JP2656350B2 - Optical semiconductor device, method for producing the same, and resin composition for encapsulating optical semiconductor used therein - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical semiconductor device having no optical unevenness, a method for producing the same, and a resin composition for encapsulating an optical semiconductor used therein.

[Conventional technology]

2. Description of the Related Art Conventionally, a light-receiving element such as a solid-state imaging device is generally sealed in a hollow shape by a ceramic package to form a device. However, the above ceramic packaging is
Resin sealing using a plastic package is being studied because of the relatively high cost of the constituent materials and the disadvantage of poor mass productivity. Among resin sealing using the plastic package, resin sealing using an epoxy resin composition is being studied. The epoxy resin composition is obtained by melting and mixing an epoxy resin, a curing agent, a curing accelerator and other additives while heating.

[Problems to be solved by the invention]

However, the epoxy resin composition for encapsulating an optical semiconductor obtained by the above method has insufficient dispersibility of the epoxy resin, the curing agent, and the components of the curing accelerator, and is not uniformly mixed and dispersed. Therefore, for example, when transfer molding is performed using the epoxy resin composition for encapsulating an optical semiconductor as described above, the following problem occurs. That is, as shown in FIG. 1, when a tablet-shaped epoxy resin composition for encapsulating an optical semiconductor is put into a cull 1 and pressed by a plunger 2, the epoxy resin composition for optical semiconductor encapsulation is indicated by an arrow. And flows into the cavity 4 through the runner 3. Then, as shown in FIG. 2, the epoxy resin composition for encapsulating an optical semiconductor passes through the gate 5 as shown by the arrow, and the frame 6 in the cavity 4 is moved.
The solid-state imaging device 7 mounted thereon is sealed with a resin. At the time of this resin sealing, when the epoxy resin composition for optical semiconductor encapsulation is cured in the cavity 4, the dispersion state of each component of the epoxy resin composition for optical semiconductor encapsulation is non-uniform, so that the curing reaction is fast. There is a problem that a difference in curing density occurs due to a difference in curing reaction speed, and optical unevenness of a striped pattern extending along the flow direction of the resin is formed in the sealing resin. For example, when the area sensor of the solid-state imaging device 7 is resin-encapsulated with the conventional epoxy resin composition for optical semiconductor encapsulation as described above, the optical element is exposed to strong parallel light on the encapsulant and the aperture is stopped. When the aperture is stopped down to F-32, the image appears as a stripe pattern.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical semiconductor encapsulating resin composition that does not cause optical unevenness in a cured product, an optical semiconductor device using the same, and a method for producing the same. And

[Means for solving the problem]

In order to achieve the above object, the present invention provides a sealing resin,
A B-staged epoxy resin composition for encapsulating an optical semiconductor, comprising an epoxy resin, a curing agent and a curing accelerator, wherein the proportion of particles having a maximum particle size of 30 μm or less is 90 wt. % Of the optical semiconductor device comprising a cured body of a resin composition set to at least%, and a B-stage optical semiconductor encapsulation comprising an epoxy resin, a curing agent and a curing accelerator as components. A second gist of an epoxy resin composition for optical semiconductor encapsulation, wherein the epoxy resin composition is finely pulverized and uniformly mixed, and the proportion of particles having a maximum particle size of 30 μm or less is set to 90% by weight or more,
A third aspect of the present invention is an epoxy resin composition for optical semiconductor encapsulation that has been tablet-formed into a tablet by cold molding using the epoxy resin composition for optical semiconductor encapsulation. The fourth gist is a method of manufacturing an optical semiconductor device in which an optical semiconductor element is encapsulated by transfer molding, wherein a sealing resin is a B-stage optical semiconductor encapsulation containing a thermosetting resin and a curing agent as components. Thermosetting resin composition for stopping, finely pulverized and uniformly mixed, maximum particle size 30μ
A fifth aspect is an optical semiconductor device composed of a cured product of a resin composition in which the proportion of particles having a particle size of m or less is set to 90% by weight or more, and a thermosetting resin and a curing agent as constituent components. A B-staged thermosetting resin composition for encapsulating an optical semiconductor, which is finely pulverized and uniformly mixed, and wherein the proportion of particles having a maximum particle size of 30 μm or less is set to 90% by weight or more. A sixth aspect is a thermosetting resin composition.

[Action]

That is, the present inventors, in the process of repeating a series of studies to obtain an epoxy resin composition for optical semiconductor encapsulation that does not cause optical unevenness, the particle size of the composition itself may affect the optical unevenness. I conceived and conducted research mainly on this. As a result, the conventional epoxy resin composition for sealing obtained by pulverizing the epoxy resin composition in the B-stage state (semi-cured state) is insufficient in the particle size of fine particles. When the finely pulverized particles accounted for 90% by weight or more (hereinafter abbreviated as "%") or more, this point was set as the critical point, and it was found that optical unevenness hardly occurred in the cured product, and the present invention was reached.

In addition, when the above-mentioned fine pulverization is uniformly mixed and optical unevenness does not occur, the surface is polished and the surface roughness of the polished surface is 1.5 μm.
Resin cured product (150 ° C x 6 minutes after transfer molding) finished into a runner-shaped flat plate (3.0 mm thick, 5 mm wide) with a 120 ° curved part with unevenness of less than m After curing for 3 hours at 150 ° C for 3 hours, a 1/2 inch (1.27 cm) solid-state image sensor mounted on a 380,000-pixel solid-state image sensor is mounted on a solid-state image sensor. At a right angle and the aperture is reduced to F-32.

The epoxy resin composition for encapsulating an optical semiconductor of the present invention is obtained by using an epoxy resin, a curing agent and a curing accelerator, and a filler such as silica powder is not used because it impairs light transmission.

The epoxy resin is not particularly limited as long as it is a conventionally known epoxy resin having little coloring. For example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolak type epoxy resin, an alicyclic epoxy resin, a heterocyclic epoxy resin such as triglycidyl isocyanurate and hydantoin epoxy, and a water-added bisphenol A Type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin and the like, and these are used alone or in combination.

As the above-mentioned curing agent, an acid anhydride with little coloring in the cured product of the resin composition during or after curing is suitable, but is not particularly limited. For example, as the acid anhydride,
Phthalic anhydride, maleic anhydride, trimellitic anhydride,
Examples include pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, and glutaric anhydride. Examples of the amine-based curing agent include metaphenylenediamine, dimethyldiphenylmethane, and diaminodiphenyl. Sulfone, m-xylenediamine, tetraethylenepentamine, diethylamine, propylamine and the like can be mentioned. Further, a phenolic resin-based curing agent may be used, and any of them may be used.

Examples of the curing accelerator include tertiary amines, imidazoles, metal salts of carboxylic acids, and phosphorus compounds.

In the epoxy resin composition for encapsulating an optical semiconductor of the present invention, conventionally known additives such as a coloring inhibitor, a denaturing agent, a deterioration preventing agent, and a release agent may be used, if necessary, in addition to the above components. .

Examples of the coloring inhibitor include conventionally known compounds such as phenol compounds, amine compounds, organic sulfur compounds, and phosphine compounds.

The epoxy resin composition for optical semiconductor encapsulation of the present invention can be produced, for example, as follows. That is,
First, a B-stage (semi-cured) epoxy resin composition for encapsulating an optical semiconductor is prepared by mixing the above component materials.
As a method for mixing the above-mentioned respective component materials, a melt mixing method is generally used. At this time, a low-temperature reaction may be performed if necessary. Next, the epoxy resin composition for encapsulating an optical semiconductor can be manufactured by pulverizing the B-staged epoxy resin composition for encapsulating an optical semiconductor and, if necessary, compressing the tablet. The tableting method is not particularly limited, but is generally performed by, for example, cold molding.
300~6000kg / cm ^2, preferably a method can be mentioned that under the conditions of 1000~2000kg / cm ^2. Thus, even if the finely pulverized epoxy resin composition for encapsulating an optical semiconductor is tableted and tabletted, optical unevenness hardly occurs in the cured product.

The above-mentioned pulverizing method is not particularly limited as long as it is a method capable of obtaining the following pulverized particles, and examples thereof include a jet mill pulverizing method.
Then, by pulverizing the epoxy resin composition by the above method, the epoxy resin composition for encapsulating an optical semiconductor needs to contain 90% or more having a maximum particle size of 30 μm or less. Preferably, 90% or more of those having a maximum particle size of 20 μm or less, more preferably 90% or more of those having a maximum particle size of 10 μm or less, and particularly preferably 90% or more of those having a maximum particle size of 1.0 μm or less. . By the way, in the present invention, the epoxy resin composition is pulverized to have a maximum particle size of 30 μm or less at least 90 μm.
%, The balance is of a particle size of 30-100 μm.

When performing the tableting step and the fine pulverizing operation, the epoxy resin composition for encapsulating an optical semiconductor is easily absorbed by the fine pulverization, and when moisture is absorbed, a cured product of the epoxy resin composition is absorbed. In order to cause the disadvantage of lowering the glass transition temperature, it is preferable to carry out the reaction in an environment with low moisture such as in a dry air stream.

The epoxy resin composition for encapsulating an optical semiconductor obtained by the above method does not cause uneven curing of the cured product as a result of adopting the above configuration. In addition, since such an epoxy resin composition for optical semiconductor encapsulation is used for resin encapsulation of an optical semiconductor element such as a light receiving element, a transparent one is preferable from an optical point of view. In this case, “transparent” means that the cured product (thickness 1 mm) of the epoxy resin composition for optical semiconductor encapsulation is 400 nm.
At 98% or more.

Encapsulation of an optical semiconductor element such as a light receiving element using such an epoxy resin composition for optical semiconductor encapsulation can be performed by ordinary transfer molding.

The optical semiconductor device obtained in this way is, for example, as shown in FIG.
A solid-state imaging device 13 which is a light-receiving element is mounted via, a color filter 15 is adhered to the upper portion thereof using a transparent adhesive, and these are resin-sealed with an optical semiconductor sealing epoxy resin composition 16. It is configured. Note that the color filter 15 is provided to obtain a color image, and is unnecessary in monochrome. In the figure, 17 is a glass plate, 18 is a bonding wire, and 19 is a lead frame.

Since the optical semiconductor device is resin-sealed with the epoxy resin composition for encapsulating an optical semiconductor of the present invention, optical unevenness does not occur in the sealing resin 16. Therefore, the image obtained by operating this does not show a stripe pattern due to optical unevenness. By the way, when an optical semiconductor device obtained by setting the thickness l of the sealing resin on the color filter 15 to a normal value of 0.5 to 2 mm was used, optical unevenness did not occur.

〔The invention's effect〕

As described above, the epoxy resin composition for encapsulating an optical semiconductor of the present invention has a value that the present inventors have found as a critical point at which optical unevenness does not occur (particles having a maximum particle size of 30 μm or less account for 90% or more). Because it is finely pulverized to satisfy
For example, when it is cured by transfer molding,
Almost no uneven curing as in the prior art. Accordingly, the epoxy resin composition for encapsulating an optical semiconductor can be suitably used particularly as a sealing material for a light receiving element of a compact disk (CD) or a line sensor or an area sensor which is a solid-state imaging device. . Then, using such an epoxy resin composition for optical semiconductor encapsulation, for example, an optical semiconductor device in which a light-receiving element such as a solid-state imaging element is resin-encapsulated,
It is a high-performance product that does not show a striped pattern due to optical unevenness of the resin on the formed image.
Demonstrates the same or better performance than ceramic packaging products.

In the above description, an epoxy resin is described as a typical example of the thermosetting resin. However, the present invention is not particularly limited to the epoxy resin. The same curing can be obtained by using the following.

 Next, examples will be described together with comparative examples.

[Examples 1 to 9, Comparative Examples 1 to 7] After heating and dissolving and mixing the respective raw materials shown in the following table at the ratios shown in the same table, the curing reaction was allowed to proceed at a low temperature,
An epoxy resin composition for encapsulating an optical semiconductor in a B stage having a gelation time of 30 seconds at a temperature of 150 ° C. was prepared. Next,
This B-staged epoxy resin composition for encapsulating an optical semiconductor was pulverized to the particle size shown in the table to obtain the desired epoxy resin composition for encapsulating an optical semiconductor. As for the pulverization method, jet mill pulverization was performed for Examples 1 to 9, and ball mill pulverization was performed for Comparative Examples 1 to 7.

Next, using the epoxy resin composition for optical semiconductor encapsulation obtained in Example 1 and assembling a camera using an area sensor, which is actually a solid-state image sensor, obtained by direct molding. The image when the camera was stopped down to F-32 with strong parallel light applied to it was transferred to the display screen. As a result, no optical unevenness was observed in the image. In addition, images were obtained in the same manner as described above for the powdery epoxy resin composition for optical semiconductor encapsulation obtained in Examples 2 to 8. As a result, no optical unevenness was observed in the image as described above. At this time, the thickness of the sealing resin on the solid-state imaging device was 1 mm, and similar results were obtained even when the thickness was 2 mm. Next, using the powdery epoxy resin composition for optical semiconductor encapsulation obtained in Comparative Example 1, the same operation as described above was performed, and an image obtained was transferred to a display screen. As a result, optical unevenness was observed, and Comparative Examples 2 to
Similar results were obtained for No. 7. The presence or absence of the above-mentioned optical unevenness is also shown in the table as optical unevenness A.

Further, using the epoxy resin compositions for encapsulating an optical semiconductor obtained in Examples and Comparative Examples, after transfer molding at 150 ° C. × 6 minutes, and after further curing at 150 ° C. × 3 hours, the surface was polished. A runner-shaped flat plate (thickness: 3.0 mm, width: 5 mm) having a surface roughness of the polished surface of 1.5 μm or less and a curved portion at 120 ° C. was produced. This runner is mounted on an area sensor encapsulant, which is a 1 / 2-inch, 380,000 pixel solid-state image sensor incorporated in a camera, and a strong parallel light with a luminous intensity of 10 candela is applied at a right angle, and the aperture is set to F. −
The presence or absence of a striped pattern in imaging when the aperture was stopped down to 32 was determined. The presence or absence of the above-mentioned optical unevenness is also shown in the table as optical unevenness B. As a result, for example, no optical unevenness was observed in the product of Example 9. Further, slight optical unevenness was observed in the product of Example 1. Also, in Examples 2 to 8, slight optical unevenness was observed as in Example 1. As described above, in the evaluation of the products of Examples 1 to 8 by optical unevenness B, slight optical unevenness was observed, but in the evaluation by optical unevenness A, no optical unevenness was observed.
Even if an area sensor as a solid-state imaging device is directly molded using the epoxy resin compositions for optical semiconductor encapsulation of Nos. To 8, there is substantially no problem. Further, in the evaluation of the optical unevenness B in the product of Comparative Example 1, optical unevenness was observed in the image thereof, and the optical unevenness was similarly observed in the products of Comparative Examples 2 to 7.

From these results, it is understood that the optical semiconductor device molded using the example product has excellent performance.

[Brief description of the drawings]

FIG. 1 is a flow diagram of a resin composition during transfer molding using a conventional epoxy resin composition for encapsulating an optical semiconductor, FIG. 2 is a flow diagram of a resin composition of a main part thereof, FIG.
The figure is a longitudinal sectional view of an optical semiconductor device resin-sealed with the epoxy resin composition for sealing an optical semiconductor of the present invention. 16 …… Epoxy resin composition for optical semiconductor encapsulation

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor: Maintenance Yoshimura 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nippon Denko Corporation (72) Inventor Yasuhiko Yamamoto 1-1-1-2 Shimohozumi, Ibaraki-shi, Osaka No. JP TOKYO Corporation (56) References JP-A-63-254752 (JP, A) JP-A-2-39460 (JP, A)

Claims (9)

(57) [Claims]

1. A B-staged epoxy resin composition for encapsulating an optical semiconductor comprising a sealing resin comprising an epoxy resin, a curing agent and a curing accelerator, wherein the epoxy resin composition is finely pulverized and uniformly mixed, and has a maximum particle size. 90% by weight of particles less than 30μm
An optical semiconductor device comprising a cured product of the resin composition set as described above.

2. A B-staged epoxy resin composition for encapsulating an optical semiconductor, comprising an epoxy resin, a curing agent and a curing accelerator, which are finely pulverized and uniformly mixed, and have a maximum particle size of 30.
An epoxy resin composition for encapsulating an optical semiconductor, wherein the proportion of particles having a particle size of μm or less is set to 90% by weight or more.

3. The composition according to claim 2, wherein the proportion of particles having a maximum particle size of 20 μm or less in the epoxy resin composition for encapsulating an optical semiconductor obtained by pulverization is set to 90% by weight or more. Epoxy resin composition for optical semiconductor encapsulation.

4. The epoxy resin composition for encapsulating an optical semiconductor obtained by pulverization, wherein the proportion of particles having a maximum particle size of 10 μm or less is set to 90% by weight or more. Epoxy resin composition for optical semiconductor encapsulation.

5. An optical resin encapsulating epoxy resin composition obtained by pulverization, wherein the proportion of particles having a maximum particle size of 1.0 μm or less is set to 90% by weight or more. Epoxy resin composition for encapsulating optical semiconductors.

6. An optical semiconductor, characterized in that the epoxy resin composition for encapsulating an optical semiconductor according to any one of (2) to (5) is formed into a tablet by cold molding. Epoxy resin composition for sealing.

7. An optical semiconductor, wherein the optical semiconductor element is encapsulated by transfer molding using the epoxy resin composition for optical semiconductor encapsulation according to any one of claims (2) to (6). Equipment manufacturing method.

8. A B-staged thermosetting resin composition for encapsulating an optical semiconductor, comprising a thermosetting resin and a curing agent, wherein the sealing resin is finely pulverized and uniformly mixed, and has a maximum particle size. 30
An optical semiconductor device comprising a cured product of a resin composition in which the proportion of particles having a particle size of μm or less is set to 90% by weight or more.

9. A B-staged thermosetting resin composition for encapsulating an optical semiconductor comprising a thermosetting resin and a curing agent as components, which are finely pulverized and uniformly mixed, and have a maximum particle size of 30 μm or less. A thermosetting resin composition for encapsulating an optical semiconductor, wherein the occupation ratio is set to 90% by weight or more.