JP2000261027A - Optical semiconductor bonding device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability and safety by covering a light emitting device and a light receiving device with an optical bonding material, and having the surface of the optical bonding material irradiated with far-ultraviolet rays having a specific peak wavelength and then sealing it with a sealing material. SOLUTION: A light emitting device 1 and a light receiving device 2 are fixed opposite to each other on a lead frame 4, having a prescribed shape with a conductive paste 3 and are bonded to prescribed positions of the lead frame 4 using gold wires 5. This is covered with a silicone resin 6 made by polymerizing dimethylsiloxane and then is cured. Thereafter, the surface of the silicone resin exposed to ozone is irradiated with far-ultraviolet rays having a peak wavelength of 180 nm or lower and activated oxygen at the same time, by using a Xe-type excimer lamp as the far-ultraviolet ray source to activate the surface. The activated surface 8 of the silicone resin is sealed tightly with a sealing material 7 made of a white epoxy resin and is subjected to heat treatment. This enables safe production of a satisfactory insulating characteristic in a short activating time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an optical semiconductor coupling device, and more particularly to a method for manufacturing an optical semiconductor coupling device with improved reliability.

[0002]

2. Description of the Related Art Conventionally, as an optical semiconductor coupling device, for example, in a reflection type optical semiconductor coupling device as shown in FIG. 5, a light emitting element 1 which emits radiation from an ultraviolet region to an infrared region by applying a voltage, and this light emitting device A light-receiving element 2 having a light-receiving sensitivity to radiation emitted from the substrate is fixed to a lead frame 4 having a predetermined shape by using a conductive paste 3 and is fixed to a predetermined position of the lead frame by using a gold wire 5. Connect. This is coated with an optical coupling material 6 which is transparent to ultraviolet to infrared radiation, is made of a silicone resin obtained by polymerizing dimethylsiloxane, and is cured. Further, a deep ultraviolet ray having a wavelength of 254 nm and 185 nm generated by a low-pressure mercury lamp whose spectral distribution is shown in FIG.
The activation treatment is performed by irradiating for about 5 minutes, and this is sealed with a sealing material 7 made of a white epoxy resin having a reflectance of 50% or more with respect to radiation in the ultraviolet to infrared region. By this activation treatment, a covalent chemical bond is formed between the silicone resin and the white epoxy resin, and the silicone resin and the white epoxy resin are firmly adhered to each other. Is destroyed while 1
Even if a voltage of 0 kV or more is applied, no breakdown occurs. This technique is disclosed in Japanese Patent Publication No. 6-104804. It is further heat-treated and commercialized.

The optical semiconductor coupling device manufactured in this way emits radiation by applying a voltage from the lead frame 4 to the light emitting device 1 via the conductive paste 3 and the gold wire 5 to emit a radiation. The light-receiving element 2 receives this radiation via the optical coupling material 6 optically closed by 7 to generate a photocurrent, which is output from the lead frame via the conductive paste 3 and the gold wire 5. This enables transmission of electrical signals in an electrically insulated state.

[0004]

In such a conventional method for manufacturing an optical semiconductor coupling device, the emission wavelength of the low-pressure mercury lamp used in the activation step is 25.
4 nm and 185 nm. Therefore, in order to obtain a low photon energy and good insulating properties, the activation time is long and the assembly margin is small. Also, the absorption by oxygen is small and the propagation is 15 to 20 cm. There is a problem that irradiation is likely to be high and there is a possibility of causing adverse effects such as inducing cancer.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing an optical semiconductor coupling device having high reliability and safety while eliminating the conventional disadvantages.

[0006]

According to the method of manufacturing an optical semiconductor coupling device of the present invention, a light emitting element and a light receiving element are coated with an optical coupling material, and the surface of the optical coupling material has a peak wavelength of 180 nm or less from a far ultraviolet source. After irradiating with ultraviolet rays, a step of sealing with a sealing material is provided.

In the method of manufacturing an optical semiconductor coupling device according to the present invention, an Xe type excimer lamp is used as the far ultraviolet light source.

Further, in the method of manufacturing an optical semiconductor coupling device according to the present invention, the optical coupling material is a silicone resin obtained by adding 1 to 20 mol% of phenylsiloxane to methylpolysiloxane. It is.

An optical semiconductor coupling device according to the present invention comprises a light emitting element fixed on a first lead frame, a light receiving element fixed on a second lead frame, and a light emitting element and a light receiving element mounted inside the light emitting element. For transmitting light from the light-emitting element to the light-receiving element, an optical coupling material comprising a silicone resin in which 1-20 mol% of phenylsiloxane is added to methylpolysiloxane, the optical coupling material, and the first and second optical coupling materials. And a resin sealing body for sealing the lead frame of (2).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to FIGS. (Embodiment 1) FIG. 1 is a sectional view showing the structure of an optical semiconductor coupling device according to the present invention. In the figure, the same or corresponding components as those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. The light emitting element 1 and the light receiving element 2 were fixed to each other on a lead frame 4 having a predetermined shape using a conductive paste 3, and were connected to a predetermined position of the lead frame using a gold wire 5. This was covered with a silicone resin 6 obtained by polymerizing dimethylsiloxane and cured.

Next, an Xe type excimer lamp whose spectral distribution is shown in FIG. 3 is used as a far ultraviolet ray source, and far ultraviolet rays having a peak wavelength of 172 nm are illuminated on the surface of the silicone resin simultaneously exposed to ozone and active oxygen (oxygen atoms). 2.8-
The activation treatment was performed by irradiation at 7.4 mW / cm 2 for 30 seconds to 50 seconds. At this time, the distance between the glass surface of the Xe type excimer lamp and the lead frame was kept at 10 mm or less. In this way, the substrate was sealed with a sealing material 7 made of a white epoxy resin so as to be in close contact with the silicone resin surface 8 which had been activated by irradiation with far ultraviolet rays having a wavelength of 172 nm, and heat-treated. It is preferable that the sealing material contains 5% or more and 40% or less of titanium oxide.

In order to evaluate the dielectric strength of the optical semiconductor coupling device thus obtained, a voltage of 10 kV was applied to 100 samples for one minute, and the number of remaining samples without destruction was expressed in%. The results are shown in Table 1.

[Table 1] As shown in Table 1, although the activation time was shortened to 1/15 or less of that of the related art, it was possible to obtain the same insulation characteristics as when a low-pressure mercury lamp was used.

Further, since the far ultraviolet rays by the Xe type excimer lamp are more likely to be absorbed by oxygen in the air about 10 times than the far ultraviolet rays by the low pressure mercury lamp, the distance between the glass surface of the excimer lamp and the lead frame is kept at 10 mm or less. On the other hand, by setting the distance between the excimer lamp and the worker to 12 mm or more, far ultraviolet rays are absorbed and attenuated by oxygen in the air, so that safety can be easily secured. Was. (Embodiment 2) As in Embodiment 1, a light emitting element and a light receiving element were fixed and connected on a lead frame. Then, this was polymerized with シ ロ キ サ ン methylsiloxane to which ヂ phenylsiloxane was added in an amount of 5 mol%, coated with a silicone resin of ヂ methylpolysiloxane, and cured. Next, the surface of the silicone resin was activated by irradiating a Xe type excimer lamp under the same conditions as in the first embodiment, sealed with a white epoxy resin, and heat-treated.

The optical semiconductor coupling device obtained in this manner was able to obtain the same insulation characteristics as in the first embodiment.

Further, regarding the cold resistance, the MIL condition (150 ° C. × 30 minutes + −65) which satisfies the US Department of Defense standards.
The temperature was evaluated by a temperature cycle test (TCT) of 30 ° C. × 30 minutes. When a silicone resin obtained by polymerizing only methyl siloxane was used, open failures sporadically started from about 100 cycles. When ヂ phenylsiloxane was added as in
No open failure occurred until the cycle. here,
In order to obtain such an effect, it is necessary that the amount of the phenylsiloxane added is 1 mol% or more, while
If it exceeds ol%, the UV and ozone weather resistance will increase and the activation will be impaired, so it is appropriate to add it in the range of 1 to 20 mol%. More preferably, it is 5 to 15 mol%.
In addition, as shown in FIG. 4, this range also coincides with the range in which the freezing point is reduced in the relationship between the phenyl group content in dimethylpolysiloxane and the freezing point, and crystallization of the silicone resin causes an open defect. It is probable that it was triggered.

As described above, although the activation time is greatly shortened as compared with the conventional method, good insulation characteristics and cold resistance of the optical semiconductor coupling device can be obtained, and safety of the worker is secured. We were able to.

[0017]

According to the present invention, it is possible to provide a method of manufacturing an optical semiconductor coupling device capable of safely obtaining good insulation characteristics with a short activation time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an optical semiconductor coupling device used in an embodiment of the present invention.

FIG. 2 is a diagram showing a spectral distribution of a low-pressure mercury lamp used in an embodiment of the present invention.

FIG. 3 is a diagram showing a spectral distribution of a Xe type excimer lamp used in the embodiment of the present invention.

FIG. 4 is a diagram illustrating the relationship between the phenyl group content in dimethylpolysiloxane and the freezing point for explaining the operation of the embodiment of the present invention.

FIG. 5 is a view showing a method for manufacturing a conventional optical semiconductor coupling device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light emitting element 2 light receiving element 3 conductive paste 4 lead frame 5 gold wire 6 optical coupling material (silicone resin) 7 sealing material (white epoxy resin) 8 silicone resin surface 9 low oxygen concentration atmosphere 10 excimer lamp 11 reflector

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyoshi Kawaguchi 1-10-1, Shimotsu, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Toshiba Kitakyushu Plant (72) Inventor Teruo Takeuchi Shimotsutsu, Kokurakita-ku, Kitakyushu-shi, Fukuoka No. 1-10 No. 1 F-term in Toshiba Corporation Kitakyushu Plant (reference) 5F089 AB01 AC15 CA01 DA02 DA14 DA15 EA03

Claims (4)

[Claims] 1. A light emitting element and a light receiving element are coated with an optical coupling material, and the surface of the optical coupling material has a peak wavelength of 1 from a far ultraviolet ray source.
A method for manufacturing an optical semiconductor coupling device, comprising a step of irradiating a deep ultraviolet ray of 80 nm or less and then sealing with a sealing material. 2. The method according to claim 1, wherein an excimer lamp of a type such as Xe, Kr, or Ar is used as the far ultraviolet light source. 3. The method for manufacturing an optical semiconductor coupling device according to claim 1, wherein said optical coupling material is a silicone resin obtained by adding 1 to 20 mol% of ヂ phenylsiloxane to ヂ methylpolysiloxane. 4. A light-emitting element fixed on a first lead frame, a light-receiving element fixed on a second lead frame, and a light-emitting element and a light-receiving element contained in the light-emitting element. Transmitting light to the light receiving element;
An optical semiconductor coupling device comprising: an optical coupling material made of a silicone resin to which 0 mol% is added; and a resin sealing body that seals the optical coupling material and the first and second lead frames.