a polymerization treatment. In the present invention, “having a copper compound as a main component” means that the ratio of the copper component to all the metal components contained in the metal compound is 50% by mass or more.

As the above-mentioned copper compound, various copper salts can be used, and examples thereof include copper acetate, copper chloride, and the like.
Copper nitrate, copper formate, copper stearate, copper benzoate, copper ethyl acetoacetate, copper pyrophosphate, copper oxalate, copper naphthenate,
Examples thereof include anhydrides and hydrates such as copper citrate.
In addition, a copper compound is not limited only to these compounds.

As a part of the ionic metal component, metal ions other than copper ions such as sodium ion, potassium ion, calcium ion, iron ion, manganese ion, cobalt ion and nickel ion can be used. In order to include such metal ions in the acrylic copolymer, a metal compound based on these metal ions can be used in the same manner as copper ions.

In the present invention, the molar ratio of the hydroxyl group in the phosphate group derived from the specific phosphate group-containing monomer constituting the component (A) to the ionic metal component is (hydroxyl group) :( ionic It is preferable that the ionic metal component is contained in the acrylic copolymer at a ratio of 0.5: 1 to 5: 1, particularly 1.5: 1 to 2.5: 1. . If the proportion of the above hydroxyl group is too small, it becomes difficult to dissolve the metal compound in the mixed monomer in the preparation of the monomer composition described below, and the ionic metal component is an acrylic copolymer. It becomes difficult to be contained in a state of being uniformly dispersed therein. On the other hand, when the ratio of the hydroxyl groups is excessive, the obtained lid material has high hygroscopicity, and may become cloudy under high temperature and high humidity.

The ionic metal component containing copper ions as a main component is in an amount of 0.1 parts by mass or more, particularly 0.1 to 20 parts by mass, based on 100 parts by mass of the specific acrylic copolymer. It is preferably contained. This ratio is 0.
When the amount is less than 1 part by mass, light in the near-infrared region cannot be absorbed with high efficiency, and a lid material having a small thickness and a good visibility correction function may not be obtained. . On the other hand, when this ratio exceeds 20 parts by mass,
It becomes difficult for the ionic metal component to be uniformly dispersed in the acrylic copolymer.

The method for incorporating the ionic metal component into the specific acrylic copolymer is not particularly limited, but may be a radical polymerization of a mixed monomer composed of the components (A) and (B). Before performing, by adding and dissolving the metal compound in the mixed monomer,
A method of preparing a monomer composition containing the metal compound, the component (A) and the component (B), and subjecting the monomer composition to a radical polymerization treatment can be preferably used.

The above monomer composition is prepared by mixing the components (A) and (B) to prepare a mixed monomer, and then adding and mixing the above-mentioned metal compound. Alternatively, after mixing the component (A) and a part of the component (B), a metal compound is added and mixed, and the remaining component (B) is added thereto and mixed. May be done. In addition, when the metal compound is added and mixed, heating can be performed as necessary. Further, an antioxidant, an ultraviolet absorber, a light stabilizer, and other additives can be added to the monomer composition as needed.

The specific method of the radical polymerization treatment of the monomer composition is not particularly limited, and a radical polymerization method using a usual polymerization initiator, that is, a radical polymerization initiator is added to the monomer composition. May be added to prepare a radical polymerizable solution, and under appropriate conditions, the components (A) and (B) in the radical polymerizable solution may be copolymerized. When the union has a crosslinked structure, the acrylic copolymer is difficult to be melt-molded. Therefore, it is preferable to use a cast polymerization method in which a molded article is directly obtained.

When an acrylic copolymer is obtained by the cast polymerization method, it is preferable to use a pair of mold plates made of glass, for example, each having an optical plane on one surface as a mold material. More specifically, the pair of mold plates are arranged at regular intervals so that the surfaces having the optical planes face each other, and the side surfaces of these mold plates are surrounded by a sealing material such as a tape or a gasket. In this way, a cavity is formed, a radical polymerizable solution containing a radical polymerization initiator is injected into the cavity, and the component (A) and the component (B) in the radical polymerizable solution are heated or irradiated with light. To obtain a sheet-shaped or plate-shaped molded product made of an acrylic copolymer.

As the radical polymerization initiator, various organic peroxide-based polymerization initiators can be used. However, tertiary polymerization initiators are obtained in that an acrylic copolymer having less coloring can be obtained.
Butyl peroxy neodecanoate, tert-butyl peroxypivalate, tert-butyl peroxy-2
It is preferable to use non-aromatic peroxyesters such as -ethylhexanoate and tert-butylperoxylaurate, and diacyl peroxides such as lauroyl peroxide and 3,5,5-trimethylhexanoyl peroxide. . Further, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4
An azo radical polymerization initiator such as -dimethylvaleronitrile) 1,1'-azobis (cyclohexane-2-carbonitrile) can also be preferably used. Also,
The radical polymerization reaction of the component (A) and the component (B) can be carried out at the same reaction temperature and reaction time as in a normal radical polymerization reaction.

According to such a method, by molding the component (A) and the component (B) in a radical polymerizable solution, a molded article made of an acrylic copolymer having an optical plane on its surface is directly formed. A lid material can be obtained by cutting the molded body as required. Therefore, since the surface polishing step, which is an essential step for forming an optical plane in the conventional production of a glass lid material, is not required, the lid material can be easily produced.

In the above, when the monomer composition is prepared, the ionic metal component in the metal compound replaces the hydrogen atom of the phosphate group in the component (A), so that the acidic component in the metal compound is liberated. You. Since this acidic component may cause a reduction in the moisture resistance of the obtained lid material, it is preferable to remove it as necessary. As means for removing such acidic components, (1) means for washing the monomer composition with water before polymerizing the monomer composition, and (2) polymerizing treatment for the monomer composition After that, the obtained specific acrylic copolymer is immersed in a solvent, whereby a means for extracting an acidic component from the specific acrylic copolymer and other means can be used.

As the solvent used in the above-mentioned means (2), it is possible to dissolve the liberated acidic components and to have a suitable affinity for a specific acrylic copolymer (specific acrylic copolymer). It is not particularly limited as long as it does not dissolve the coalesced but has an affinity enough to penetrate into the specific acrylic copolymer). Examples of such organic solvents include water, lower aliphatic alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, and isopropyl alcohol, ethers such as diethyl ether and petroleum ether, and aromatic solvents such as benzene, toluene, and xylene. It can be appropriately selected from hydrocarbons and the like.

As described above, since the lid material obtained by removing acidic components from the monomer composition or from the specific acrylic copolymer has excellent moisture resistance,
Even under high temperature and high humidity, cloudiness due to moisture absorption hardly occurs. However, the above-described operation of removing the acidic component is not essential in the present invention, and may not be performed, for example, when the released acidic component is small.

The molded article made of the acryl-based copolymer thus obtained is a sheet or plate having a specific gravity of 1.0 to 1.8 and a thickness of 0.1 to 2.0 mm. , Visible light transmittance of 80% or more, flexural modulus of 300
0MPa or more, heat-resistant temperature (Vicat softening point temperature, load 5
kg) has a performance of 130 ° C. or higher. Moreover, it does not substantially contain a substance that emits radiation such as α rays, and is extremely suitable as a lid material for a solid-state imaging device (CCD) package. Further, the molded article made of the acrylic copolymer absorbs light in the near infrared region with high efficiency, and thus has a good visibility correction function.

In the plastic lid material for a solid-state imaging device (CCD) package of the present invention, a diffraction grating having an optical low-pass filter function can be formed on the surface thereof. Such a lid material is suitable as a lid material for a solid-state imaging device (CCD) package of a solid-state imaging device that requires an optical low-pass filter function for removing high spatial frequency components of subject light and preventing generation of a false signal. It is something.

Various methods can be used to form a diffraction grating on the surface of the molded body. In the above-described casting polymerization method, at least one surface (an inner surface) of a pair of mold plates is used. ) Is used to form a cavity by using a diffraction grating negative pattern,
A method of performing a radical polymerization treatment of a radically polymerizable solution in this cavity is preferable. According to such a method, the production of the molded article of the acrylic copolymer and the formation of the diffraction grating can be performed in the same step, and therefore, the raw material for producing the lid material of the present invention, that is, ( A molded article having a diffraction grating formed on the surface can be directly produced from the component (A), the component (B) and the metal compound.

Further, in the plastic lid material for a solid-state imaging device (CCD) package of the present invention, a hard coat layer, an antireflection layer, and the like can be formed on the surface by post-processing.

[0040]

The present invention will be described below with reference to examples, but the present invention is not limited by these examples. In the following, “parts” means “parts by mass”.

<Example 1> [Preparation of monomer composition] 13.23 parts of a specific phosphoric acid group-containing monomer represented by the following formula (3) and a monomer represented by the following formula (4) 7.77 parts of a specific phosphate group-containing monomer, 10 parts of glycidyl methacrylate, and methyl methacrylate 8
Parts, 2,2-bis (4-methacryloxyethoxyphenyl) propane, 20 parts, phenoxyethyl methacrylate 9 parts, isobornyl methacrylate 30 parts, α
-2 parts of methyl styrene were sufficiently mixed to prepare a mixed monomer. To this mixed monomer, 16 parts of copper benzoate was added and sufficiently dissolved by stirring and mixing at 60 ° C. to prepare a monomer composition.

[0042]

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To the monomer composition thus prepared was added tert-butylperoxy-2 as a polymerization initiator.
A radical polymerizable solution was prepared by adding 1.5 parts of -ethylhexanoate.

[Polymerization] A pair of glass mold plates each having an optical plane on one surface and measuring 100 mm × 100 mm × 5 mm are arranged so as to face each other at an interval of 1 mm. Side thickness is 1m
A cavity was formed between each of the mold plates by surrounding with a sealing material made of a silicone rubber gasket having a width of 5 mm and a width of 5 mm. The prepared radical polymerizable solution is poured into the cavity and heated at 60 ° C. for 8 hours.
From 120 ° C to 120 ° C in 2 hours.
By heating for a period of time, the radical polymerizable solution was subjected to a polymerization treatment to obtain a colorless and transparent plate-like molded article made of an acrylic copolymer containing copper ions and having a thickness of 0.9 mm. In the above, the molar ratio of the hydroxyl group in the phosphoric acid group derived from the specific phosphoric acid group-containing monomer to the copper ion is 2.2: 1, and the ratio of the copper ion to 100 parts of the acrylic copolymer Is 3.3 parts. The molded body was cut into a size of 9 mm × 9 mm to obtain a plastic lid material for a solid-state imaging device (CCD) package of the present invention.

Using the obtained plate-shaped compact and lid material, specific gravity at 23 ° C., refractive index (n _D ), wavelength 500
In addition to measuring the light transmittance and bending elastic modulus at nm and 1000 nm, the following items were evaluated. [Heat resistance] In the casting polymerization, the thickness was 3 mm in the same manner except that a cavity was formed by arranging the molded bodies from which a pair of mold plates were obtained at an interval of 3 mm.
A plate-shaped molded product was obtained. This molded body was cut into a suitable size and used as a test piece, according to JIS K7206.
The Vicat softening point temperature was measured according to the B method. In addition,
If the Vicat softening point temperature exceeds 150 ° C, 15
The displacement at 0 ° C. was measured. [Cutting workability] Using a dicing saw 2H6T (manufactured by Disco Corporation), a plate-shaped molded body was cut with a diamond blade, and its etched portion was observed. Was evaluated. [Adhesive Toughness] An epoxy composite package material and a lid material are adhered to each other with an epoxy-based thermosetting adhesive, and the temperature is raised while being pressed by a jig.
After holding for a period of time and cooling, the lid material was observed, and the case where no crack or deformation occurred was evaluated as ○, and the case where adhesion failure or crack or deformation occurred occurred was evaluated as x. [Solvent resistance] After immersing the lid material in methyl alcohol, acetone, and toluene at 23 ° C. for 24 hours, observing the lid material, when the lid material is not damaged at all, swelling or dissolving in the solvent, or The case where cracks occurred was evaluated as x. The results are shown in Table 1.

<Example 2> [Preparation of monomer composition] 11.34 parts of the specific phosphate group-containing monomer represented by the above formula (3) and the above formula (4) 6.66 parts of a specific phosphoric acid group-containing monomer, 30 parts of methyl methacrylate, 10 parts of 2,2-bis (4-methacryloxyethoxyphenyl) propane, 26 parts of isobornyl methacrylate, and α-methyl One part of styrene and 15 parts of ethylene glycol dimethacrylate were sufficiently mixed to prepare a mixed monomer. To this mixed monomer, 10.3 parts of copper acetate was added and sufficiently dissolved by stirring and mixing at 60 ° C. for 4 hours to prepare a monomer composition. A radical polymerizable solution was prepared by adding 1.3 parts of tert-butyl peroxypivalate as a polymerization initiator to the monomer composition thus prepared.

[Polymerization Polymerization] The prepared radically polymerizable solution was poured into the cavity formed in the same manner as in Example 1, and was heated at 40 ° C. for 10 hours, at 65 ° C. for 4 hours, and at 80 ° C. for 1 hour. By heating at 100 ° C. and sequentially at different temperatures for 1 hour, the radical polymerizable solution is polymerized, and a blue transparent plate of 0.9 mm thick made of an acrylic copolymer containing copper ions is formed. A shaped body was obtained. In the above, the molar ratio of the hydroxyl group in the phosphate group derived from the specific phosphate group-containing monomer to the copper ion is 1.
7: 1, and the ratio of copper ions to 100 parts of the acrylic copolymer was 3.3 parts.

[Removal of Acid Content]
mm and cut in methanol at room temperature.
By immersing for 4 days, the acetic acid contained in the acrylic copolymer is extracted, and then the acetic acid is placed in a vacuum dryer.
By leaving methanol at 0 ° C. for 2 hours to evaporate methanol, a plastic lid material for a solid-state imaging device (CCD) package of the present invention was obtained. The evaluation was performed in the same manner as in Example 1 using the obtained plate-shaped molded body and the lid material. Table 1 shows the results.

Example 3 [Preparation of Monomer Composition] 6.3 parts of a specific phosphoric acid group-containing monomer represented by the above formula (3) and a compound represented by the above formula (4) 3.7 parts of a specific phosphoric acid group-containing monomer, 25 parts of methyl methacrylate, 19 parts of 1,6-hexanedimethacrylate, 25 parts of isobornyl methacrylate, and α-
One part of methylstyrene and 10 parts of tert-butyl methacrylate were thoroughly mixed, and then 9.2 parts of copper acetate was added and dissolved sufficiently by stirring and mixing at 80 ° C. for 4 hours, followed by cooling. Thereafter, 10 parts of glycidyl methacrylate was further added and mixed to prepare a monomer composition. A radically polymerizable solution was prepared by adding 2.0 parts of tert-butyl peroxy-2-ethylhexanoate as a polymerization initiator to the monomer composition thus prepared.

[Polymerization] A pair of circular glass mold plates each having an optical plane on one surface and having a thickness of 5 mm and a diameter of 120 mm are arranged so as to face each other at an interval of 1.1 mm. A cavity was formed between each of the mold plates by surrounding the side surface of the mold plate with a sealing material made of an adhesive tape having a silicone-based adhesive layer. The prepared radically polymerizable solution is poured into the cavity and heated at 55 ° C. for 10 hours. Thereafter, the temperature is changed from 55 ° C. to 70 ° C. in 4 hours, and from 70 ° C. to 12 ° C.
The temperature was raised to 0 ° C. in 2 hours, and further heated at 120 ° C. for 1 hour, thereby polymerizing the radically polymerizable solution, and the thickness of the acrylic copolymer containing copper ions was 1. A blue transparent plate-shaped molded product of 0 mm was obtained.
In the above, the molar ratio of the hydroxyl group in the phosphate group derived from the specific phosphate group-containing monomer to the copper ion is 1.
The ratio was 1: 1 and the ratio of copper ions to 100 parts of the acrylic copolymer was 1.9 parts. 9mm ×
By cutting to a size of 9 mm, a plastic lid material for a solid-state imaging device (CCD) package of the present invention was obtained. Using the obtained plate-shaped molded body and lid material,
The evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

<Example 4> [Preparation of monomer composition] 20.8 parts of a specific phosphoric acid group-containing monomer represented by the above formula (3) and a compound represented by the above formula (4) 12.2 parts of a specific phosphoric acid group-containing monomer, 22 parts of methyl methacrylate, 17 parts of 1,6-hexanedimethacrylate, 1 part of α-methylstyrene, and tert-
27 parts of butyl methacrylate were sufficiently mixed to prepare a mixed monomer. To this mixed monomer was added 26 parts of copper benzoate, and the mixture was stirred and mixed at 80 ° C. for 4 hours to sufficiently dissolve, thereby preparing a monomer composition.
A radically polymerizable solution was prepared by adding 1.2 parts of 1-1′-azobis (cyclohexane-2-carbonitrile) as a polymerization initiator to the monomer composition thus prepared.

[Polymerization] A pair of mold plates was set at 0.66
A cavity was formed in the same manner as in Example 3 except that the cavity was arranged at an interval of mm, and the prepared radically polymerizable solution was injected into the cavity, and the solution was heated at 68 ° C. for 10 hours for 85 hours.
By heating sequentially at different temperatures of 4 hours at 110 ° C., 1 hour at 110 ° C., and 1 hour at 130 ° C., the radical polymerizable solution is polymerized, and is made of an acrylic copolymer containing copper ions. A blue transparent plate-like molded product having a thickness of 0.6 mm was obtained. In the above, the molar ratio of the hydroxyl group in the phosphate group derived from the specific phosphate group-containing monomer to the copper ion is 2.1: 1, and the ratio of the copper ion to 100 parts of the acrylic copolymer Is 5.4 parts. The molded body was cut into a size of 9 mm × 9 mm to obtain a plastic lid material for a solid-state imaging device (CCD) package of the present invention. The evaluation was performed in the same manner as in Example 1 using the obtained plate-shaped molded body and the lid material. Table 1 shows the results.

<Comparative Example> A lid material made of a polymethyl methacrylate resin having a thickness of 1 mm was prepared and evaluated in the same manner as in Example 1. Table 1 shows the results.

[0054]

[Table 1]

As is clear from Table 1, the lid materials according to Examples 1 to 4 have the same specific gravity, transparency and flexural modulus as those of the lid material made of polymethyl methacrylate resin. It was confirmed that the composition was very excellent in heat resistance, cutting workability, adhesive toughness and solvent resistance. Moreover, the lid materials according to Examples 1 to 4 have high absorptivity of light in the near-infrared region and have a good visibility correction function.

Example 5 In the cast polymerization of a radical polymerizable solution, as one of a pair of mold plates, a silicon dioxide (SiO ₂ ) vapor-deposited film was formed on the inner surface forming a cavity. The present invention in which a diffraction grating is formed on the surface in the same manner as in Example 1 except that a trapezoidal diffraction grating negative pattern having a depth of 0.5 μm and a pitch of 0.4 mm is used. A plastic lid material for a solid-state imaging device (CCD) package was manufactured. When a solid-state imaging device (CCD) sealed with the lid material and the package was incorporated into a solid-state imaging device and a practical test was performed, it was confirmed that the solid-state imaging device had a good optical low-pass filter function.

[0057]

Industrial Applicability The plastic lid material according to the present invention has a low specific gravity, is excellent in molding workability, and has high transparency,
It has excellent adhesive toughness, heat resistance, and solvent resistance.
It has sufficiently high strength as a lid material for a solid-state imaging device (CCD) package. Moreover, according to the plastic lid material of the present invention, since it has a good visibility correction function, when configuring a solid-state imaging device, it becomes unnecessary to use a visibility correction filter in the optical system,
As a result, the cost and size of the solid-state imaging device can be reduced.

According to the production method of the present invention, a diffraction grating having an optical low-pass function is formed on the surface by polymerizing a monomer composition containing the components (A) and (B). Since the molded article of the acrylic copolymer thus obtained is directly obtained, a lid member on which a diffraction grating having an optical low-pass function is formed can be advantageously produced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroki Uenono 16 Nishimachi Ochiai, Iwaki-shi, Fukushima Kureha Chemical Industry Nishiki Plant Co., Ltd.

Claims (5)

[Claims] 1. A copolymer obtained by copolymerizing a mixed monomer comprising the following component (A) and the following component (B):
A plastic lid material for a solid-state imaging device (CCD) package, characterized by containing an ionic metal component containing copper ions as a main component. Component (A): Phosphate group-containing monomer represented by the following formula (1) Component (B): Monomer copolymerizable with component (A) 2. The molar ratio of the hydroxyl group in the phosphate group derived from the phosphate group-containing monomer constituting the component (A) to the ionic metal component is in the range of 0.5: 1 to 5: 1. The solid-state imaging device (CC) according to claim 1,
D) Plastic lid material for packaging. 3. The solid-state imaging device (CCD) package according to claim 1, wherein an acrylate compound or a methacrylate compound having a glycidyl group is used as a part or all of the component (B). Plastic lid material. 4. A plastic lid for a solid-state imaging device (CCD) package according to claim 1, wherein a diffraction grating having an optical low-pass function is formed on the surface. Wood. 5. A cavity is formed by arranging a pair of mold plates each having a negative pattern of a diffraction grating formed on one surface of at least one mold plate so that the respective surfaces face each other. In a tee, a molded product of the copolymer is obtained by copolymerizing a metal compound containing a copper compound as a main component, and a monomer composition containing the following component (A) and the following component (B). A solid-state imaging device (CC)
D) A method of manufacturing a plastic lid material for a package. Component (A): Phosphate group-containing monomer represented by the following formula (1) Component (B): Monomer copolymerizable with component (A)