JP2019046981A - Optical sensor device and method for manufacturing the same - Google Patents

Abstract

To provide an optical sensor device which enables the reduction in size and which can adapt to every optical element quickly and inexpensively, and a method for manufacturing such an optical sensor device.SOLUTION: An optical sensor device 1 is arranged by mounting an optical waveguide plate 2 on a base module 3. The base module 3 comprises optical elements of a light-emitting element 4 and a light-receiving element 5, which are arrayed over a substrate 6. A surface of the substrate 6 covering the light-emitting element 4 and the light-receiving element 5 is covered with a protection film 7 formed from a transparent potting material or the like. In the optical waveguide plate 2, a core 8 and a clad 9 are formed. The core 8 makes a light-guide part for guiding light that the optical element 4 sends and receives. The clad 9 forms a light-guide part surrounding part for surrounding the periphery of the core 8 to confine light guided by the core 8 in the core 8.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical sensor device including an optical element on a substrate and a method of manufacturing the same.

  Conventionally, as an optical sensor device of this type, for example, there is an optical proximity sensor disclosed in Patent Document 1. The proximity sensor comprises a printed circuit board on which a light emitting diode, a photodiode and an ambient light sensor are mounted. Light emitted by the light emitting diode and reflected from the object is detected by the photodiode to detect that the object is approaching the sensor.

  The light emitting diode, the photodiode and the ambient light sensor are covered by a metal shield. Openings are respectively formed in the top of the metal shield directly above the light emitting diode, the photodiode and the ambient light sensor attached to the substrate. In addition, a space portion in which the light emitting diode in the metal shield is mounted and a space portion in which the photodiode and the peripheral light sensor are mounted are separated by the light barrier. The light emitted from the light emitting diode is guided to the external space by the optical path formed by the light barrier and the opening in the metal shield on the upper side thereof. Also, the light arriving at the sensor is guided to the light path formed by the light barriers and the openings formed in the metal shields on the top of the photodiode and the ambient light sensor, and is received by the photodiode and the ambient light sensor, respectively. Ru. This minimizes crosstalk between the light emitting diode and the photodiode and the ambient light sensor.

JP, 2011-180121, A

  However, in the above-mentioned conventional light sensor device, the light path for guiding light transmitted and received by the light elements mounted on the circuit board such as light emitting diodes, photodiodes, and peripheral light sensors is by the respective openings opened in the metal shield and the light barrier. It is formed. For this reason, it is difficult to miniaturize the above conventional light sensor device. In addition, since the manufacture of a metal shield or a light barrier requires an expensive mold, the manufacture of the optical sensor device is costly. Also, if the light elements mounted on the circuit board are different, it is necessary to rework the metal shield to provide the openings and light barriers that fit the new light elements. For this reason, in the above-mentioned conventional photosensor device, it is difficult to cope with changes to various light elements quickly and inexpensively.

The present invention has been made to solve such problems.
In an optical sensor device configured to include an optical element on a substrate,
A light guide plate comprising a light guiding portion for guiding light transmitted and received by the light element, and a light guiding portion surrounding portion for covering the light guiding portion and surrounding the light guiding portion in the light guiding portion. It is characterized by being provided on top.

  According to this configuration, the light transmitted and received by the optical element is guided by the optical waveguide plate provided on the substrate. The optical waveguide plate can be easily made thin. Therefore, the optical sensor device can be easily miniaturized. In addition, since an expensive mold is not required as in the prior art, the cost of the optical sensor device can be reduced. In addition, the light guide portion and the light guide portion surrounding portion in the optical waveguide plate have a degree of freedom in design. For this reason, according to the optical element provided in the substrate on which the optical waveguide plate is mounted, it is possible to easily change and adjust the formation position and size of the light guide and the light guide surrounding portion, the light refractive index, etc. It is possible to provide an optical sensor device capable of responding to an optical element quickly and inexpensively.

  Further, the present invention is characterized in that a light shielding layer is provided on the substrate side of the light guide portion surrounding portion.

  According to this configuration, the surface of the substrate provided with the optical element is covered by the light shielding layer of the optical waveguide plate mounted on the substrate except under the light guide. Therefore, disturbance light that is noise is prevented from entering the substrate including the optical element, and light that is a signal is transmitted through the light guide and reliably transmitted to the optical element. Therefore, an optical sensor device capable of reliably transmitting and receiving a minute optical signal without being affected by disturbance light is provided.

Also, the present invention is
The light element is configured by arranging the light emitting element and the light receiving element side by side,
The light guide unit guides the light emitted from the light emitting element and emits the light to the external space. The output light guiding unit disposed on the light emitting element, and the light incident from the external space to the light receiving element. It is characterized in that it comprises: and an incident light guide part arranged.

  According to this configuration, the light sensor device for performing proximity detection capable of detecting the detection target by receiving the light emitted and reflected from the light emitting device by the light receiving device is miniaturized, and all light The device can be used to provide it quickly and inexpensively.

  Furthermore, the present invention is characterized in that the optical element is covered with a transparent protective film.

  According to this configuration, by covering the optical element with the transparent protective film, the optical sensor device can be manufactured without damaging the optical element.

  Further, in the present invention, the light guide portion surrounding portion is a clad formed of a transparent resin, and the light guide portion is formed of a transparent resin having a light refractive index higher than the light refractive index of the light guide portion surrounding portion. It is characterized by being a core.

  According to this configuration, the light transmitted through the light guiding portion is confined in the light guiding portion by the light guiding portion surrounding portion due to the light refractive index difference between the cladding and the core.

  In the present invention, the step of forming the light guide portion surrounding portion in the uncured state by the clad resin, and the step of forming the light guide portion in the uncured state by the core resin having a higher light refractive index than the clad resin And a step of holding the clad resin and the core resin in an uncured state and waiting for a predetermined time, thereby forming an optical waveguide composed of the core and the clad on the optical waveguide plate.

  According to the present manufacturing method of the optical sensor device, it is uncured by providing the step of waiting for a predetermined time with the clad resin forming the light guide portion surrounding portion and the core resin forming the light guide portion uncured. Diffusion of the dopant occurs between the core resin and the cladding resin, and a light refractive index distribution is formed in the core resin. The light refractive index distribution can be set as desired by appropriately selecting a predetermined time for waiting, and a graded index optical waveguide having a desired light refractive index distribution in the core can be obtained.

  In the present invention, a light shielding material is formed by filling a cladding resin containing a light shielding material in the formation region of the light guide portion surrounding portion on a transparent substrate that transmits ultraviolet light, and irradiating the light shielding material with ultraviolet light from the transparent substrate side. And curing the clad resin to a predetermined thickness from the transparent substrate side to form a light shielding layer, removing the uncured cladding resin on the light shielding layer, and a formation region of the light guide portion surrounding portion on the light shielding layer And a step of filling with a clad resin to form an optical waveguide plate.

  According to the present manufacturing method of the optical sensor device, when the clad resin including the light shielding material filled in the formation region of the light guide portion surrounding portion is irradiated with ultraviolet light from the transparent substrate side to be hardened, the ultraviolet light is shielded Since it is difficult to transmit the clad resin containing the material, only the shallow portion of the clad resin containing the light shielding material can be cured. Therefore, the light shielding layer can be easily formed to a predetermined thickness below the cladding.

  According to the present invention, it is possible to provide an optical sensor device that can be reduced in size and that can respond to any light element quickly and inexpensively, and a method of manufacturing the same.

(A) is a cross-sectional view of an optical sensor device according to an embodiment of the present invention, (b) is a cross-sectional view of an optical waveguide plate constituting the optical sensor device shown in (a), (c) is (a) It is sectional drawing of the basic module which comprises the optical sensor apparatus shown to these. FIG. 1 is a perspective view of a light sensor device according to one embodiment. (A)-(c) is a perspective view which shows the manufacturing method of the type | mold used for manufacture of the optical waveguide plate which comprises the optical sensor apparatus by one Embodiment. (A)-(h) is sectional drawing which shows the manufacturing method of the optical waveguide plate which comprises the optical sensor apparatus by one Embodiment.

  Next, an embodiment for carrying out the light sensor device of the present invention will be described.

  FIG. 1A is a cross-sectional view of a light sensor device 1 according to an embodiment of the present invention. The optical sensor device 1 is configured by mounting the optical waveguide plate 2 shown in FIG. 6B on the basic module 3 shown in FIG. FIG. 2 is a perspective view of the light sensor device 1.

  The basic module 3 is configured by arranging the light elements of the light emitting element 4 and the light receiving element 5 side by side on the substrate 6. An IC (highly integrated circuit) not shown may be formed on the substrate 6. The surface of the substrate 6 covering the light emitting element 4 and the light receiving element 5 is covered with a protective film 7 formed of a transparent potting material or the like.

  The core 8 and the clad 9 are formed on the optical waveguide plate 2. The core 8 constitutes a light guiding portion for guiding light transmitted and received by the light elements of the light emitting element 4 and the light receiving element 5. The clad 9 covers the periphery of the core 8 and constitutes a light guide portion surrounding the light guided by the core 8 in the core 8. The cladding 9 is formed of a transparent resin, and the core 8 is formed of a transparent resin having a light refractive index higher than that of the cladding 9.

  In the present embodiment, the core 8 is composed of an emission core 8a and an incidence core 8b. The emission core 8 a constitutes an emission light guiding unit for guiding the light emitted from the light emitting element 4 and emitting the light to the external space, and the optical waveguide plate 2 is mounted on the basic module 3, whereby the emission core 8 a is mounted on the light emitting element 4. Be placed. The incident core 8 b constitutes an incident light guiding section for guiding light incident from the external space to the light receiving element 5, and the optical waveguide plate 2 is mounted on the basic module 3 and thus disposed on the light receiving element 5. Further, in the present embodiment, the optical waveguide plate 2 is provided with the light shielding layer 10 at a predetermined thickness on the substrate 6 side of the clad 9.

  FIGS. 3A to 3C are perspective views showing a method of manufacturing a mold used for manufacturing the optical waveguide plate 2 constituting the optical sensor device 1.

  First, a mold 12 shown in FIG. 6A, in which the hole 11 is formed only in the formation area of the core 8, is manufactured. Next, a resin that transmits ultraviolet light is poured into the transparent resin frame 13 surrounding four sides of the upper space of the mold 12 shown in FIG. 6B, and the resin is cured. Next, the cured resin is inverted to obtain a mold 14 used in the manufacture of the optical sensor device 1 shown in FIG. The mold 14 has a projection 15 in the formation region of the core 8.

  4A to 4H are cross-sectional views showing a method of manufacturing the optical waveguide plate 2.

  The same figure (a) shows the type | mold 14 produced as mentioned above. First, a clad resin 16 containing a light shielding material is filled in a resin frame (not shown) surrounding the upper space including the convex portion 15 of the mold 14 as shown in FIG. As the cladding resin 16, a UV curable transparent resin is used. Next, ultraviolet light is irradiated from the back surface side of the mold 14 as shown in FIG. 6C, and the cladding resin 16 is cured. Since the cladding resin 16 containing the light shielding material is difficult to transmit light, only the shallow predetermined thickness portion is cured. Therefore, the portion of the uncured cladding resin 16 can be easily removed, and the light shielding layer 10 shown in FIG. 6D is formed below the cladding layer formation region.

  Next, a transparent cladding resin 17 which does not contain the light shielding material is filled in a portion from which the cladding resin 16 containing the light shielding material is removed as shown in FIG. Thereafter, ultraviolet light is irradiated from the surface side of the mold 14 to cure the cladding resin 17. This curing is not completely performed, and the cladding resin 17 is in a semi-cured state. Next, the convex portion 15 at the top of the mold 14 is removed, and a hole 18 is formed in the formation area of the core 8 as shown in FIG. Next, the core resin 19 is filled in the formed holes 18 as shown in FIG. A UV curable transparent resin is also used as the core resin 19 and UV light is irradiated from the surface side of the mold 14 to cure the core resin 19. This curing is not completely carried out, and the core resin 19 is also brought into a semi-cured state like the cladding resin 17.

  Thereafter, after the step of waiting for a predetermined time with the clad resin 17 and the core resin 19 in an uncured state is provided, the clad resin 17 and the core resin 19 are completely cured. Then, the mold 14 is removed to obtain the optical waveguide plate 2 provided with the core 8 composed of the emitting core 8a and the incident core 8b, the clad 9 and the light shielding layer 10 as shown in FIG. Be By mounting the optical waveguide plate 2 on the basic module 3, the optical sensor device 1 having a packaged structure shown in FIG. 1A is completed.

  According to the optical sensor device 1 according to the present embodiment, the light transmitted through the light guide is confined in the light guide by the light guide surrounding portion due to the difference in light refractive index between the cladding 9 and the core 8. The light transmitted and received by the optical elements such as the light emitting element 4 and the light receiving element 5 is efficiently guided at low loss by the optical waveguide plate 2 provided on the substrate 6. Such an optical waveguide plate 2 can be easily formed thin. For this reason, size reduction of the optical sensor apparatus 1 can be achieved easily. In addition, since an expensive mold is not required as in the prior art, the price of the optical sensor device 1 can be reduced. Further, the light guide surrounding portion formed by the light guiding portion and the clad 9 formed by the core 8 in the optical waveguide plate 2 has a degree of freedom in design. For this reason, according to the optical element provided on the substrate 6 on which the optical waveguide plate 2 is mounted, the formation position and size of the core 8 and the clad 9, the light refractive index and the like can be easily changed and adjusted. Can be provided quickly and inexpensively.

  Further, according to the light sensor device 1 according to the present embodiment, the surface of the substrate 6 provided with the light emitting element 4 and the light receiving element 5 is excluded from below the core 8 by the light shielding layer 10 of the optical waveguide plate 2 mounted on the substrate 6 Covered. Therefore, disturbance light that is noise is prevented from entering the substrate 6 including the light emitting element 4 and the light receiving element 5, and light that is a signal passes through the core 8 and is reliably transmitted to the light emitting element 4 and the light receiving element 5. Be exchanged. Since the light blocking layer 10 is formed at a position close to the light emitting element 4 and the light receiving element 5, its effect is particularly high. For this reason, the optical sensor device 1 suitable for applying to a pulse sensor etc. which can transmit and receive a minute optical signal reliably without receiving to the influence of disturbance light is provided.

  Further, in the light sensor device 1 according to the present embodiment, the light emitting element 4 and the light receiving element 5 are arranged side by side on the substrate 6. Further, since the emitting core 8a and the incident core 8b are formed immediately above the light emitting element 4 and the light receiving element 5, the signal light can be efficiently confined in the emitting core 8a and the incident core 8b. Therefore, according to the light sensor device 1 according to the present embodiment, the light sensor device 6 receives the light emitted and reflected from the light emitting element 4 by the light receiving element 6, and performs the proximity detection capable of detecting the detection target. 1 can be miniaturized and provided quickly and inexpensively using any light element.

  In addition, according to the light sensor device 1 according to the present embodiment, the light emitting element 4 and the light receiving element 5 are covered with the transparent protective film 7, whereby the light waveguide plate 2 is not damaged. Can be mounted on the basic module 3 to manufacture the optical sensor device 1.

  Moreover, in the optical sensor device 1 according to the present embodiment, as shown in FIG. 4B, a cladding resin including a light shielding material in the formation region of the cladding 9 on the transparent substrate configured by the mold 14 that transmits ultraviolet light. By irradiating ultraviolet light from the transparent substrate side as shown in FIG. 4C and the step of filling 16, the clad resin 16 including the light shielding material is cured to a predetermined thickness from the transparent substrate side, as shown in FIG. Step of forming the light shielding layer 10 shown in (d), step of removing the uncured cladding resin 16 on the light shielding layer 10 as shown in FIG. 4D, and light shielding shown in FIG. And filling the cladding resin 17 in the formation region of the cladding 9 on the layer 10 to form the optical waveguide plate 2.

  According to the method of manufacturing the light sensor device 1 according to the present embodiment, when curing the clad resin 16 including the light shielding material filled in the formation region of the clad 9 from the transparent substrate side by irradiating the ultraviolet light, As described above, ultraviolet light is difficult to transmit through the cladding resin 16 containing the light shielding material, and therefore only the shallow portion of the cladding resin 16 containing the light shielding material can be cured. Therefore, according to the present manufacturing method of the light sensor device 1, the light shielding layer 10 can be easily formed to a predetermined thickness below the cladding 9.

  Further, in the optical sensor device 1 according to the present embodiment, the step of forming the clad 9 in the uncured state by the clad resin 17 shown in FIG. 4 (e) and the core 8 shown in FIG. Forming a core resin 19 having a light refractive index higher than 17 in an uncured state, and waiting the clad resin 17 and the core resin 19 in an uncured state for a predetermined time, An optical waveguide 9 is formed in the optical waveguide plate 2.

  According to the manufacturing method of the optical sensor device 1 according to the present embodiment, the uncured core resin 19 and the clad are provided by providing the step of waiting for a predetermined time with the clad resin 17 and the core resin 19 in the uncured state. The diffusion of the dopant occurs at the interface between the resins 17 and a light refractive index distribution is formed in the core resin 17. The light refractive index distribution can be set as desired by appropriately selecting a predetermined time for waiting, and a graded index optical waveguide having a desired light refractive index distribution in the core 8 as shown in FIG. 4 (h) is obtained. be able to.

  When such a graded index optical waveguide is provided in the optical waveguide plate 2, the light emitting element 4 is constituted by a vertical cavity surface emitting laser (VCSEL) or the like to emit light from the light emitting element 4. The direction of the emitted laser beam can be controlled by the light refractive index distribution of the core 8. For example, the direction of the laser beam can be bent inside the core 8.

  In addition, by appropriately selecting the numerical aperture NA determined by the light refractive index of the emission core 8a and the light refractive index of the cladding 9, it is possible to appropriately select the emission angle of the light emitted from the emission core 8a. Further, by appropriately selecting the numerical aperture NA determined by the light refractive index of the incident core 8b and the light refractive index of the cladding 9, it is possible to control the light receiving angle of the light received by the incident core 8b.

  In the above embodiment, the core resin 19 is formed after the cladding resin 17 is formed, but, conversely, the cladding resin 17 is formed after the core resin 19 is formed. May be Also in this case, the same effects as those of the above embodiment can be obtained.

  The optical sensor device 1 according to the above-described embodiment can be used as a proximity detection sensor of a smartphone, a pulse sensor for measuring a human pulse, or the like. Moreover, the light receiving element 5 can also be used for the use of illumination intensity detection by not making the light emitting element 4 light.

1 ... optical sensor device 2 ... optical waveguide plate 3 ... basic module 4 ... light emitting element (optical element)
5 ... light receiving element (optical element)
6 ... substrate 7 ... protective film 8 ... core (light guide portion)
8a ... outgoing core (outgoing light guide part)
8b: Incident core (incident light guiding part)
9 ・ ・ ・ Clad (light guide portion surrounding portion)
DESCRIPTION OF SYMBOLS 10 ... Light-shielding layer 11, 18 ... Hole 12 ... Mold 13 ... Resin frame 14 ... Type (transparent substrate)
15: Convex part 16: Clad resin with light shielding material 17: Transparent clad resin 19: Core resin

Claims (7)

In an optical sensor device configured to include an optical element on a substrate,
An optical waveguide comprising a light guiding portion for guiding light transmitted and received by the optical element, and a light guiding portion surrounding portion which covers the periphery of the light guiding portion and confines the light guided by the light guiding portion in the light guiding portion. An optical sensor device comprising a plate on the substrate.   The light sensor device according to claim 1, further comprising a light shielding layer on the substrate side of the light guide portion surrounding portion. The light element is configured by arranging a light emitting element and a light receiving element side by side,
The light guiding unit guides the light emitted from the light emitting element and emits the light to the external space, and the light emitting light guiding unit disposed on the light emitting element and guides the light incident from the external space to the light receiving element. The incident light guide part arrange | positioned on the said light receiving element is comprised. The optical sensor apparatus of Claim 1 or Claim 2 characterized by the above-mentioned.   The optical sensor device according to any one of claims 1 to 3, wherein the optical element is covered with a transparent protective film.   The light guide portion surrounding portion is a clad formed of a transparent resin, and the light guide portion is a core formed of a transparent resin having a light refractive index higher than the light refractive index of the light guide portion surrounding portion. The optical sensor device according to any one of claims 1 to 4, characterized in that:   The step of forming the light guide portion surrounding portion in an uncured state by a clad resin, the step of forming the light guide portion in an uncured state by a core resin having a higher light refractive index than the clad resin, and the clad The method of manufacturing an optical sensor device according to claim 1, further comprising: a step of waiting for a predetermined time with the resin and the core resin left uncured, to form an optical waveguide composed of a core and a clad on the optical waveguide plate.   A step of filling a cladding resin containing a light shielding material in a formation region of the light guide portion surrounding portion on a transparent substrate which transmits ultraviolet light, and irradiating the ultraviolet light from the transparent substrate side; Are cured to a predetermined thickness from the transparent substrate side to form the light shielding layer, a step of removing the uncured cladding resin on the light shielding layer, and the light guide portion surrounding portion on the light shielding layer 3. The method of manufacturing an optical sensor device according to claim 2, further comprising the step of: filling a cladding resin in a formation region of the optical waveguide plate to form the optical waveguide plate.

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