JPH07221128A - Sealing of optical semiconductor device - Google Patents

Abstract

PURPOSE:To provide a method of sealing an optical semiconductor device, which seals the optical semiconductor device using a resin, which is specially superior in productivity and moldability and moreover, is superior in heat resistance and has a superior adhesion to a light-transmitting resin and a lead frame, in the method of sealing the optical semiconductor device of a form that a photodetector and a light-emitting element are simultaneously mounted in an element, such as a photo coupler and a photo interrupter, and the transfer of a signal is conducted between the photodetector and the light-emitting element. CONSTITUTION:A method of sealing an optical semiconductor device, which seals the optical semiconductor device with a light-transmitting resin, then, seals the optical semiconductor device with a nought-transmitting resin composition, is characterized by that the non-light-transmitting resin composition is made it an essential condition that a thermoplastic norbonane resin is added to a composition. which consists of a polyallylenesulfide resin and an inorganic filler, and the thermal deformation temperature of the resin composition exceeds 180 deg.C in a load of 66 psi.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor in which a light receiving element and a light emitting element are simultaneously mounted in an element such as a photo coupler and a photo interrupter, and signals are transmitted and received between the light receiving element and the light emitting element. Productivity, especially productivity,
The present invention relates to an optical semiconductor encapsulation method in which encapsulation is performed using a resin having excellent moldability, heat resistance, and a translucent resin or an adhesiveness with a lead frame.

[0002]

2. Description of the Related Art A photo-coupler, photo-interrupter, a light-receiving element and a light-emitting element are simultaneously mounted in the element, and signals are transmitted and received between the light-receiving element and the light-emitting element. The semiconductor is formed by sealing the light receiving element and the light emitting element with a transparent resin such as an epoxy resin or a silicone resin, and then further sealing with a non-transparent resin. Conventionally, thermosetting resins such as epoxy resins, silicone resins, and phenol resins have been used as such non-translucent resins. However, such resins require a long time to cure, which results in poor productivity. There was an inferior problem. Therefore, in recent years, polyphenylene sulfide resin (PPS)
Has excellent heat resistance, rigidity, electrical insulation, chemical resistance, and flame retardancy, and because it is a thermoplastic resin, molding time can be greatly shortened and productivity can be improved. It is being investigated as a non-translucent resin for encapsulating optical semiconductors that replaces the transparent resin. However, since PPS is crystalline, if it exceeds the melting point, the fluidity is extremely increased, making it difficult to control the fluidity, and there is a problem that burrs are generated during molding. Further, there is anisotropy in the molding shrinkage rate and the linear expansion coefficient, so that after the optical semiconductor is sealed with a light-transmitting resin, PPS is used as a non-light-transmitting resin.
If sealed with a simple substance, cracks may occur due to its anisotropy when taken out from the mold at the time of molding, or cracks or deformation due to heat applied during soldering Depending on the structure of the semiconductor, it may be difficult to exchange signals between the light receiving element and the light emitting element. Further, PPS has a drawback that it has poor adhesiveness to other resins and metals due to the characteristics of its chemical structure. Therefore, an optical semiconductor sealed by using PPS simple substance as a non-translucent resin is a translucent resin. There is a problem that the adhesiveness with PPS is not sufficient, a gap may be generated and moisture may enter, and the sealing function cannot be fulfilled. Also, due to the anisotropy of PPS due to the heat when soldering the optical semiconductor, the transparent resin and PPS
When a high voltage is applied between the lead wire for external connection on the light emitting element side and the lead wire for external connection on the light receiving element side, a discharge is generated in the gap between the transparent resin and the PPS interface. There is a problem that the light emitting element and the light receiving element are destroyed, or dielectric breakdown occurs at the interface. Further, since the sealing PPS and the lead wire or the lead frame are poor in adhesion, water intrudes from the interface between them, which causes a problem that electrical insulation is deteriorated and electrodes are corroded.

As a technique for improving the adhesion between the translucent resin and the non-translucent resin, the light emitting element and the light receiving element are sealed with the translucent resin, and then the surface of the translucent resin is treated with ultraviolet rays or ozone. And then sealing with a non-translucent resin.
It is disclosed in Japanese Patent Laid-Open No. 94679, Japanese Patent Laid-Open No. 3-22553, and the like. However, the method disclosed in the above-mentioned publication has a problem that productivity is lowered due to the step of surface-treating the transparent resin. Further, these methods do not improve the adhesion between the non-translucent resin and the lead wire or the lead frame. In particular, when a resin having poor adhesiveness such as PPS is used as the non-translucent resin, the above-mentioned drawback becomes remarkable.

As a technique for improving the adhesion of PPS to a lead wire or a lead frame, a method of applying a specific adhesion agent to the lead wire or the lead frame in advance and then sealing with PPS is disclosed in JP-A-62-120036. Publication, JP-A-3-
Japanese Patent Publication No. 59-20911 and Japanese Patent Publication No. 4-4746 disclose a method of using PPS mixed with a specific additive as a sealing material.
No. 0, JP-A-63-189458 and the like. However, the method of applying the adhesive to the lead wires or the lead frame and then sealing with the PPS has a problem in that the work process is complicated and the productivity is deteriorated. On the other hand, in the PPS composition to which the additive disclosed in the above-mentioned publication is added, the heat resistance temperature of the other additive is low, so that the heat resistance, which is an advantage of PPS, is impaired. Therefore, such a PPS composition The optical semiconductor sealed with is inferior in thermal deformability at high temperature, and there is a problem that the optical semiconductor is deformed by high temperature heat in the soldering process. Under these circumstances, heat resistance, which is an advantage of PPS, is not deteriorated, and further, the anisotropy of molding shrinkage and linear expansion coefficient, the adhesion with lead wires and lead frames, the adhesion with a light-transmitting resin, which are the drawbacks of PPS, There is a demand for a method for sealing an optical semiconductor which has improved adhesiveness and excellent productivity, but none of the conventionally known methods has been able to satisfy such a demand.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems all at once, and is excellent in productivity and moldability, and is also excellent in heat resistance and adhesiveness with a translucent resin or a lead frame. An optical semiconductor sealing method is provided.

[0006]

The method for sealing an optical semiconductor according to the present invention is a method for sealing an optical semiconductor in which an optical semiconductor is sealed with a transparent resin and then with a non-transparent resin composition. At
The non-translucent resin composition is required to add a thermoplastic norbornene-based resin to a composition composed of a polyarylene sulfide resin and an inorganic filler, and the heat deformation temperature of the resin composition capable of withstanding solder heat resistance is a load. It is characterized by exceeding 180 ° C. at 66 psi.

The thermoplastic norbornene resin used in the present invention has a norbornane skeleton in its repeating unit. For example, the thermoplastic resin includes a norbornane skeleton represented by any of the general formulas (I) to (IV).

[0008]

[Chemical 1]

[0009]

[Chemical 2]

[0010]

[Chemical 3]

[0011]

[Chemical 4]

(In the formula, A, B, C and D represent a hydrogen atom or a monovalent organic group.) The thermoplastic resin having a norbornane skeleton used in the present invention is required to have sufficient strength. And its weight average molecular weight is 5,000 to 1,000,000, preferably 8,000 to 20.
In many cases.

Examples of the thermoplastic resin having a norbornane skeleton which can be used in the present invention include, for example, JP-A-60-168708 and JP-A-62-2524.
No. 06, No. 62-252407, No. 2-133413, No. 63-145324, No. 63-264626, and No. 1-2.
Resins described in JP-B No. 40517, JP-B No. 57-8815 and the like can be mentioned. Specific examples of the thermoplastic resin include at least one tetracyclododecene derivative represented by the following general formula (V),
Alternatively, a hydrogenated polymer obtained by hydrogenating a polymer obtained by metathesis polymerization of the tetracyclododecene and an unsaturated cyclic compound copolymerizable therewith can be mentioned.

[0014]

[Chemical 5]

(In the formula, A to D are the same as above.)

Specific examples of the specific monomer represented by the general formula (V) include 5-carboxymethylbicyclo [2.
2.1] hept-2-ene, 5-methyl-5-carboxymethylbicyclo [2.2.1] hept-2-ene, 5
-Cyanobicyclo [2.2.1] hept-2-ene, 8
-Carboxymethyltetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-carboxyethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-
Dodecene, 8-carboxy n-propyl tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-
Carboxyisopropyl tetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] -3-dodecene, 8-carboxy n-butyl tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3
-Dodecene, 8-methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-methyl-8-carboxyethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-
Methyl-8-carboxy n-propyl tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-
Methyl-8-carboxyisopropyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-
Methyl-8-carboxy n-butyl tetracyclo [4.
4.0.1 ^2,5 . 1 ^{7, 10]} -3-dodecene, and the like. In the tetracyclododecene derivative represented by the general formula (V), the inclusion of a polar group among A, B, C and D makes it possible to adhere to lead wires and lead frames, heat resistance and compatibility with PPS. From the point of, it is preferable. Further, the polar group - (CH _{2) n} COOR
¹ (wherein R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 0 to 10) is a carboxylic acid ester group, and the resulting hydrogenated polymer has a high glass transition. It is preferable because it has a temperature. In particular, one polar substituent consisting of this carboxylic acid ester group is contained per molecule of the tetracyclododecene derivative of the general formula (V). It is preferable in terms of adhesion.

In the above general formula, R ¹ has 1 to 2 carbon atoms.
Although it is a hydrocarbon group of 0, it is preferable as the number of carbon atoms increases so that the hygroscopic property of the obtained hydrogenated polymer decreases.
From the viewpoint of the balance with the glass transition temperature of the obtained hydrogenated polymer, a chain alkyl group having 1 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms is preferable, and a methyl group or ethyl group is particularly preferable. And a cyclohexyl group are preferred. Furthermore, since the tetracyclododecene derivative of the general formula (V) in which a hydrocarbon group having 1 to 10 carbon atoms is simultaneously bonded as a substituent to the carbon atom to which the carboxylic acid ester group is bonded reduces hygroscopicity. preferable. In particular,
The tetracyclododecene derivative represented by the general formula (V) in which the substituent is a methyl group or an ethyl group is preferable from the viewpoint of easy synthesis. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4,4,0,1 ^2.5, 1
^7.10 ] Dodeca-8-ene is preferred. Examples of the monomer represented by the general formula (V) include (a) W, Mo, Re and T.
at least one selected from the compounds of a, and (b) a compound of group Ia, IIa, IIIa, IVa, or IVb of the Deming Periodic Table, which has at least one element-carbon or element-hydrogen bond. Polymerized with a metathesis catalyst including a combination with at least one selected from the group consisting of: In addition to the components (a) and (b), the component (c) can be added to obtain a more highly active catalyst. As the polymerization solvent, cyclohexane, benzene,
Examples thereof include toluene, xylene, 1,2-dimethoxyethane, butyl acetate and the like. Further, a known hydrogenation catalyst is used to hydrogenate a polymer polymerized using the above catalyst. Here, the hydrogenation reaction is performed at room temperature to 300.
It can be carried out at 0 to 200 ° C., preferably 20 to 180 ° C. in a hydrogen gas atmosphere at atmospheric pressure, preferably 3 to 200 atm.

In the present invention, the hydrogenated polymer used as the thermoplastic resin has an intrinsic viscosity (η _inh ) measured at 30 ° C. in chloroform of 0.2 to 1.5 dl /
g, especially in the range of 0.3 to 0.5 dl / g,
It is preferable from the viewpoint of preventing wire deformation during molding. Further, the softening temperature of the hydrogenated polymer is 90 ° C. or higher, and the glass transition temperature is 100 ° C. or higher, particularly 130 ° C. or higher, which means that when blended with the polyarylene sulfide resin, the heat resistance of the polyarylene sulfide resin is increased. It is preferable because it does not damage. The hydrogenation rate of the hydrogenated polymer is 60 MHz, ¹
The value measured by 1 H-NMR is 50% or more, preferably 90%.
% Or more, more preferably 98% or more. The higher the hydrogenation rate, the better the stability to heat and light.

The polyarylene sulfide resin used in the present invention has a main structural unit of the general formula: -Ar-S-.
(In the formula, Ar represents a divalent aromatic group). Examples of the divalent aromatic group constituting the polyarylene group include n-phenylene group, m-phenylene group, 2,6-naphthalene group, 4,4′-biphenylene group, p, p′-bibenzyl group, and Typical examples thereof include these nuclear substituents. Among these, poly-p-phenylene sulfide having a p-phenylene group as a nuclear substituent is preferable in terms of moldability.

In the present invention, the polyarylene sulfide resin needs to contain at least 70 mol% or more of the above structural units in one molecule. This main component is 7
If it is less than 0 mol%, the resulting polyarylene sulfide resin may have poor crystallinity, a low transition temperature, or the physical properties of the encapsulated semiconductor may be unfavorable. Further, in the present invention, if the polyarylene sulfide resin is less than 30 mol% in one molecule,
Aromatic group having a trivalent or more bond, for example, 1,2,4
It may contain a bonded phenylene nucleus, an aliphatic group, a hetero atom-containing group, or the like. As the method for producing the polyarylene sulfide resin, a condensation reaction of a dihalogenated aromatic compound and a diol aromatic compound, or a monohalogenated aromatic thiol, or a dihalogenated aromatic compound and an alkali sulfide, or an alkali hydrosulfide and an alkali. , Or a method utilizing a desalting condensation reaction of hydrogen sulfide and an alkali compound can be exemplified, but the method is not limited thereto.

The above-mentioned resin composition was developed as a non-translucent encapsulant for optical semiconductor elements. Considering that the encapsulated optical semiconductor is soldered, the heat of the resin composition is considered. The deformation temperature is preferably higher than 180 ° C. and particularly preferably higher than 200 ° C. under a load of 66 psi. Since the thermoplastic norbornene-based resin used in the present invention is amorphous, there is no extreme increase in the fluidity at the time of melting as compared with the crystalline polyarylene sulfide resin, and the anisotropy of the molding shrinkage ratio and the linear expansion coefficient. Is small. Therefore, by blending the thermoplastic norbornene-based resin with the polyarylene sulfide resin, the above drawbacks of the polyarylene sulfide resin can be remarkably improved. Moreover, the thermoplastic norbornene-based resin is a resin having a high glass transition temperature, and even if blended with the polyarylene sulfide resin, the high heat resistance originally possessed by the polyarylene sulfide resin is not significantly impaired. However, if the thermoplastic norbornene-based resin is excessively blended, the heat distortion temperature becomes 1
If the temperature of the optical semiconductor is reduced to 80 ° C. or lower and the optical semiconductor is sealed with such a resin composition, the high temperature heat applied during the soldering step may deform the sealed portion of the optical semiconductor or significantly reduce the reliability. There is. Particularly in recent years, many of electronic components including optical semiconductors are surface mount products, and the heat applied to the electronic components during the hand attaching process is higher than that of the conventional lead-through mount product. The drawbacks are even more pronounced.

Therefore, in the non-translucent resin composition of the present invention, in order to satisfy the above-mentioned heat distortion temperature and to improve the various defects due to the crystallinity of the polyarylene sulfide resin, the thermoplastic norbornene resin and poly The inorganic filler is preferably contained in the range of 5 to 400 parts by weight with respect to the total 100 parts by weight of the arylene sulfide resin, and the thermoplastic norbornene-based resin and the polyarylene sulfide resin are each 1 to 60% by weight, 99-40% by weight, preferably 5-45% by weight, 95-
It is desirable that the content is 55% by weight. When the thermoplastic norbornene-based resin is less than 1% by weight, various defects due to the crystallinity of the polyarylene sulfide resin are not improved, and the anisotropy of the molding shrinkage rate and the linear expansion coefficient of the resin composition becomes large, and The fluidity of the resin becomes too large and burrs are easily generated, and the adhesiveness to the translucent resin or the lead wire or the lead frame becomes poor. Therefore, an optical semiconductor sealed with such a composition is used. Has poor reliability such as low withstand voltage. Further, when the thermoplastic norbornene-based resin exceeds 60% by weight, the heat distortion temperature of the composition is remarkably lowered, and the optical semiconductor encapsulated with such a composition is exposed to high temperature heat applied during the soldering process. There is a risk of deformation. In particular, when the thermoplastic norbornene-based resin is a resin having no polar substituent in the norbornane skeleton, it is preferably within the range of 1 to 45% by weight.

In mixing the thermoplastic norbornene-based resin and the polyarylene sulfide resin, a compatibilizing agent can be used to enhance the compatibility. As one example thereof, a copolymer mainly composed of an olefin unit and an unsaturated compound unit having at least one functional group selected from a carboxyl group, an acid anhydride group, an oxazoline group and an epoxy group, and at least one vinyl When a polymer having a multilayer structure composed of a vinyl (co) polymer of a compound is used as a compatibilizing agent, the thermoplastic norbornene resin and the polyarylene sulfide resin become more compatible with each other. The proportion of the compatibilizer used is usually 0.1 to 20 parts by weight based on 100 parts by weight of the total of the thermoplastic norbornene resin and the polyarylene sulfide resin. here,
A copolymer mainly composed of an olefin unit in a polymer having a multilayer structure and an unsaturated compound unit having at least one functional group selected from a carboxyl group, an acid anhydride group, an oxazoline group and an epoxy group (hereinafter , "Copolymer I") is, for example, a binary, ternary or multi-component copolymer of an olefin and an unsaturated compound having the above-mentioned functional group and, if necessary, another unsaturated compound. As the olefin in the above copolymer I, ethylene and propylene are preferable, and ethylene is particularly preferable.

As the carboxyl group-containing unsaturated compound, acrylic acid, methacrylic acid, maleic acid, etc., and as the acid anhydride group-containing unsaturated compound, maleic anhydride, itaconic anhydride, etc., are used as the oxazoline group-containing unsaturated compound. Examples of the epoxy group-containing unsaturated compound such as vinyl oxazoline include glycidyl methacrylate and allyl glycidyl ether. Preferred functional groups are an epoxy group and an acid anhydride group. The amount of the olefin of the polymer I is usually 60 to 99.5% by weight, and the amount of the unsaturated compound monomer having a functional group is usually 0.5 to 40.
% By weight, other unsaturated monomers are usually 0-39.5% by weight
Is. Further, the vinyl-based copolymer composed of at least one vinyl compound in the multiphase structure specifically includes styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorostyrene, α-methylstyrene, Aromatic vinyl monomers such as α-ethyl styrene, esters of (meth) acrylic acid methyl, ethyl, dodecyl and octadecyl, vinyl ethers such as vinyl methyl ether and vinyl ethyl ether,
Number average obtained by polymerizing one or two or more vinyl compounds having no carboxyl group, acid anhydride group, oxazoline group, and epoxy group, such as vinyl cyan compounds such as acrylonitrile and methacrylonitrile, and acrylic acid amide compounds. A polymer having a degree of polymerization of usually 5 to 10,000, preferably 10 to 10,000.

The multi-phase structural component is a copolymer I or vinyl-based (co) polymer matrix in which the vinyl copolymer or copolymer I, which is a different component, is uniformly dispersed in a spherical shape. Is. The particle size of the dispersed polymer is 0.001 to 10 μm, preferably 0.01 to 5 μm.
Is. If the particle diameter of the dispersed polymer is less than 0.001 μm or exceeds 10 μm, the mechanical strength of the obtained composition is lowered, which is not preferable. The polyphase structural component is usually 5 to 95% by weight, preferably 20 to 95% by weight of the copolymer.
The content of 90% by weight is preferable for achieving the object of the present invention. The method for producing the multi-phase structural component may be any method such as a well-known chain transfer method and ionizing radiation irradiation property, but the most preferable method is described in JP-A-64-48856. Is the way.

The inorganic filler used in the present invention is blended for the purpose of increasing the mechanical strength of the encapsulating material, and is usually 1 in total of the thermoplastic resin and the polyarylene sulfide resin.
It is used in an amount of 5 to 400 parts by weight based on 00 parts by weight. Examples of the inorganic filler include, for example, glass fiber, potassium titanate fiber, asbestos, silicon carbide, silicon nitride, ceramic fiber, zirconia fiber, silica fiber, alumina fiber, fibrous filler such as gypsum fiber, and barium sulfate. , Calcium sulfate, calcium sulfite, kaolin, clay, bilophyllite, bentonite, sericite,
Zeolite, mica, mica, nepheline sinite, talc, atharbulite, wollastonite, PMF, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, antimony oxide, zinc oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide Inorganic fillers such as alumina, iron oxide, molybdenum disulfide, gypsum, glass beads, glass balloons, glass powder, glass flakes, silica powder, and silica beads. In particular, it is preferable to use a filler containing at least one kind of fibrous filler, because the crack resistance of the optical semiconductor sealed with the non-translucent resin composition of the present invention is improved. The non-translucent resin composition of the present invention may be blended with another thermoplastic resin as long as the effect of the present invention is not impaired.

In addition, the non-translucent resin composition of the present invention comprises
If necessary, an antistatic agent, a coloring agent, a flame retardant, an antioxidant, such as 2,6-di-t-butyl-4-methylphenol, 2- (1-methylcyclohexyl) -4,6-dimethylphenol, 2,2-methylene-bis- (4-ethyl-6-t-butylphenol), tris (di-nonylphenylphosphite): UV absorber, eg p-
t-Butylphenyl salicylate, 2,2'-dihydroxy-4-methoxy-benzophenone, 2- (2'-dihydroxy-4'-m-octoxyphenyl) benzotriazole, "TINUVIN 320" [manufactured by Ciba Geigy], "TINUVIN 329". [Ciba Geigy], "TINUVIN 622LD" [Ciba Geigy], "CHIMASSORB 119FL" [Ciba Geigy]: Lubricants such as paraffin wax, stearic acid, hardened oil, stearamide, methylenebis stearamide, m-butyl stearate. , Ketone wax,
Octyl alcohol, hydroxystearic acid triglyceride and the like may be added in the required amounts.

The non-translucent resin composition used in the present invention has a melt viscosity of ^{1 at a} temperature of 300 ° C. and a shear rate of 1000 sec ⁻¹ .
It is preferably in the range of 00 to 4000 poise, and particularly preferably in the range of 200 to 2000 poise. If the melt viscosity is less than 100 poise, the fluidity becomes too large and burrs are easily generated, resulting in deterioration of moldability and productivity. On the other hand, if it exceeds 4000 poise, the lead wire or the lead frame may be damaged during sealing. The non-translucent resin composition used in the present invention, using a mixer such as a single-screw extruder, a multi-screw extruder, a Banbury mixer, a kneader, a mixing roll, a resin composition and a filler, a flame retardant, further necessary Obtained by mixing the additives used accordingly.

An example of the method for producing the non-translucent resin composition used in the present invention is as follows. After mixing the respective components with a mixer, the mixture is melt-kneaded at 240 to 360 ° C. using an extruder to give a granulated product. As a more convenient method, there may be mentioned a method in which each component is directly melt-kneaded in a molding machine to obtain pellets. Further, there is a method in which a filler and a flame retardant are added later while kneading a resin component using a twin-screw extruder to prepare pellets. The above-mentioned method for encapsulating an optical semiconductor is not particularly limited as long as it encapsulates the optical semiconductor with a translucent material and then with the non-translucent resin of the present invention, and mainly injection molding and transfer. Methods such as molding, compression molding and dipping can be used.

In the present invention, the light-transmitting material for sealing the optical semiconductor is not particularly limited as long as it is transparent.
Epoxy resin, silicone resin, 4-methyl-1-pentene resin, thermoplastic norbornene-based resin and the like are preferably used. Among these, it is preferable that the thermoplastic norbornene-based resin is compatible with the thermoplastic norbornene-based resin in the non-translucent resin composition used in the present invention so that the adhesiveness becomes particularly high. When a thermoplastic norbornene-based resin is used as the translucent resin, the structure thereof may be the same as or different from the structure of the thermoplastic norbornene-based resin in the non-translucent resin composition. It is particularly preferable to use the same type of norbornene resin.

As an example of the sealing method of the present invention, after sealing an optical semiconductor with a transparent resin, the optical semiconductor is put in a mold to close the mold, and then the above non-transparent resin composition is injected. Then, after the molding is completed, the mold may be opened and the molded product may be taken out. At this time, the lead wire of the optical semiconductor, the lead frame, or the translucent resin may be preliminarily treated with a treatment for enhancing the adhesiveness, for example, an adhesive or a coupling agent. As these adhesives and coupling agents, known ones which are generally used can be used, and examples thereof include an epoxy adhesive, a polyimide adhesive, a silane coupling agent and a titanate coupling agent.

The material of the semiconductor lead wire and lead frame in the present invention is not particularly limited, but any material in which various metals such as iron, nickel, copper, aluminum, tin, zinc, cobalt and zirconium are combined is used. Can be used. The optical semiconductor encapsulated by the method of the present invention can be used as a composite optical device such as a photocoupler and photointerrupter in a wide range of applications such as computers and communication devices.

[0033]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In the examples, parts and% are based on weight unless otherwise specified. Further, various measurements in the examples are as follows. Heat-resistant heat distortion temperature (HDT) is sequentially set to ASTM D648,
A test piece having a thickness of ½ ″ was used and the load was measured at 66 psi. Solder reflow test Reflow Tecker RC-8 manufactured by Malcolm Co. was used. After preheating at 180 ° C. for 2 minutes, main heating was performed. 260 ° C
For 30 seconds, the maximum surface temperature of the test piece, appearance change, and shrinkage in the flow direction were measured. 5.0 kV, 8.0 k between the lead wire for external connection on the light emitting element side and the lead wire for external connection on the light receiving element side of the withstand voltage optical semiconductor.
A non-defective rate was calculated by applying a voltage of V and 10.0 kV for 10 seconds each. Translucent resin, adhesion to lead frame Opto-semiconductor is immersed in red ink liquid, pressure: 5kgf / cm
^{After 2} G, temperature: 80 ° C., time: 16 h, the degree of penetration of red ink at the interface between the non-translucent resin and the translucent resin and the interface between the non-translucent resin and the lead frame was examined. As a result, by visual inspection, A indicates that no red ink has penetrated at all, B indicates that a slight amount of red ink has penetrated, C indicates that a slight amount of red ink has penetrated into the interface, and C indicates that red ink has completely penetrated into the interface. The intruder is represented by D.

[0034] Production of Reference Example (a) a thermoplastic norbornene resin (a) -1: 8- methyl-8-methoxycarbonyltetracyclo [4,4,0,1 ^2.5, 1 ^7,10] dodeca-3
100 g of ene, 60 g of 1,2-dimethoxyethane, 240 g of cyclohexane, 9 g of 1-hexene, and 3.4 ml of a toluene solution of 0.96 mol / liter of diethylaluminum chloride were added to an autoclave having an internal volume of 1 liter. On the other hand, 20 ml of 1,2-dimethoxyethane solution containing 0.05 mol of tungsten hexachloride / Litto and 10 ml of a 1,2-dimethoxyethane solution containing 0.1 mol / l of paraaldehyde were mixed in another flask. 4.9 ml of this mixed solution was added to the mixture in the autoclave. After sealing, the mixture was heated to 80 ° C. and stirred for 3 hours. In the obtained polymer solution,
2/8 of 1,2-dimethoxyethane and cyclohexane
(Weight ratio) mixed solvent was added to give a polymer / solvent ratio of 1/10.
After adjusting to (weight ratio), 20 g of triethanolamine was added and stirred for 10 minutes. To this polymerization solution, methanol 5
00 g was added, and the mixture was stirred for 30 minutes and allowed to stand. The upper layer separated into two layers was removed, methanol was added again, and the mixture was stirred and left standing, and then the upper layer was removed. The same operation was repeated twice, and the obtained lower layer was appropriately diluted with cyclohexane and 1,2-dimethoxyethane to obtain a cyclohexane-1,2-dimethoxyethane solution having a polymer concentration of 10%. 2 in this solution
0 g of palladium / silica magnesia [JGC Corporation
Manufactured, palladium amount = 5%] was added, and the mixture was reacted in an autoclave at a hydrogen pressure of 40 kg / cm ² at 165 ° C. for 4 hours, and then the hydrogenation catalyst was removed by filtration to obtain a hydrogenated polymer solution. In addition, pentaerythrityl-tetrakis [3- (3,3 which is an antioxidant is added to the hydrogenated polymer solution.
5-di-t-butyl-4-hydroxyphenyl) propionate] was added to the hydrogenated polymer in an amount of 0.1%, and the solvent was removed under reduced pressure at 380 ° C. Next, the molten resin was pelletized by an extruder in a nitrogen atmosphere, an intrinsic viscosity of 0.5 dl / g (30 ° C., in chloroform), a weight average molecular weight of 7.0 × 10 ⁴ , and a hydrogenation rate of 99.5.
%, A thermoplastic resin (a) -1 having a glass transition temperature of 168 ° C.
Got

(A) -2: Metathesis ring-opening polymerization was carried out in the same manner as in (a) -1 except that the polymerization time was changed to 3 hours and a half, followed by hydrogenation and pelletization to obtain an intrinsic viscosity of 0.61 dl / g (3
A thermoplastic norbornene-based resin (a) -2 having a hydrogenation rate of 99% and a glass transition temperature of 166 ° C. was obtained.

Metathesis ring-opening polymerization of (a) -3: 6-ethylidene-2-tetracyclododecene was carried out in the same manner as in Reference Example 1, followed by hydrogenation and pelletization to obtain an intrinsic viscosity of 0.45 dl.
/ G (30 ° C, in chloroform), weight average molecular weight 5.
A thermoplastic resin (a) -3 having 5 × 10 ⁴ , a hydrogenation rate of 99% and a glass transition temperature of 140 ° C. was obtained.

(A) -4: 55 mol% of ethylene and 2-methyl-1,4,5,8-dimethano-1,2,3-4,4
45 mol% of a, 5,8,8a-octahydronaphthalene
And addition-polymerized and pelletized to give an intrinsic viscosity of 0.64d
1 / g (35 ° C. in decalin), weight average molecular weight 10.
0 × 10 ^4, to obtain a glass transition temperature of 140 ° C. for the thermoplastic resin (a) -4.

(B) Polyarylene sulfide (b) -1: Polyphenylene sulfide M2088 (linear type) manufactured by Toray Industries, Inc. (b) -2: Polyphenylene sulfide M2100 (crosslinked type) manufactured by Toray Industries, Inc. (c) Inorganic filling Material (c) -1: Glass fiber CS03MA486A (long fiber, diameter 13 μm) manufactured by Asahi Fiber Glass Co., Ltd. (c) -2: Silica powder Crystallite 5X (average particle size 7 μm, maximum particle size 10 μm) Tatsumori Co., Ltd. (D) Compatibilizer: MODIPER A4101 NOF CORPORATION

Examples 1 to 8 and Comparative Examples 1 to 4 The thermoplastic norbornene resins, polyarylene sulfide resins, inorganic fillers and compatibilizers of Reference Examples were blended as shown in Table 1 using a twin-screw extruder. The mixture was melt-mixed at 300 ° C. to produce a pellet-shaped thermoplastic resin composition. These resin compositions were subjected to heat resistance measurement and solder reflow test. Further, using these resin compositions, an optical semiconductor in which a light-receiving element and a light-emitting element are sealed with a translucent thermoplastic norbornene-based resin (a) -1 in advance is placed in a molding die, and non-translucent by injection molding. Resin sealing was performed.
For these optical semiconductors, the dielectric strength of the optical semiconductors, the adhesion of the non-translucent resin to the translucent resin, and the adhesion to the lead frame were measured. The results are shown in Table 1.

[0040]

[Table 1]

As is clear from Table 1, the non-translucent resin compositions (Examples 1 to 8) of the present invention are excellent in heat resistance and are also excellent in adhesion to the translucent resin and the lead frame. In addition, the optical semiconductor encapsulated with the non-translucent resin composition of the present invention has excellent withstand voltage. On the other hand, Comparative Examples 1 to 3 are those in which the thermoplastic norbornene-based resin was excessively contained, and these had a thermal deformation temperature of less than 190 ° C. under a load of 66 psi, and thermal deformation was found in the solder reflow test. It is inferior in heat resistance required for optical semiconductors. In Comparative Example 4, the amount of the thermoplastic norbornene-based resin blended is extremely small, and the adhesiveness to the translucent resin or the lead frame is poor, and the light sealed with such a non-translucent resin composition is used. When a high voltage is applied to a semiconductor, many defective products are generated.

[0042]

INDUSTRIAL APPLICABILITY The non-translucent resin composition used in the present invention is excellent in productivity and heat resistance, and is also excellent in adhesion to lead wires, lead frames and translucent resins. The optical semiconductor encapsulated with the composition becomes extremely reliable without any deterioration in performance such as deformation during the soldering process or during long-term use and reduction in dielectric strength.

Claims (1)

[Claims] 1. A method of encapsulating an optical semiconductor, which comprises encapsulating an optical semiconductor with a translucent resin and then with an opaque resin composition, wherein the opaque resin composition comprises A light characterized in that it is essential to add a thermoplastic norbornene-based resin to a composition comprising an arylene sulfide resin and an inorganic filler, and the heat distortion temperature of the resin composition exceeds 180 ° C. under a load of 66 psi. Semiconductor encapsulation method.