JP2006216887A - Optodevice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optodevice which improves efficiency of light emitting and of light receiving, and which prevents breakage of devices and wiring disconnection caused by stress of a resin portion overlying an element without increasing any processes or components. <P>SOLUTION: A reflector 28 made of a first resin is provided around a photodiode 24, and a lens 30 made of a second resin is provided overlying the photodiode 24. The reflector 28 covers a surface of a substrate 22 around the photodiode 24, and has an inclined plane 28a surrounding the photodiode 24. The lens 30 is provided so as to adhere to the inclined plane 28a of the reflector 28. A border plane of the reflector 28 and the lens 30 in the optodevice works as a reflecting plane. The reflector 28 and the lens 30 are formed easily in a series of resin forming processes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical device equipped with one or both of a light-emitting element and a light-receiving element, and in particular, emits light without additional modification of processing and manufacturing processes and without causing deterioration in quality such as wire breakage, The present invention relates to a device capable of increasing the efficiency of light reception.

  In general, in order to increase the efficiency of light emission or light reception in an optical device, it is effective to provide a lens or a reflector that reflects light.

  6 to 8 are cross-sectional views showing an example of a conventional optical device, showing the structure of a conventional light receiving sensor equipped with a light receiving element. In the light receiving sensor shown in FIG. 6, a photodiode 4 and an IC 6 are mounted on a substrate 2, a translucent resin portion 8 for sealing the photodiode 4 and the IC 6 is provided, and a convex lens is formed thereon. A lens 10 is mounted. Further, in this light receiving sensor, the lens 10 is fixed on the translucent resin portion 8 by attaching the shield case 12 having a hole 12a for projecting the center of the lens 10 to the outside of the translucent resin portion 8. is doing. In this light receiving sensor, infrared light or the like irradiated from the outside is condensed by the lens unit 10 so that a large amount of light hits the photodiode 4 to increase the light receiving efficiency.

  In the light receiving sensor shown in FIG. 7, the photodiode 4 and the IC 6 are mounted on the substrate 2, and the reflector 14 having the reflecting surface 14 a inclined so as to spread outward is provided around the photodiode 4. Yes. The reflector 14, the photodiode 4, and the IC 6 are covered and sealed with a translucent resin portion 18. The translucent resin portion 18 has a central portion that rises like a convex lens and protrudes from the hole 12a of the shield case 12, and thus also functions as a lens. In this light receiving sensor, light is collected by a convex lens-shaped translucent resin portion 18 and further, light of a wide angle is collected in the direction of the photodiode 4 by the reflector 14 to improve the light receiving efficiency.

  In the light receiving sensor shown in FIG. 8, the concave portion 2a is formed by carrying out spotting or the like on the substrate 2, the photodiode 4 is mounted on the bottom thereof, and the inclined reflecting surface 2b is provided on the inner peripheral wall of the concave portion 2a. . The photodiode 4 in the recess 2a and the IC 6 mounted on the surface of the substrate 2 are sealed by a translucent resin portion 18 formed in a convex lens shape. In this light receiving sensor, light is reflected and collected by the reflecting surface 2b formed on the substrate 2 instead of the reflector 14 shown in FIG.

  However, the provision of the lens 10 as shown in FIG. 6 cannot sufficiently increase the light receiving or light emitting efficiency. Further, the provision of the reflector 14 as shown in FIG. 7 has a problem that the number of parts and the mounting process increase. Furthermore, in order to form the recess 2a as shown in FIG. 8, it is necessary to process the substrate 2, which leads to a decrease in mass productivity and an increase in cost due to the processing.

  On the other hand, when the resin portion for sealing the light emitting element or the like is formed in a lens shape, the resin portion may be rotated or tilted due to the weight of the raised portion in the lens shape, and the wire of the light emitting element or the like may be disconnected. For this reason, it has been proposed to strengthen the bond between the substrate and the resin portion by performing a process such as forming a groove at the bottom of the cup portion of the substrate on which the light emitting element or the like is mounted (see Patent Document 1). . However, in this apparatus, it is necessary to process the shape of the substrate in a complicated manner, resulting in a decrease in mass productivity and an increase in cost.

In addition, in order to prevent damage and disconnection of the light emitting element due to stress when the resin part sealing the light emitting element is cured, the resin material covering the light emitting element etc. and the resin material covering the entire substrate are changed. Therefore, it has been proposed to prevent breakage due to stress (see Patent Document 2). However, in this structure, only two types of sealing resin are used, so in order to improve the light emission or light receiving efficiency, it is necessary to process the substrate and install a reflector, and processing and parts addition are required. It was necessary.
JP 2003-332627 A JP 2003-179267 A

  The problem to be solved by the present invention is to increase the light emission or light reception efficiency of the light emitting element or the light receiving element without increasing the number of processing and the number of parts, and to damage the element due to the stress of the resin part covering the light emitting element or the light receiving element or to wire It is an object of the present invention to provide an optical device that can prevent disconnection.

  An optical device of the present invention is a flat plate having a conductive pattern formed on its surface, an optical element composed of one or both of a light emitting element and a light receiving element mounted on the substrate, and a periphery of the optical element. A reflector made of a first resin having an inclined surface surrounding the optical element and a lens made of a second resin that covers the optical element and is in close contact with the reflector, and a boundary surface between the reflector and the lens Light is reflected or condensed as a reflecting surface. In this optical device, the first resin is made of a light-shielding resin, and the second resin is made of a light-transmitting resin. The lens has a Fresnel lens shape. The reflector and the lens are formed by molding the reflector with the first resin and then molding the lens with the second resin. The lens is fitted in a recess surrounded by the inclined surface of the reflector, and is attached in a state where a space is provided between the lens and the optical element.

  In the optical device of the present invention, a reflector formed by resin molding is provided around the light emitting element or the light receiving element, and the lens is formed by the resin covering the light emitting element or the light receiving element, thereby increasing the number of processing and parts. The light emission or light reception efficiency can be improved without doing so.

  In addition, a resin that efficiently reflects light is used as a resin for forming the reflector, and a material having low stress and a material having good adhesion to the reflector can be selected as the resin for forming the lens. It is possible to increase the efficiency of light reception and to suppress a decrease in yield due to element breakage or the like.

  In addition, since a space is provided between the lens and the element, it is possible to prevent damage to the element and disconnection of the wire due to the stress of the resin covering the upper part of the element, and the quality can be further improved.

  In addition, since the lens is formed in the Fresnel lens shape, the overall height of the product can be suppressed and the size and thickness can be reduced while obtaining the lens effect.

  In addition, since the reflector and the lens can be formed by a series of resin molding processes, it is possible to manufacture the conventional manufacturing process almost without changing the manufacturing process.

  In addition, since no special processing or special manufacturing process of the substrate is required, an increase in manufacturing cost can be suppressed.

  In the optical device of the present invention, the reflector made of the first resin is provided around the optical element made of one or both of the light emitting element and the light receiving element mounted on the substrate, and made of the second resin so as to cover the optical element. A lens is provided. This reflector covers the substrate surface around the optical element, and has an inclined surface that surrounds the optical element and is inclined so as to spread outward. The lens is provided so as to be in close contact with the inclined surface of the reflector. In this optical device, the boundary surface between the reflector and the lens acts as a reflecting surface, and reflects light from the outside in the direction of the optical element, or reflects light from the optical element in the outward radiation direction, Increasing light reception or light emission efficiency.

  The reflector and the lens in the optical device of the present invention are both formed by resin molding, and can be formed by a series of steps.

  FIG. 1 is a cross-sectional view showing the structure of an optical device according to Embodiment 1 of the present invention. In the first embodiment and other embodiments described later, a light receiving sensor will be described as an example of an optical device. Reference numeral 22 denotes a substrate, which has a flat plate shape and insulation, and a plurality of conductive patterns are formed on the surface thereof.

  Reference numeral 24 denotes a photodiode as a light receiving element. The photodiode 24 is mounted by die bonding and wire bonding to a conductive pattern on the substrate 22. Reference numeral 26 denotes an IC that outputs a signal when the photodiode 24 receives light, and is mounted on the substrate 22.

  Reference numeral 28 denotes a reflector formed of the first resin. The reflector 28 covers the surface of the substrate 22 around the photodiode 24 and seals the IC 26, and has an inclined surface 28 a having a truncated cone shape that is inclined so as to spread outwardly surrounding the photodiode 24. ing. In addition, the first resin forming the reflector 28 in the present embodiment has a light shielding property and is colored in a color tone such as white or black.

  Reference numeral 30 denotes a lens formed into a convex lens shape by the second resin. This lens 30 is resin-molded so as to seal the photodiode 24, fill the space surrounded by the inclined surface 28a of the reflector 28, and rise upward. Therefore, the lens 30 is formed in close contact with the inclined surface 28 a of the reflector 28. In addition, the second resin forming the lens in this embodiment has translucency.

  Reference numeral 32 denotes a shield case that blocks outside light, and has a box shape with the lower part opened in the figure so as to cover the upper surface and side surfaces of the reflector 28. The shield case 32 is provided with a hole 32a at a position facing the photodiode 24, and the upper portion of the lens 30 protrudes outward from the hole 32a.

  In the light receiving sensor having the above configuration, since the reflector 28 has a light shielding property, a reflection surface is formed on a boundary surface where the inclined surface 28a of the reflector 28 and the outer surface 30a of the lens 30 are in contact with each other. . For this reason, not only the light from the outside is condensed by the lens 30, but also the light is reflected by the reflecting surface so that more light hits the photodiode 24, and the light receiving efficiency of the photodiode 24 can be improved. .

  On the other hand, the reflector 28 and the lens 30 in this optical device are resin-molded as follows. First, after mounting the photodiode 24 and the IC 26 on the substrate 22, as shown in FIG. 2, the photodiode 24 is surrounded by a pipe 34 having a truncated cone shape. Next, the reflector 28 is resin-molded outside the pipe 34, and then the pipe 34 is removed and the lens 30 is molded by potting or the like. Thereafter, the shield case 32 is attached as necessary.

  FIG. 3 is a sectional view showing the structure of an optical device according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Example 1 shown in FIG. This light receiving sensor is different from the first embodiment in that the lens 40 is formed in a Fresnel lens shape, and other parts are the same as those in the first embodiment. Similar to the lens 30, the lens 40 having the Fresnel lens shape has translucency, covers the photodiode 24, and is in close contact with the reflector 28. The Fresnel lens-shaped lens 40 has a large number of fine irregularities formed in a ring shape on the upper surface formed of a substantially flat surface, and collects light from the outside in the same manner as the convex lens-shaped lens 30 by the irregularities. Acts as follows. In particular, since the lens 40 does not protrude upward like the lens 30, the height can be reduced compared to the lens 30, and the height of the light receiving sensor as a product can be kept low and the size and thickness can be reduced. It is possible to do.

  The first resin forming the reflector 28 in the first and second embodiments is preferably white so that the reflection efficiency of the reflecting surface is improved, and is relatively hard because it forms an outer shape. Is preferred. Further, the second resin forming the lenses 30 and 40 is such that excessive stress is not applied to the photodiode 24 or the wire, such as a low coefficient of thermal expansion, and the photodiode 24 or the wire is not damaged or disconnected. Is preferred. Further, in the case where the first resin and the second resin protrude upward like the lens 30, it is necessary to firmly fix the first resin and the second resin.

  FIG. 4 is a sectional view showing the structure of an optical device according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Example 1 shown in FIG. This light receiving sensor is configured such that a space S is generated around the photodiode 24 by providing a constant distance between the bottom surface 50b of the lens 50 formed of resin in a convex lens shape and the photodiode 24. . Note that the lower end portion of the inclined surface 28 a of the reflector 28 is formed so as to be substantially perpendicular to the substrate 22, and is set so as to be spaced apart from the photodiode 24. For this reason, the photodiode 24 is sealed inside the room surrounded by the space 28 between the reflector 28 and the lens 50 while leaving the space S therebetween.

  When configured as described above, the stress when the resin hardens or thermally expands as it is sealed inside the resin is not directly applied to the element or the wire, It is possible to prevent wire breakage.

  In addition, as described above, in order to form the space S between the bottom surface 50b of the lens 50 and the photodiode 24, the height is set so that the bottom surface 50b does not contact the photodiode 24, and the lens 50 is resinated in advance. Then, the lens 50 is fitted and fixed in a recess surrounded by the inclined surface 28a of the reflector 28. Thereby, a predetermined space S can be formed between the bottom surface 50 b of the lens 50 and the photodiode 24.

  FIG. 5 is a cross-sectional view showing the structure of an optical device according to Embodiment 4 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Example 1 shown in FIG. In this light receiving sensor, a lens 60 having a Fresnel lens shape similar to that of the second embodiment is used, and a space S is provided between the bottom surface 60b and the photodiode 24 as in the third embodiment. Similarly to the third embodiment, the lens 60 is also formed in advance so that the bottom surface 60b does not come into contact with the photodiode 24, and the lens 60 is molded with resin, and the lens 60 is formed on the inclined surface 28a of the reflector 28. Fit along and stick. As a result, a space S is provided between the lens 60 and the photodiode 24, so that the photodiode 24 can be prevented from being damaged or broken.

  In the first to fourth embodiments, the light receiving sensor using the photodiode 24 has been described as an example. However, in the case of the light receiving sensor, an LED chip as a light emitting element is mounted instead of the photodiode 24 and the IC 26. Similarly to the above, it is possible to form a light emitting device that has the effects of increasing the light emission efficiency and preventing damage to the elements and disconnection of the wires. In this case, it is not necessary to provide the shield case 32 that shields the outside.

  The present invention can be used for a light receiving sensor in which a light receiving element is mounted as described above, or a light emitting device in which a light emitting element is mounted. In addition, a photo interrupter in which both a light receiving element and a light emitting element are mounted, and the like It can also be used for other sensors.

It is sectional drawing which shows the structure of the optical device which concerns on Example 1 of this invention. It is sectional drawing which shows the resin molding process of the reflector and lens shown in FIG. It is sectional drawing which shows the structure of the optical device which concerns on Example 2 of this invention. It is sectional drawing which shows the structure of the optical device which concerns on Example 3 of this invention. It is sectional drawing which shows the structure of the optical device which concerns on Example 4 of this invention. It is sectional drawing which shows the structure of the conventional light receiving sensor. It is sectional drawing which shows the structure of the conventional light receiving sensor. It is sectional drawing which shows the structure of the conventional light receiving sensor.

Explanation of symbols

2,22 Substrate 2a Recess 2b Reflecting surface 4, 24 Photodiode (light receiving element)
6,26 IC
8, 18 Translucent resin portion 10 Lens 12, 32 Shield case 12a, 32a Hole 14 Reflector 14a Reflecting surface 28 Reflector 28a Inclined surface 30, 40, 60 Lens 30a Outer surface 50b, 60b Bottom surface

Claims (5)

A substrate having a flat plate shape and a conductive pattern formed on the surface;
An optical element composed of one or both of a light emitting element and a light receiving element mounted on the substrate;
A reflector made of a first resin covering the periphery of the optical element and having an inclined surface surrounding the optical element;
A lens made of a second resin that covers the optical element and adheres closely to the reflector;
Consists of
An optical device characterized in that light is irradiated or condensed by using a boundary surface between the reflector and the lens as a reflection surface.   2. The optical device according to claim 1, wherein the first resin is made of a light-shielding resin, and the second resin is made of a light-transmitting resin.   The optical device according to claim 1, wherein the lens has a Fresnel lens shape.   The optical device according to claim 1, wherein the reflector and the lens are formed by molding a reflector with the first resin and then molding the lens with the second resin.   The optical device according to claim 1, wherein the lens is fitted in a recess surrounded by an inclined surface of the reflector, and is attached in a state where a space is provided between the lens and the optical element.

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