Pulse oximeter probe

Abstract

To provide a probe for a pulse oximeter that includes a light-emitting part and a light receiving part which do not project, can suppress temperature rise in the light-emitting part, and eliminates the need of positioning of the light-emitting part and the light receiving part when being fitted to a subject.SOLUTION: A probe for a pulse oximeter includes: a semiconductor light-emitting element of a bare chip that is mounted to a ring-shaped flexible substrate; and a semiconductor light receiving element is mounted on wiring at a surface of an outer periphery of the substrate. The semiconductor light receiving element receives light emitted from the semiconductor light-emitting element and passing through a subject and a transparent substrate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a probe for a pulse oximeter, which is equipped with a light source unit and a light receiving unit. [Background technology]

[0002] A pulse oximeter has a probe attached to a fingertip or other part of the body, and emits light (red and infrared) from a light-emitting part inside the probe onto the fingertip or other part of the body. The light that passes through the fingertip or other part of the body is received by a light-receiving part inside the probe. This allows the ratio of oxygenated hemoglobin (which is bound to oxygen) to reduced hemoglobin (which is not bound to oxygen) in the blood to be measured using the difference in the absorption rates of red and infrared light.

[0003] Disposable probes are often used in medical settings to prevent infection. Disposable probes have a light-emitting and light-receiving unit located inside an adhesive tape large enough to cover the finger, and are fixed by attaching the tape to the fingertip. Commercially available pulse oximeter probes use a pre-packaged LED mounted on a rigid circuit board such as glass epoxy as the light-emitting unit, and a photodiode as the light-receiving unit. These are each mounted on adhesive tape.

[0004] Patent Document 1 addresses the problem that heat generated by the LED is trapped inside the adhesive tape, raising the subject's body temperature at the probe attachment point by 5 to 6 degrees Celsius and potentially causing low-temperature burns to the subject. To solve this problem, the patent proposes a probe that uses a flexible, thermally conductive holding material (adhesive tape). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3156114 Summary of the Invention [Problem to be solved by the invention]

[0006] The pulse oximeter probe in Patent Document 1 uses a thermally conductive holding material (adhesive tape) to prevent heat from building up in the light-emitting unit, and attempts to solve the problem of the light-emitting unit protruding from the adhesive tape by using the flexibility of the holding material. However, the size of the light-emitting unit, which is made up of an LED pre-packaged on a rigid circuit board such as glass epoxy, protrudes 1.5-3 mm from the adhesive surface of the adhesive tape, making it difficult for the flexibility of the adhesive tape to completely absorb the protrusion of the light-emitting unit.

[0007] When the protruding light-emitting and light-receiving parts are pressed against the finger with adhesive tape, blood flow is restricted, making it difficult for heat from the light-emitting part to escape to the surrounding area, causing the finger's temperature to rise. The interaction between the pressure on the finger and the increased temperature makes the finger's skin more susceptible to marks and rashes, and wearing the device for long periods of time can cause low-temperature burns. To avoid low-temperature burns, medical professionals must frequently replace the probe - approximately every eight hours for adults, and more frequently than every eight hours for newborns, the elderly, and patients with sensitive skin - which places a burden on medical professionals.

[0008] For this reason, it is important to have a structure in which the light emitting section and the light receiving section do not protrude in order to prevent stagnation of blood flow and low-temperature burns.

[0009] Furthermore, when attaching conventional pulse oximeter probes, the optical axes of the light-emitting and light-receiving parts must be precisely aligned by pinching the finger, and adhesive tape must then be attached to the finger. This means that the task of aligning the probe when replacing it is also a burden on medical professionals.

[0010] The object of the present invention is to provide a probe for a pulse oximeter in which the light-emitting unit and the light-receiving unit do not protrude, the temperature rise of the light-emitting unit can be suppressed, and there is no need to align the light-emitting unit and the light-receiving unit when attaching it to a subject. [Means for solving the problem]

[0011] To achieve the above object, the present invention provides a pulse oximeter probe having a flexible substrate, a semiconductor light-emitting element and a semiconductor light-receiving element mounted on the substrate, and a sealant that seals the semiconductor light-emitting element and the light-receiving element. Wiring is provided on the surface of the substrate. The semiconductor light-emitting element is a bare chip. The bare chip includes a semiconductor light-emitting layer and a pair of electrode layers for supplying current to the semiconductor light-emitting layer. The bare chip is directly bonded to the wiring on the substrate with a bonding material. The semiconductor light-receiving element is mounted on one of the two surfaces of the substrate opposite the surface facing the subject, and is bonded to the wiring provided on this surface. The substrate is transparent at least in the area where the semiconductor light-receiving element is located. The semiconductor light-receiving element receives light emitted from the semiconductor light-emitting element and passing through the transparent substrate. [Effects of the Invention]

[0012] The pulse oximeter probe of the present invention has a light-emitting unit and a light-receiving unit that do not protrude from the base material, and the light-emitting unit is a bare chip, so it has good thermal conductivity and can suppress temperature rise, and there is no need to align the optical axes of the light-emitting unit and the light-receiving unit when attaching it to the subject. [Brief explanation of the drawings]

[0013] [Figure 1] 1(a) and 1(b) are cross-sectional views of a pulse oximeter probe according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is a perspective view of the pulse oximeter probe of the first embodiment, and FIG. 2(b) is a side view. [Figure 3] 1(a) to 1(d) are explanatory views showing the manufacturing process of the pulse oximeter probe of FIG. 1(a) according to the first embodiment. [Figure 4] 1(a) to 1(f) are explanatory views showing the manufacturing process of the pulse oximeter probe of FIG. 1(a) according to the first embodiment. [Figure 5] 1(a) to 1(e) are explanatory views showing the manufacturing process of the pulse oximeter probe of FIG. 1(a) according to the first embodiment, and FIG. 1(f) is a cross-sectional view of the manufactured probe. [Figure 6]3A to 3C are explanatory views showing the manufacturing process of the pulse oximeter probe of FIG. 1(b) according to the first embodiment. [Figure 7] (a-1) and (a-2) are a top view and a cross-sectional view of a wiring 11b on which LED elements 21a and 21b of a pulse oximeter probe according to embodiment 1 are mounted, and (b-1) and (b-2) are a top view and a cross-sectional view of a wiring 11b on which LED elements 21a and 21b of a pulse oximeter probe according to embodiment 2 are mounted. [Figure 8] FIG. 10 is a side view of a pulse oximeter probe according to a third embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a pulse oximeter probe according to a fourth embodiment. [Figure 10] 1 is a table showing experimental results when using pulse oximeter probes according to the first and second embodiments and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to the drawings.

[0015] <<<Embodiment 1>>> <<Configuration>> 1(a) and 1(b) show cross-sectional views of a plane including the central axis of a pulse oximeter probe of this embodiment, and FIG. 2(b) shows a side view.

[0016] 1(a) and 1(b), the pulse oximeter probe of this embodiment has a structure in which wiring 11a or 11b is provided on a ring-shaped flexible substrate 10, and bare-chip semiconductor light-emitting elements (LED elements) 21a and 21b are directly bonded with a bonding material onto the wiring 11a or 11b of the substrate 10. The surface on which the LED elements 21a and 21b are mounted may be the inner circumferential surface of the substrate 10 that comes into contact with the subject 1 (FIG. 1(a)) or the outer circumferential surface (FIG. 1(b)).

[0017] It is preferable to use a sintered body of metal particles as the bonding material for bonding the LED elements 21a, 21b onto the wiring 11a or 11b of the substrate 10. By using a sintered body of metal particles, it is possible to sinter at a temperature that does not damage the flexible substrate 10.

[0018] The LED element 21a emits red light, and the LED element 21b emits infrared light.

[0019] The LED elements 21a and 21b are sealed with a transparent sealing material 22.

[0020] The height (thickness) of the bare chips of the LED elements 21a and 21b can generally be made 100 μm or less, so the bare chips can be embedded in the transparent sealing material 22 to make the surface of the sealing material 22 flat. Therefore, the light-emitting unit 20 can be configured without any protrusions that press against the skin of the subject 1.

[0021] Furthermore, the bare-chip LED elements 21a, 21b can conduct the heat they generate directly to the wiring 11a or 11b, and dissipate the heat while conducting it to the wiring 11a or 11b. In other words, compared to packaged LEDs, the bare-chip LED elements 21a, 21b have excellent heat dissipation characteristics and can dissipate heat efficiently from the wiring 11a or 11b because there are no components, such as a package substrate or cavity, that can bottleneck heat conduction or store heat between the wiring 11a or 11b and the LED element. This makes it possible to suppress a temperature rise in the light-emitting section 20.

[0022] Meanwhile, the semiconductor light receiving element 31 constituting the light receiving unit 30 is mounted on one of the two surfaces of the ring-shaped substrate 10, namely, on the surface (outer surface) opposite to the surface (inner surface) facing the test object 1, and is joined to wiring 11b provided on the outer surface. The periphery of the semiconductor light receiving element 31 is sealed with a transparent sealing material 32. At least the region of the substrate 10 where the semiconductor light receiving element 31 is disposed is transparent. The semiconductor light receiving element 31 receives light that is emitted from the LED elements 21a and 21b, passes through the test object 1, and further passes through the transparent substrate 10 and sealing material 32.

[0023] By mounting the semiconductor light receiving element 31 on the outer peripheral surface of the ring-shaped flexible base material 10, even when a packaged semiconductor light receiving element 31 is used, the semiconductor light receiving element 31 does not protrude from the inner peripheral surface of the base material 10 and does not press against the subject 1. Note that it is also possible to use an unpackaged bare chip as the semiconductor light receiving element 31.

[0024] Furthermore, because the substrate 10 is ring-shaped, the LED elements 21a, 21b and the semiconductor light-receiving element 31 can be mounted in opposing positions across the space inside the ring-shaped substrate 10 where the subject 1 is placed. Therefore, when mounting the LED elements 21a, 21b and the semiconductor light-receiving element 31 on the substrate 10, alignment to match the optical axes can be completed. Therefore, when attaching the probe of this embodiment to the subject 1, it is sufficient to simply fit the ring-shaped substrate 10 onto the finger of the subject 1, and there is no need to align the LED elements 21a, 21b and the semiconductor light-receiving element 31. This reduces the burden of alignment on medical professionals and the subject.

[0025] As described above, the LED elements 21a and 21b may be bonded onto the wiring 11a on the inner peripheral surface of the substrate 10, as shown in FIG. 1(a), and may emit light toward the test object 1 in the space inside the ring-shaped substrate 10. Alternatively, as shown in FIG. 1(b), the LED elements 21a and 21b may be bonded onto the wiring 11b on the outer peripheral surface of the substrate 10, and the LED elements 21a and 21b may emit light toward the substrate 10, and the emitted light may pass through the substrate 10 and be irradiated toward the test object 1 in the space inside the ring-shaped substrate 10. In the configuration of FIG. 1(b), the substrate 10 used should be transparent at least in the area where the LED elements 21a and 21b are mounted.

[0026] It is desirable that the transparent encapsulant 22 that encapsulates the periphery of the LED elements 21a and 21b and the transparent encapsulant 32 that encapsulates the periphery of the semiconductor light-receiving element are covered with light-reflective encapsulants 23 and 33 on their surfaces (side surfaces and outer peripheral surfaces) excluding the surface facing the test object 1. This allows the light emitted from the LED elements 21a and 21b to be reflected by the light-reflective encapsulant 23 and directed toward the test object 1, thereby increasing the amount of light irradiated onto the test object 1. Furthermore, among the light that passes through the test object 1 and reaches the light-receiving unit 30, the light that does not directly enter the light-receiving surface of the semiconductor light-receiving element 31 can be reflected by the light-reflective encapsulant 33 and made to enter the light-receiving surface, thereby improving the light-receiving efficiency.

[0027] 2(b), a side view of the probe of this embodiment is shown. It is desirable that the area on the substrate 10 other than the area where the light-emitting unit 20 and the light-receiving unit 30 are disposed be sealed with a protective sealant 70. The protective sealant 70 covers and protects the substrate 10 and the wiring 11a, 11b on the substrate 10. It is desirable that the protective sealant 70 be light-blocking. By using a light-blocking protective sealant, light leaking from the side surface of the light-reflective sealant 33 of the light-emitting unit 20 is prevented from propagating through the protective sealant 70 and reaching the light-receiving unit 30.

[0028] It is desirable that the transparent encapsulants 22 and 32, the light-reflective encapsulants 23 and 33, and the protective encapsulant 70 are made of elastic materials. The light-reflective encapsulants 23 and 33 and the protective encapsulant 70 can be made of the same material that has light reflectivity and light blocking properties.

[0029] As described above, the pulse oximeter probe of this embodiment has bare chip LED elements 21a and 21b as the light-emitting unit 20 and semiconductor light-receiving element 31 as the light-receiving unit 30 directly mounted on a wired ring-shaped flexible substrate 10. This prevents the LED elements 21a and 21b of the light-emitting unit 20 and the semiconductor light-receiving element 31 of the light-receiving unit 30 from directly contacting the finger of the subject 1, minimizing unevenness in the area where the finger comes into contact during measurement and preventing pressure on the finger. In particular, the structure shown in FIG. 1(b), in which the LED elements 21a and 21b and the semiconductor light-receiving element 31 are mounted on the outer peripheral surface of the ring-shaped substrate 10, ensures that when worn on a finger, the light-emitting unit 20 and the light-receiving unit 30 are both positioned on the opposite side of the finger, eliminating unevenness that would otherwise come into contact with the finger and preventing pressure on the finger.

[0030] In the ring-shaped probe of this embodiment, the wiring 11a, 11b is connected to a power supply / signal extraction wiring 50 for supplying power to the LED elements 21a, 21b and extracting the output signal of the semiconductor light receiving element 31, and a connection terminal 60 is attached to the tip of the wiring 50.

[0031] When using the probe, as shown in FIG. 2(a), the probe is fitted onto the finger of the subject 1, the terminal 60 is connected to the pulse oximeter device, and power is supplied to the LED elements 21a and 21b via the power supply / signal extraction wiring 50 and wiring 11a or 11b. The red light and infrared light emitted from the LED elements 21a and 21b pass through the finger and are received by the semiconductor light receiving element 31. The output of the semiconductor light receiving element 31 is input to the pulse oximeter via wiring 11b and the power supply / signal extraction wiring 50. The pulse oximeter calculates and displays the ratio of oxygenated hemoglobin to the hemoglobin in the blood (SpO2) from the output of the semiconductor light receiving element 31, such as the intensity ratio of the red light and the infrared light.

[0032] <<Detailed structure and manufacturing method>> The detailed structure and manufacturing method of the pulse oximeter probe of this embodiment will be described with reference to Figures 3 and 4. First, the manufacturing method of the probe having the structure shown in Figure 1(a) will be described.

[0033] (Process for Producing Substrate 10 with Wirings 11a and 11b) As shown in FIG. 3(a), an uncured transparent polyimide layer 100 is applied to a copper foil 11 (for example, 12 μm thick) with a constant thickness (for example, 70 μm) using a die coater.

[0034] 3(b), the copper foil 11 with the uncured polyimide layer 100 is pre-dried by heating it at a predetermined temperature for a predetermined time (for example, 100°C, 10 minutes) using a hot plate or the like. At this time, a hole may be provided in the hot plate, and the copper foil 11 with the polyimide layer 100 may be heated while being adsorbed to the hot plate. If necessary, a frame may be placed on top of the copper foil 11 with the polyimide layer 100 to press it down.

[0035] As shown in Fig. 3(c), the copper foil 11 with the polyimide layer 100 is heated in an oven under a nitrogen atmosphere at a predetermined temperature for a predetermined time (e.g., 260°C, 60 min) to perform final drying, thereby forming a transparent substrate 10 (transparent polyimide: thickness 35 µm) integrated with the copper foil 11 (Fig. 3(d)).

[0036] Next, the copper foil on the substrate 10 in Figure 3(d) is etched to form the pattern of the wiring 11a on which the LED elements 21a and 21b are mounted, the pattern of the wiring 11b on which the semiconductor light-receiving element 31 is mounted, and the pattern of the power supply and signal extraction wiring 50. A gold plating layer is formed on the processed copper foil surface by electroless plating. Note that both wirings 11a and 11b are formed by processing the copper foil on the same side of the substrate 10.

[0037] (Mounting process of LED elements 21a and 21b) LED elements 21a and 21b are mounted on wiring 11a on substrate 10. LED elements 21a and 21b are of the flip-chip type, with electrodes on the same side and light emitted from the surface opposite the electrodes.

[0038] 4(a), Au ink 80 is prepared by dispersing gold particles with an average particle size of 30 nm in a solvent (glycerin) at a concentration of 82 wt%, and is applied with a dispenser to the portion of wiring 11a where LED elements 21a and 21b will be mounted. At this time, it is preferable that the substrate 10 is mounted on a silicon substrate and then on a glass substrate.

[0039] Next, as shown in FIG. 4(b), the Au ink 80 is dried by heating on a hot plate at a predetermined temperature for a predetermined time (for example, 50° C., 45 to 60 minutes).

[0040] As shown in Figure 4(c), the substrate 10 is set in an optical bonding device 81, and as shown in Figure 4(d), the electrodes of the LED elements 21a and 21b are mounted on the Au ink 80, and the LED elements 21a and 21b are pressed against the wiring 11a with a predetermined pressure using a load collet 82.

[0041] As shown in Figure 4(e), blue laser light with a predetermined beam diameter is irradiated from the underside of the substrate 10 onto the area of ​​the wiring 11a where the Au ink 80 is mounted. The area of ​​the wiring 11a irradiated with the blue laser light absorbs the blue laser light and heats up, and this heat is conducted to the Au ink 80, heating it. Because the gold particles in the Au ink 80 have a small average particle size of 30 nm, they are sintered at a temperature lower than the melting point of Au to form a sintered body, and a bonding material 83 is formed that bonds the wiring 11a to the electrodes of the LED elements 21a and 21b.

[0042] At this time, since the substrate 10 is transparent, it does not absorb the blue laser light and is not directly heated. The heat of the wiring 11a heated by the blue laser light is conducted to areas of the wiring 11a that are not irradiated with the blue laser light and is rapidly dissipated. Therefore, the LED elements 21a and 21b can be mounted on the wiring 11a by optical bonding using the gold particle sintered body bonding material 83 without damaging the LED elements 21a and 21b or the resin substrate 10.

[0043] (Mounting process of semiconductor light receiving element 31) The semiconductor light receiving element 31 is a flip-chip type photodiode in which a pair of electrodes are on the same side, and the light receiving surface is between the pair of electrodes.

[0044] The semiconductor light receiving element 31 is mounted on the wiring 11b of the base material 10. The mounting method may be the optical bonding method similar to that shown in Figures 4(a) to 4(f), or, since the semiconductor light receiving element 31 is larger in size than the LED elements 21a and 21b, it may be joined by soldering.

[0045] (Sealing and assembly process) As shown in FIG. 5(a), a substrate 10 having wiring 11a on which LED elements 21a and 21b are mounted and wiring 50 for power supply and signal extraction connected thereto formed thereon, and a substrate 10 having wiring 11b on which semiconductor light receiving elements 31 are mounted and wiring 50 for power supply and signal extraction connected thereto formed thereon are cut out as separate parts A and B.

[0046] 5(b), an uncured white resin made by dispersing titanium oxide, zinc oxide, or aluminum oxide in silicone resin is prepared, and is applied in a frame shape surrounding the LED elements 21a, 21b and the semiconductor light-receiving element 31 at positions a predetermined distance away from the LED elements 21a, 21b and the semiconductor light-receiving element 31, respectively, to form uncured light-reflective encapsulants 23, 33. The frame-shaped light-reflective encapsulants 23, 33 are formed to have a pre-designed height that is higher than the heights of the LED elements 21a, 21b and the semiconductor light-receiving element 31.

[0047] 5(c), a transparent silicone resin is poured into the formed frame-shaped light-reflective sealants 23 and 33 to form uncured transparent sealants 22 and 32. Thereafter, the substrate 10 is heated at a predetermined temperature and time (e.g., 150°C, 4 hours) to cure the light-reflective sealants 23 and 33 and the transparent sealants 22 and 32. In this way, the light-reflective sealants 23 and 33 and the transparent sealants 22 and 32 having a thickness of 30 μm in the optical axis direction are formed.

[0048] As shown in Figure 5(d), part A of the substrate 10 on which the LED elements 21a and 21b are mounted and part B of the substrate 10 on which the semiconductor light-receiving element 31 is mounted are bonded together at their back surfaces. An adhesive layer of resin or adhesive tape can be used for bonding. The adhesive layer used for bonding is preferably light-blocking.

[0049] The substrate 10 is set in a ring shape along a mold in which a ring-shaped recess is formed. At this time, the power supply / signal output wiring 50 and the portion of the substrate 10 on which it is mounted are set so that they are pulled out from the mold. A light-blocking silicone resin is filled around the substrate 10. This forms a light-blocking protective sealant 70. At this time, the mold is formed so that the light-blocking protective sealant 70 does not adhere to the inner surfaces of the light-emitting section 20 and the light-receiving section 30.

[0050] The protective sealant 70 in the mold is cured under pressure at a predetermined temperature for a predetermined time (e.g., 150°C, 4 hours). After curing, the entire ring-shaped substrate 10 covered with the protective sealant 70 is removed from the mold, as shown in FIG. 5(e). A cross-sectional view of the ring-shaped substrate 10 covered with the protective sealant 70 in FIG. 5(e) is shown in FIG. 5(f). As shown in FIG. 5(f), the protective sealant 70 covers the inner peripheral surface of the substrate 10 around the light-emitting unit 20, covers the outer peripheral surface of the substrate 10 around the light-receiving unit 30, and covers both the inner and outer peripheral surfaces of the substrate 10 between the light-emitting unit 20 and the light-receiving unit 30, and the protective sealant 70 has a smooth ring-shaped outer shape.

[0051] Finally, a connection terminal 60 is connected to the tip of the power supply / signal extraction wiring 50 drawn out from the ring-shaped substrate 10 .

[0052] As a result of the above, the ring-shaped pulse oximeter probe of this embodiment is completed as shown in FIG. 5(e).

[0053] Next, a method for manufacturing the probe having the structure shown in FIG. 1(b) will be described.

[0054] The probe having the structure shown in FIG. 1(b) differs from the probe having the structure shown in FIG. 1(a) in that both the LED elements 21a and 21b and the semiconductor light-receiving element 31 are mounted on the wiring 11b on the outer peripheral surface of the substrate 10. Therefore, in the manufacturing process of the probe having the structure shown in FIG. 1(a), it is not necessary to cut out the substrate 10 into two parts A and B in the step shown in FIG. 5(a), and it is also not necessary to bond the parts A and B of the two substrates 10 together in the step shown in FIG. 5(d). Therefore, in the manufacturing process of the probe having the structure shown in FIG. 1(a), it is sufficient to cut out a single part on which both the LED elements 21a and 21b and the semiconductor light-receiving element 31 are mounted, as shown in FIG. 6. The pattern of the wiring 11b differs from that of the probe having the structure shown in FIG. 1(a), and must be appropriately designed.

[0055] The other steps are the same as those for the probe having the structure shown in Fig. 1(a), and therefore will not be described here. In the step shown in Fig. 5(e), the protective sealant 70 is formed into a ring shape, covering the outer peripheral surface of the substrate 10 around the light-emitting section 20, around the light-receiving section 30, and in the area between them.

[0056] In this way, a probe having the structure shown in FIG. 1(b) can be manufactured.

[0057] <<<Embodiment 2>>> A pulse oximeter probe according to the second embodiment will be described with reference to FIG.

[0058] In the probe of the first embodiment having the structure shown in Fig. 1(b), the LED elements 21a and 21b of the light-emitting unit 20 are mounted on the wiring 11b on the outer circumferential surface of the ring-shaped substrate 10, and light emitted from the LED elements 21a and 21b passes through the gaps in the wiring 11b and the transparent substrate 10, and is then irradiated onto the subject 1. To increase the amount of light irradiated from the light-emitting unit 20 onto the subject 1, it is desirable to reduce the width of the wiring 11b and increase the gaps between the wiring 11b. On the other hand, the wiring 11b also serves to diffuse and dissipate heat generated by the LED elements 21a and 21b. To prevent low-temperature burns and reduce the burden on the patient, it is desirable to increase the area of ​​the wiring 11b where the LED elements 21a and 21b are mounted.

[0059] Therefore, in the second embodiment, the wiring 11b to which the LED elements 21a and 21b are joined is shaped so that its width increases with increasing distance from the LED elements 21a and 21b.

[0060] This will be explained using Fig. 7. Fig. 7(a-1) and (a-2) are a top view and a cross-sectional view of the mounting area of ​​the LED elements 21a and 21b on the wiring 11b of the first embodiment, and Fig. 7(b-1) and (b-2) are a top view and a cross-sectional view of the mounting area of ​​the LED elements 21a and 21b on the wiring 11b of the second embodiment.

[0061] The wiring 11b of embodiment 1 in Figure 7(a-1) is rectangular and has a constant width, whereas the wiring 11b of embodiment 2 in Figure 7(b-1) is trapezoidal, with the width of the wiring 11b narrowed at the portion where the LED elements 21a, 21b are mounted, and the width increases as it moves away from the LED elements 21a, 21b.

[0062] This reduces the area covered by the wiring 11b in the region on the base material 10 that is irradiated with light from the LED elements 21a and 21b. Therefore, as shown in Fig. 7(b-2), the amount of light emitted from the LED elements 21a and 21b that is reflected by the surface of the wiring 11b can be made smaller than that of the rectangular wiring 11b in Fig. 7(b-1).

[0063] Therefore, the wiring 11b of the second embodiment can increase the amount of light that enters the substrate 10 through the gaps between the wirings 11b, passes through the substrate 10, and is irradiated onto the test object 1.

[0064] Furthermore, since the wiring in the second embodiment becomes wider as it gets farther away from the LED elements 21a and 21b, it is possible to maintain the heat dissipation effect by diffusing the heat generated by the LED elements 21a and 21b, and therefore it is possible to increase the amount of light to the subject 1 while maintaining the heat dissipation characteristics.

[0065] In addition, in FIG. 7(b-1), an example of the wiring 11b is shown in which the wiring 11b is a trapezoid whose width increases continuously, but it may be a shape whose width increases stepwise.

[0066] The configuration and manufacturing method of the probe of the second embodiment other than the shape of the wiring 11b are the same as those of the first embodiment, and therefore a description thereof will be omitted.

[0067] <<<Embodiment 3>>> A pulse oximeter probe according to a third embodiment will be described with reference to FIG.

[0068] In the probe of the third embodiment, a metal film 90 is disposed on the outer peripheral surface of the light-emitting section 20, the light-receiving section 30, and the light-shielding protective sealing material 70, as shown in FIG.

[0069] The metal film 90 can enhance the heat dissipation effect of the probe by dissipating the heat generated by the light-emitting unit 20. The metal film 90 also acts as an electromagnetic shield, preventing external electromagnetic noise from entering the light-emitting unit 20, the light-receiving unit 30, and the wiring 11a and 11b.

[0070] Highly conductive metals such as copper and aluminum can be used as the material for the metal film 90. The film thickness is preferably 1 μm to 100 μm.

[0071] The metal film 90 can be formed by vapor deposition or plating after the step of forming the protective sealant 70 in Fig. 5(e). Alternatively, a metal foil may be arranged along the outer periphery when the protective sealant 70 is formed and cured at the same time, or a metal ring that has been separately formed in advance using metal processing technology may be attached to the outside of the protective sealant 70 in Fig. 5(e) after it is formed and fixed thereto by fitting or with an adhesive.

[0072] Furthermore, in this embodiment 3, a structure in which a metal film 90 is disposed on the outermost surface of the probe is shown, but it is also possible to form a metal film before the step of forming the protective sealing material 70 in Figure 5(e), and then perform the step of Figure 5(e) to form the protective sealing material 70 on the metal film 90.

[0073] <<<Embodiment 4>>> A pulse oximeter probe according to a fourth embodiment will be described with reference to FIG.

[0074] In the first to third embodiments, the base material 10 is a ring-shaped probe, but in the fourth embodiment, a planar reflective probe will be described that employs the structure of Fig. 1(b) of the first embodiment. The planar probe is used by being attached to the sole of a newborn baby's foot, and the light emitted from the light-emitting unit 20 is reflected from the subject 1 and received by the light-receiving unit 30.

[0075] As shown in Figure 9, the probe of embodiment 4 has a structure in which the ring-shaped substrate 10 of the structure in Figure 1(b) is flattened, and bare chips of LED elements 21a and 21b and a semiconductor light-receiving element 31 are directly mounted on the wiring 11b on the upper surface of the substrate 10.

[0076] As a result, although it is a reflection type probe, the surface that comes into contact with the subject 1 is smooth, and the same effect as in the first embodiment can be obtained.

[0077] Other than being flat and receiving reflected light, the structure and operation are the same as those of the first embodiment, and detailed description thereof will be omitted.

[0078] In the structure of FIG. 9, the metal film 90 of the third embodiment is also disposed. <<<Verification of the effect of the probe of this embodiment>>> In order to evaluate the risk of low-temperature burns, an experiment was conducted in which the probe of embodiment 1 (cross-sectional structure shown in Figure 1(a)), the probe of embodiment 2 (cross-sectional structure shown in Figure 1(b)), and a commercially available comparative probe (manufactured by AS ONE Corporation, model number: NF503-16) were attached to a hand mannequin, and the temperature rise at the attachment point was measured.

[0079] For each probe, a continuous current of 5 mA was applied to the red and infrared LED elements simultaneously, and the temperature rise at the attachment point of the hand mannequin was measured. The results are shown in the table in Figure 10.

[0080] As is clear from FIG. 10, it was confirmed that the probes of the first and second embodiments suppressed the temperature rise more than the comparative example.

[0081] Since a temperature rise can cause rashes and low-temperature burns on the subject 1, the probe of this embodiment can reduce the burden on the subject 1.

[0082] <<<Application to products>>> The pulse oximeter probe of this embodiment can also be used as a light source unit for other wearable devices that optically acquire biological information, such as a smart ring. [Explanation of symbols]

[0083] 1. Subject 10 Base material 11 Copper foil 11a wiring 11b Wiring 20 Light-emitting part 21a LED element 21b LED element 22 Transparent encapsulant 23 Light reflective encapsulant 30 Light receiving section 31 Semiconductor photodetector 32 Transparent encapsulant 33 Light reflective encapsulant 50 Wiring 60 Connection terminal 70 Protective Encapsulant 80 ink 81 Optical bonding equipment 82 Load collet 83 Bonding material 90 Metal Film 100 Polyimide layer

Claims

1. a flexible substrate, a semiconductor light emitting element and a semiconductor light receiving element mounted on the substrate, respectively, and a sealing material that seals the semiconductor light emitting element and the semiconductor light receiving element; the substrate is ring-shaped, and wiring is provided only on the surface of the substrate; the wiring has an inner peripheral wiring provided on the inner peripheral side of the ring-shaped substrate and an outer peripheral wiring provided on the outer peripheral side of the substrate, the semiconductor light-emitting element is a bare chip including a semiconductor light-emitting layer and a pair of electrode layers for supplying a current to the semiconductor light-emitting layer, the bare chip being directly bonded onto the inner peripheral wiring of the base material with a bonding material; the semiconductor light receiving element is bonded to the peripheral wiring provided on one of both surfaces of the base material opposite to the surface facing the test object, the substrate is transparent at least in the region where the semiconductor light receiving element is disposed; the semiconductor light emitting element is bonded to the inner peripheral wiring on the inner peripheral surface of the ring-shaped base material, and emits light toward a space inside the ring-shaped base material; The semiconductor light-receiving element is mounted on the outer surface of the substrate at a position opposite the semiconductor light-emitting element, across the space inside the ring-shaped substrate, and receives light emitted from the semiconductor light-emitting element and passing through the transparent substrate.

2. 2. The pulse oximeter probe according to claim 1, wherein the substrate has a first substrate on which the semiconductor light-emitting element is mounted and a second substrate on which the semiconductor light-receiving element is mounted, and the back surface of the first substrate on which no wiring is formed is bonded to the back surface of the second substrate to form an integrated unit.

3. The pulse oximeter probe according to claim 1, a protective sealing material is formed on the ring-shaped base material other than the semiconductor light emitting element and the semiconductor light receiving element; the periphery of the semiconductor light emitting element covers the inner peripheral surface side of the ring-shaped base material, the periphery of the semiconductor light receiving element covers the outer peripheral surface side of the ring-shaped base material, A pulse oximeter probe, characterized in that the space between the semiconductor light emitting element and the semiconductor light receiving element covers both the inner and outer peripheral surfaces of the ring-shaped substrate.

4. a flexible substrate; a semiconductor light emitting element and a semiconductor light receiving element mounted on the substrate; a sealing material that seals the semiconductor light emitting element and the semiconductor light receiving element; a connection terminal; Wiring is provided on the surface of the substrate, the semiconductor light emitting element is a bare chip including a semiconductor light emitting layer and a pair of electrode layers for supplying current to the semiconductor light emitting layer, the bare chip is directly bonded onto the wiring of the base material with a bonding material; the semiconductor light receiving element is bonded to the wiring provided on one of both surfaces of the base material opposite to the surface facing the test object, the substrate is transparent at least in an area where the semiconductor light emitting element and the semiconductor light receiving element are disposed; the semiconductor light receiving element receives light that is emitted from the semiconductor light emitting element and passes through the transparent base material; the substrate has a main body portion on which the semiconductor light emitting element, the semiconductor light receiving element, and the sealing material are provided, and an extraction portion connecting the main body portion and the connection terminal, The lead-out portion is formed with power supply and signal extraction wiring that is an extension of the wiring to which the semiconductor light emitting element and the semiconductor light receiving element of the main body portion are joined. A probe for a pulse oximeter.

5. The pulse oximeter probe according to claim 4, the substrate is a ring-shaped substrate, The semiconductor light emitting element and the semiconductor light receiving element are both bonded to the outer peripheral surface of the base material on which the wiring is formed. A probe for a pulse oximeter.

6. 2. The pulse oximeter probe according to claim 1, wherein the bonding material is a sintered body of metal particles.

7. 2. The pulse oximeter probe according to claim 1, wherein the sealing material includes a transparent sealing material that seals the periphery of each of the semiconductor light-emitting element and the semiconductor light-receiving element, a light-reflective sealing material that covers the side surfaces of the transparent sealing material, and a light-blocking sealing material that seals an area of ​​the substrate where the semiconductor light-emitting element and the semiconductor light-receiving element are not mounted.

8. 8. The pulse oximeter probe according to claim 7, wherein a metal film is disposed on an upper surface of the sealing material.

9. 2. The pulse oximeter probe according to claim 1, wherein the wiring to which the semiconductor light emitting element is joined increases in width with increasing distance from the semiconductor light emitting element.

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