KR20240049925A - Temperature-Humidity Hybrid Sensor with Digital Output and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a digital output temperature and humidity complex sensor, and more specifically, using a semiconductor manufacturing process or micro-electromechanical systems (MEMS) technology on a signal processing circuit (ROIC: Read-Out Integrated Circuit). This relates to a digital output temperature and humidity composite sensor that can be miniaturized by manufacturing a temperature and humidity sensor and can efficiently sense external temperature and humidity, and a method of manufacturing the same.

Description

Temperature-Humidity Hybrid Sensor with Digital Output and Manufacturing Method Thereof}

The present invention relates to a digital output temperature and humidity complex sensor, and more specifically, to a temperature and humidity sensor using a semiconductor manufacturing process or microelectromechanical systems (MEMS) technology on a signal processing circuit (ROIC: Read-Out Integrated Circuit). It relates to a digital output temperature and humidity composite sensor that can be miniaturized and efficiently sense external temperature and humidity and a method of manufacturing the same.

Figure 1 is a perspective view showing the structure of a digital output temperature and humidity sensor according to the prior art.

Referring to FIG. 1, conventionally, an insulating film 410 made of an oxide film (SiO ₂ ), a nitride film (Si ₃ N ₄ ), etc. is formed on the silicon substrate 400, and then ROIC 420 is formed using a semiconductor process, etc. was formed, and the humidity sensor 430 was formed in one area of the upper part of the ROIC 420.

Figure 2 is a perspective view of another digital output temperature and humidity sensor according to the prior art.

Referring to FIG. 2, the ROIC 520 and the humidity sensor 530 are manufactured separately and formed on the PCB board 500, and then electrically connected through die bonding and wire bonding. A production method was adopted to do so.

In this way, the digital output temperature and humidity sensor according to the prior art was used by forming only the humidity sensor separately, and the temperature sensor used a pre-equipped temperature sensor inside the ROIC, so it was difficult to measure the temperature accurately and the temperature characteristics were not good. In particular, there was a problem that a separate precision correction process was needed for excellent linearity at high temperatures.

In addition, in the case of the conventional technology illustrated in FIG. 1, the digital output temperature and humidity sensor requires the ROIC (420) and humidity sensor (430) to be located on the top of one silicon substrate (400), so the overall chip size is large and manufactured in a small size. There was a problem that there were limits to this.

In addition, in the case of the prior art illustrated in FIG. 1, since the humidity sensor 430 is manufactured in a one-chip process with the ROIC 420, the type of electrode thin film and moisture-sensitive film material for manufacturing the humidity sensor Because there are limitations in its application, there was a problem in that it was difficult to improve performance by forming a moisture-reducing film with excellent moisture-reducing properties.

In addition, in the case of the prior art illustrated in FIG. 2, since the humidity sensor 530 is manufactured and applied separately, there are relatively fewer restrictions on the moisture sensitive material and moisture sensitive layer as in the example of FIG. 1, but the ROIC (520) and The humidity sensor 530 is manufactured separately and die bonded on the PCB board 500, and the ROIC 520 and the humidity sensor 530 are electrically connected through wire bonding. There was a problem with the chip size becoming larger.

The matters described as background technology above are only for the purpose of improving understanding of the background of the present invention, and should not be taken as recognition that they correspond to prior art already known to those skilled in the art.

The present invention was devised to solve the problems of the prior art described above. By forming a temperature sensor and a humidity sensor on an ROIC board without employing a separate PCB board or silicon board, the metal thin film for the electrode of the humidity sensor is selected. The purpose is to provide a digital output temperature and humidity complex sensor that can eliminate limitations on performance and moisture-sensitive materials and reduce the overall chip size.

In addition, the present invention provides a digital output temperature and humidity composite sensor that simplifies subsequent packaging work by simultaneously forming a temperature sensor and a humidity sensor on an ROIC substrate, increases manufacturing yield, enables mass production, and reduces production costs. There is a purpose.

In addition, the present invention has another purpose of providing a digital output temperature and humidity composite sensor with excellent temperature and humidity sensing performance, eliminating the need for precise correction of temperature and humidity data by simultaneously forming a temperature sensor and a humidity sensor on the ROIC substrate.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description of the present invention. .

According to one aspect of the present invention, which was devised to solve the problems of the prior art described above, an insulating layer is formed on an ROIC substrate having an ROIC electrode pad, and the insulating layer is patterned so that the upper region of the ROIC electrode pad is open. steps; simultaneously forming a temperature sensor electrode and a humidity sensor electrode in contact with the ROIC electrode pad; Forming a pad layer on an area where the ROIC electrode pad and the temperature sensor electrode, and the ROIC electrode pad and the humidity sensor electrode are respectively connected; and forming a moisture-sensitive layer on a side of the pad layer to cover an area where the temperature sensor electrode and the humidity sensor electrode are exposed.

In the present invention, forming and patterning the insulating layer includes applying a polyimide solution on the insulating layer; Preliminary heat treatment at 140°C to 150°C for 180 to 300 seconds using a hot plate; removing part of the insulating layer by patterning the area where the upper part of the ROIC electrode pad is to be opened using a photoresist process; and post-heat treatment at 300°C to 400°C for 50 to 70 minutes in a nitrogen atmosphere using heat treatment equipment.

In the present invention, forming the temperature sensor electrode and the humidity sensor electrode simultaneously includes patterning the temperature sensor electrode and the humidity sensor electrode on the insulating layer through a photoresist process; Simultaneously forming a temperature sensor electrode layer and a humidity sensor electrode layer to a thickness of 200 to 1,000 nm using semiconductor deposition equipment; And removing the photoresist through a lift off process and heat treating for 1 to 4 hours at 600 to 1000°C in a nitrogen atmosphere using heat treatment equipment; It is desirable to have a.

In the present invention, the pad layer forming step includes patterning the ROIC electrode pad, the humidity sensor electrode, and the temperature sensor electrode using a photoresist process on the upper part of each connection portion to electrically connect the electrode pad, humidity sensor electrode, and temperature sensor electrode; Depositing a metal thin film forming a pad layer using semiconductor deposition equipment and then removing the photoresist through a lift off process; And performing heat treatment at 350°C in a nitrogen atmosphere for 30 minutes using heat treatment equipment; It is desirable to have a.

In the present invention, forming the moisture sensitive layer includes coating polyimide on areas where the temperature sensor electrode and the humidity sensor electrode are exposed; Preliminary heat treatment at 140°C to 150°C for 180 to 300 seconds using a hot plate, or prior heat treatment at 140°C to 150°C for 10 to 20 minutes using an oven; Patterning the area where a moisture-sensitive layer will be formed on the temperature sensor electrode and the humidity sensor electrode using a photoresist process; It is preferable to provide a step of performing post-heat treatment for 50 to 70 minutes at 300°C to 400°C in a nitrogen atmosphere using heat treatment equipment.

According to another aspect of the present invention to solve the problems of the prior art described above, an ROIC substrate having an ROIC electrode pad; an insulating layer formed on the ROIC substrate and patterned to open the top of the ROIC electrode pad; A temperature sensor electrode formed on one side of a pair of ROIC electrode pads; A humidity sensor electrode formed on one side of another pair of ROIC electrode pads; A pad layer electrically connecting the ROIC electrode pad and the temperature sensor electrode, and the ROIC electrode pad and the humidity sensor electrode, respectively; and a moisture-sensitive layer formed to cover the temperature sensor electrode and the humidity sensor electrode exposed on the side of the pad layer. It provides a digital output temperature and humidity complex sensor including.

In the present invention, the insulating layer is formed using polyimide, and is preferably formed to a thickness of 100 to 500 nm.

In the present invention, the moisture sensitive layer is formed of thermosetting polyimide, and the thickness is preferably within the range of 5.5 ㎛ to 6.5 ㎛.

In the present invention, the pad layer is preferably formed of aluminum (Al) with a thickness of 0.8 μm to 1.2 μm.

In the present invention, the humidity sensor electrode and the temperature sensor electrode are preferably formed using at least one metal selected from aluminum (Al), nickel (Ni), platinum (Pt), or gold (Au).

In the present invention, the temperature sensor electrode is preferably formed of a RTD (Resistance Temperature Detector) thin film having a zigzag or meandering structure, and the humidity sensor electrode is preferably formed of a thin film of an IDT (InterDigiTated) structure. .

In the present invention, it is preferable to form an insulating layer on each of the four sides of the ROIC substrate.

According to the digital output temperature and humidity composite sensor of the present invention, the temperature sensor and the humidity sensor are formed on the ROIC board without employing a separate silicon board or PCB board, thereby reducing the selectivity of the metal thin film for the electrode of the humidity sensor and the limitations on moisture absorbing materials. This has the effect of providing a miniaturized digital output temperature and humidity complex sensor by eliminating the overall chip size.

In addition, according to the present invention, by simultaneously forming a temperature sensor and a humidity sensor on the ROIC substrate, subsequent packaging work is simplified, thereby increasing manufacturing yield, enabling mass production, and reducing production costs.

In addition, according to the present invention, by simultaneously forming a temperature sensor and a humidity sensor on the ROIC substrate, precise correction of temperature and humidity data is unnecessary and excellent temperature and humidity sensing performance is achieved.

The effects of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a perspective view of a digital output temperature and humidity sensor according to the prior art.
Figure 2 is a perspective view of a digital output temperature and humidity sensor according to the prior art.
3A to 7C are step-by-step manufacturing flowcharts of the digital output temperature and humidity composite sensor according to the present invention.
Figure 8 is an optical microscope photograph of the digital output temperature and humidity composite sensor according to the present invention.
9 to 10 are graphs showing the characteristics of the digital output temperature and humidity composite sensor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately use the concept of terms to explain his or her invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle of definability. Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so at the time of filing the present application, various options that can replace them are available. It should be understood that equivalents and variations may exist.

3A to 7B are a step-by-step manufacturing flowchart of the digital output temperature and humidity composite sensor according to the present invention, showing step by step how a temperature sensor and a humidity sensor are simultaneously formed in a single process on a signal processing circuit (ROIC) board.

In the present invention, the base substrate uses an ROIC substrate 100 as a lower base substrate for converting physical signals from an externally connected temperature sensor and humidity sensor into electrical signals, and the ROIC substrate 100 is installed inside the ROIC substrate 100. For electrical connection with the ROIC pad electrode 110 and external sensing-related devices for electrical shielding of the ROIC circuit protection and the temperature sensor electrode 220 and humidity sensor electrode 210 provided on top thereof. It is characterized in that all areas except the pad (not shown) are covered with an insulating layer 200 made of thermosetting polymer.

Since the upper part of the ROIC substrate 100 is manufactured through a MEMS (MicroElectroMechanical Systems) process, the surface can become very rough. This roughness of the upper surface of the ROIC substrate increases the specific surface area, which is a good condition for manufacturing a humidity sensor. You can.

And, on the upper part of the ROIC substrate 100, a plurality of pairs of ROIC electrode pads 110 may be formed to connect the temperature sensor electrode 220 and the humidity sensor electrode 210, respectively.

In the present invention, rather than forming the ROIC, temperature sensor electrode, and humidity sensor electrode on a separate silicon substrate or PCB board, the temperature sensor electrode 220 and the humidity sensor electrode 210 are formed simultaneously on the ROIC substrate 100. And, by additionally forming the pad layer 230 and the moisture sensitive layer 240, miniaturization of the temperature and humidity composite sensor becomes possible.

Figures 3a and 3b show a plurality of pairs of ROIC electrode pads formed on an ROIC substrate.

In the present invention, ROIC (ReadOut Integrated Circuits) refers to a device that receives sensor signals from the outside through semiconductor equipment and CMOS processes and converts them into digital signals through calculation, comparison, and processing within the ROIC. In particular, the implementation of the present invention According to an example, the ROIC substrate 100 is characterized by configuring a circuit therein to digitally process analog signals from an external temperature sensor and a humidity sensor.

Therefore, the ROIC substrate 100 applied to the present invention includes a capacitance-to-digital converter (CDC) and an RDC (RDC) that can receive and process analog signals (e.g., capacitance value, resistance value, etc.) from a temperature sensor or humidity sensor. resistance-to-digital converter) and two or more pairs of ports (not shown) connected to a temperature sensor and a humidity sensor, respectively.

Meanwhile, as described above, two or more pairs of ROIC electrode pads 110 may be formed on the ROIC substrate 100 to connect the temperature sensor electrode 220 and the humidity sensor electrode 210, respectively.

Figures 4a and 4b show the electrode pad 110 being opened after applying the insulating layer 200 on the ROIC substrate.

First, in the present invention, an insulating layer 200 is formed on an ROIC substrate 100 having an ROIC electrode pad 110, and the insulating layer 200 is patterned so that the upper region of the ROIC electrode pad 110 is open. Go through the steps.

In addition, as described above, when forming the insulating layer 200, the ROIC substrate forms insulating layers on each of the four sides of the ROIC substrate, so that the area where the ROIC electrode pad 110 is formed and the external sensing-related device (e.g. : The insulating state can be maintained except for the area where the port (second ROIC electrode pad; not shown) connected to the sensing data display device, etc. is formed.

That is, after forming the insulating layer 200 for electrical insulation on the ROIC substrate 100, the ROIC electrode pad 110 is electrically connected to the temperature sensor electrode 220 and the humidity sensor electrode 210. And patterning is performed to expose the port (second ROIC electrode pad) for ROIC operation of the ROIC substrate 100.

In the present invention, a port (second ROIC electrode pad) for the ROIC operation may be formed in the lower part of the ROIC substrate 100 according to the needs of the invention.

The insulating layer 200 can be formed using a thermosetting polymer, preferably polyimide.

For example, after applying polyimide on the ROIC substrate 100, prior heat treatment is performed at 140°C to 150°C for 180 to 300 seconds using a hot plate, and then a photoresist process is performed. A portion of the insulating layer is removed by patterning the area where the upper part of the ROIC electrode pad will be exposed, and the insulating layer 200 is formed by post heat treatment at 300°C to 400°C for 60 minutes in a nitrogen atmosphere using heat treatment equipment. You can.

At this time, polyimide can be patterned in a photoresist developer to simplify the process, and the insulating layer 200 after post-heat treatment is preferably formed to have a thickness within the range of 100 nm to 500 nm.

Figures 5a and 5b show the humidity sensor electrode 210 and the temperature sensor electrode 220 being formed simultaneously on the ROIC electrode pad 110 and the insulating layer 200.

That is, the present invention goes through the step of simultaneously forming the temperature sensor electrode 220 and the humidity sensor electrode 210, which are in contact with the ROIC electrode pad 110, respectively. This will be described in detail as follows.

The process of simultaneously forming the temperature sensor electrode 220 and the humidity sensor electrode 210 includes i) patterning the temperature sensor electrode and the humidity sensor electrode on the insulating layer through a photoresist process, and ii) semiconductor deposition. After simultaneously forming the temperature sensor electrode layer and the humidity sensor electrode layer to a thickness of 200 to 1,000 nm using equipment, iii) remove the photoresist through a lift off process, and heat treatment equipment to 600 ~ 600 nm in a nitrogen atmosphere. It goes through a heat treatment process at 1000°C for 1 to 4 hours.

The temperature sensor electrode 220 and the humidity sensor electrode 210 are each deposited in the form of a metal thin film using at least one metal selected from aluminum (Al), nickel (Ni), platinum (Pt), or gold (Au). It can be formed by heat treatment afterward.

In addition, the metal thin film of the temperature sensor electrode and the humidity sensor electrode is deposited to a metal thickness of about 200 nm to 1000 nm using deposition equipment such as a sputter or E-Beam Evaporator, and then subjected to a high temperature heat treatment process to form a humidity sensor. Electrodes and temperature sensor electrodes can be formed.

If the temperature sensor electrode 220 and the humidity sensor electrode 210 are formed using platinum (Pt), the thickness is approximately 2,000 Å to 10,000 Å using a deposition method using an E-Beam Evaporator or a sputtering deposition method. It is desirable to form it by depositing a thickness of , followed by a high-temperature heat treatment process. Platinum has excellent stability, linearity, and chemical resistance over a wide temperature range (-200 to 850℃).

Meanwhile, in order to improve the adhesion between the temperature sensor electrode 220 and the humidity sensor electrode 210 and the insulating layer 200 and the moisture sensitive layer 240 according to the needs of the invention, the temperature sensor electrode 220 and the humidity sensor electrode 220 An adhesive layer (not shown) may be deposited to a thickness of 100 Å to 500 Å on the upper and lower portions of the sensor electrode 210, respectively.

The adhesive layer (not shown) can be deposited using magnesium oxide (MgO), chromium (Cr), or titanium (Ti), and is heated at 1,000°C so that the metal thin film forming the temperature sensor electrode and humidity sensor electrode approaches bulk properties. It is desirable to perform the heat treatment process for about 1 to 4 hours.

And, as can be seen in Figure 5a, the temperature sensor electrode 220 is formed as a resistance temperature detector (RTD) thin film structure having a zigzag or meandering structure, and the humidity sensor electrode 210 has a comb tooth structure. Alternatively, it can be formed in the form of a thin film with an IDT (Interdigitated) structure in which the fingers of both hands are crossed.

As such, in the present invention, the mask is designed and manufactured to integrate the temperature sensor electrode 220 and the humidity sensor electrode 210, thereby simplifying the process by reducing the number of unit processes, reducing manufacturing costs, and miniaturizing the size of individual chips for mass production. There are possible advantages to this.

Figures 6a and 6b show the formation of a pad layer 230 for electrical connection between each of the humidity sensor electrode 210 and the temperature sensor electrode 220 and the ROIC electrode pad 110.

In the present invention, a pad layer 230 is formed on the area where the ROIC electrode pad 110 and the temperature sensor electrode 220, and the ROIC electrode pad 110 and the humidity sensor electrode 210 are respectively connected. .

To explain in more detail, the pad layer 230 forming step is: i) the upper part of each connection portion for electrical connection between the ROIC electrode pad 110, the humidity sensor electrode 210, and the temperature sensor electrode 220; patterning using a photoresist process ii) depositing a metal thin film forming the pad layer 230 using semiconductor deposition equipment and then removing the photoresist through a lift off process, iii) Heat treatment may be performed at 350°C in a nitrogen atmosphere for 30 minutes using heat treatment equipment.

Aluminum (Al) can be applied as a metal thin film for forming the pad layer 230, patterned using a semiconductor photo process, and formed into a metal thin film using deposition equipment such as an E-Beam Evaporator. It is deposited.

The thickness of the pad layer 230 is preferably within the range of 0.8㎛ to 1.2㎛ to facilitate metal thin film formation and wire bonding work that may be required later.

Meanwhile, the pad layer 230 is formed in the upper area of the connection area between the ROIC electrode pad 110 and the temperature sensor electrode 220 and the connection area between the ROIC electrode pad 110 and the humidity sensor electrode 210 according to the needs of the invention. It is also possible to further form a getter (not shown) in the upper area.

As a material to form the getter, a metal that is highly reactive with moisture and oxygen, has a low melting point, and can easily evaporate is used. Moisture or moisture that has penetrated into the pad layer 230 due to the adsorption effect of this metal is used. It can perform the function of removing gas.

The getter includes one or more metal alloys selected from the group consisting of Ba-Al, Zr-Al, and Zr-Ni, or a metal consisting of Ba, Ti, V, Zr, Nb, Ta, Th, and Ce. It may be formed of a material containing one or more selected from the group.

On the other hand, the pad layer 230 may be formed as a separate pad layer in consideration of the type and thickness of the metal thin film used to form the temperature sensor electrode 220 and the humidity sensor electrode 210 according to the needs of the invention. If there is no problem with the electrical connection between the temperature sensor electrode 220, the humidity sensor electrode 210, and the ROIC electrode pad 110, the pad layer 230 forming process may be omitted.

Figures 7a and 7b show a moisture-sensitive layer 240 formed on the humidity sensor electrode 210 and the temperature sensor electrode 220.

The present invention goes through the step of forming a moisture sensitive layer 240 on the side of the pad layer 230 to cover the area where the temperature sensor electrode 220 and the humidity sensor electrode 210 are exposed.

To explain in more detail, the step of forming the moisture sensitive layer 240 includes i) coating polyimide on the area where the temperature sensor electrode and humidity sensor electrode are exposed, ii) hot plate ( Preliminary heat treatment at 140°C to 150°C for 180 to 300 seconds using a Hot Plate, or preheating at 140°C to 150°C for 10 to 20 minutes using an oven, iii) Photo patterning the area where the moisture-sensitive layer will be formed on the temperature sensor electrode and the humidity sensor electrode using a resist process; iv) performing post-heat treatment for 50 to 70 minutes at 300°C to 400°C in a nitrogen atmosphere using heat treatment equipment; You can go through the steps.

The moisture sensitive layer 240 may be formed using a thermosetting polymer, but it is preferable to use a photosensitive thermosetting polyimide. After coating the upper area of the ROIC substrate 100 with polyimide, prior heat treatment is performed, the area where the moisture reduction layer 240 is formed is patterned using a photoresist process, and the photoresist in the remaining area is removed using acetone and cleaned. After this, post-heat treatment may be performed to form the moisture reduction layer 240.

In the present invention, the moisture sensitive layer 240 is preferably formed to have a thickness within the range of 5.5 ㎛ to 6.5 ㎛ after performing a post-heat treatment process.

Meanwhile, according to the needs of the invention, the moisture sensitive layer 240 is prepared by synthesizing Poly(pyromellitic dianhydride - co-4, 4'-oxydianiline), amic acid solution, and Polyimide Varnish in a 1:1 or 1:2 ratio and then stirring. However, it can also be applied by coating with a thickness of 100 Å ~ 500 Å (7um ~ 8um) at 3000RPM ~ 5000RPM using a spin coater.

At this time, a buffer layer (not shown) can be formed with an adhesion enhancing material between the moisture sensitive layer 240 and the insulating layer 200. A process of applying an HMDS-based solution and depositing it to a thickness of 150Å to 200Å can be added. It may be possible.

Figure 7c is a perspective view of the digital output temperature and humidity composite sensor according to the present invention, and Figure 8 is an optical microscope photograph of the digital output temperature and humidity composite sensor according to the present invention.

The digital output temperature and humidity composite sensor of the present invention includes an ROIC substrate 100 having an ROIC electrode pad 110, is formed on the ROIC substrate 100, and is patterned so that a portion of the ROIC electrode pad 110 is exposed. an insulating layer 200, a temperature sensor electrode 220 formed on one side of a pair of ROIC electrode pads, a humidity sensor electrode 210 formed on one side of another pair of ROIC electrode pads, and the ROIC electrode A pad layer 230 that electrically connects the pad and the temperature sensor electrode, the ROIC electrode pad and the humidity sensor electrode, respectively, and a moisture sensitive layer 240 formed to cover the temperature sensor electrode and the humidity sensor electrode exposed on the side of the pad layer. ) can be formed including.

The insulating layer 200 is formed using polyimide, and may be formed to a thickness of 100 to 500 nm, and the moisture sensitive layer 240 is made of thermosetting polyimide or graphene oxide. However, the thickness may be within the range of 5.5 ㎛ to 6.5 ㎛.

The pad layer 230 is made of aluminum (Al) and can be formed to a thickness of 0.8㎛ to 1.2㎛, and the humidity sensor electrode 210 and temperature sensor electrode 220 are each made of aluminum (Al). , may be formed using any one or more metals of nickel (Ni), platinum (Pt), or gold (Au).

The temperature sensor electrode 220 is formed of a resistance temperature detector (RTD) metal thin film having a zigzag or meandering structure, and the humidity sensor electrode 210 is formed of a metal thin film of an IDT (InterDigiTated) structure. can be formed.

The ROIC substrate 100 may have an insulating layer 230 formed on its lower portion and on its four sides.

Referring to the optical microscope image of FIG. 8, it shows the temperature sensor electrode, humidity sensor electrode, pad layer, and moisture loss layer formed on the ROIC substrate. For convenience of understanding, a moisture loss layer is placed on top of the temperature sensor electrode 220. is not formed, and a moisture-sensitive layer is formed only on the upper part of the humidity sensor electrode 210. After completing this process, individual devices are formed through wafer dicing, and additional packaging operations are performed to complete the product.

9 to 10 are graphs showing the characteristics of the digital output temperature and humidity composite sensor according to the present invention.

Figure 9 is a graph showing the capacitance according to the adsorption/desorption (change) of moisture of the digital output temperature and humidity sensor according to the present invention.

As can be seen in Figure 9, the digital output temperature and humidity composite sensor of the present invention shows a constant capacitance over time, confirming that it functions as a highly reliable humidity sensor.

In addition, the present invention shows linear characteristics in which the capacitance increases and decreases consistently as the amount of moisture increases and decreases. When the humidity increases or decreases based on a specific relative humidity, it shows a constant capacitance, thereby providing high reliability. It can be confirmed that it is guaranteed.

Figure 10 is a graph showing the resistance value according to the change in temperature of the digital output temperature and humidity sensor according to the present invention.

The digital output temperature and humidity composite sensor of the present invention exhibits linear characteristics in which the resistance value increases and decreases consistently as the temperature increases, and it can be confirmed that this also ensures high reliability as a temperature sensor.

In this way, the present invention goes beyond the existing method of manufacturing the sensor and ROIC separately and connecting them through wire bonding, etc., by simultaneously forming a temperature sensor and a humidity sensor on the ROIC chip, thereby using the temperature sensor inside the ROIC chip. Compared to existing products, it has the advantage of providing a small digital output temperature and humidity complex sensor that has excellent sensing performance and simplifies subsequent packaging work, resulting in high yield and reduced production costs.

In addition, the present invention forms a temperature sensor electrode and a humidity sensor electrode on an ROIC chip, so that a temperature and humidity composite sensor can be freely manufactured without restrictions on the selectivity of the metal thin film for forming the electrode of the humidity sensor and the adoption of moisture sensitizing materials. There is an advantage.

Although the present invention has been described above in relation to specific embodiments of the present invention, this is only an example and the present invention is not limited thereto. A person of ordinary skill in the technical field to which the present invention pertains may change or modify the described embodiments without departing from the scope of the present invention, and within the scope of equivalency of the technical idea of the present invention and the scope of the patent claims described below. Various modifications and variations are possible.

100: ROIC substrate
110: ROIC electrode pad
200: insulating layer
210: Temperature sensor electrode
220: Humidity sensor electrode
230: Pad layer
240: Humidification layer
400: Silicon substrate
410: insulating film
420, 520: ROIC
430, 530: Humidity sensor
500: PCB board
510: Electrode pad

Claims (12)

Forming an insulating layer on an ROIC substrate having an ROIC electrode pad, patterning the insulating layer so that an upper region of the ROIC electrode pad is open;
simultaneously forming a temperature sensor electrode and a humidity sensor electrode each in contact with the ROIC electrode pad;
Forming a pad layer on an area where the ROIC electrode pad and the temperature sensor electrode, and the ROIC electrode pad and the humidity sensor electrode are respectively connected; and
forming a moisture-sensitive layer on a side of the pad layer to cover an area where the temperature sensor electrode and the humidity sensor electrode are exposed;
A method of manufacturing a digital output temperature and humidity composite sensor including.
The method of claim 1, wherein the insulating layer forming and patterning steps include:
Applying a polyimide solution on the insulating layer;
Preliminary heat treatment at 140°C to 150°C for 180 to 300 seconds using a hot plate;
removing part of the insulating layer by patterning the area where the upper part of the ROIC electrode pad is to be opened using a photoresist process; and
Post-heat treatment at 300°C to 400°C for 50 to 70 minutes in a nitrogen atmosphere using heat treatment equipment;
A method of manufacturing a digital output temperature and humidity composite sensor comprising:
The method of claim 1, wherein forming the temperature sensor electrode and the humidity sensor electrode simultaneously comprises:
Patterning a temperature sensor electrode and a humidity sensor electrode on the insulating layer using a photoresist process;
Simultaneously forming a temperature sensor electrode layer and a humidity sensor electrode layer to a thickness of 200 to 1,000 nm using semiconductor deposition equipment; and
Removing the photoresist through a lift off process and heat treating it at 600 to 1000°C in a nitrogen atmosphere for 1 to 4 hours using heat treatment equipment;
A method of manufacturing a digital output temperature and humidity composite sensor comprising:
The method of claim 1, wherein the pad layer forming step includes:
Patterning the upper part of each connection portion using a photoresist process to electrically connect the ROIC electrode pad, the humidity sensor electrode, and the temperature sensor electrode;
Depositing a metal thin film forming a pad layer using semiconductor deposition equipment and then removing the photoresist through a lift off process; and
Performing heat treatment at 350°C in a nitrogen atmosphere for 30 minutes using heat treatment equipment;
A method of manufacturing a digital output temperature and humidity composite sensor comprising:
The method of claim 1, wherein forming the moisture loss layer comprises:
Coating polyimide on areas where the temperature sensor electrode and the humidity sensor electrode are exposed;
Preliminary heat treatment at 140°C to 150°C for 180 to 300 seconds using a hot plate, or prior heat treatment at 140°C to 150°C for 10 to 20 minutes using an oven;
Patterning the area where a moisture-sensitive layer will be formed on the temperature sensor electrode and the humidity sensor electrode using a photoresist process;
Performing post-heat treatment at 300°C to 400°C in a nitrogen atmosphere for 50 to 70 minutes using heat treatment equipment;
A method of manufacturing a digital output temperature and humidity composite sensor comprising:
ROIC substrate having ROIC electrode pads;
an insulating layer formed on the ROIC substrate and patterned to open the top of the ROIC electrode pad;
A temperature sensor electrode formed on one side of a pair of ROIC electrode pads;
A humidity sensor electrode formed on one side of another pair of ROIC electrode pads;
A pad layer electrically connecting the ROIC electrode pad and the temperature sensor electrode, and the ROIC electrode pad and the humidity sensor electrode, respectively; and
a moisture-sensitive layer formed to cover the temperature sensor electrode and the humidity sensor electrode exposed on the side of the pad layer;
Digital output temperature and humidity complex sensor including.
According to clause 6,
A digital output temperature and humidity composite sensor, wherein the insulating layer is formed using polyimide and is formed to a thickness of 100 to 500 nm.
According to clause 6,
A digital output temperature and humidity composite sensor, wherein the moisture layer is formed of thermosetting polyimide and has a thickness within the range of 5.5 ㎛ to 6.5 ㎛.
The method of claim 6, wherein the pad layer is:
A digital output temperature and humidity composite sensor made of aluminum (Al) with a thickness of 0.8㎛ to 1.2㎛.
According to clause 6,
A digital output temperature and humidity composite sensor, wherein the humidity sensor electrode and the temperature sensor electrode are each formed using at least one metal selected from aluminum (Al), nickel (Ni), platinum (Pt), or gold (Au).
According to clause 6,
The temperature sensor electrode is formed of a resistance temperature detector (RTD) thin film having a zigzag or meandering structure,
A digital output temperature and humidity composite sensor, wherein the humidity sensor electrode is formed of a thin film with an IDT (InterDigiTated) structure.
According to clause 6,
A digital output temperature and humidity composite sensor, characterized in that the ROIC substrate forms an insulating layer on each of its four sides.