JP2008147501A - Photoelectric sensor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable photoelectric sensor capable of lengthening a detection distance while minimizing upsizing, and to provide a manufacturing method of the photoelectric sensor. <P>SOLUTION: The photoelectric sensor has: a light receiving element 11 including a bare chip IC converting light received from a detection region to an electric signal; a wiring board 41, where the light receiving element 11 is packaged by flip-chip mounting and a through hole 42 is provided for guiding light from the detection region to the light receiving region of the light receiving element 11; and a non-transparent ultraviolet curing resin 31 filled between the light receiving element 11 and the wiring board 41 excluding at least a part of the light reception region of the light receiving element 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photoelectric sensor including a light receiving element mounted on a wiring board and a method for manufacturing the photoelectric sensor.

  Conventionally, a photoelectric sensor that detects the presence or absence of a detection object in a detection region by receiving detection light projected toward the detection region has been used. The photoelectric sensor includes a light receiving element that receives detection light from the detection region and a lens that collects the detection light on the light receiving element.

  16 and 17 are cross-sectional views showing the structure of a conventional photoelectric sensor. FIG. 16 shows a case where the light receiving element 11 is mounted on the surface of the wiring board 41 by COB (chip on board) mounting. Here, the wiring board 41 and the light receiving element 11 are electrically connected by a wire 81, and the wire 81 is covered with a resin 71.

  Electronic components such as an SMD (surface mount device) 51 are mounted on the back surface of the wiring board 41. Further, a lens 61 is disposed so as to face the light receiving portion 12 of the light receiving element 11.

  The photoelectric sensor shown in FIG. 17 shows a case where a package including the light receiving element 11 is mounted on the wiring substrate 41 by soldering or the like. The light receiving element 11 is COB-mounted on the surface of the interposer 21, and the surfaces of the light receiving element 11 and the interposer 21 are covered with a transparent resin 71 that can transmit detection light. The electrodes of the interposer 21 and the electrodes of the wiring board 41 are connected by solder. This package is also mounted on the surface side of the wiring board 41.

  FIG. 18 is an exploded perspective view showing the structure of a conventional photoelectric sensor. As shown in FIG. 18, the wiring board 41 on which the light receiving element 11 is mounted having the above-described structure is housed in a housing composed of a front side case 101 and a back side case 102 provided with a lens 61. Is done. A cord 111 is connected to the electrode of the wiring board 41.

Examples of such photoelectric sensors include Patent Document 1 (Japanese Patent Laid-Open No. 2000-322990) and Patent Document 2 (Japanese Patent Laid-Open No. 2002-252357). Patent Document 1 describes a photoelectric sensor in which a photoelectric element is flip-chip mounted on a circuit board. Patent Document 2 discloses a light receiving element package in which a photoelectric element is flip-chip mounted on an MID (injection molded circuit component).
JP 2000-322990 A JP 2002-252357 A

  In recent years, there is an increasing demand for photoelectric sensors that have a long detection distance, excellent positioning accuracy, and are thin. Generally, in order to increase the detection distance, it is conceivable to increase the amount of light received by using a lens having a large effective diameter.

However, there is a limit to the numerical aperture of a lens that can be used for a general photoelectric sensor. Therefore, when the effective diameter of the lens is increased, the focal length is increased accordingly. When the focal length becomes longer, it is necessary to increase the distance between the lens and the light receiving element. In order to keep the lens and the light receiving element away from each other, it is necessary to keep the circuit board away from the lens. For this reason, it has been difficult to achieve both a longer detection distance and a thinner photoelectric sensor.

  Therefore, the inventors arrange the light receiving element 11 that has been mounted on the front surface side (the lens 61 side) of the wiring substrate 41 on the back surface side of the wiring substrate 41 provided with a through hole, so that the wiring substrate 41 It has been devised to increase the distance between the lens 61 and the light receiving element 11 without changing the position. This makes it possible to use a lens having a larger effective diameter without changing the thickness of the photoelectric sensor, so that a thin photoelectric sensor with a long detection distance can be configured.

  On the other hand, conditions required for photoelectric sensors are becoming strict, and long-term high reliability is strongly demanded. The demand for high reliability as described above is the same for thin photoelectric sensors.

  The present invention has been made to solve the above-described problems, and provides a photoelectric sensor that can increase the detection distance while minimizing an increase in size, and at the same time can obtain high reliability, and a method for manufacturing the photoelectric sensor. With the goal.

  According to the photoelectric sensor according to the present invention, the bare chip IC that constitutes a light receiving element that converts light received from the detection region into an electrical signal, and the bare chip IC are mounted by flip chip mounting, and the light receiving region of the bare chip IC is mounted. Except for a wiring board provided with a through hole for guiding light from a detection area and at least a part of a light receiving area of the bare chip IC, a non-translucent material filled between the bare chip IC and the wiring board UV curable resin.

In the photoelectric sensor, the ultraviolet curable resin may contain a filler.
In the photoelectric sensor, the ultraviolet curable resin may be injected while irradiating at least an outer peripheral portion of at least a part of the light receiving region while irradiating the ultraviolet ray, thereby preventing the ultraviolet curable resin from flowing into the region. Good.

  In the photoelectric sensor, the wiring board may be provided with an injection hole for injecting the ultraviolet curable resin between the wiring board and the bare chip IC.

  In the photoelectric sensor, a light shielding portion may be formed of an ultraviolet curable resin on the light receiving region of the bare chip IC.

  In the photoelectric sensor, the light shielding portion may be configured by injecting an ultraviolet curable resin while irradiating ultraviolet light to a non-light-shielded region of the light receiving region of the bare chip IC.

  In the photoelectric sensor, a lens may be attached to the through hole of the wiring board.

  In the photoelectric sensor, a light shielding unit that restricts light reaching the light receiving region around the through hole of the wiring board may be used.

According to the photoelectric sensor manufacturing method based on the present invention, a bare chip IC that constitutes a light receiving element that converts light received from a detection region into an electrical signal, and the bare chip IC are mounted by flip chip mounting. Except at least a part of the light receiving area of the bare chip IC and a wiring board in which a through hole for guiding light from the detection area is provided in the light receiving area, the non-filling filled between the bare chip IC and the wiring board A method of manufacturing a photoelectric sensor comprising a translucent ultraviolet curable resin, wherein the ultraviolet curable resin is applied to the light receiving element and the wiring substrate while irradiating at least an outer peripheral portion of at least a part of the light receiving region with ultraviolet light. By injecting between the step of curing the ultraviolet curable resin at the outer periphery of the region during the injection of the ultraviolet curable resin, After the input is completed, and a step of curing the remaining ultraviolet curing resin.

  According to the photoelectric sensor and the manufacturing method thereof according to the present invention, it is possible to provide a photoelectric sensor that can increase the detection distance while minimizing an increase in size and at the same time obtain high reliability.

  Hereinafter, the structure of the photoelectric sensor and the manufacturing method thereof in each embodiment based on the present invention will be described with reference to the drawings. In each embodiment, common structures are denoted by the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)
Hereinafter, a first embodiment according to the present invention will be described with reference to FIGS. Here, FIG. 1 is a cross-sectional view showing the structure of the photoelectric sensor in the present embodiment and the conventional photoelectric sensor, and FIG. 2 is a cross-sectional process view showing the manufacturing process of the photoelectric sensor of the present embodiment, FIG. These are the flowcharts which show the manufacturing process of the photoelectric sensor of this Embodiment.

  In the photoelectric sensor of the present embodiment, as shown in FIG. 1C, the light receiving element 11 composed of a bare chip IC that converts light received from the detection region into an electric signal, and the light receiving element 11 are mounted by flip chip mounting. The light receiving element 11 and the wiring board 41 except for the wiring board 41 provided with a through hole 42 for guiding light from the detection area in the light receiving area of the light receiving element 11 and at least a part of the light receiving area of the light receiving element 11. And a non-translucent ultraviolet curable resin 31 filled in between.

  The lens 61 is made of a colorless transparent or colored transparent resin. The lens 61 condenses the detection light from the detection region on the light receiving unit 12 of the light receiving element 11. Although not shown here, the light projecting unit is configured integrally or separately from the photoelectric sensor.

  The wiring board 41 is made of a non-translucent material such as a colored glass fiber reinforced epoxy resin. The wiring board 41 may be made of other materials.

  In order to guide the detection light condensed by the lens 61 to the light receiving element 11, a through hole 42 is provided in the wiring board 41. Electronic components such as SMD 51 are mounted on the surface side of the wiring board 41 (the lens 61 side). An electrode is provided on the back side of the wiring board 41.

  The light receiving element 11 is composed of a bare chip IC, and a light receiving portion 12 is provided in a part thereof. The light receiving element 11 can generate an electrical signal in accordance with the light incident on the light receiving unit 12. Gold bumps 13 are provided on the surface of the light receiving element 11 facing the wiring substrate 41. The electrodes of the wiring board 41 and the gold bumps 13 of the light receiving element 11 are electrically connected by solder 45.

There is a gap corresponding to the thickness of the solder 45 and the gold bump 13 between the wiring board 41 and the light receiving element 11. The gap is filled with an ultraviolet curable resin 31 as an underfill resin. However, in the present embodiment, the ultraviolet curable resin 31 is not provided on the surface of the light receiving portion 12 of the light receiving element 11.

  The ultraviolet curable resin 31 is non-translucent. Here, a filler made of silica or the like is mixed in the ultraviolet curable resin 31. This filler adjusts the linear expansion coefficient after the ultraviolet curable resin 31 is cured. The filler is not limited to silica.

  In order to ensure long-term high reliability, it is preferable that the linear expansion coefficient of the ultraviolet curable resin 31 and the linear expansion coefficients of the light receiving element 11 and the wiring substrate 41 are equal or close to each other. Therefore, in the photoelectric sensor of the present embodiment, the linear expansion coefficient is adjusted by mixing a filler into the ultraviolet curable resin 31.

  Specifically, the linear expansion coefficient between the wiring board 41 and the light receiving element 11 can be approximated by setting the linear expansion coefficient to about 45 PPM / ° C. Here, about 45 to 55% of filler is mixed with the total weight of the ultraviolet curable resin 31 and the filler. Since the viscosity increases as the amount of filler mixed increases, the upper limit of the amount of filler is about 60%. About 45 to 55% of the above is ideal from the viewpoint of both the workability of filling the ultraviolet curable resin mixed with the filler and the adjustment of the linear expansion coefficient.

  The ultraviolet curable resin 31 is not provided on the surface of the light receiving unit 12. Therefore, the ultraviolet curable resin 31 does not need to have translucency. The amount of filler can be determined based only on the filling workability as described above and the viewpoint of adjusting the linear expansion coefficient.

  In this embodiment, since the ultraviolet curable resin 31 is filled between the wiring board 41 and the light receiving element 11, both can be strongly bonded. Thereby, the long-term reliability of the photoelectric sensor can be improved. Further, since the filler is mixed in the ultraviolet curable resin 31 so that the linear expansion coefficient is close to that of the wiring board 41 and the light receiving element 11, it is resistant to temperature changes and long-term reliability can be further improved.

  Further, in the photoelectric sensor of the present embodiment, since a non-translucent ultraviolet curable resin is used, the space between the wiring board 41 and the light receiving element 11 is shielded from light. As a result, stray light is generated between the wiring board 41 and the light receiving element 11 as in the case where nothing is provided between the wiring board 41 and the light receiving element 11 or when a translucent resin is used for the underfill. There is no fear of entering from.

  Next, when the photoelectric sensor of the present embodiment and the light receiving element 11 using the conventional package structure are mounted on the surface side of the wiring substrate 41 (FIG. 1A), the light receiving element 11 is mounted using the COB structure. Comparison is made with the case of mounting on the surface side of the wiring board 41 (FIG. 1B).

  In the present embodiment, the light receiving element 11 is mounted on the back side of the wiring board 41, and the detection light is guided to the light receiving element 11 through the through hole 42 of the wiring board 41. As is apparent from FIG. 1, the distance L with respect to the lens 61 can be increased without changing the position of the wiring board 41. Thereby, the lens 61 with a large effective diameter can be employ | adopted, preventing an enlargement. As a result, the amount of light incident on the light receiving element 11 increases, so that the detection distance can be increased.

  The detection light emitted from the light projecting unit is reflected by the detection target 1 located in the detection region and enters the light receiving element 11. The presence / absence of the detection object 1 can be detected by the electrical signal from the light receiving element 11.

  As a method for detecting the presence or absence of the detection target 1, a light projecting unit may be provided on the opposite side of the detection target 1 and the light receiving element 11 may detect whether or not the detection target 1 is shielded from the detection light.

  Next, the manufacturing process of the photoelectric sensor of this embodiment will be described with reference to FIG. In FIG. 2, the upper side is the back side, and the lower side is the front side (the side facing the lens).

  As shown in FIG. 2A, the wiring board 41 is previously provided with a wiring pattern and electrodes connected thereto. In addition, a through hole 42 is provided in the wiring board 41. In this state, solder 45 is applied to the electrodes. The solder 45 is applied by a dispensing method, a transfer method, etc., in addition to a solder printing method.

  As shown in FIG. 2B, the solder 45 and the gold bumps 13 of the light receiving element 11 are arranged so as to face each other. At this time, it arrange | positions so that the through-hole 42 and the light-receiving part 12 of the light receiving element 11 may correspond.

  As shown in FIG. 2 (c), reflow is performed by heating to a predetermined temperature in this state. The solder 45 is melted by reflow, and the solder 45 and the gold bump 13 are connected. Here, the solder and the gold bump are joined, but both the wiring substrate 41 side and the light receiving element 11 side may be composed of solder, or both may be composed of gold. When both solders are used, a thermocompression bonding method can be used. When both are made of gold, an ultrasonic bonding method or a thermocompression bonding method can be used.

  In this state, a gap exists between the light receiving element 11 and the wiring board 41 due to the thickness of the solder 45 and the gold bump 13.

  As shown in FIG. 2D, an ultraviolet curable resin 31 is dropped from the outer periphery of the light receiving element 11 and injected into the gap. At this time, the light receiving unit 12 of the light receiving element 11 is continuously irradiated with ultraviolet rays through the through hole 42 of the wiring substrate 41. Although the irradiation method of an ultraviolet-ray is not specifically limited, By using an LED type ultraviolet irradiation machine, it can irradiate to a desired range correctly.

  Thereby, the ultraviolet curable resin 31 that is about to enter the surface of the light receiving unit 12 is cured outside the light receiving unit 12. The cured ultraviolet curable resin 31 becomes an obstacle, and the ultraviolet curable resin 31 can be prevented from flowing into the light receiving unit 12. As a result, a structure in which the surface of the light receiving unit 12 is not covered with the ultraviolet curable resin 31 as shown in FIG.

  Note that the ultraviolet irradiation is not necessarily performed on the entire surface of the light receiving unit 12 and may be performed only on the outer peripheral portion thereof. Further, instead of irradiating the light receiving unit 12 with ultraviolet light, a continuous rib-shaped protrusion may be provided around the light receiving unit 12 so that the ultraviolet curable resin does not flow into the surface of the light receiving unit 12.

  FIG. 3 explains the manufacturing process of the photoelectric sensor of this embodiment in more detail. Here, as shown in FIG. 3, first, solder printing is performed on the back side of the wiring board 41. Next, an SMD (not shown in FIGS. 1 and 2) is mounted on the back side as necessary. Subsequently, the light receiving element 11 is flip-chip mounted on the back surface side. Thereafter, reflow is performed, and an underfill resin made of an ultraviolet curable resin is applied in the above-described process.

  Next, the process proceeds to the process on the front surface side of the wiring board 41, and SMD mounting and flip chip mounting are performed as necessary, similarly to the back surface side. Thereby, the wiring board 41 with electronic components mounted on both sides can be produced.

  FIG. 4 is a flowchart showing a process of assembling the wiring board on which the electronic component is mounted on the housing, and FIG. 5 is an exploded perspective view of the same.

  As shown in FIG. 4, first, the cord 111 is connected to the electrode of the wiring board 41 by soldering or the like. Next, the wiring board 41 is positioned inside the casing constituted by the front side case 101 and the back side case 102. At this time, the wiring board 41 is arranged so that the through hole 42 of the wiring board 41 faces the front side case 101.

  A lens 61 is attached to the front side case 101. The front side case 101 and the back side case 102 are integrally molded to complete the photoelectric sensor.

(Embodiment 2)
Next, a second embodiment will be described with reference to FIGS. Here, FIG. 6 is a cross-sectional view showing the structure of the photoelectric sensor of the present embodiment, FIG. 7 is a cross-sectional view showing the structure of the modification, and FIG. 8 is a cross-sectional view of the photoelectric sensor of the present embodiment. It is the figure which compared with the conventional photoelectric sensor.

  In the photoelectric sensor, it may be required to limit the detection region. In other words, it may be necessary to detect only a narrow detection area. In that case, a light shielding part is provided on the surface side of the light receiving part 12 of the light receiving element 11.

  In the present embodiment, a light shielding portion is formed around the through hole 42 of the wiring board 41. FIG. 6A shows a case where the through hole 42 is provided large and the detection area is set wide, and FIG. 6B shows a case where the through hole 42 is provided small and the detection area is set narrow. . As apparent from a comparison between the two, the detection region can be limited by making the through hole 42 smaller. Thus, the width of the detection region can be adjusted by changing the size of the through hole 42.

  At this time, the dimensional error of the through hole 42 should be avoided as much as possible. As a method of providing the through hole 42, drilling, laser processing, etching, or the like can be used.

  In addition, it is desirable that the inner wall of the through hole 42 reduce asperities as much as possible in order to prevent diffusion of light and improve the light collection degree. In particular, when a resin substrate is used, irregularities are likely to occur during processing.

  Therefore, as shown in FIG. 7, a metal film 43 may be provided on the inner peripheral surface of the through hole 42 by plating. Thereby, unevenness can be reduced. As a result, light diffusion can be prevented, and the degree of light collection is improved.

  FIGS. 8A and 8B are longitudinal sectional views showing the structure of the photoelectric sensor when the packaged light receiving element 11 is mounted and when the light receiving element 11 is mounted by COB. When the light receiving element 11 is mounted on the surface side of the wiring board 41, a separate housing 91 is provided so as to cover them.

  The housing 91 is provided with a slit 92 having a predetermined size at a position facing the light receiving portion 12 of the light receiving element 11. In this case, considering the height of the wire 81 and the height of the resin 71 covering them, the distance D between the slit 92 and the light receiving element 11 is 1.0 mm or more.

  In this case, as shown in FIGS. 8A and 8B, all of the light incident from the lens 61 cannot be incident on the light receiving unit 12. Therefore, the light receiving loss is large and the detection distance of the photoelectric sensor is shortened. Further, it is necessary to provide a separate housing 91.

On the other hand, in the photoelectric sensor of the present embodiment shown in FIG. 8C, the distance D between the slit and the light receiving element 11 is about 0.08 mm corresponding to the height of the gold bump 13. Can do. Thereby, substantially all of the light collected by the lens 61 can be made incident on the light receiving element, and the light receiving loss is reduced. As a result, the detection distance of the photoelectric sensor can be increased. Further, it is not necessary to provide a separate member housing or the like, and the slit can be easily provided.

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIGS. Here, FIG. 9 is a longitudinal sectional view showing the structure of the photoelectric sensor of the first embodiment, and FIG. 10 is a longitudinal sectional view showing the structure of the photoelectric sensor of the present embodiment.

  In the present embodiment, the light-shielding part that restricts the incidence of light to the light-receiving part 12 of the light-receiving element 11 is formed of an ultraviolet curable resin.

  As shown in FIG. 9, in the first embodiment, the ultraviolet curable resin 31 is injected while irradiating ultraviolet rays so as to cover the entire light receiving unit 12. At this time, the ultraviolet curable resin 31a located outside the light receiving unit 12 is cured first by ultraviolet rays. Thereby, the ultraviolet curable resin 31 can be prevented from flowing onto the light receiving unit 12.

  In the present embodiment shown in FIG. 10, the shielding part is provided on the light receiving part 12 by reducing the area irradiated with the ultraviolet rays. Specifically, a light shielding plate 121 that restricts a region irradiated with ultraviolet rays is provided between the wiring board 41 and the ultraviolet irradiation device. The light shielding plate 121 is provided with a light transmitting hole 122 having a predetermined size. By changing the size of the light transmitting hole 122, it is possible to change the region irradiated with ultraviolet rays.

  As shown in FIG. 10, when the region irradiated with ultraviolet rays is reduced, the ultraviolet curable resin 31a outside the region irradiated with ultraviolet rays is cured first. Thereby, light can be made incident only on the region irradiated with ultraviolet rays.

  According to this structure, the light shielding part is provided in close contact with the surface of the light receiving part 12. Since the distance between the light shielding unit and the light receiving unit 12 is zero, the light receiving loss of light incident on the light receiving unit 12 can be further reduced. Moreover, since it can form simultaneously with injection | pouring of the ultraviolet curable resin 31, it can form, without increasing a process.

  Here, the light-shielding plate 121 is provided to limit the region irradiated with ultraviolet rays, but an ultraviolet irradiation device that irradiates small-diameter ultraviolet rays may be used.

  FIG. 11 shows a manufacturing process of the photoelectric sensor of the present embodiment, where (a) is a sectional view and (b) is a bottom view. In the present embodiment, a shielding part made of an ultraviolet curable resin 31a is formed around a predetermined region on the light receiving part 12.

  As shown in FIG. 11, an injection hole 46 for injecting the ultraviolet curable resin 31 is provided at a position surrounding the through hole 42 of the wiring board 41. By injecting the ultraviolet curable resin 31 through the injection hole 46, the ultraviolet curable resin 31 can be injected in a state where the bare chip IC constituting the light receiving element 11 is positioned below the wiring board 41. For example, in the injection step of the ultraviolet curable resin 31 in the embodiment shown in FIG. 10, the injected ultraviolet curable resin may leak from the through hole 42. On the other hand, in the injection process of the present embodiment shown in FIG. 11, the ultraviolet curable resin 31 can be injected with the bare chip IC positioned below the wiring substrate 41. The ultraviolet curable resin 31 does not spread from the outer peripheral portion of the bare chip IC due to the tension. Thereby, it can prevent that the ultraviolet curable resin 31 leaks.

(Embodiment 4)
Next, a fourth embodiment will be described with reference to FIG. 12 and FIG. Here, FIG. 12 is a longitudinal sectional view showing the structure of the photoelectric sensor of the present embodiment, and FIG. 13 is a longitudinal sectional view showing the structure of the modification.

  In the present embodiment, as shown in FIGS. 12 and 13, a lens 62 is attached to the through hole 42 of the wiring board 41. By directly attaching the lens 62 to the wiring board 41, the relative positional relationship between the lens 62 and the wiring board 41 can be accurately maintained without adjusting the position.

  FIG. 12 shows a case where light is condensed on the light receiving element 11 only by the lens 62 attached to the through hole 42.

  In FIG. 13, a lens 63 is provided in the through hole 42, and a lens 61 that guides light to the lens 63 is provided. According to this structure, since light is condensed by the two lenses 61 and 63, more light can be condensed on the light receiving element 11. As a result, the detection distance can be further increased.

  14 and 15 are diagrams showing the effects of the photoelectric sensor according to the embodiment of the present invention. FIG. 14A shows a conventional photoelectric sensor, in which the light receiving element 11 is mounted on the surface side of the wiring board 41 (hereinafter, surface mounting). On the other hand, FIG. 14B shows the photoelectric sensor of the present embodiment, in which the light receiving element 11 is mounted on the back surface side of the wiring board 41 (hereinafter, back surface mounting).

  In FIG. 14B showing the present embodiment, the focal length can be increased by the distance shown in FIG. Accordingly, the lens 61 having a larger effective diameter can be used without changing the thickness of the photoelectric sensor.

  In the structure shown in FIG. 14, the distance between the lens 61 and the wiring board 41 was variously changed, and the amount of incident light and the detection distance were measured for the front surface mounting and the back surface mounting.

  FIG. 15 is a graph showing the experimental results. The horizontal axis represents the distance between the lens and the wiring board, and the vertical axis represents the increase rate of the back surface mounting relative to the front surface mounting. Here, the total of the thickness of the wiring board 41, the thickness of the interposer 21, and the thickness of the light receiving element 11 is 1.0 mm. Accordingly, the increase in the focal length shown in FIG. 14 is 1.0 mm.

  As can be seen from FIG. 15, it was confirmed that the amount of incident light and the detection distance were both increased when the back surface mounting was used than when the surface mounting was performed. In addition, it can be seen that when the distance between the lens 61 and the wiring board 41 is short, that is, the thinner the photoelectric sensor, the higher the increase rate. Thus, it was confirmed that the present invention is more effective when a thin photoelectric sensor is constructed.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It does not become the basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the claims. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

It is sectional drawing which shows the structure of the photoelectric sensor in Embodiment 1 based on this invention, and the conventional photoelectric sensor. It is sectional process drawing which shows the manufacturing process of the photoelectric sensor in Embodiment 1 based on this invention. It is a flowchart which shows the manufacturing process of the photoelectric sensor in Embodiment 1 based on this invention. It is a flowchart which shows the process of assembling | attaching the wiring board which mounted the electronic component in Embodiment 1 based on this invention to a housing | casing. It is a disassembled perspective view which shows the process of assembling | attaching the wiring board which mounted the electronic component in Embodiment 1 based on this invention to a housing | casing. It is sectional drawing which shows the structure of the photoelectric sensor in Embodiment 2 based on this invention. It is sectional drawing which shows the structure of the modification of the photoelectric sensor in Embodiment 2 based on this invention. It is the figure which compared the photoelectric sensor in Embodiment 2 based on this invention with the conventional photoelectric sensor. It is a longitudinal cross-sectional view which shows the structure of the photoelectric sensor in Embodiment 1 based on this invention. It is a longitudinal cross-sectional view which shows the structure of the photoelectric sensor in Embodiment 3 based on this invention. The manufacturing process of the photoelectric sensor in Embodiment 3 based on this invention is shown, (a) is sectional drawing, (b) is a bottom view. It is a longitudinal cross-sectional view which shows the structure of the photoelectric sensor in Embodiment 4 based on this invention. It is a longitudinal cross-sectional view which shows the structure of the modification of the photoelectric sensor in Embodiment 4 based on this invention. It is a figure which shows the effect of the photoelectric sensor in embodiment based on this invention. It is a graph which shows the effect of the photoelectric sensor in embodiment based on this invention. It is sectional drawing which shows the structure of the conventional photoelectric sensor. It is sectional drawing which shows the structure of the conventional photoelectric sensor. It is a disassembled perspective view which shows the structure of the conventional photoelectric sensor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Light receiving element, 12 Light receiving part, 13 Gold bump, 21 Interposer, 31 UV curable resin, 41 Wiring board, 42 Through hole, 43 Metal film, 45 Solder, 46 Injection hole, 61 Lens, 71 Resin, 81 Wire, 91 Housing , 92 Slit, 101 Front side case, 102 Back side case, 111 code, 121 Light shielding plate, 122 Translucent hole.

Claims (9)

A bare chip IC constituting a light receiving element that converts light received from the detection region into an electrical signal;
The wiring board in which the bare chip IC is mounted by flip chip mounting, and a through hole for guiding light from a detection region is provided in a light receiving region of the bare chip IC;
A photoelectric sensor comprising a non-translucent ultraviolet curable resin filled between the bare chip IC and a wiring board except for at least a part of the light receiving region of the bare chip IC.   The photoelectric sensor according to claim 1, wherein the ultraviolet curable resin contains a filler.   The structure according to claim 1 or 2, wherein an ultraviolet curable resin is injected while irradiating at least an outer peripheral portion of at least a part of the light receiving region while irradiating the ultraviolet curable resin to the region to prevent the ultraviolet curable resin from flowing into the region. The photoelectric sensor as described.   4. The photoelectric sensor according to claim 1, wherein the wiring board is provided with an injection hole for injecting the ultraviolet curable resin between the wiring board and the bare chip IC. 5.   5. The photoelectric sensor according to claim 1, wherein a light shielding portion is formed of an ultraviolet curable resin on a light receiving region of the bare chip IC.   6. The photoelectric sensor according to claim 5, wherein the light shielding portion is configured by injecting an ultraviolet curable resin while irradiating ultraviolet light to an unshielded region of the light receiving region of the bare chip IC.   The photoelectric sensor according to claim 1, wherein a lens is attached to the through hole of the wiring board.   5. The photoelectric sensor according to claim 1, wherein a light-shielding portion that restricts light reaching the light-receiving region around the through-hole of the wiring board is used. A bare chip IC that constitutes a light receiving element that converts light received from the detection region into an electrical signal, and the bare chip IC is mounted by flip chip mounting, and a through hole that guides light from the detection region is provided in the light receiving region of the bare chip IC And a non-translucent ultraviolet curable resin filled between the bare chip IC and the wiring board except for at least a part of the light receiving area of the bare chip IC. A manufacturing method of
By injecting an ultraviolet curable resin between the light receiving element and the wiring board while irradiating at least an outer peripheral portion of at least a part of the light receiving region with an ultraviolet ray, the outer peripheral portion of the region is injected during the injection of the ultraviolet curable resin. Curing the ultraviolet curable resin in
And a step of curing the remaining ultraviolet curable resin after the injection of the ultraviolet curable resin is completed.

Images