Optical biosensing module and optical biosensor

Abstract

The present application discloses an optical biosensing module and an optical biosensor. The optical biosensing module comprises an optical biological detection chip, and a power supply circuit board and electronic chips which are sequentially stacked on the optical biological detection chip. The power supply circuit board is used for supplying power to the electronic chips. The optical biological detection chip comprises a substrate, and an optical path and a detection element which are disposed on the substrate, and the optical path comprises a detection optical path and / or a conduction optical path. Two oppositely disposed side surfaces of the power supply circuit board are each provided with a heat-conducting metal layer, and the two heat-conducting metal layers are respectively connected to the electronic chips and the optical biological detection chip. The power supply circuit board is further provided with multiple through holes, the through holes are filled with a heat-conducting metal material, and the heat-conducting metal material is connected to the two heat-conducting metal layers, the electronic chips, and the optical biological detection chip, respectively. According to the present invention, the temperature distribution inside the sensor can be more balanced and synchronized, thereby improving the signal stability of the sensor.

Description

Optical biosensor modules, optical biosensors Technical Field

[0001] The present invention relates to the technical field of medical equipment, and more specifically, to an optical biosensor module and an optical biosensor. Background Art

[0002] An implantable optical biosensor is a device that is implanted into human tissue and can continuously detect biological parameters of human tissue or tissue fluid (such as blood sugar, ketones, uric acid, lactic acid, etc.).

[0003] Implantable optical biosensors detect weak signals of substances, and the accuracy of the detection signal is at the picoampere level (10 -12 A), therefore, very high requirements are placed on the accuracy and stability of detection. Technical issues

[0004] The existing implantable optical biosensor includes a coating layer and a light source, an optical biological detection chip, a photoelectric converter, a power supply circuit board and an electronic chip contained inside the coating layer. The photoelectric converter and the electronic chip are both arranged on the power supply circuit board. The power supply circuit board is used to supply power to the photoelectric converter and the electronic chip. The optical biological detection chip includes an optical path and a detection element. The optical path includes a detection optical path and / or a conduction optical path. The detection element includes an active substance (such as an enzyme, an antibody, etc.) that can specifically bind to the substance to be detected. The coating layer is provided with an opening to expose the detection element. The detection element adsorbs the substance to be detected. The light source is irradiated onto the substance to be detected through the conduction optical path. The substance to be detected absorbs light to produce a specific absorption spectrum. The absorption spectrum enters the photoelectric converter through the detection optical path. The photoelectric converter converts the light signal of the absorption spectrum into an electrical signal. The electronic chip receives, processes the electrical signal and transmits the electrical signal to an external device.

[0005] In the above-mentioned implantable optical biosensors, the optical biodetection chip is usually a silicon-based semiconductor device made based on silicon photonics technology, with an area of ​​about 2cm x 3cm. A power supply circuit board and an electronic chip are usually stacked in sequence above the optical biodetection chip. Among them, the electronic chip is the main heat source in the sensor. The heat generated by the electronic chip will be transferred to the optical biodetection chip through the power supply circuit board, and then further transferred to the implant environment to achieve thermal equilibrium. However, the power supply circuit board is composed of a cross-stacked insulating dielectric layer and a circuit layer along the thickness direction. The thermal conductivity coefficients of the two are different, and the thermal conductivity coefficient of the insulating layer material is generally low, resulting in uneven heat conduction of the power supply circuit board in both the plane and thickness directions: uneven temperature distribution along the plane of the circuit board, and uneven temperature distribution along the thickness direction. The two uneven distributions will cause the differential optical path in the optical chip and the differential circuit on the circuit board to experience different temperature distributions and change trends. In optical bio-detection chips, silicon-based optical devices are very sensitive to temperature changes. Temperature instability will affect the refractive index of the optical path on the optical bio-detection chip, resulting in changes in the effective refractive index, amplitude and phase of the propagating light, as well as the dispersion performance of the waveguide, resulting in unstable detection signals and errors. In the circuit of the circuit board, voltage will be generated on the interface of different metal materials (such as wire bonding) due to temperature difference, which will introduce additional interference signals. Especially when the accuracy of the detection signal is only at the picoampere level (10 -12 A) when milli-degrees Celsius (10 -3 Temperature changes of the order of 100°C will also have a direct impact on detection accuracy.

[0006] Temperature instability includes two aspects: first, it refers to the unstable change of the temperature of the optical biodetection chip body over time; second, it refers to the uneven distribution of temperature in the sensor over space. Different optical functional modules are distributed at different positions of the chip. When their temperatures are in different changing trends and this trend cannot be repeated, the interference to the detection signal will show randomness. Technical Solutions

[0007] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide an optical biosensor module and an optical biosensor, so that the temperature distribution inside the sensor reaches a more balanced and synchronized state, thereby improving the signal stability of the sensor.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] In a first aspect, an optical biosensor module includes an optical biosensor chip and a power supply circuit board and an electronic chip sequentially stacked on the optical biosensor chip, the power supply circuit board being used to supply power to the electronic chip. The optical biosensor chip includes a substrate and an optical path and a detection element disposed on the substrate, the optical path including a detection optical path and / or a transmission optical path.

[0010] Both side surfaces of the power supply circuit board are oppositely arranged and provided with a thermally conductive metal layer, and the two thermally conductive metal layers are respectively connected to the electronic chip and the optical biological detection chip. The power supply circuit board is also provided with a plurality of through holes, and the through holes are filled with thermally conductive metal material, and the thermally conductive metal material is respectively connected to the two thermally conductive metal layers, the electronic chip and the optical biological detection chip.

[0011] In a second aspect, an optical biosensor includes the above-mentioned optical biosensor module. Beneficial effects

[0012] The implementation of the present invention will have the following beneficial effects:

[0013] Embodiments of the Invention The present invention provides a heat-conducting metal layer on the upper surface of the power supply circuit board, so that the heat generated by the electronic chip is evenly distributed on the plane of the power supply circuit board to avoid heat concentration, and provides through holes on the power supply circuit board and heat-conducting metal materials filled in the through holes, so that the heat is rapidly diffused into the optical biodetection chip along the thickness direction, and provides a heat-conducting metal layer on the lower surface of the power supply circuit board, so that the heat is evenly diffused into the optical biodetection chip. In short, the present invention can quickly and evenly diffuse the heat generated by the electronic chip into the optical biodetection chip, enhance the signal stability and accuracy of the sensor, reduce the detection error, and can stably measure picoamperes (10 -12 A) level of current. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] in:

[0016] FIG1 is a schematic side view of the structure of an optical biosensor module according to a specific embodiment of the present invention.

[0017] FIG. 2 is a schematic top view of the structure of an optical biosensor module according to a specific embodiment of the present invention.

[0018] FIG3 is a relationship diagram of the equivalent heat conduction efficiency and the ratio of the through-hole area of ​​a power supply circuit board according to a specific embodiment of the present invention.

[0019] FIG4 is a schematic structural diagram of a through-hole unit on a power supply circuit board according to a specific embodiment of the present invention.

[0020] FIG5 is a schematic cross-sectional view of a power supply circuit board according to a specific embodiment of the present invention.

[0021] FIG6 is a schematic structural diagram of an optical biosensor according to a specific embodiment of the present invention. Modes for Carrying Out the Invention

[0022] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] In the first aspect, the present invention discloses an optical biosensor module 10, which includes an optical biodetection chip 11 and a power supply circuit board 12 and an electronic chip 13 stacked in sequence on the optical biodetection chip 11. The power supply circuit board 12 is used to supply power and communicate with the electronic chip 13. The optical biodetection chip 11 includes a substrate 111 and an optical path 113 and a detection element 112 disposed on the substrate 111. The optical path 113 includes a detection optical path and / or a conductive optical path. The detection element 112 includes but is not limited to a detection element capable of communicating with the object to be detected. Active substances (such as enzymes, antibodies, etc.) that specifically bind to substances, or substances can be detected directly by light, and heat-conducting metal layers 121 are provided on the two opposite surfaces of the power supply circuit board 12. The two heat-conducting metal layers 121 are respectively connected to the electronic chip 13 and the optical biological detection chip 11. The power supply circuit board 12 is also provided with a plurality of through holes 122, and the through holes 122 are filled with heat-conducting metal materials 123. The heat-conducting metal materials 123 are respectively connected to the two heat-conducting metal layers 121, the electronic chip 13 and the optical biological detection chip 11.

[0024] The present invention provides a heat-conducting metal layer 121 on the upper surface of the power supply circuit board 12, so that the heat generated by the electronic chip 13 is evenly dissipated on the plane of the power supply circuit board 12 to avoid heat concentration. By providing a through hole 122 on the power supply circuit board 12 and a heat-conducting metal material 123 filled in the through hole 122, the heat is quickly diffused into the optical biological detection chip 11 along the thickness direction. By providing a heat-conducting metal layer 121 on the lower surface of the power supply circuit board 12, the heat is evenly diffused into the optical biological detection chip 11. In short, the present invention can quickly and evenly diffuse the heat generated by the electronic chip 13 into the optical biological detection chip 11, enhance the signal stability and accuracy of the sensor, reduce the detection error, and can stably measure picoamperes (10 -12 A) level of current.

[0025] In the above technical solution, the number of the electronic chip 13 is at least one.

[0026] In the above technical solution, the thermally conductive metal layer 121 covers the entire upper and lower surfaces of the power supply circuit board 12. The heat generated by the electronic chip 13 is first evenly distributed within the plane through the thermally conductive metal layer 121. Then, the thermally conductive metal material 123 connected to the thermally conductive metal layer 121 quickly transfers the heat to the optical bio-detection chip 11 in the thickness direction. The optical bio-detection chip 11 easily dissipates heat, and the heat is quickly and evenly conducted throughout the optical bio-detection chip 11, achieving thermal equilibrium in both temporal and spatial distribution, thereby enhancing the stability of the detection signal. Of course, if circuits are provided on the upper and lower surfaces of the power supply circuit board 12, the thermally conductive metal layer 121 should be kept away from the circuits to avoid affecting the normal operation of the power supply circuit board 12.

[0027] In a specific embodiment, the area of ​​the through hole 122 accounts for 1% to 25% of the total area of ​​the power supply circuit board 12, preferably 15% to 25%. When the area occupied by the through hole 122 exceeds 15%, it can provide a thermal conductivity coefficient equivalent to that of the relatively good thermal conductive material Al2O3, which greatly improves the heat dissipation efficiency and also significantly reduces the cost.

[0028] Referring to Figure 3 , in one embodiment, the power supply circuit board 12 includes a cross-laminated FR4 insulating dielectric layer 126 and a circuit layer 125. As can be seen from the figure, the thermal conductivity of the circuit board without vias 122 is 0.4 W / mK, making it a very poor thermal conductor. However, when the vias 122 occupy more than 15% of the total area of ​​the circuit board, the overall thermal conductivity of the power supply circuit board 12 exceeds 25 W / mK. When the vias 122 account for approximately 20% of the total area of ​​the circuit board, the heat dissipation performance of the FR4-based circuit board is comparable to that of Al2O3. A relatively good thermally conductive material is Al2O3, which has a thermal conductivity of 30 W / mK.

[0029] In a specific embodiment, the number of through holes 122 is multiple, and the multiple through holes 122 are distributed on the power supply circuit board 12. The diameter of the through holes 122 is 5μm~5000μm, and the distance between adjacent through holes 122 is 5μm~1200μm. Referring to Figure 4, in this specific embodiment, the through holes 122 are evenly distributed on the power supply circuit board 12 in the form of a square matrix. The diameter of the through holes 122 is 50μm, and the distance between adjacent through holes 122 is 200μm. At this time, the area of ​​the through holes 122 accounts for 19.6%. It can effectively improve the heat dissipation function of the circuit board. The effective thermal conductivity can be increased to 30W / mK, which is equivalent to Al2O3.

[0030] 5 , in one embodiment, the through hole 122 may be filled with the heat-conducting metal material 123 to form a vertical structure or a staggered structure. The staggered structure is mainly formed by filling the heat-conducting metal material 123 above and below the circuit inside the circuit board.

[0031] Referring to Figure 1 , in one embodiment, the optical biosensor module 10 further includes an adhesive layer 14 disposed between the optical biosensor chip 11 and the power supply circuit board 12. This adhesive layer 14 integrates the optical biosensor chip 11, the power supply circuit board 12, and the electronic chip 13 into a single unit. During production, the optical biosensor chip 11, the power supply circuit board 12, and the electronic chip 13 can be pressed together using upper and lower pressure molds at high temperature and high pressure to minimize the formation of air bubbles between the layers.

[0032] Furthermore, the power supply circuit board 12 also has a through hole 124 with a larger diameter. The diameter of the through hole 124 is 0.005mm~5mm. The purpose of providing the through hole 124 is to facilitate the discharge of bubbles in the adhesive layer 14 during gluing to prevent bubbles from affecting the uniformity of heat transfer.

[0033] In a specific embodiment, the substrate 111 is a silicon-based semiconductor substrate, specifically, a pure silicon semiconductor substrate, a silicon nitride semiconductor substrate, a silicon carbide semiconductor substrate, etc.

[0034] The power supply circuit board 12 includes a cross-stacked circuit layer 125 and an insulating dielectric layer 126. The insulating dielectric layer 126 has a low thermal conductivity. Therefore, it is preferable to use a thin insulating dielectric layer 126 to improve the efficiency of temperature transfer. The thickness of the insulating dielectric layer 126 is 10μm~150μm, and the thickness of the power supply circuit board 12 is 50μm~400μm.

[0035] The material of the insulating dielectric layer 126 can be selected from PI, FR4 or SiO2.

[0036] 5 , the power supply circuit board 12 includes at least one circuit layer 125. Preferably, at least one side surface of the power supply circuit board 12 is the circuit layer 125. The circuit layer 125 is directly connected to the optical biological detection chip 11 and / or the electronic chip 13. A heat-conducting metal layer 121 is provided on the circuit layers 125 on both sides where there is no circuit. On the one hand, the circuit layer 125 can enhance heat transfer, and on the other hand, it can reduce the thickness of the insulating dielectric layer 126 so that heat can be transferred quickly.

[0037] In another embodiment, the two side surfaces of the power supply circuit board 12 are insulating layers, and a thermally conductive metal layer 121 can be respectively provided on the insulating layers on the two side surfaces, so that the thermally conductive metal layer 121 is respectively connected to the thermally conductive metal material 123, the electronic chip 13 and the optical biological detection chip 11. The thermally conductive metal layer 121 above the optical biological detection chip 11 can make the heat transferred by the thermally conductive metal material 123 enter the optical biological detection chip 11 more evenly.

[0038] In a specific embodiment, the optical biological detection chip 11 also includes a reference element 114 arranged on the substrate 111. The detection element 112 is used to detect dual information of the detected substance and the detection environment. The reference element 114 is used to detect environmental information. The dual-path information can exclude environmental information and only leave information of the detected substance, thereby greatly improving the detection accuracy.

[0039] In the second aspect, referring to Figure 6, the present invention also provides an optical biosensor, including a coating layer 20 and the above-mentioned optical biosensor module 10, light source 30 and photoelectric converter 40 contained in the coating layer 20, the light source 30, photoelectric converter 40 and electronic chip 13 are respectively arranged on a power supply circuit board 12, the power supply circuit board 12 provides power for the photoelectric converter 40, light source 30 and photoelectric converter 40, and an opening 21 is provided on the coating layer 20 to expose the detection element 112.

[0040] The optical path 113 of the present invention uses evanescent waves to measure the substance being tested within tissue. Evanescent waves are electromagnetic waves that are blocked by total internal reflection at the interface of the medium in optical path 113 and then attenuated at the interface. Their electric and magnetic fields are perpendicular to the interface, decaying exponentially and existing only within a region near the interface. Evanescent waves are unconventional electromagnetic waves that do not propagate within the medium, but can interact with active substances on the surface of the medium. They are commonly used in fields such as optical measurement of interfaces and biosensing.

[0041] During detection, the detection element 112 combines with the substance to be detected, and the light source 30 irradiates the substance to be detected through the conductive light path. The substance to be detected absorbs the light to produce a specific absorption spectrum. The absorption spectrum enters the photoelectric converter 40 through the detection light path. The photoelectric converter 40 converts the optical signal of the absorption spectrum into an electrical signal. The electronic chip 13 receives and processes the electrical signal and transmits the electrical signal to an external device.

[0042] The optical biosensor of the present invention is further an implantable optical biosensor, which can continuously monitor the detected substance in the tissue, and can help patients more accurately grasp the real-time content changes of the detected substance in the tissue.

[0043] The optical biosensor of the present invention has a detection signal accuracy of only picoampere level (10 -12 A).

[0044] The optical biosensor of the present invention can be used to detect urea, creatinine, triglyceride, protein, cholesterol, ethanol, ketone bodies, hormones or lactic acid in tissue fluid.

[0045] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An optical biosensor module, characterized in that: The optical biological detection chip comprises a power supply circuit board and an electronic chip which are sequentially stacked on the optical biological detection chip, wherein the power supply circuit board is used to supply power to the electronic chip, and the optical biological detection chip comprises a substrate and an optical path and a detection element arranged on the substrate, wherein the optical path comprises a detection optical path and / or a transmission optical path; The two oppositely disposed surfaces of the power supply circuit board are both provided with heat-conducting metal layers, and the two heat-conducting metal layers are respectively connected to the electronic chip and the optical biological detection chip. The power supply circuit board is also provided with a plurality of through holes, and the through holes are filled with heat-conducting metal materials, and the heat-conducting metal materials are respectively connected to the two heat-conducting metal layers, the electronic chip and the optical biological detection chip.

2. The optical biosensor module according to claim 1, characterized in that: The area of ​​the through hole accounts for 1% to 25% of the total area of ​​the power supply circuit board.

3. The optical biosensor module according to claim 2, characterized in that: The through holes are distributed on the power supply circuit board, and the diameter of the through holes is 5 μm-5000 μm; the distance between adjacent through holes is 5 μm-1200 μm.

4. The optical biosensor module according to claim 1, characterized in that: It also includes an adhesive layer disposed between the optical biological detection chip and the power supply circuit board.

5. The optical biosensor module according to claim 4, characterized in that: The power supply circuit board also has a through hole, and the diameter of the through hole is 0.005mm~5mm.

6. The optical biosensor module according to claim 1, characterized in that: The substrate is a silicon-based semiconductor substrate.

7. The optical biosensor module according to claim 1, characterized in that: The power supply circuit board comprises a cross-stacked circuit layer and an insulating medium layer, the thickness of the insulating medium layer is 10 μm to 150 μm, and the thickness of the power supply circuit board is 50 μm to 400 μm.

8. The optical biosensor module according to claim 1, characterized in that: The optical biological detection chip also includes a reference element disposed on the substrate.

9. An optical biosensor, characterized in that: Comprising the optical biosensor module as described in any one of claims 1 to 8.

10. The optical biosensor according to claim 9, characterized in that It also includes a covering layer, a light source and a photoelectric converter. The optical biosensor module, the light source and the photoelectric converter are all contained in the covering layer. The light source and the photoelectric converter are arranged on the power supply circuit board. The power supply circuit board also supplies power to the light source and the photoelectric converter. The covering layer is provided with an opening to expose the detection element.

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