JP2005243795A - Optical semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor device capable of emitting high-brightness light and broadband light from short to long wavelength without using a ceramic, a glass, or an expensive material, such as a metal or the like, for the body of an optical semiconductor device or a light transmission unit, and without complicating the structure. <P>SOLUTION: The optical semiconductor device 12 is placed on a lead frame 10 which is provided on the inner bottom of a hollow container-shape body 1 comprising a heat-dissipating silicone, and a transparent silicone resin is filled in the body 1 to form the light transmission unit 2, thus enabling the optical semiconductor device to emit light of high-brightness as well as of broadband from short to long wavelength. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical semiconductor device capable of supporting high luminance and light emission in a wide band from a short wavelength to a long wavelength band.

  As a conventional optical semiconductor device, in an optical semiconductor device having a lead frame on which an optical semiconductor element is placed inside a package, it is formed in a hollow container shape that is open in one direction made of a heat-resistant thermoplastic resin, There was a body formed by exposing the side of the lead frame on which the optical semiconductor element was placed on the inner bottom of the hollow container, and a transparent resin filled inside the body ( For example, see Patent Document 1).

  FIG. 2 shows a conventional optical semiconductor device described in Patent Document 1. In FIG.

  In FIG. 2, 10 is a lead frame, 10a is an external lead terminal which is a part of the lead frame 10, 10b is an external lead terminal which is a part of the lead frame 10, 10c is a die pad which is a part of the lead frame 10, Denotes a body, 12 denotes an optical semiconductor element, 13 denotes a bonding wire connecting the optical semiconductor element 12 and the external lead terminal 10b, and 14 denotes a light transmitting portion.

In particular, the body 11 was made of a heat-resistant thermoplastic resin, and the light transmitting portion 14 was made of a transparent resin, and had a solder heat resistance of about 280 ° C., which is a short-time heat treatment.
JP-A-7-283441

  However, in the conventional configuration, when the body 11 is made of a heat-resistant thermoplastic resin and the transparent portion 14 is made of a transparent resin, it is used as an optical semiconductor device for high brightness of 0.5 W or more and for a short wavelength band of 550 nm or less, for example. When this happens, the phenomenon of discoloration due to heat and light irradiation due to long-term operation occurs. This phenomenon is caused by the fact that the cyclic group in the molecular structure of the resin is decomposed by short-wavelength light (hereinafter referred to as UV discoloration), and a light stabilizer (HALS etc.) added to improve this even a little. However, since it absorbs short-wavelength light and converts it into heat, it becomes easier to oxidize due to heat than in the past, and discolors (hereinafter referred to as thermal discoloration). Further, when a phosphoric antioxidant is added to the resin in order to reduce thermal discoloration, the UV discoloration increases.

  For the reasons described above, a polymer having a cyclic group in the main chain in the molecular structure is inferior in heat resistance and light resistance.

  For the optical semiconductor device, these discoloration causes the discoloration inside the body 11 having the function of a light reflecting plate to affect the reflectance of light emitted from the optical semiconductor element 12, and the discoloration of the light transmitting portion 14 through which light is transmitted. Affects light transmission and spectrum. Therefore, there has been a problem that high brightness and short wavelength of the optical semiconductor device are limited by the characteristics of the resin.

  In addition to these things, the difference in expansion coefficient due to the difference in material between the body 11 and the light transmitting portion 14 causes internal stress during heat generation, and the reliability of the operation of the optical semiconductor element 12 and the airtightness of the package, etc. It was supposed to have a negative effect.

  Moreover, when considering ceramics or white liquid crystal polymer (LCP) as a commonly used material, ceramics has a problem of reliability as a semiconductor package because of its water absorption property, and red light is reflected in terms of light reflection. It cannot be used in the infrared band due to external absorption. In the case of white liquid crystal polymer (LCP), since it has water absorption, there is a problem in reliability as a semiconductor package, and it cannot be used in a short wavelength band of 550 nm or less in terms of light reflection and light resistance.

  The present invention solves the above-mentioned conventional problems, without using expensive materials such as ceramics, glass or metal, and without complicating the structure. An object of the present invention is to provide an optical semiconductor device capable of emitting light corresponding to the above optical semiconductor elements.

  In order to solve the above-described conventional problems, an optical semiconductor device of the present invention has a heat resistance and light resistance in a low thermal resistance optical semiconductor device having a lead frame on which an optical semiconductor element is placed. A fuselage that is formed in a hollow container shape that is open in one direction and that is made of a highly heat-conductive resin and that is disposed with the side of the lead frame on which the optical semiconductor element is placed exposed at the inner bottom of the hollow container shape. And an optical semiconductor device comprising a transparent resin having both heat resistance and light resistance filled inside the body.

  With this configuration, an optical semiconductor device capable of emitting light corresponding to an optical semiconductor element up to a long wavelength band as well as a high luminance and short wavelength band can be obtained.

  As described above, according to the optical semiconductor device of the present invention, high brightness and short wavelength band as well as long wavelength are used without using expensive materials such as ceramic, glass or metal, and without complicating the structure. An optical semiconductor device capable of emitting light corresponding to an optical semiconductor element up to a band can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an optical semiconductor device according to an embodiment of the present invention.

  In FIG. 1, 1 is a body, 2 is a light transmission part, 10 is a lead frame, 10a is an external lead terminal which is a part of the lead frame, 10b is an external lead terminal which is a part of the lead frame, and 10c is a part of the lead frame. A certain die pad, 12 is an optical semiconductor element, and 13 is a bonding wire connecting the optical semiconductor element 12 and the external lead terminal 10b. Here, in particular, the body 1 is made of a white heat-dissipating silicone resin, and the light transmitting portion 2 is made of a transparent silicone resin.

  According to such a configuration, the silicone resin does not have a cyclic group in the molecular structure, so that UV discoloration does not occur, and it has a heat resistance of 5 minutes at a maximum of 280 ° C. and 200 ° C. for normal use. Discoloration does not occur and the thermal conductivity is 0.02 W / m · K for the liquid crystal polymer (LCP), whereas the heat-dissipating silicone resin is an order of magnitude 5 W / m · K. Therefore, when liquid crystal polymer (LCP) is used for the body 1, the maximum power consumption is 0.5 W, whereas when heat dissipation silicone is used, the maximum power consumption is 3 W.

  Further, since the light reflection of the body 1 has a reflectance of 90% or more from the ultraviolet band of 350 nm to the infrared band of 2100 nm, it can cope with a wide band from a short wavelength band to a long wavelength band.

  Further, since the silicone resin has water repellency and the body 1 and the light transmitting portion 2 are both silicone resins, the thermal expansion coefficients can be matched, which is advantageous in terms of generation of internal stress. For this reason, the conditions are excellent in moisture resistance and operational stability of the optical semiconductor element 12.

  As described above, according to the present invention, an optical semiconductor device capable of handling light in a wide range from a short wavelength band to a long wavelength band with high brightness and stable operation of an optical semiconductor element and high reliability. Can do.

(Embodiment 2)
Hereinafter, the same contents as those in Embodiment 1 are omitted.

  In FIG. 1, by making the silicone resin of the body 1 transparent, an optical semiconductor device in which light irradiation develops by 180 ° can be obtained. Furthermore, if a silicone resin in which 1 to 20 mol% of diphenylsiloxane is added to polydimethylsiloxane is selected, a transmittance of 90% or more can be obtained for light in the ultraviolet band to the infrared band. This is useful for sensors that require a wide range of sensing.

  Note that the present invention is not limited to the above-described embodiment, and an LD or the like having high directivity of light irradiation by changing the shape of the inside of the body 1 having the function of reflecting light or the shape of the light transmitting portion 2. It is good. Further, the body 1 may be provided with a heat radiating plate or the like in order to cope with higher brightness. In addition, it goes without saying that modifications can be made without departing from the scope of the present invention.

  It is useful in the field of optical semiconductors and is particularly suitable for high-luminance short wavelength bands.

Sectional drawing of the optical semiconductor device in embodiment of this invention Sectional view of a conventional optical semiconductor device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Body 2,14 Light transmissive part 10 Lead frame 10a External lead terminal 10b External lead terminal 10c Die pad 12 Optical semiconductor element 13 Bonding wire

Claims (4)

In a low thermal resistance optical semiconductor device having a lead frame in which an optical semiconductor element is placed inside a package,
The package is formed in a hollow container shape in which one direction is made of a highly heat conductive resin having both heat resistance and light resistance,
A body installed on the inner bottom of the hollow container so as to expose a side of the lead frame on which the optical semiconductor element is mounted;
An optical semiconductor device comprising a transparent resin having both heat resistance and light resistance filled inside the body. 2. The optical semiconductor device according to claim 1, wherein the body is a white thermosetting silicone resin having low heat resistance and having both heat resistance and light resistance. 2. The optical semiconductor device according to claim 1, wherein the body is a transparent thermosetting silicone resin having low heat resistance and having both heat resistance and light resistance. 2. The optical semiconductor device according to claim 1, wherein the transparent resin is a thermosetting silicone resin having both heat resistance and light resistance.

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