JP2012222126A - Optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that when a surface mount type optical semiconductor device is manufactured by a method which prints a light reflectivity resin on a sealing resin side surface, large scale facilities are needed and thus it is difficult to manufacture the semiconductor device at low cost.SOLUTION: A resin sealing an optical semiconductor element and the like is covered by a heat sensitive part containing a heat sensitive material. Then, while a portion corresponding to a light emission part or a light incident part is transparentized by heating, the other portion remains opaque and is used as a reflection part or a shielding part. A method that does not require large scale facilities such as spraying or potting is used for forming the heat sensitive part. Thus, the optical semiconductor device is manufactured at low cost.

Description

  The present invention relates to an optical semiconductor device using an optical semiconductor element such as a light emitting element or a light receiving element.

  Surface mount type optical semiconductor devices are widely used at present. In particular, since the demand for miniaturization of electronic equipment is increasing, surface mount type optical semiconductor devices are increasingly required.

JP2008-187030

Patent Document 1 discloses a method for manufacturing a surface-mounted light-emitting device. By this method, a reflective member was formed by applying a TiO ₂ -containing resin to the sealing resin surface excluding the light emitting portion, and a smaller light emitting device could be manufactured. However, this technique requires a fine masking process so as not to apply the TiO ₂ -containing resin to the electrodes. For this reason, a holding jig or the like for maintaining the airtightness of the masking requires a large capital investment. Furthermore, if an attempt is made to manufacture a smaller light emitting device, higher application accuracy is required, and thus a larger capital investment is required. Accordingly, there has been a demand for a method capable of manufacturing a light emitting device and the like with simpler processes.

  According to one aspect of the present invention, a step of arranging an optical semiconductor element on a wiring board, a step of covering the optical semiconductor element with a sealing resin, a step of covering the sealing resin with an opaque heat-sensitive part, There is disclosed a method of manufacturing an optical semiconductor device having a step of applying heat to a part of the heat sensitive part to make the part transparent.

  In the manufacturing method according to the present invention, the light emitting portion or the light incident portion of the optical semiconductor device is obtained by making the heat-sensitive material transparent, while the other reflecting portions or the shielding portions are used in the color-sensitive heat-sensitive material. There are features. That is, the light emitting part or the light incident part can be formed only by performing heating for changing the color of the heat sensitive material in an arbitrary part. Since the resin portion including the heat sensitive material can be easily manufactured from the resin for sealing the optical semiconductor element by a technique that does not require accuracy such as spraying or potting, a large capital investment is not required.

It is explanatory drawing of the manufacturing method of the optical semiconductor device by 1st embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 1st embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 1st embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 1st embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 2nd embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 2nd embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 2nd embodiment of this invention. It is explanatory drawing of the manufacturing method of the optical semiconductor device by 2nd embodiment of this invention. It is explanatory drawing of the optical semiconductor device by 2nd embodiment of this invention.

  The present invention will be described below with reference to the drawings. 1 to 4 are views showing a method of manufacturing an optical semiconductor device according to the first embodiment of the present invention. First, as shown in FIG. 1, an optical semiconductor element 3 such as a light emitting diode element or a photodiode element is arranged on a wiring board 1 on which a wiring pattern 2 is formed. The optical semiconductor element 3 is electrically connected to the wiring pattern 2 by a conductive paste (not shown), a wire 4 or the like. Thereafter, the optical semiconductor element 3 and the wire 4 are sealed with a transparent sealing resin 5.

  Next, as shown in FIG. 2, the sealing resin 5 is covered with an opaque heat-sensitive part 6. As the heat sensitive part 6, for example, a heat sensitive material mixed with a binder material composed of a resin and an organic solvent is used. For example, a spray method, a dipping method, a screen printing method, or a potting method can be selected as the step of covering the sealing material 5. After coating, the organic solvent is vaporized and the resin is cured by heating, and the heat sensitive part 6 is fixed on the sealing resin 5.

  Next, as shown in FIG. 3, the upper part of the heat sensitive part 6 corresponding to the optical semiconductor element 3 is heated to form a transparent heat sensitive part 6 a. In order to heat only this part, the method of pressing the heated metal block against the heat sensitive part 6 can be selected, for example.

  Finally, as shown in FIG. 4, the wiring board 1 and the opaque heat-sensitive portion 6b are divided into individual pieces by a method such as dicing or braking. Thereafter, the individual optical semiconductor devices are treated as normal electronic components such as being fixed to a mounting substrate by soldering or the like.

  A suitable material is selected for the heat sensitive part 6 according to the viewpoint of the manufacturing method and function. As the heat-sensitive material, a substance that is opaque at room temperature and becomes irreversibly transparent when the color change point is exceeded is used. Examples thereof include salicylidene aniline compounds and fluorane compounds. Here, the discoloration point needs to be higher than the temperature in the process that becomes the highest temperature after forming the heat sensitive portion 6. For example, when solder mounting is performed through a reflow process after singulation, the reflow process is typically about 230 ° C. Therefore, in such a case, a material having a color change point higher than 230 ° C. should be used. This is because the opaque heat-sensitive portion 6b should not be transparent when exposed to this environment. Generally speaking, the color change point is more preferably 20 ° C. or more than the temperature in the process that becomes the highest temperature after the formation of the heat sensitive portion 6, because temperature control in the process does not need to be so strict. The color of the heat-sensitive material can be selected, but when a light-emitting element is used as the optical semiconductor element, if the color matches the emission wavelength, it also serves as an emission color display and improves the light extraction efficiency. .

  The optical semiconductor element 3 is preferably a light receiving element such as a light emitting diode element or a photodiode. In the case of a light-emitting diode element, the opaque heat-sensitive part 6b acts as a reflecting part, reflects light that is about to be emitted toward the side surface of the sealing resin 5 back to the inside, and more light is transmitted from the transparent heat-sensitive part 6a. To be released. On the other hand, in the case of the light receiving element, the opaque heat-sensitive part 6b acts as a shielding part, shields light that is about to enter from the side surface direction of the sealing resin 5, and allows light to enter from the transparent heat-sensitive part 6a. .

  In addition, since the wiring board 1, the wiring pattern 2, the wire 4, the sealing resin 5 and the like are the same as those conventionally used, the description thereof is omitted.

  5 to 8 are views showing a method of manufacturing an optical semiconductor device according to the second embodiment of the present invention. This device is a so-called optical sensor in which a light receiving element 7 and a light emitting element 8 are present in a single package with a light shielding portion 9 therebetween. First, as shown in FIG. 5, the light receiving element 7 and the light emitting element 8 are arranged on the wiring substrate 1 on which the wiring pattern 2 is formed. The light receiving element 7 and the light emitting element 8 are electrically connected to the wiring pattern 2 by a conductive paste (not shown), a wire 4 or the like. Thereafter, the optical semiconductor element 3 and the wire 4 are sealed with a transparent sealing resin 5. Further, a light shielding portion 9 is provided between the light receiving element 7 and the light emitting element 8 so that light from the light emitting element 8 is not directly emitted to the light receiving element 7 side.

  Next, as shown in FIG. 6, the sealing resin 5 is covered with the opaque heat-sensitive part 6. After coating, the organic solvent is vaporized and the resin is cured by heating, and the heat sensitive part 6 is fixed on the sealing resin 5.

  Next, as shown in FIG. 7, the upper part of the heat sensitive part 6 corresponding to the light receiving element 7 is heated to form a transparent heat sensitive part 6a. In order to heat only this part, it is possible to select a method such as pressing a heated metal block against the heat sensitive part 6 as in the first embodiment. Note that the transparent heat-sensitive portion 6a may be formed by heating not only above the portion corresponding to the light receiving element 7 but also above the portion corresponding to the light emitting element 8.

  Finally, as shown in FIG. 8, the wiring board 1 and the opaque heat-sensitive portion 6b are divided into individual pieces by a method such as dicing or braking. Thereafter, the individual optical sensor devices are treated as ordinary electronic components such as being fixed to a mounting substrate by soldering or the like.

  FIG. 9 shows the configuration of the completed optical sensor device. As shown in the left perspective view of FIG. 9, only the portion corresponding to the upper side of the light receiving element 7 is transparent. Therefore, as shown on the right side of FIG. 9, the light receiving element 7 can receive light emitted from the light emitting element 8 and reflected by the object to be detected. On the other hand, stray light entering from other directions is blocked by the opaque heat sensitive part 6 b and does not enter the light receiving element 7. Therefore, the signal-noise ratio (S / N ratio) can be increased.

  As in the first embodiment, the heat-sensitive part 6 includes a heat-sensitive material that is opaque at room temperature and becomes irreversibly transparent when the color change point is reached. In addition, as with the first embodiment, the wiring board 1 and the like that have been conventionally used can be adopted.

DESCRIPTION OF SYMBOLS 1 Wiring board 2 Wiring pattern 3 Optical semiconductor element 4 Wire 5 Sealing resin 6 Heat sensitive part 6a Transparent heat sensitive part 6b Opaque heat sensitive part 7 Light receiving element 8 Light emitting element 9 Light shielding part

Claims (2)

A wiring board;
An optical semiconductor element disposed on the wiring board;
A sealing resin covering the optical semiconductor element;
A heat-sensitive part covering the sealing resin,
The heat-sensitive part is an optical semiconductor device in which light from the optical semiconductor element is emitted or incident part is transparent and other parts are opaque. Arranging the optical semiconductor element on the wiring board;
Covering the optical semiconductor element with a sealing resin;
Covering the sealing resin with an opaque heat-sensitive part;
Applying heat to a part of the heat sensitive part to make the part transparent;
The manufacturing method of the optical semiconductor device which has this.

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