JP2008147502A - Photoelectric sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable photoelectric sensor capable of lengthening a detection distance while minimizing upsizing. <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 transparent resin 31 that covers the light receiving region of the light receiving element 11 and is filled between the light receiving element 11 and the wiring board 41. <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.

  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.

  18 and 19 are cross-sectional views showing the structure of a conventional photoelectric sensor. FIG. 18 shows a case where the light receiving element 11 is mounted on the surface of the wiring board 41 by COB (chip on board). 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. 19 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. 20 is an exploded perspective view showing the structure of a conventional photoelectric sensor. As shown in FIG. 20, the wiring board 41 having the structure described above and mounted with the light receiving element 11 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, which increases the thickness of the photoelectric sensor. 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 stricter year by year, 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 an object of the present invention is 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. .

  According to the photoelectric sensor based on the present invention, the bare chip IC that constitutes a light receiving element that converts light received from the detection region into an electric signal, and the bare chip IC are mounted by flip chip mounting, and the light receiving region of the bare chip IC is mounted. A wiring board provided with a through-hole for guiding light from the detection area; and a translucent resin filled between the bare chip IC and the wiring board so as to cover the light receiving area of the bare chip IC.

  Preferably, in the photoelectric sensor, a filler is added to the translucent resin, and the amount of the filler added is 60% or less of the total weight of the resin and the filler.

  In the photoelectric sensor, the light-transmitting resin preferably has a light transmittance of 55 percent or more in a light wavelength region of 450 nm to 800 nm.

  In the photoelectric sensor, the translucent resin preferably has a glass transition point of 100 ° C. or higher and a linear expansion coefficient of 60 ppm / ° C. or lower at the glass transition temperature or lower.

In the photoelectric sensor, preferably, the light-transmitting resin has a bandpass function.
In the photoelectric sensor, the inner wall of the through hole of the wiring board is preferably metal-plated.

  Preferably, the photoelectric sensor further includes a lens having a protrusion adapted to the inner diameter of the through hole of the wiring board, and the lens is fixed in a state where the protrusion is inserted into the through hole.

  Preferably, the photoelectric sensor further includes a housing that covers an outer surface, and the housing is provided with a lens that guides light to the light receiving portion of the bare chip IC.

  Preferably, the photoelectric sensor further includes an optical fiber insertion guide having a recess into which a tip of the optical fiber is fitted, and a protrusion that fits the inner diameter of the through hole of the wiring board, the optical fiber insertion guide being It is fixed in a state where the protrusion is inserted into the through hole.

  Preferably, in the photoelectric sensor, a countersink portion into which an end portion of the optical fiber is fitted is provided around the through hole of the wiring board.

  According to the photoelectric sensor of 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 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 shows the case where the amount of filler added to the translucent resin is changed. FIG. 3 is a cross-sectional process diagram illustrating a manufacturing process of the photoelectric sensor of the present embodiment, and FIG. 4 is a cross-sectional view illustrating a resin injection process. FIG. 5 is a flowchart showing a manufacturing process of the photoelectric sensor of the present embodiment.

  In the photoelectric sensor of this 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. A 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 a space between the light receiving element 11 and the wiring board 41 so as to cover the light receiving area of the light receiving element 11 And a translucent resin 31.

  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 a translucent resin 31 as an underfill resin. . The resin 31 is provided so as to cover the surface of the light receiving portion 12 of the light receiving element 11.

  Since the resin 31 has translucency, the light from the detection region can be guided to the light receiving unit even if the surface of the light receiving unit 12 is covered. Further, when no film is provided on the surface of the light receiving unit 12, the light receiving performance may be deteriorated due to the thin film absorption effect, but this influence is avoided by covering with the translucent resin 31. be able to. Further, as an environment in which photoelectric sensors are often used, an environment of high temperature, low temperature, and high humidity is assumed. However, by covering the surface of the light receiving unit 12 with a translucent resin 31, weather resistance against them is improved. The light-transmitting resin 31 serving as a thin-film absorption and protective film also serves as an underfill resin, so that a special process is not added to provide it.

  Here, the most important function of the underfill resin is composed of the gold bump 13 and the solder 45 even when the connection between the wiring substrate 41 and the light receiving element 11 is strengthened and both of them repeatedly undergo thermal expansion and contraction. It is to avoid applying a large stress to the connecting portion and to improve long-term reliability. For this purpose, the translucent resin 31 as the underfill resin is required to have a predetermined performance. On the other hand, since the resin 31 is provided so as to cover the surface of the light receiving unit 12, it is necessary to ensure a predetermined translucency.

  Therefore, in the present embodiment, this is achieved by using a resin material having specific performance as the resin 31 and adding a specific amount of filler to the resin 31. In the present embodiment, it is only an example, but a filler made of silica powder is added so as to be 55% of the total weight of the resin 31 and the filler. As a result, the reliability of bonding between the wiring board 41 and the light receiving element 11 is improved, and necessary translucency is ensured.

  Here, in the photoelectric sensor generally used for FA (Factory Automation), the performance required for the translucent resin 31 is as follows. In order to ensure translucency, it is preferable that the light transmittance is 55% or more in the light wavelength region of 450 nm to 800 nm. When a longer detection distance is required, it is more preferably 70% or more. Further, the glass transition point of the translucent resin is preferably 100 ° C. or higher, and more preferably 120 ° C. or higher. Furthermore, the linear expansion coefficient (CTE1) below the glass transition point is preferably 60 ppm / ° C. or less, and more preferably 45 ppm / ° C. or less.

  Referring to FIG. 2, which is a graph showing the relationship between the wavelength and the transmittance when the amount of filler added to the light-transmitting resin is changed, the light transmittance in the wavelength region of 450 nm to 800 nm is 55%. In order to achieve the above, the filler amount needs to be 60% or less. FIG. 2 shows a case where silica is used as the filler and an epoxy resin is used as the translucent resin.

  In order to set the glass transition point to 100 ° C. or higher, such a grade of resin may be used. At this time, CTE1 is preferably 60 ppm / ° C. or lower, but such characteristics can be realized by the following composition, for example. In a general epoxy resin having no benzene ring and a resin in which the curing agent is an acid anhydride type, 30% or more of a filler made of silica is mixed. Thereby, CTE1 can be 60 ppm / degrees C or less.

  The linear expansion coefficient of the resin 31 is preferably approximated to the linear expansion coefficient of the wiring board 41 and the linear expansion coefficient of the light receiving element 11. When the mixing amount of the filler of the resin 31 is less than 30%, the linear expansion coefficient increases, and it becomes difficult to ensure the reliability of the photoelectric sensor in a general FA environment. Here, the reliability required in a general FA environment is, for example, between a light receiving element and a wiring board even if 500 cycles or more have passed in a heat cycle test that repeatedly applies conditions of −20 ° C. and 60 ° C. Say that no open failure occurs.

  The light-transmitting resin 31 having the above characteristics is filled between the light receiving element 11 and the wiring board 41, and the surface of the light receiving unit 12 is covered with the resin 31. Improvement in reliability, improvement in reliability of the light receiving unit 12, and solution of the problem of thin film absorption can be achieved at the same time.

  Next, when the photoelectric sensor of this embodiment (FIG. 1C) and the light receiving element 11 using the conventional package structure are mounted on the surface side of the wiring board 41 (FIG. 1A), the COB structure Compared with the case where the light receiving element 11 is mounted on the surface side of the wiring board 41 using FIG. 1B (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. 3, the upper side is the back side, and the lower side is the front side (the side facing the lens).

  As shown in FIG. 3A, 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. 3B, 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.3 (c), it reflows by heating to predetermined temperature in the 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. 3D, a resin 31 is dropped from the outer periphery of the light receiving element 11 and injected into the gap. At this time, the resin 31 is distributed over the surface of the light receiving portion 12 of the light receiving element 11. As shown in FIG. 4, the resin 31 may be injected from the through hole 42 of the wiring substrate 41.

  FIG. 5 explains the manufacturing process of the photoelectric sensor of this embodiment in more detail. Here, as shown in FIG. 5, first, solder printing is performed on the back side of the wiring board 41. Next, an SMD (not shown in FIGS. 1 and 3) 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 the underfill 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. 6 is a flowchart showing a process of assembling the wiring board on which the electronic component is mounted on the housing, and FIG. 7 is an exploded perspective view of the same.

  As shown in FIG. 6, 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, as shown in FIG. 7, the wiring substrate 41 is arranged so that the through hole 42 of the wiring substrate 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.

  As a method of providing the through hole 42, drilling, laser processing, etching processing, or the like can be used. It is desirable that the inner wall of the through-hole 42 reduce asperities as much as possible in order to prevent light diffusion and improve the degree of light collection. In particular, when a resin substrate is used, irregularities are likely to occur during processing.

  Therefore, as shown in FIG. 8, 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.

(Embodiment 2)
Next, the second embodiment will be described with reference to FIGS. Here, FIG. 9 is a longitudinal sectional view showing the structure of the photoelectric sensor of the present embodiment, FIG. 10 is a flowchart showing the manufacturing process, FIG. 11 is a longitudinal sectional view showing the structure of the modification, and FIG. The flowchart which shows a process and FIG. 13 are longitudinal cross-sectional views which show the further modification.

  In the present embodiment, as shown in FIG. 9, a lens 62 is attached to the through hole 42 of the wiring board 41. The lens 62 has a protrusion 65 that matches the inner diameter of the through hole 42. The lens 62 is fixed to the wiring board 41 with the protrusion 65 inserted into the through hole 42.

  The lens 62 is adhered to the resin 31 without a gap by a transparent resin 32 provided on the surface of the resin 31.

  The through hole 42 is formed with reference to a pattern provided in the wiring board 41. At this time, the position accuracy of the through hole 42 with respect to the pattern is generally about ± 0.05 mm. On the other hand, the light receiving element 11 is also fixed on the basis of the pattern of the wiring board 41, but the positional accuracy is below the measurement limit. Then, by providing the lens 62 with the through hole 42 as a reference, the relative positional accuracy between the lens 62 and the light receiving element 11 can be arranged with a high accuracy of ± 0.05 mm without any alignment.

  The process of attaching the lens 62 will be described in more detail with reference to FIG. The process shown in FIG. 5 and the process of applying the underfill resin are substantially the same. Next, the resin 31 is cured. Subsequently, the transparent resin 32 is applied to the surface of the resin 31 and the lens 62 is mounted. The lens 62 can be fixed by curing the transparent resin 32 in this state.

  In the modification shown in FIG. 11, the lens 62 is directly fixed by the resin 31 without using the transparent resin 32. The protrusion 65 of the lens 62 has a protruding length that slightly bites into the resin 31 in order to ensure that the protrusion 65 of the lens 62 is in close contact with the resin 31. That is, the protrusion length of the protrusion 65 is configured to be slightly larger than the thickness of the wiring board 41.

  In the case of this structure, as shown in FIG. 12, the underfill resin 31 is applied, and the lens 62 is mounted before it is cured. Thereafter, the lens 62 can be fixed by curing the resin 31.

  By adopting these structures, the lens 62 can be attached easily and with high accuracy.

  In a further modification shown in FIG. 13, a lens 62 is attached to the through hole 42, and a lens 61 that guides light to the lens 62 is further provided. According to this structure, since light is condensed by the two lenses 61 and 62, more light can be condensed on the light receiving element 11. As a result, the detection distance can be further increased.

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIG. Here, FIG. 14 is a longitudinal sectional view showing the structure of the photoelectric sensor of the present embodiment.

  In the present embodiment, a through hole 42 provided in the wiring board 41 has a recess 95b in which the tip of the optical fiber 91 is fitted, and an outer diameter lens 95a that matches the inner diameter of the through hole 42 in the wiring board 41. And an optical fiber insertion guide 95 having the following. The insertion guide 95 is made of a transparent resin.

  The inner diameter of the recess 95b is set slightly smaller than the outer diameter of the outer sheath 92 of the optical fiber 91. The optical fiber 91 can be fixed to the optical fiber insertion guide 95 by fitting the end of the optical fiber 91 into the recess 95b.

  Further, by setting the inner diameter of the concave portion 95b to be slightly larger than the outer diameter of the outer sheath 92 of the optical fiber 91, the wiring substrate 41 and the light receiving element 11 when the end portion of the optical fiber 91 is fitted into the concave portion 95b. It is good also as performing alignment with respect to easily. In this case, it is desirable that the optical fiber 91 is fixed to the outer shell case in which the wiring board 41 is accommodated by a holding member (not shown).

  The optical fiber 91 guides light from the detection region to the light receiving element 11. Normally, the light irradiated to the detection region is also irradiated through another optical fiber, and the reflected light is received by the optical fiber 91 connected to the light receiving element 11. You may comprise coaxially the optical fiber for guiding the light to irradiate, and the optical fiber for guiding the received light.

  The lens 95 a condenses the light guided by the optical fiber 91 on the light receiving unit 12 of the light receiving element 11. Since more light can be made incident on the light receiving unit 12 by condensing with the lens 95a, the detection distance can be increased.

  In the present embodiment, the outer diameter of the lens 95a and the inner diameter of the through-hole 42 are adapted. By inserting the lens 95a into the through hole 42, the optical fiber insertion guide 95 can be accurately positioned. Thereby, the optical fiber 91 can also be accurately positioned with respect to the wiring board 41 and the light receiving element 11.

  In the present embodiment, the lens 95a is provided in the optical fiber insertion guide 95. However, when it is not necessary to collect light, a simple cylindrical protrusion may be provided instead of the lens 95a.

(Embodiment 4)
Next, a fourth embodiment will be described with reference to FIG. Here, FIG. 15 is a longitudinal sectional view showing the structure of the photoelectric sensor of the present embodiment.

  In the present embodiment, a countersunk portion 41 a is provided around the through hole 42 provided in the wiring board 41. The inner diameter of the countersunk portion 41 a is set to be slightly smaller than the outer diameter of the outer skin 92 provided on the outer periphery of the optical fiber 91. The optical fiber 91 can be easily fixed by inserting the optical fiber 91 into the countersunk portion 41a.

  Further, by setting the inner diameter of the countersunk portion 41a to be slightly larger than the outer diameter of the outer sheath 92 of the optical fiber 91, the alignment when the end portion of the optical fiber 91 is fitted to the countersink portion 41a is adjusted. It may be easy to do.

  Also in the present embodiment, the position of the end of the optical fiber 91 is positioned by the counterbore 41a, so that the optical fiber can be accurately positioned.

  FIG. 16 and FIG. 17 are diagrams showing the effect of the photoelectric sensor according to one embodiment of the present invention. FIG. 16A 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. 16B 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. 16B showing this 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. 16, 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. 17 is a graph showing the experimental results. The horizontal axis indicates the distance between the lens and the wiring board, and the vertical axis indicates the increase rate of the back surface mounting with respect 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. 17, it was confirmed that the amount of incident light and the detection distance were both increased when using the back surface mounting than when using the front surface mounting. 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 a graph which shows the relationship between a wavelength and the transmittance | permeability at the time of changing the quantity of the filler added to the translucent resin in Embodiment 1 based on this invention. It is sectional process drawing which shows the manufacturing process of the photoelectric sensor in Embodiment 1 based on this invention. It is sectional drawing which shows the resin injection | pouring process 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 modification 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 2 based on this invention. It is a flowchart which shows the manufacturing process of the photoelectric sensor in Embodiment 2 based on this invention. It is a longitudinal cross-sectional view which shows the structure of the modification of the photoelectric sensor in Embodiment 2 based on this invention. It is a flowchart which shows the manufacturing process of the modification of the photoelectric sensor in Embodiment 2 based on this invention. It is a longitudinal cross-sectional view which shows the structure of the further modification of the photoelectric sensor in Embodiment 2 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. 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 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 Resin, 32 Transparent resin, 41 Wiring board, 41a Countersink part, 42 Through-hole, 43 Metal film, 45 Solder, 61, 62 Lens, 65 Projection, 91 optical fiber, 92 outer sheath, 95 optical fiber insertion guide, 95a lens, 95b recess, 101 front side case, 102 back side case, 111 cord.

Claims (10)

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 light-transmitting resin filled between the bare chip IC and a wiring board so as to cover a light receiving region of the bare chip IC.   The photoelectric sensor according to claim 1, wherein a filler is added to the translucent resin, and an amount of the filler added is 60% or less of a total weight of the resin and the filler.   2. The photoelectric sensor according to claim 1, wherein the translucent resin has a light wavelength in a region of 450 nm to 800 nm and a light transmittance of 55 percent or more.   4. The photoelectric sensor according to claim 1, wherein the translucent resin has a glass transition point of 100 ° C. or higher and a linear expansion coefficient of 60 ppm / ° C. or lower below the glass transition point.   The photoelectric sensor according to claim 1, wherein the translucent resin has a bandpass function.   The photoelectric sensor according to claim 1, wherein an inner wall of the through hole of the wiring board is metal-plated. A lens having a protrusion that fits the inner diameter of the through hole of the wiring board;
The photoelectric sensor according to claim 1, wherein the lens is fixed in a state where the protrusion is inserted into the through hole. A housing that covers the outer surface;
The photoelectric sensor according to claim 1, wherein the housing is provided with a lens that guides light to a light receiving portion of the bare chip IC. An optical fiber insertion guide further comprising a recess into which the tip of the optical fiber is fitted, and a protrusion adapted to the inner diameter of the through hole of the wiring board;
The photoelectric sensor according to claim 1, wherein the optical fiber insertion guide is fixed in a state where the protrusion is inserted into the through hole.   The photoelectric sensor according to any one of claims 1 to 6, wherein a countersink portion into which an end portion of the optical fiber is fitted is provided around the through hole of the wiring board.

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