JPH1164690A - Optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to normally and stably operate an optical semiconductor element for a long period by making the hermetic sealing of the optical semiconductor element perfect. SOLUTION: This package has an optical semiconductor element S loading part 1a in the central part of its front surface and consists of a base body 1 which is provided with a frame part 2 enclosing the loading part on its outer peripheral part, the optical semiconductor element S which is adhered and fixed onto the loading part 1a of the base body 1, an optical fiber 6 which is mounted through the frame part 2 and of which one end faces the optical semiconductor element S and a sealing packing material 7 which is packed in the inner side of the frame part 2 and seals the optical semiconductor element S. In such a case, the sealing packing material 7 consists of an org. resin having an average coefft. of thermal expansion at 0 to 300 deg.C of 0.7×10<-5> to 1.1×10<-5> / deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical semiconductor device used for optical communication and the like.

[0002]

2. Description of the Related Art Conventionally, an optical semiconductor device used for optical communication or the like is made of an electrically insulating material such as an aluminum oxide sintered body or an epoxy resin, and an optical semiconductor element is mounted on a substantially central portion of an upper surface thereof. And a base having a frame portion provided with a through hole in the outer peripheral portion of the upper surface, and a through hole provided in the frame portion of the base, through an adhesive such as glass, resin, or the like. An optical fiber that is fixedly attached to the frame, and a plurality of optical fibers provided at both ends of the frame of the base so as to protrude inside and outside the frame, and one end protruding outside the frame is connected to an external electric circuit. An optical semiconductor element housing package comprising a lead member and a lid attached to the upper surface of the frame portion of the base via a sealing material to hermetically seal the inside of the frame portion is prepared. It is made of silicon on the mounting part on the top surface of the base of the element storage package An optical semiconductor element such as a laser diode or a photodiode mounted on a transmission module substrate is mounted and fixed, and each electrode of the optical semiconductor element is electrically connected to a lead member via an electrical connection means such as a bonding wire. Thereafter, a lid is bonded to the upper surface of the frame via a sealing material, and the optical semiconductor element is air-tightly housed in a container including the base having the frame and the lid. .

In such an optical semiconductor device, an electric signal supplied from an external electric circuit is applied to the optical semiconductor element via a lead member to excite the optical semiconductor element and transmit the excited light to an optical fiber. Or irradiating the optical semiconductor element with light transmitted through the optical fiber,
The optical semiconductor device is used for optical communication by generating an electric signal corresponding to the light applied to the optical semiconductor element and extracting the generated electric signal through a lead member.

[0004] When the base having a frame portion on the outer periphery of the upper surface is made of, for example, an aluminum oxide sintered body, aluminum oxide, silicon oxide, magnesium oxide,
An organic binder, a solvent, etc. are added to and mixed with a ceramic raw material powder such as calcium oxide to form a slurry, and the slurry is formed into a sheet by a doctor blade method, a calendar roll method, or the like to obtain a ceramic green sheet. The ceramic green sheet is manufactured by performing a predetermined punching process and laminating a plurality of the green sheets and firing at a high temperature of about 1500 ° C. When the ceramic green sheet is formed of an organic resin such as an epoxy resin, a transfer molding method is used. By adopting, specifically, an epoxy resin such as bisphenol A type, 0-cresol novolak type, a filler such as silica and alumina, other curing agents, a flexible Agent, flame retardant aid,
A tablet-like epoxy resin raw material powder containing a colorant, a release agent,
It is manufactured by thermosetting at a temperature of from 200C to 200C.

However, recently, there has been a strong demand for small and inexpensive optical semiconductor devices used for communication equipment. Based on this requirement, optical semiconductor devices having a simpler manufacturing process and fewer parts than conventional optical semiconductor devices have been required. Specifically, the package for housing the optical semiconductor element is formed of a base having a frame on the outer peripheral portion of the upper surface, the optical semiconductor element is fixed on the upper surface of the base, the optical fiber is fixed on the frame, and an epoxy resin or the like is provided on the inside of the frame. An optical semiconductor device in which an optical semiconductor element is hermetically sealed by filling an encapsulant filler made of the same has been proposed and used.

[0006]

However, in an optical semiconductor device in which an optical semiconductor element is hermetically sealed with the sealing resin filler, an organic resin such as an epoxy resin is generally used as the sealing filler. Has a coefficient of thermal expansion of 2
The thermal expansion coefficient of the optical semiconductor device is about 0 × 10 ⁻⁵ / ° C. (0.7 × 10 5 when the optical semiconductor element is made of gallium-arsenic).
^-5 / ° C), the optical semiconductor element is hermetically sealed with a sealing filler, and when heat acts on the optical semiconductor element and the sealing filler, the coefficient of thermal expansion between the two increases. A large thermal stress is generated due to the difference, the optical semiconductor element is damaged by the generated thermal stress, or separation occurs between the optical semiconductor element and the sealing filler, and the hermetic sealing of the optical semiconductor element is not performed. This has caused a drawback that the optical semiconductor element cannot be normally and stably operated for a long period of time.

Further, since the organic resin such as an epoxy resin constituting the sealing filler is inferior in moisture resistance, moisture contained in the air enters the sealing filler and comes into contact with the optical semiconductor element, and the electrode of the optical semiconductor element is exposed. For example, the optical semiconductor element cannot always operate normally and stably due to oxidation corrosion.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to provide an optical semiconductor device in which the hermetic sealing of the optical semiconductor element is completed and the optical semiconductor element can operate normally and stably for a long time. Is to provide.

[0009]

According to the present invention, there is provided a base having an optical semiconductor element mounting portion provided at the center of the upper surface and a frame surrounding the mounting portion at the outer peripheral portion, and a mounting portion of the base. An optical semiconductor element adhered and fixed to the optical fiber, an optical fiber which is attached through the frame portion and has one end facing the optical semiconductor element, and a seal filled inside the frame portion to seal the optical semiconductor element An optical semiconductor device comprising: a filler;
The average coefficient of thermal expansion at 300 ° C is 0.7 × 10 ^-5 / ° C.
It is characterized by being made of an organic resin of 1 × 10 ⁻⁵ / ° C.

Further, the present invention is characterized in that the sealing filler contains 1 to 50% by weight of a moisture absorbent having pores having a radius of 10 to 100 angstroms on the surface.

According to the optical semiconductor device of the present invention, the sealing filler for hermetically sealing the optical semiconductor element has an average thermal expansion coefficient at 0 to 300 ° C. of 0.7 × 10 ⁻⁵ / ° C. to 1.1. × 10
^-5 / ° C., since the thermal expansion coefficient of the optical semiconductor element was approximated, the optical semiconductor element was hermetically sealed with a sealing filler,
Even when heat acts on the optical semiconductor element and the sealing filler, a thermal stress is generated between the two due to a difference in thermal expansion coefficient between the two, and the generated thermal stress may damage the optical semiconductor element, No delamination occurs between the semiconductor element and the encapsulant, which completes the hermetic sealing of the optical semiconductor element and allows the optical semiconductor element to operate normally and stably for a long period of time Becomes

Further, according to the optical semiconductor device of the present invention, when the sealing filler contains 1 to 50% by weight of a moisture absorbent having pores having a radius of 10 to 100 angstroms on its surface, it can be used in the atmosphere. Even if the moisture contained in the semiconductor material enters the sealing filler, the infiltrated moisture is efficiently adsorbed by the hygroscopic material and hardly comes into contact with the optical semiconductor element. It is possible to always operate the optical semiconductor element normally and stably without causing oxidative corrosion on the electrodes and the like.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of an optical semiconductor device according to the present invention, wherein 1 is a base, and 2 is a frame formed on the outer peripheral portion of the upper surface of the base 1. The optical semiconductor element S is housed inside the frame 2 formed on the outer peripheral portion of the upper surface of the base 1.

The base 1 functions as a support member for supporting the optical semiconductor element S, and has a mounting portion 1a for mounting the optical semiconductor element S at substantially the center of the upper surface thereof.
An optical semiconductor element S mounted on an optical transmission module substrate L made of silicon or the like is mounted and fixed on the mounting portion 1a via an adhesive such as glass or resin.

A frame 2 is formed on the outer periphery of the upper surface of the base 1 so as to surround a mounting portion 1a on which the optical semiconductor element S is mounted. This serves to form a space for accommodating the optical semiconductor element S.

The base 1 having the frame portion 2 on the outer peripheral portion of the upper surface is made of an electrically insulating material such as an aluminum oxide sintered body or an epoxy resin. An organic binder, a solvent, and the like are added to and mixed with ceramic raw material powders such as silicon oxide, magnesium oxide, and calcium oxide to form a slurry, and the slurry is formed into a sheet shape by a doctor blade method, a calendar roll method, or the like to form a ceramic green. After obtaining a sheet, a predetermined punching process is performed on the ceramic green sheet, and a plurality of sheets are laminated.
It is manufactured by firing at a high temperature of 00 ° C., and when it is formed of an organic resin such as an epoxy resin, a transfer mold method is employed, and specifically, a bisphenol A type, -Tablets composed of epoxy resin such as clay sol novolac type, filler such as silica and alumina, and other curing agents, flexible agents, flame retardant aids, coloring agents, release agents, etc. It is manufactured by injecting a molded epoxy resin raw material powder and thermally curing the same at a temperature of 150 ° C. to 200 ° C.

Both ends of the frame 2 of the base 1 are frame 2
Are provided with a plurality of lead members 3 protruding inward and outward.
Each electrode of the optical semiconductor element S is connected to a region of the lead member 3 protruding inside the frame portion 2 through an electric connection means 4 such as a bonding wire, and a region protruding outside the frame portion 2 is connected to an external electric circuit. When the electrodes are electrically connected to each other, the respective electrodes of the optical semiconductor element S are electrically connected to an external electric circuit via the lead member 3.

The lead member 3 is a base 1 having a frame 2
Is made of a metal such as tungsten, molybdenum or the like, and a metal paste obtained by adding and mixing an organic solvent and a solvent to the metal powder is screen-printed on a ceramic green sheet serving as a substrate 1 Is formed from the inside to the outside of the frame portion 2 by printing and applying a predetermined pattern in advance by, for example, an iron-nickel-cobalt alloy when the base 1 having the frame portion 2 is made of an organic resin such as an epoxy resin. When the base member 1 made of a metal plate such as iron or nickel alloy and having the frame portion 2 is formed by the transfer molding method, the lead member 3 is set at a predetermined position in the mold in advance so that the frame portion 2 has a predetermined shape. At the position, both ends are integrally attached with the both ends protruding inside and outside of the frame portion 2.

The lead member 3 is coated on its exposed outer surface with a metal such as nickel or gold having good conductivity and excellent corrosion resistance and good wettability with a brazing material by a plating method to a predetermined thickness (1).
２０20 μm), it is possible to effectively prevent oxidative corrosion of the lead member 3 and to connect the lead member 3 to an electrical connection means 4 such as a bonding wire and to connect the lead member 3 to an external electric circuit. Connection can be made highly reliable. Therefore, the lead member 3
It is preferable that a metal such as nickel or gold having good conductivity and excellent corrosion resistance and good wettability with a brazing material is applied to the exposed outer surface to a thickness of 1 to 20 μm by plating.

The frame 2 of the base body 1 is further formed with a through hole 5 penetrating the frame 2, and an optical fiber 6 described later extends from the outside to the inside of the frame 2 in the through hole 5. It is inserted and fixed so that the front end faces the optical semiconductor element S.

The through-hole 5 of the frame 2 is formed by drilling the frame 2 with a drill or a laser, or by forming a mold in advance when the base 1 having the frame 2 is formed. The green sheet is formed into a predetermined shape at a predetermined position by performing a punching process at a predetermined position of the green sheet in advance.

The optical fiber 6 inserted and fixed in the through hole 5 of the frame 2 transmits light emitted from the optical semiconductor element S to the outside or transmits light from the outside to the optical semiconductor element S. Acts as a transmission path.

Further, in the base 1 having the frame portion 2 on the outer peripheral portion of the upper surface, the optical semiconductor element S is mounted and fixed on the mounting portion 1a located inside the frame portion 2 via the optical transmission module substrate L.
After the respective electrodes of the optical semiconductor element S fixed to the mounting portion 1a are connected to predetermined lead members 3 via electrical means 4 such as bonding wires, the sealing is filled inside the frame portion 2. It is completely hermetically sealed by the filler 7.

The sealing filler 7 is made of, for example, an organic resin such as an epoxy resin. An amine-based curing agent, an imidazole-based curing agent, a bisphenol A-type epoxy resin, a novolak-type epoxy resin, a glycidyl ester-type epoxy resin, and the like are used. A curing agent such as an acid anhydride-based curing agent is added and mixed to obtain a paste-like epoxy resin precursor, and the epoxy resin precursor is filled inside the frame portion 2 so as to cover the optical semiconductor element S. Thereafter, it is heat-treated at a temperature of about 80 to 200 [deg.] C. for 0.5 to 3 hours, and is thermally cured.

[0025] The sealing filler 7 0.7 average thermal expansion coefficient of 0 to 300 ° C. is × 10 ^-5 /℃~1.1×10 ^-5 /
° C. and a thermal expansion coefficient close to the thermal expansion coefficient of the optical semiconductor element S.
Even if heat acts on the optical semiconductor element S and the sealing filler 7, a thermal stress is generated between the optical semiconductor element S and the sealing filler 7 due to a difference in the coefficient of thermal expansion between the two. As a result, the optical semiconductor element S is not damaged or the optical semiconductor element S is not peeled off from the sealing filler 7, whereby the hermetic sealing of the optical semiconductor element S is completed. S can be operated normally and stably for a long period of time.

[0026] Incidentally, the sealing filler 7 of 0-300 average thermal expansion coefficient 0.7 × 10 ^-5 /℃~1.1×10 ^-5 of ℃
/ [Deg.] C., a filler such as alumina or silica is added to the inside of the epoxy resin constituting the sealing filler 7 in a range of 80 to 9%.
It is performed by containing about 0% by weight.

When the sealing filler 7 contains 1.0 to 50% by weight of a hygroscopic material having pores having a radius of 10 to 100 angstroms on its surface, moisture contained in the atmosphere is reduced. Invasion into the sealing filler 7 and contact with the optical semiconductor element S, the lead member 3, and the electrical connection means 4 such as a bonding wire can be effectively prevented. Oxidative corrosion does not occur in the electrical connection means 4 such as electrodes, lead members 3 or bonding wires, and the optical semiconductor element S
Can always be operated normally and stably.
Therefore, it is preferable that the base 1 having the frame portion 2 contains 1 to 50% by weight of a hygroscopic material having pores having a radius of 10 to 100 angstroms on its surface.

The hygroscopic material contained in the sealing filler 7 is composed of, for example, spherical silica particles having pores having a radius of 10 to 100 angstroms on the surface. By adding a predetermined amount, it is contained in the sealing filling 7.

If the surface of the moisture absorbing material contained in the sealing filler 7 has a pore radius of less than 10 angstroms, it is difficult to completely adsorb the moisture that has entered the sealing filler 7 to the moisture absorbing material. If it exceeds 100 angstroms, the specific gravity of the hygroscopic material becomes light, and the hygroscopic material becomes
, It is difficult to disperse and contain the whole. Therefore, when a moisture absorbing material is contained in the sealing filler 7, the pore radius of the surface of the moisture absorbing material is preferably set in a range of 10 Å to 100 Å.

If the content of the hygroscopic material contained in the sealing filler 7 is less than 1% by weight, it is impossible to effectively prevent the penetration and passage of moisture in the sealing filler 7, If the content is more than 10% by weight, the flowability of the epoxy resin precursor deteriorates, and there is a risk that the optical semiconductor element S or the like cannot be completely and densely coated. Therefore, when a moisture absorbing material is contained in the sealing filler 7, the content of the moisture absorbing material is preferably set in the range of 1 to 50% by weight.

Thus, according to the optical semiconductor device of the present invention,
By applying an electric signal supplied from an external electric circuit to the optical semiconductor element S via the lead member 3 to excite the optical semiconductor element S and transmit the excited light to the optical fiber 6, or The optical semiconductor element S is used for optical communication by irradiating the optical semiconductor element S with light transmitting the light, generating an electric signal corresponding to the light irradiated on the optical semiconductor element S, and extracting the generated electric signal through the lead member 3. You.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

[0033]

According to the optical semiconductor device of the present invention, the sealing filler for hermetically sealing the optical semiconductor element has an average coefficient of thermal expansion at 0.7 to ^10-5 / ° C. .1 × 1
After the optical semiconductor element was hermetically sealed with a sealing filler, heat was applied to the optical semiconductor element and the sealing filler because the coefficient of thermal expansion was set to 0 ⁻⁵ / ° C. and approximated to the thermal expansion coefficient of the optical semiconductor element. However, a thermal stress is generated between the two due to a difference in thermal expansion coefficient between the two, and the generated thermal stress damages the optical semiconductor element or causes separation between the optical semiconductor element and the sealing filler. Therefore, the hermetic sealing of the optical semiconductor element is completed, and the optical semiconductor element can be operated normally and stably for a long period of time.

Further, according to the optical semiconductor device of the present invention, when the sealing filler contains 1 to 50% by weight of a moisture absorbent having pores having a radius of 10 to 100 Å on the surface, it is possible to obtain Even if the moisture contained in the semiconductor material enters the sealing filler, the infiltrated moisture is efficiently adsorbed by the hygroscopic material and hardly comes into contact with the optical semiconductor element. It is possible to always operate the optical semiconductor element normally and stably without causing oxidative corrosion on the electrodes and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an optical semiconductor device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 1a ... Mounting part 2 ... Frame part 3 ... Lead member 5 ... Through-hole 6 ... Optical fiber 7 ... Sealing filler S ... Optical semiconductor element

Claims (2)

[Claims] An optical semiconductor device in which a mounting portion of an optical semiconductor element is provided at a central portion of an upper surface, a frame having an outer peripheral portion provided with a frame surrounding the mounting portion, and an optical semiconductor device adhesively fixed to the mounting portion of the substrate. And an optical fiber attached through the frame portion, one end of which faces the optical semiconductor element, and a sealing filler filled inside the frame portion and sealing the optical semiconductor element. a is, the sealing filler is characterized in that the average thermal expansion coefficient of 0 to 300 ° C. consists 0.7 × 10 ^-5 /℃~1.1×10 ^-5 / ℃ at which the organic resin Optical semiconductor device. 2. The sealing filler according to claim 1, further comprising 1 to 50% by weight of a moisture absorbent having pores having a radius of 10 to 100 Å on the surface.
The optical semiconductor device according to the above.