JPH11189712A - Production of optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an optical device capable of remarkably reducing the level of molding defectiveness, for example, such as displacement of the optical axes and the like by according the thermal movement of a molding frame of an optical device with that of a lead frame. SOLUTION: The optical device is sealed with a resin by using a molding jig and/or a molding frame comprising cured heat curable resin composition satisfying the following requirements of (i) and (ii).(i) shrinkage factor in curing time is <=0.1%. (ii) coefficient of thermal expansion at normal termperature -180 deg.C is 0.7×10<-5> -1.6×10<-5> / deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an opto-device, and more particularly, to a method in which thermal movement between a molding frame for an opto-device and a lead frame is harmonized, and the optical axis shifts. The present invention relates to a method for manufacturing an opto device, which can remarkably improve a defective molding rate.

[0002]

2. Description of the Related Art In recent years, the field of opto-devices such as LEDs, photo sensors, and lasers has been remarkably developed. Among them, LED plays an important role as a function display material in the electronics field, and is rapidly growing as a component industry. Furthermore, the realization of light brightness by the development of a new crystal growth technique is expected to be used as a light source in the future.

[0003] On the other hand, the reduction of manufacturing costs by innovation of production technology is being promoted at an unimaginable speed.
Needless to say, the review of each constituent material mainly from the viewpoint of cost, the rationalization of the manufacturing process itself is also proceeding at a rapid pace.

In general, an opto-device is manufactured by a method of injecting a liquid thermosetting resin into a molding resin mold having a lamp shape, inserting a lead frame, and curing the resin in a reaction furnace. . TPX resin, polycarbonate, or the like is used as a resin molding mold in consideration of heat resistance and releasability. Steel is used as the lead frame. From the viewpoint of productivity, 20 to 30 chips are connected to one lead frame, and are separated into a plurality of products after curing.

[0005] One of the serious problems in the above production process is the occurrence of defective products due to the deviation of the optical axis.
This is because the thermal expansion coefficient between the lead frame and the resin molding frame is different, so that the light source does not come to the design position of the lamp as it approaches the end of the lead frame. As the product has a thinner lamp tip and stronger light directivity, the defective rate due to such an optical axis shift becomes higher.

Although the above problem can be solved by using a resin molding mold as a mold, the number of types of molds for the opto device is said to be several tens per company, which is not practical.
For this reason, the mold is used about 10 times while restraining the movement based on the thermal expansion, and is discarded before the deformation becomes severe. Of course, the occurrence rate of defective products due to the deviation of the optical axis is high,
The fact is that they are sorted and shipped.

A jig for fixing a formwork or a lead frame at a predetermined position is also generally a steel product, and it is extremely difficult to absorb heat distortion during the processing and maintain a predetermined accuracy. It is difficult, and the cost of preparing a large number of pieces greatly affects the production cost. If a thermosetting resin that is excellent in moldability and heat resistance and that can follow the thermal movement of the lead frame is found, application to not only the mold but also a jig is expected.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to reconcile the thermal movement between a molding frame of an opto device and a lead frame, and to remarkably improve a molding defect rate such as an optical axis shift. It is an object of the present invention to provide a method for manufacturing an opto device.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the object of the present invention is achieved when a cured product of a thermosetting resin composition having specific requirements is used. And completed the present invention. That is, the present invention is characterized in that a cured body of a thermosetting resin composition having the following requirements (i) and (ii) is used as a molding jig and / or a mold, and an optical device is sealed with a resin. And a method of manufacturing an opto-device. (I) The shrinkage rate during curing is 0.1% or less. (Ii) Coefficient of thermal expansion from room temperature to 180 ° C. is 0.7 × 10 ⁻⁵
〜1.6 × 10 ⁻⁵ / ° C.

The present invention also provides a thermosetting resin composition comprising:
(A) unsaturated polyester, (B) diallyl phthalate,
(C) a thermoplastic resin having a Tg of 160 ° C. or lower, (D)
An object of the present invention is to provide a method for producing the above-mentioned opto device, comprising an inorganic filler and (E) a radical polymerization initiator.

Further, the present invention provides a method for manufacturing the above-mentioned opto-device, wherein the molding jig and / or the mold is formed by injection molding, transfer molding or press molding.

Still further, the present invention provides a composition wherein the inorganic filler which is the component (D) is a silica filler, and at least 50% of the silica filler is used.
It is an object of the present invention to provide a method for producing the above-mentioned opto device, wherein at least% by weight is spherical silica, and the spherical silica has a particle size distribution ranging from 1 to 100 microns.

Further, the present invention provides the above-mentioned method for producing an optical device, wherein the unsaturated polyester as the component (A) is a high melting point unsaturated polyester having a melting point of 120 to 180 ° C.

Further, the present invention provides a method for producing the above-mentioned opto-device, wherein Tg after curing of the thermosetting resin composition is 250 ° C. or higher.

Further, the present invention provides a thermoplastic resin, wherein the component (C) has a Tg of 160 ° C. or lower, comprising polymethyl methacrylate, polystyrene, polyvinyl acetate, saturated polyester, modified urethane, polyethylene and copolymers thereof. An object of the present invention is to provide a method for manufacturing the above-mentioned opto-device, which is at least one selected from the group consisting of:

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the cured product of the thermosetting resin composition used in the present invention has a shrinkage rate of 0.1% or less upon curing and a normal temperature (23 ° C.) ~ 180 ° C
Is required to be in the range of 0.7 × 10 ^{−5 to} 1.6 × 10 ⁻⁵ / ° C. When the shrinkage ratio of the cured product of the thermosetting resin composition exceeds 0.1%, not only is it difficult to design a high-precision optical device as the object of the present invention, but also the internal strain during curing is reduced. Due to these factors, a problem arises in durability in long-term use. Further, when the coefficient of thermal expansion of the cured product of the thermosetting resin composition is out of the above range, the difference in thermal movement with respect to the lead frame becomes remarkably large, and for example, the product failure rate due to the deviation of the optical axis increases.

In the present invention, the cured product of the thermosetting resin composition preferably has no anisotropy in strength, coefficient of thermal expansion, and shrinkage during curing. The coefficient of thermal expansion and the rate of shrinkage during curing can be measured directly from the molded product, and TMA (Th
It can also be calculated using a measuring device such as thermal mechanical analysis. In that case, it is desirable that the shrinkage ratio be substantially the same in any three-dimensional direction. In the present invention, it is also possible to apply a reinforcing material such as glass fiber, carbon fiber, and steel wire to the cured body of the thermosetting resin composition, if necessary. The expansion rate and the curing shrinkage rate are obtained.

In the present invention, the thermosetting resin composition used for the molding jig and / or the mold frame is based on epoxy resin, phenol resin, vinyl ester resin, unsaturated polyester resin, silicone resin and the like. The composition can be used. Further, a polyphenylene sulfide resin having a cross-linking property among engineering plastics can also be used. Among the above thermosetting resins, unsaturated polyester resins and vinyl ester resins are advantageous in that shrinkage during curing is reduced.

The most suitable thermosetting resin composition in the present invention is (A) an unsaturated polyester, (B) diallyl phthalate, (C) a thermoplastic resin having a Tg of 160 ° C. or less,
The composition contains (D) an inorganic filler and (E) a radical polymerization initiator. Hereinafter, these components will be described.

(A) The unsaturated polyester is obtained by polycondensing propylene glycol as a polyhydric alcohol component, phthalic anhydride as a saturated polybasic acid, and maleic anhydride or fumaric acid as an unsaturated polybasic acid component. A polymer is dissolved in a monomer such as styrene or methyl methacrylate, and is copolymerized and cross-linked with these monomers to be used as a three-dimensional cured product. In the present invention, of course, the above-mentioned general-purpose polyester can be used,
Particularly, a high melting point unsaturated polyester having a melting point of 120 to 180 ° C is desirable. A high melting point unsaturated polyester having a melting point of 120 to 180 ° C is synthesized using the following constituent materials. That is, as the saturated polybasic acid, terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid,
One or a mixture of two or more selected from the group consisting of biphenyldicarboxylic acid and esters thereof is exemplified. Fumaric acid is used as the unsaturated polybasic acid, but as is generally used, it is also possible to use cis-type maleic anhydride to utilize the transition to fumaric acid at a high temperature. is there. As polyhydric alcohols, 1,4
-Butanediol, 1,4-cyclohexanedimethanol, ethylene glycol, bisphenol A, hydrogenated bisphenol A and the like are used. In the present invention,
By using the above high melting point unsaturated polyester,
The heat resistance of the cured body is improved. It should be noted that those having a melting point of more than 180 ° C. have a high risk of gelling due to the reaction of a double bond of fumaric acid with glycol during synthesis, and are not practical.

As the monomer for dissolving the high-melting-point unsaturated polyester used in the present invention and for three-dimensionally curing the high-melting-point unsaturated polyester in a skewered shape during curing, general-purpose monomers such as styrene and methyl titacrylate can be used. Although it is possible to use, diallyl phthalate (B) can be particularly preferably used. Of diallyl phthalate, diallyl terephthalate is particularly preferred.

The component (C) used has a Tg of 1
It is a thermoplastic resin having a temperature of 60 ° C. or less. As a thermoplastic resin having a Tg of 160 ° C. or lower, polymethyl methacrylate,
It is desirable to use one or more selected from polystyrene, polyvinyl acetate, saturated polyester, modified urethane, polyethylene and copolymers thereof. As a form at the time of addition of these thermoplastic resins, styrene,
It is preferable to use as a solution of a solvent and a monomer such as methyl methacrylate and diallyl phthalate, and it is desirable to keep the amount of these monomers to the minimum necessary so as not to impair the heat resistance of the cured resin (in addition, phthalic acid). When diallyl is used, it is considered as a part of the component (B)).

The following can be exemplified as (D) the inorganic filler. Asbestos, alumina, attapulgite, kaolin clay, volcanic ash, carbon black,
Graphite, finely divided silica, calcium silicate, diatomaceous earth, magnesium oxide, titanium oxide, iron oxide, magnesium hydroxide, slate powder, sericite, calcium carbonate, talc, feldspar powder, pearlite, vermiculite, kaishi, whiting, mica, wax Stone clay, plaster, various hydraulic cements. In the present invention, a silica filler is particularly preferred. As the silica filler, there can be used crystalline silica produced by pulverizing natural high-purity silica, fused silica produced by fusing silica to form quartz glass and then pulverizing, or a mixture thereof. Since properties such as electrical insulation, water resistance, low coefficient of thermal expansion, and high thermal conductivity are different from each other, it is necessary to select silica in accordance with required properties. In general, the performance of the composition is improved as the loading amount of the silica filler increases, so that the silica loading is preferably maximized as long as fluidity during molding is allowed. As a condition for this, it can be said that it is ideal that the shape of the silica filler is spherical and its particle size distribution is wide, and the silica filler is as close as possible to fine packing. In the present invention, at least 50% by weight or more of the silica filler is spherical and 1% by weight.
Preferably, it has a broad particle size distribution ranging from １００100 microns.

Examples of the radical polymerization initiator (E) include organic peroxides, such as dialkyl peroxide, acyl peroxide, hydroperoxide,
Known compounds such as ketone peroxides and peroxyesters can be used, and specific examples include the following. Benzoyl peroxide, t-butylperoxy-2-ethylhexanate, 2,5-dimethyl-2,5-di (2-ethylhexanoyl) peroxyhexane, t-butylperoxybenzoate, t-butylhydroper Oxide, cumene hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, 1,1,3,3-trimethylbutylperoxy-2-ethylhexanate, 2,5-dimethyl-
2,5-dibutylperoxyhexane.

(B) The mixing ratio of diallyl phthalate is
The content is preferably 10 to 70% by weight based on the total of the components (A), (B), (C) and (E). (C) The mixing ratio of the thermoplastic resin having a Tg of 160 ° C. or less is preferably 1 to 30% by weight based on the total of the components (A), (B), (C) and (E). (D) The mixing ratio of the inorganic filler is (A), (B),
75 to 75 based on the sum of components (C), (D) and (E)
95% by weight is good. (E) The mixing ratio of the radical polymerization initiator is (A)
0.5 with respect to the sum of components (B), (C) and (E)
~ 4% by weight is good.

In order to obtain a thermosetting resin composition using the above components (A) to (E), it is desirable to mix the components as uniformly as possible using a kneader such as a kneader.
In addition, in order to improve hardness, durability, weather resistance, water resistance, corrosion resistance, etc., an ultraviolet absorber, a light stabilizer, an antioxidant,
Additives such as an antifoaming agent, a leveling agent, a release agent, and an ion scavenger can be added to further improve the performance. The composition is also composed of a material that is easily available in large quantities and can be said to be extremely practical.

When the Tg after curing of the thermosetting resin composition used in the present invention is 250 ° C. or more, the dimensional change of the molding jig or the mold frame is sufficient even during the heat treatment at the time of manufacturing the optical device. It is particularly preferable because not only is it possible to expect a stable and small yield, and it is possible to improve the durability of a molding jig or a formwork as well as to improve the yield.

In order to manufacture a molding jig and / or a mold from the thermosetting resin composition as described above, cutting may be performed from a previously cured block or plate, but injection molding and transfer molding are preferred. Alternatively, it is practical to use press molding. Although it is extremely difficult to set the processing conditions by employing these molding methods with phenolic resin, epoxy resin and the like, it is easy with a resin composition using unsaturated polyester. The reason is that the latter is a radical polymerization, in which no reaction takes place until a certain temperature is reached, and once the reaction starts, it is completed very quickly. On the other hand, in the case of phenol resin, epoxy resin and the like which proceed by a sequential reaction, the reaction always partially proceeds even at room temperature, and it is necessary to carry out molding with a processing machine in mind.

The opto device according to the present invention is LE
D, a photosensor, and a device including a device using light such as a laser. Also, as the opto device sealing resin, a thermosetting resin, for example, a polyester resin,
An unsaturated polyester resin, a vinyl ester resin, a silicone resin, and the like are included.

[0030]

The reason that the method of the present invention has significantly improved the occurrence of defective products due to, for example, optical axis shift in the manufacture of opto devices is that the thermal expansion coefficients of the lead frame and the resin mold are at the same level, This is probably because the light source is accurately located at the lamp design position even at the end of the lead frame.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention. Example 1 The unsaturated polyester (A-1) used in the present example was synthesized as follows. 470 g (5.20 mol) of 1,4-butanediol, 583 g (3.0 mol) of dimethyl terephthalate were placed in a 3-liter flask equipped with a thermometer, a stirrer, a fractionating condenser, and a gas introduction tube.
3.0 g of zinc octylate was added, and a transesterification reaction was performed at 140 to 180 ° C. Next, the temperature was lowered to 170 ° C., 232 g (2.0 mol) of fumaric acid and 0.5 g of hydroquinone were added, and esterification was further continued at a temperature of 170 to 200 ° C. to obtain an acid value of 22. 1.3 g of titanate and 0.2 g of phosphorous acid were added, and 19
7-10 Torr at 0-200 ° C, 5T at the end
The pressure was reduced to orr. After the reaction for 4 hours, the resin in the flask was poured into a metal vat and solidified by cooling. GPC in pale yellow
Was found to have a number average molecular weight of 5,300, a weight average molecular weight of 11,200, and a melting point of 145 ° C. by DSC. This resin is designated as (A-1).

(A-1) 63 parts by weight of a resin are weighed into a flask, (B) 27 parts by weight of diallyl terephthalate are added, heated to 150 ° C., thoroughly stirred and mixed, cooled to 60 ° C., and then cooled. (C) 10 parts by weight of a 30% styrene solution of polystyrene (Tg = 95 ° C.) obtained by graft-copolymerizing polyvinyl acetate was added, and the contents were poured into a metal vat and further solidified by cooling.

Next, a predetermined amount of the following component (D) and other additives, and finally, a predetermined amount of the component (E) were combined with the obtained resin composition using a roll heated to 90 ° C.
After cooling, it was pulverized into fine particles.

Component (D) and Other Additives Fused Silica Powder A: Central Diameter of Particle Size Distribution 2 μ 200
Parts by weight ground silica powder B: center diameter of particle size distribution 10μ 400
Parts by weight fused silica powder C: central diameter of particle size distribution 40 μ 400
Parts by weight wax 1 part by weight carbon black 10 parts by weight microencapsulated red phosphorus 10 parts by weight γ-methacryloxytriethoxysilane 1 part by weight (E) component dicumyl peroxide 2 parts by weight

Using the thermosetting resin composition thus obtained, a test specimen for bending test was press-formed at 160 ° C. for 5 minutes in accordance with JIS K-6911. The test specimen was further subjected to after-curing at 170 ° C. for 1 hour, and then the strength was measured. The cure shrinkage was measured according to JIS K-6911. In addition, TMA
g and the coefficient of thermal expansion were measured. The results are summarized in Table 1.

Next, using the above thermosetting resin composition, L
A mold for ED injection molding was formed by transfer molding. In this case, a mold designed for this example (10 pieces connected) was used. The mold temperature was 165 ° C. and the mold could be released in 3 minutes. After-cure 170 ° C
, And then subjected to a trial production test of an LED resin sealing body. A jig for fixing the lead frame at a predetermined position on the mold was manufactured by injection molding using the above-mentioned thermosetting resin composition. At the time of injection molding, the screw tip temperature was 95 ° C., or the temperature in the mold was 165 ° C., and the mold could be removed in 2 minutes. Similarly, after the after-curing was performed at 170 ° C. for 1 hour, it was subjected to a trial production test of an LED resin sealed body.

A transparent sealing resin composition comprising a vinyl ester resin, a monomer, and an organic peroxide was injected into the mold, and a lead frame having 30 GaAlAs LEDs mounted thereon was fixed to the jig at 130 ° C. For 30 minutes. The demolding after cooling to about 50 ° C. was extremely smooth. The prototype manufacturing cycle was continuously performed for 100 cycles, but the variation in the luminance of the product was 40% at the maximum and 15% at the average in the conventional manufacturing process. The use of GaN significantly improved the maximum at 13% and the average at 4%.

Example 2 Instead of the unsaturated polyester (A-1) used in Example 1, the following epoxy resin composition and various additives were blended using a roll heated to 70 ° C. Composite,
After cooling, the mixture was pulverized into fine particles to obtain a thermosetting resin composition.

Composition 1 of dicyclopentadiene-type epoxy resin and curing agent phenolized dicyclopentadiene
20 parts by weight Curing accelerator Triphenylphosphine 1 part by weight Fused silica powder A: Central diameter of particle size distribution 2μ 200 parts by weight Ground silica powder B: Central diameter of particle size distribution 10μ 400
Parts by weight fused silica powder C: central diameter of particle size distribution 40 μ 400
Parts by weight wax 1 part by weight carbon black 1 part by weight microencapsulated red phosphorus 10 parts by weight γ-glycidoxytriethoxysilane 1 part by weight

Using the thermosetting resin composition thus obtained, a test specimen for bending test was press-formed at 160 ° C. for 5 minutes in accordance with JIS K-6911. The test specimen was further subjected to after-curing at 170 ° C. for 1 hour, and then the strength was measured. The cure shrinkage was measured according to JIS K-6911. In addition, TMA
g and the coefficient of thermal expansion were measured. The results are summarized in Table 1.

Next, using the above thermosetting resin composition, L
A mold for ED injection molding was formed by transfer molding. In this case, a mold designed for this example (10 pieces connected) was used. The mold temperature was 165 ° C. and the mold could be released in 3 minutes. After-cure 170 ° C
, And then subjected to a trial production test of an LED resin sealing body. The jig for fixing the lead frame at a fixed position on the resin mold was the same as that used in Example 1, and was used for a trial production test of an LED resin sealing body. A resin composition for transparent encapsulation comprising a vinyl ester resin, a monomer and an organic peroxide is injected into the resin mold, and a lead frame equipped with 30 GaAlAs LEDs is fixed to the jig and fixed at 130 ° C. for 30 minutes. Was cured. The demolding after cooling to about 50 ° C. was extremely smooth. The prototype manufacturing cycle was continuously performed for 100 cycles, and the variation in luminance of the product was 40% at the maximum and 15% at the average in the conventional manufacturing process. Is improved by 28% at the maximum and 10% at the average.

[0042]

[Table 1]

[0043]

According to the present invention, for example, the thermal movement between the molding frame of the opto device and the lead frame is harmonized,
Provided is a method for manufacturing an opto-device, which can significantly improve a molding failure rate such as a deviation of an optical axis.

Claims (7)

[Claims] An optical device is characterized in that a cured body of a thermosetting resin composition satisfying the following requirements (i) and (ii) is used as a molding jig and / or a mold, and an optical device is sealed with a resin. Manufacturing method of an opto-device. (I) The shrinkage rate during curing is 0.1% or less. (Ii) Coefficient of thermal expansion from room temperature to 180 ° C. is 0.7 × 10 ⁻⁵
〜1.6 × 10 ⁻⁵ / ° C. 2. A thermosetting resin composition comprising (A) an unsaturated polyester, (B) diallyl phthalate, and (C) a Tg of 1
A thermoplastic resin having a temperature of 60 ° C. or lower, (D) an inorganic filler,
The method for producing an optical device according to claim 1, further comprising (E) a radical polymerization initiator. 3. The method according to claim 2, wherein the molding jig and / or the mold is formed by injection molding, transfer molding or press molding. 4. The inorganic filler as component (D) is a silica filler, at least 50% by weight or more of which is spherical silica, and said spherical silica has a particle size distribution ranging from 1 to 100 microns. 3. The method for manufacturing an opto-device according to item 2. 5. The method according to claim 2, wherein the unsaturated polyester as the component (A) is a high melting point unsaturated polyester having a melting point of 120 to 180 ° C. 6. The thermosetting resin composition has a Tg of 2 after curing.
The method according to claim 2, wherein the temperature is 50 ° C. or higher. 7. The thermoplastic resin having a Tg of 160 ° C. or lower as the component (C) is selected from the group consisting of polymethyl methacrylate, polystyrene, polyvinyl acetate, saturated polyester, modified urethane, polyethylene and copolymers thereof. 3. The method for manufacturing an opto-device according to claim 2, wherein the method is at least one kind.