KR20230030211A - Chip Package and Apparatus of MEMS Gas Sensor to provide Variable Output Voltage - Google Patents

Abstract

The present invention relates to a MEMS gas sensor chip package capable of variable output voltage supply. The MEMS gas sensor chip package includes: a MEMS gas sensing unit (100) provided on a printed circuit board (10); a signal processing unit (200) placed on the printed circuit board (10), apart from the MEMS gas sensing unit (100) to be electrically connected; a first chip cover (20a) having a gas inlet (21) formed on one side, and provided on the printed circuit board (10) to surround the MEMS gas sensing unit (100) and the signal processing unit (200) in a spaced state; and a housing cover (30) having a gas inlet (31) formed on one side, and provided on the printed circuit board (10) to surround the first chip cover (20) in a spaced state. The signal processing unit (200) includes a variable output voltage charge pump unit (210) supplying a variable voltage to the MEMS gas sensing unit (100). Therefore, the present invention is capable of variably controlling a heating temperature.

Description

MEMS gas sensor chip package and MEMS gas sensor device capable of supplying variable output voltage {Chip Package and Apparatus of MEMS Gas Sensor to provide Variable Output Voltage}

The present invention relates to a MEMS gas sensor chip package and a MEMS gas sensor device. Specifically, it relates to a MEMS gas sensor chip package capable of supplying a variable output voltage and a MEMS gas sensor device.

The gas sensor is a sensor that measures the concentration of a specific gas. The method of measuring the concentration of a specific gas is an electrochemical method that measures the change in electrical conductivity of a thin film by an electrochemical reaction and an optical method that measures the gas concentration by irradiating a characteristic absorption line and measuring the amount of absorbed light (NDIR, Non -dispersive Infra-Red).

Here, the electrochemical method is inexpensive and can be miniaturized, but has a disadvantage in that reliability is low because it varies greatly depending on temperature and humidity. The optical method is composed of an infrared irradiation unit, a sensor unit, and a waveguide unit, and has a large size, takes a long time to measure and consumes large power, so it is difficult to implement a gas sensor capable of implementing low-cost and rapid measurement. There is a problem.

The present invention is a chemical (gas) sensor related to an electrochemical method.

Uniform temperature distribution is very important in chemical sensor operation. Thermal uniformity is a factor that increases the sensitivity and selectivity of the sensor. Also, a micro-heater is required for reproducibility.

In order to obtain a uniform temperature distribution, heater structure design is important, and various heater structure designs have been studied. Even if the heater design is excellent, it is very important to supply a constant voltage corresponding to the design.

Conventional chemical sensors have been developed in the form of housings composed of a MEMS gas sensing unit chip composed of a microheater, a compensation element formed of electrodes and a detection element, and a PCB circuit board including a signal processing chip.

It cannot be packaged together with other semiconductor chips, it is sensitive to moisture, shock, heat dissipation of the PCB board, etc., and must be protected with filtering for gas collection and a housing acting as an unstable chamber.

In addition, there are problems in that it is relatively expensive and difficult to mass-produce, such as requiring manual labor or expensive automation equipment for calibrating each housing product. In addition, there is a difficulty accompanied by a high defect cost.

On the other hand, the MEMS chemical (gas) sensor device using semiconductor packaging technology is advantageous for miniaturization, can be mass-produced with a semiconductor process while maintaining uniform quality, and can be produced by adding a housing, so it can be applied to various application groups. there is.

Since semiconductor packaging can be performed, active biasing can be provided to the sensing unit and the micro-heater. To provide this active biasing, a charge pump circuit may be used.

Since existing micro heaters for chemical (gas) sensors were designed with specific specifications, circuits that fit each specification had to be designed individually in order to apply to MEMS sensors with various specifications.

In addition, when design specifications such as the structure of the micro-heater, the size of the electrodes and the sensing unit are changed, there is a problem in that the circuit must be redesigned.

However, redesigning the voltage supply circuit (charge pump) for each specification of the MEMS sensor may increase development and manufacturing costs and cause inefficiency, such as a process and layout change accordingly.

If the supply voltage of the MEMS micro-heater can be variably supplied, the micro-heater design and process development period can be shortened. In addition, effects such as reducing process costs, making mass production easier, and reducing defective costs will occur.

(Document 1) Korea Patent Registration No. 10-1773954 (2017.08.28)

The MEMS gas sensor chip package and the MEMS gas sensor device capable of supplying a variable output voltage according to the present invention have the following problems.

First, it is intended to variably supply the supply voltage of the MEMS micro heater.

Second, it is intended to variably control the heating temperature of the micro-heater.

Third, it is intended to manufacture the gas sensing unit in the form of a semi-finished product.

The problems 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.

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas sensing unit provided on a printed circuit board; a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; and a chip cover having a gas injection hole formed on one side thereof and provided on a printed circuit board to enclose the MEMS gas sensing unit and the signal processing unit in a spaced apart state, wherein the signal processing unit has a variable voltage applied to the MEMS gas sensing unit. A variable output voltage charge pump unit for supplying may be provided.

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas sensing unit provided on a printed circuit board; a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; and a chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas sensing unit in a spaced apart state, wherein the signal processing unit supplies a variable voltage to the MEMS gas sensing unit. A voltage charge pump unit may be provided.

In the present invention, the MEMS gas sensing unit includes a compensation element having a micro-heater; and a detection element having a micro-heater and having a sensing material formed on the micro-heater.

In the present invention, the signal processing unit may include: the variable output voltage charge pump unit; a detection signal detection unit that detects a potential difference value from the detection circuit and outputs a detection signal; and an output signal amplifying unit that amplifies the detection signal Vs and outputs the gas sensor output signal to the outside.

In the present invention, the variable output voltage charge pump unit may step up the power supply voltage according to a voltage selection signal and a reference voltage according to characteristics of the compensation element and detection element of the MEMS gas sensing unit, and output the variable output voltage.

In the present invention, the variable output voltage charge pump unit is obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N according to a voltage selection signal specifying the division ratio n/N (a natural number of 1≤=n≤=N). a voltage level controller generating an oscillator control signal to be activated or deactivated according to a result of comparing the divided voltage with the reference voltage; an oscillator outputting a clock signal having a predetermined frequency when the oscillator control signal is activated; and a charge pump outputting the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator.

In the present invention, the voltage level control unit includes a voltage divider receiving feedback of the variable output voltage of the charge pump and generating N divided voltages distributed at predetermined voltage intervals; a voltage selector for selecting an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputting the selected n-th division voltage; and comparing the nth divided voltage with the reference voltage, activating the operation of the oscillator when the nth divided voltage is lower than the reference voltage, and inactivating the operation of the oscillator when higher than or equal to the reference voltage, the oscillator A comparator for generating a control signal may be included.

In the present invention, the voltage divider generates an n-th division voltage corresponding to a division ratio n/N of the voltage divider among the N division voltages output from nodes of the N series-connected resistive elements or diodes. It is selected by the voltage selection signal and can operate to output the selected n-th distribution voltage.

In the present invention, the charge pump may further include a low pass filter for removing a ripple component of the variable output voltage caused by repeated activation and deactivation of the charge pump.

The present invention is a MEMS gas sensor device capable of supplying a variable output voltage, comprising: a MEMS gas sensing unit provided on a printed circuit board; a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; a first chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas sensing unit and the signal processing unit in a spaced apart state; and a housing cover having a gas injection hole formed on one side thereof and provided on the printed circuit board to enclose the first chip cover in a spaced apart state, wherein the signal processing unit supplies a variable voltage to the MEMS gas sensing unit. A voltage charge pump unit may be provided.

The present invention is a MEMS gas sensor device capable of supplying a variable output voltage, comprising: a MEMS gas sensing unit provided on a printed circuit board; a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; a second chip cover having a gas injection hole formed on one side and provided on the printed circuit board to surround the MEMS gas sensing unit in a spaced state; and a housing cover having a gas injection hole formed on one side and provided on the printed circuit board to enclose the second chip cover and the signal processing unit in a spaced apart state, wherein the signal processing unit supplies a variable voltage to the MEMS gas sensing unit. A variable output voltage charge pump unit may be provided.

In the present invention, a filter unit in the form of a thin film may be provided in each of the gas injection holes.

The present invention is a charge pump circuit capable of supplying a variable output voltage, wherein the variable output voltage of the charge pump is multiplied by the division ratio n/N according to a voltage selection signal specifying the division ratio n/N (a natural number where 1≤=n≤=N). a voltage level controller for generating an oscillator control signal to activate or deactivate the divided voltage according to a result of comparing the obtained divided voltage with the reference voltage; an oscillator outputting a clock signal having a predetermined frequency when the oscillator control signal is activated; and a charge pump outputting the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator.

In the present invention, the voltage level control unit includes a voltage divider generating N divided voltages distributed at predetermined voltage intervals by receiving feedback of the variable output voltage of the charge pump; a voltage selector for selecting an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputting the selected n-th division voltage; and comparing the nth divided voltage with the reference voltage, activating the operation of the oscillator when the nth divided voltage is lower than the reference voltage, and inactivating the operation of the oscillator when higher than or equal to the reference voltage, the oscillator A comparator for generating a control signal may be included.

In the present invention, the voltage divider generates an n-th division voltage corresponding to a division ratio n/N of the voltage divider among the N division voltages output from nodes of the N series-connected resistive elements or diodes. It is selected by the voltage selection signal and can operate to output the selected n-th distribution voltage.

In the present invention, the charge pump may further include a low pass filter for removing a ripple component of the variable output voltage caused by repeated activation and deactivation of the charge pump.

The present invention is a method for driving a variable output voltage charge pump device including a voltage level controller, an oscillator, and a charge pump, wherein the voltage level controller selects a voltage specifying a division ratio n/N (a natural number where 1≤=n≤=N). Step S100 of generating an oscillator control signal to be activated or deactivated according to a result of comparing the divided voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N according to the signal with the reference voltage; Step S200 of the oscillator outputting a clock signal having a preset frequency when the oscillator control signal is activated; and step S300 in which the charge pump outputs the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator.

In the present invention, step S100 includes step S110 in which a voltage divider receives feedback of the variable output voltage of the charge pump and generates N divided voltages distributed at predetermined voltage intervals; a step S120 in which a voltage selector selects an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputs the selected n-th division voltage; And a comparator compares the n-th divided voltage with the reference voltage, activates the operation of the oscillator when the n-th divided voltage is lower than the reference voltage, and disables the operation of the oscillator when higher than or equal to the reference voltage, A step S130 of generating the oscillator control signal may be included.

In the present invention, in step S110, the voltage divider divides the nth distribution corresponding to the division ratio n/N of the voltage divider among the N division voltages output from the nodes of the N series-connected resistive elements or diodes. A voltage can be selected by the voltage selection signal and operated to output the selected n-th divided voltage.

In the present invention, in step S300, the charge pump may further include a low-pass filter for removing a ripple component of the variable output voltage caused by repetitive activation and deactivation of the charge pump.

The MEMS gas sensor chip package and the MEMS gas sensor device capable of supplying a variable output voltage according to the present invention have the following effects.

First, there is an effect of variably supplying the supply voltage of the MEMS micro heater by using a variable output voltage charge pump.

Second, since a variable voltage can be supplied to the micro-heater, there is an effect of variably controlling the heating temperature.

Third, through a structure in which the MEMS gas sensing unit 100 and the signal processing unit 200 are packaged together in a chip cover or a structure in which the MEMS gas sensing unit 100 is packaged in a chip cover, it is manufactured in the form of a semi-finished product and the performance evaluation is performed. There are possible effects.

Fourth, even if the application is changed, it can be applied to a new application by simply changing the output voltage setting without the need to redesign the charge pump, so there is an effect of providing versatility and scalability.

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

1 is a first embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
2 is a second embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
3 is an embodiment of a block diagram related to a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.
4 is an embodiment of a block diagram related to a variable output voltage charge pump according to the present invention.
5 is a circuit diagram of a voltage divider of a variable output voltage charge pump according to an embodiment of the present invention.
6 is a circuit diagram of a voltage selector of a variable output voltage charge pump according to an embodiment of the present invention.
7 is a graph illustrating output voltages of a variable output voltage charge pump according to an embodiment of the present invention.
8 is a flowchart of a driving method of a variable output voltage charge pump device according to the present invention.
9 is a detailed flowchart of step S100 according to the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described so that those skilled in the art can easily practice it. As can be easily understood by those skilled in the art to which the present invention pertains, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible, identical or similar parts are indicated using the same reference numerals in the drawings.

The terminology used in this specification is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite.

As used herein, the meaning of "comprising" specifies particular characteristics, regions, integers, steps, operations, elements, and/or components, and other specific characteristics, regions, integers, steps, operations, elements, components, and/or components. It does not exclude the presence or addition of groups.

All terms including technical terms and scientific terms used in this specification have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. The terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the currently disclosed content, and are not interpreted in an ideal or very formal meaning unless defined.

Expressions related to directions used in this specification, for example, expressions of front/back/left/right, top/bottom, and longitudinal/lateral directions may be interpreted with reference to directions disclosed in the drawings.

Hereinafter, the present invention will be described with reference to the drawings. For reference, the drawings may be partially exaggerated in order to explain the features of the present invention. In this case, it is preferable to interpret in light of the whole purpose of this specification.

A uniform temperature distribution is very important in the operation of a gas sensor. Thermal uniformity is a factor that increases the sensitivity and selectivity of gas sensors. To this end, the design and development of micro heaters in the MEMS gas sensing unit (detection element and compensation element) are very important.

In addition, a uniform temperature distribution must be made at a level corresponding to the characteristics (application amount or thin film thickness) of the sensing material formed by dispensing, screen printing, thin film deposition, etc. on top of the micro heater.

The sensing material may be a compound or synthetic compound that reacts to gas (eg, hydrogen), and a complex compound synthesized with a catalyst capable of lowering activation energy, which is manufactured as a semi-finished sensor (micro heater/sensing unit and signal processing unit). After being formed (without chip case or housing case), performance evaluation can proceed.

If voltage can be variably supplied to the micro-heater, the heat generation temperature can be variably adjusted and a uniform temperature distribution corresponding to the characteristics of the sensing material can be maintained, thereby greatly improving performance such as preventing loss of the sensing material and durability. .

In addition, semiconductor packaging becomes possible, and tuning is possible even in the case of a sensor semi-finished product (chip cover) or finished product (housing), making it possible to produce various products that can be used in the field of hydrogen vehicles and other fields.

The present invention can be implemented as an MEMS gas sensor chip package capable of supplying a variable output voltage, an MEMS gas sensor device, a charge pump circuit invention, and a charge pump device driving method invention.

Hereinafter, each invention will be sequentially described. In addition, each invention is intended to be explained based on differentiated main contents rather than overlapping contents.

First, the invention of a MEMS gas sensor chip package capable of supplying a variable output voltage will be described. Chip package invention is possible in two embodiments.

A first embodiment of the chip package invention according to the present invention is as follows (see FIG. 1).

The present invention is a MEMS gas sensor chip package capable of supplying a variable output voltage, comprising: a MEMS gas sensing unit 100 provided on a printed circuit board 10; a signal processing unit 200 electrically connected to and spaced apart from the MEMS gas sensing unit 100 on the printed circuit board 10; and a chip cover 20 having a gas injection hole 21 formed on one side and provided on the printed circuit board 10 to surround the MEMS gas sensing unit 100 and the signal processing unit 200 in a spaced apart state. The signal processing unit 200 may include a variable output voltage charge pump unit 210 supplying a variable voltage to the MEMS gas sensing unit 100 .

A second embodiment of the chip package invention according to the present invention is as follows (see FIG. 2).

The present invention includes a MEMS gas sensing unit 100 provided on a printed circuit board 10; a signal processing unit 200 electrically connected to and spaced apart from the MEMS gas sensing unit 100 on the printed circuit board 10; and a chip cover 20 having a gas injection hole 21 formed on one side thereof and provided on the printed circuit board 10 to surround the MEMS gas sensing unit 100 in a spaced apart state, wherein the signal processing unit 200 may include a variable output voltage charge pump unit 210 supplying a variable voltage to the MEMS gas sensing unit 100 .

Due to manufacturing characteristics of the electrochemical gas sensor as in the present invention, it is necessary to check the operation and performance of the sensor's detection element (sensing material) and reactive gas.

However, the conventional chemical sensor has a problem in that the gas sensor is processed after manufacturing the finished product, and most of the finished product must be disposed of in the case of insufficient performance later.

Thus, the present invention can be manufactured as a semi-finished sensor, like the first and second embodiments of the chip package described above.

The present invention is characterized in that performance evaluation can be performed in the semi-finished product state of the first and second embodiments.

In the MEMS gas sensor chip package according to the first and second embodiments of the present invention, the MEMS gas sensing unit 100 includes a compensation element 110 having a micro heater 111; and a detection element 120 having a micro-heater 121 and having a sensing material 122 formed on the micro-heater 121 .

The MEMS gas sensing unit 100 according to the present invention includes a compensation element 110 on which a micro-heater 111 is formed, and a detection element 120 on which a sensing material 122 is formed on the micro-heater 121 having the same specifications as the compensation element. consists of

The MEMS gas sensing unit 100 and the signal processing unit 200 may be packaged together after being formed on separate chips in separate processes, or may be formed during the same process on a single wafer. For convenience of description, in FIG. 3, the two chips 100 and 200 are separately formed and then packaged.

On the MEMS gas sensing unit 100, the MEMS compensation element 110 and the detection element 120 are formed.

Voltage is supplied to the compensation element 110 and the detection element 120 by the variable output voltage Vcpo applied through the voltage input terminal 130 . The resistance of the detection element 120 changes according to the heat change due to the heat of reaction with the target gas (eg, hydrogen), and in FIG. The voltage (V1-V2) output value is input to the detection signal detector 220 according to the Wheatstone bridge detection method for the resistance change value.

The signal processing unit 200 according to the present invention includes a variable output voltage charge pump unit 210; a detection signal detection unit 220 that detects a potential difference value from the detection circuit and outputs a detection signal; and an output signal amplifier 230 that amplifies the detection signal Vs and outputs the gas sensor output signal to the outside.

The variable output voltage charge pump unit 210 according to the present invention supplies power supply voltage according to the voltage selection signal Vref according to the characteristics of the compensation element 110 and the detection element 120 of the MEMS gas detection unit 100 and the reference voltage. (Vcc) can be boosted and output as a variable output voltage (Vcpo).

The variable output voltage charge pump unit 210 according to the present invention multiplies the variable output voltage of the charge pump by the division ratio n/N according to the voltage selection signal specifying the division ratio n/N (1≤=n≤=N factor constant). a voltage level control unit 211 for generating an oscillator control signal to be activated or deactivated according to a result of comparing the obtained divided voltage with the reference voltage; an oscillator 212 outputting a clock signal having a preset frequency when the oscillator control signal is activated; and a charge pump 213 outputting the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator 212 .

The detection signal detection unit 220 detects the value of the potential difference (V1-V2) from the Wheatstone bridge detection circuit and outputs the detection signal (Vs).

The output signal amplifier 230 amplifies the detection signal Vs and outputs it to the outside as a chemical sensor output signal Vout.

The operation and configuration of the variable output voltage charge pump unit 210 according to the present invention will be described in detail.

4 is an embodiment of a block diagram related to a variable output voltage charge pump according to the present invention.

Referring to FIG. 3 together, it may seem that the variable output voltage charge pump unit 210 of FIG. 4 can be used only in the MEMS chemical gas sensor device, but the variable output voltage charge pump according to the present invention is a MEMS chemical gas sensor device. It is not a circuit that is limitedly applied to the application field of The present invention intends to clarify that when designing a device that normally requires a charge pump, if it is desirable for the charge pump to provide different output DC voltages according to purposes or specifications, it can be applied to any application field.

In FIG. 4 , the variable output voltage charge pump unit 210 includes a voltage level control unit 211 , an oscillator 212 and a charge pump 213 .

The voltage level controller 211 according to the present invention includes a voltage divider 2111 generating N divided voltages distributed at predetermined voltage intervals by receiving feedback of the variable output voltage of the charge pump 213; a voltage selector 2112 for selecting an n-th division voltage corresponding to a division ratio n/N among N division voltages by the voltage selection signal and outputting the selected n-th division voltage; and comparing the nth divided voltage with the reference voltage, if the nth divided voltage is lower than the reference voltage, the operation of the oscillator 212 is activated, and if it is higher than or equal to the reference voltage, the operation of the oscillator 212 is activated. To deactivate, a comparator 2113 generating the oscillator control signal is included.

The voltage level control unit 211 according to the present invention is a distribution ratio n/N (a natural number of 1≤=n≤=N) determined according to the specifications of the compensation element 110 and the detection element 120 in the MEMS gas detection unit 100. According to the result of comparing the division voltage V_n obtained by multiplying the division ratio n/N by the variable output voltage Vcpo of the charge pump 213 according to the voltage selection signal Vsel specifying the oscillator with the reference voltage Vref An oscillator control signal (ENb) that is activated or deactivated to control the operation of 212 is generated.

The voltage values corresponding to the specifications of the compensation element 110 and the detection element 120 in the MEMS gas sensing unit 100 are: For example, it may be selected within a range from the minimum output possible voltage of the charge pump 213 to the maximum output possible voltage.

In addition, in order for the variable output voltage Vcpo to reach and maintain a desired voltage value, the division voltage V_n obtained by multiplying the variable output voltage Vcpo by the division ratio n/N must equal the reference voltage Vref.

Accordingly, the division ratio n/N may be referred to as a ratio obtained by dividing the value of the reference voltage Vref by a desired voltage value, that is, a target variable output voltage Vcpo.

Therefore, the variable output voltage charge pump unit 210 of the present invention is a variable output voltage fixed at a higher voltage level as the division ratio n/N is lowered within the range from the minimum output voltage to the maximum output voltage of the charge pump 213. The output voltage Vcpo can be obtained, and when the division ratio n/N is increased, a variable output voltage Vcpo fixed at a low voltage level can be obtained.

Meanwhile, in FIG. 4 , the oscillator control signal ENb is exemplified as a signal activated when the logic is low, but may be generated as a signal activated when the logic is high.

Specifically, the voltage level controller 211 may include a voltage divider 2111, a voltage selector 2112, and a comparator 2113.

The voltage divider 2111 according to the present invention is the nth division corresponding to the division ratio n/N of the voltage divider 2111 among the N division voltages output from the nodes of the N series-connected resistive elements or diodes. A division voltage may be selected by the voltage selection signal, and the selected n-th division voltage may be output.

The voltage divider 2111 receives the variable output voltage Vcpo of the charge pump 213 as feedback and generates N divided voltages V_1 ...*V_N distributed at predetermined voltage intervals, preferably at equal voltage intervals. generate

For example, as shown in FIG. 5, the voltage divider 2111 may be implemented with N series-connected resistive elements or N series-connected diodes (D_1, D_2, D_3, …*, D_n, …*D_N). there is. Divided voltages (V_1, V_2, V_3, …*, Vn, …*V_N) can be output from the contact nodes of two resistive elements or two diodes.

The voltage selector 2112 is a voltage divider 2111 corresponding to the division ratio n/N among the N division voltages V_1, ...*, V_N output from respective nodes of the N series-connected resistive elements or diodes. The nth division voltage V_n is selected by the voltage selection signal Vsel, and the selected division voltage V_n is output.

Preferably, the voltage selector 2112 is the n-th node corresponding to the division ratio n/N of the voltage divider 2111 among the N division voltages V_1, ...*, V_N, that is, the n-th resistive element or diode from the bottom. and the n+1th resistive element or diode, the n-th division voltage (V_n) output from the node is selected by the voltage selection signal (Vsel), and the selected division voltage (V_n) is output.

At this time, the voltage selector 2112 selects the Nth division voltage (V_N) when the division ratio n/N is maximum (n=N), and selects the 1st division voltage (V_N) when the division ratio n/N is minimum (n=1). Note that we choose the voltage (V_1).

For example, as shown in FIG. 6, the voltage selector 2112 includes N switches (SW_1 to SW_N) connected to a divided voltage (one of V_1 to V_N) and the other side to a comparator 2113 in parallel. , and by selectively energizing only one (SW_n) of the switches (SW_1 to SW_N) by the voltage selection signal (Vsel), the nth of the N divided voltages (V_1 to V_N) provided from the voltage divider 2111 The divided voltage (V_n) may be selectively output to the comparator 2113.

The comparator 2113 compares the n-th division voltage V_n corresponding to the division ratio n/N with the reference voltage Vref, so that the n-th division voltage V_n corresponding to the division ratio n/N is higher than the reference voltage Vref. The oscillator control signal ENb is generated to activate the operation of the oscillator 212 if it is low, and to deactivate the operation of the oscillator 212 otherwise (if it is high or equal).

On the other hand, in FIG. 4, the comparator 2113 is illustrated as receiving the n-th division voltage (V_n) corresponding to the division ratio n/N from the (+) terminal and receiving the reference voltage (Vref) from the (-) terminal. . Oscillator 212 to increase variable output voltage Vcpo while the n-th division voltage V_n corresponding to the division ratio n/N is lower than the reference voltage Vref, that is, while logic Low is output from the comparator 2113. ) must be operated, the comparator 2113 exemplarily outputs the oscillator control signal ENb as a signal ENb activated when the logic is low.

Depending on the embodiment, the comparator 2113 may be implemented by receiving the n-th division voltage (V_n) corresponding to the division ratio n/N from the (-) terminal and receiving the reference voltage (Vref) from the (+) terminal. there is. In this case, increasing the variable output voltage Vcpo while the n-th division voltage V_n corresponding to the division ratio n/N is higher than the reference voltage Vref, that is, while logic High is output from the comparator 2113. Since the oscillator 212 must be operated for this purpose, the comparator 2113 may output an oscillator control signal as a signal activated when the logic is high.

Subsequently, the oscillator 212 may output clock signals CLK and CLKb having predetermined frequencies to the charge pump 213 according to whether the oscillator control signal ENb is activated. When the oscillator control signal ENb is inactivated (that is, when the division voltage V_n of the division ratio n/N in the comparator 2113 in FIG. 4 becomes higher than the reference voltage Vref), the clock signal of the oscillator 212 ( CLK, CLKb) itself may cease to be produced.

The charge pump 213 boosts the power supply voltage Vcc while the clock signal CLK is applied from the oscillator 212 to output a variable output voltage Vcpo.

The output of the clock signal CLK from the oscillator 212 is activated by the oscillator control signal Enb of the voltage level controller 211 until the variable output voltage Vcpo of the charge pump 213 reaches a desired voltage level. The variable output voltage (Vcpo) continues to rise.

When the variable output voltage Vcpo reaches a certain voltage level, the output of the clock signal CLK from the oscillator 212 is deactivated by the oscillator control signal Enb of the voltage level control unit 211, so that the charge pump 213 Actions are also disabled. Accordingly, the variable output voltage Vcpo does not rise anymore and decreases according to the equivalent time constant inside the compensating element 110 and the detecting element 120, but the reduction of the variable output voltage Vcpo is the voltage level control unit 211 When the detection level is exceeded by the comparator 2113 in the inside, the output of the clock signal CLK of the oscillator 212 is activated again, and the variable output voltage Vcpo rises again. In this way, the charge pump 213 maintains a constant level of the variable output voltage Vcpo while repeating activation/deactivation.

The charge pump 213 according to the present invention may further include a low pass filter for removing a ripple component of the variable output voltage caused by repetitive activation and deactivation of the charge pump.

According to an embodiment, a ripple component of the variable output voltage Vcpo according to activation/deactivation of the charge pump 213 may be removed by using the low pass filter 214 including a capacitor at the output terminal of the charge pump 213. may be

Hereinafter, an MEMS gas sensor device capable of supplying a variable output voltage according to the present invention will be described. Technical features of the aforementioned MEMS gas sensor chip package invention are substantially the same. Therefore, we will omit the overlapping contents and focus on the differentiation.

1 is a first embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention. 2 is a second embodiment of a MEMS gas sensor device capable of supplying a variable output voltage according to the present invention.

A first embodiment of the MEMS gas sensor device according to the present invention is as follows.

The present invention includes a MEMS gas sensing unit 100 provided on a printed circuit board 10; a signal processing unit 200 electrically connected to and spaced apart from the MEMS gas sensing unit 100 on the printed circuit board 10; A gas injection hole 21 is formed on one side, and a first chip cover 20a provided on the printed circuit board 10 to surround the MEMS gas sensing unit 100 and the signal processing unit 200 in a spaced apart state. ); and a housing cover 30 having a gas injection hole 31 formed on one side and provided on the printed circuit board 10 to surround the first chip cover 20a in a spaced apart state, wherein the signal processing unit 200 may include a variable output voltage charge pump unit 210 supplying a variable voltage to the MEMS gas sensing unit 100 .

A second embodiment of the MEMS gas sensor device according to the present invention is as follows.

The present invention includes a MEMS gas sensing unit 100 provided on a printed circuit board 10; a signal processing unit 200 electrically connected to and spaced apart from the MEMS gas sensing unit 100 on the printed circuit board 10; a second chip cover 20b having a gas injection hole 21 formed on one side and provided on the printed circuit board 10 to surround the MEMS gas sensing unit 100 in a spaced state; and a housing cover 30 provided on the printed circuit board 10 so as to surround the second chip cover 20b and the signal processing unit 200 in a spaced state with a gas injection hole 31 formed on one side thereof. The signal processing unit 200 may include a variable output voltage charge pump unit 210 supplying a variable voltage to the MEMS gas sensing unit 100 .

The first embodiment of the MEMS gas sensor device shown in FIG. 1 includes the first embodiment (related to the first chip cover) of the MEMS gas sensor chip package according to the present invention.

The second embodiment of the MEMS gas sensor device shown in FIG. 2 includes the second embodiment (related to the second chip cover) of the MEMS gas sensor chip package according to the present invention.

1 and 2, the MEMS gas sensor device according to the present invention may include a gas injection hole 21 formed in the chip cover 20 and a gas injection hole 22 formed in the housing cover 30. can

A filter unit 40 in the form of a thin film may be provided in each gas injection hole 21 or 31 according to the present invention. The filter unit 40 may be provided differently depending on the type and purpose of gas.

The two filter units provided in the gas injection holes 21 and 31 may play a role of minimizing poisoning (moisture or carbon monoxide, etc.). A material used for the filter unit may be attached to a case (housing, chip cover) including a gas injection hole by using a material capable of filtering a specific gas in the form of a thin film or film.

As an embodiment, moisture/moisture poisoning is performed step by step in the order of the filter unit provided in the gas injection hole 31 of the housing cover 30 and the filter unit provided in the gas injection hole 210 of the chip cover 20. It is possible to filter step by step.

When passing through the filter part of the chip cover, the amount of moisture poisoning is minimized, and depending on the size of the chamber (gas collection amount), it can affect the recovery time and reaction time.

As another embodiment, the filter part of the housing cover prevents moisture, and the filter part of the chip cover part prevents other gases to prevent poisoning.

The MEMS gas sensor device according to the present invention can be divided into a housing chamber and a chip cover chamber. The volume of the chamber can determine the amount of gas collection. That is, the size of the chamber means the amount of gas collection. Depending on the amount of gas, the recovery and response time performance of the gas sensor may be affected.

Since the conventional chamber size is equal to the volume of the housing case, it is larger than the embodiment of FIGS. 1 and 2 according to the present invention.

In the case of the embodiment of FIG. 1, it is larger than the embodiment of FIG. 2, but is about 70% smaller than the conventional size, and the smallest size is the case in which only the MEMS part is encased as shown in FIG.

Among the performance of a gas sensor, recovery time and response time after responding to a specific gas are very important measures. As described above, through the configuration shown in FIGS. 1 and 2 and the micro-heater technology according to the present invention, very fast recovery time and response time can be reduced. In addition, reproducibility and accuracy can be improved.

Hereinafter, the invention of a charge pump circuit capable of supplying a variable output voltage according to the present invention will be described. Technical features of the aforementioned MEMS gas sensor chip package invention are substantially the same. Therefore, we will omit the overlapping contents and focus on the differentiation.

The present invention is a charge pump circuit capable of supplying a variable output voltage, wherein the variable output voltage of the charge pump is multiplied by the division ratio n/N according to a voltage selection signal specifying the division ratio n/N (1≤=n≤=N factor constant). a voltage level control unit 211 for generating an oscillator control signal to be activated or deactivated according to a result of comparing the obtained divided voltage with the reference voltage; an oscillator 212 outputting a clock signal having a preset frequency when the oscillator control signal is activated; and a charge pump 213 outputting the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator 212 .

5 is a circuit diagram of a voltage divider of a variable output voltage charge pump according to an embodiment of the present invention. 6 is a circuit diagram of a voltage selector of a variable output voltage charge pump according to an embodiment of the present invention. 7 is a graph illustrating output voltages of a variable output voltage charge pump according to an embodiment of the present invention.

Referring to FIG. 7, the variable output voltage charge pump of the MEMS gas sensor device according to the present invention is the voltage between the compensation element 110 and the detection element 120, and the distribution ratio n/N is When the division ratio n/N is small (close to 0), one of the variable output voltages may be output as a bias voltage signal.

Hereinafter, an invention of a method for driving a charge pump device capable of supplying a variable output voltage according to the present invention will be described. Technical features of the aforementioned MEMS gas sensor chip package invention are substantially the same. Therefore, we will omit the overlapping contents and focus on the differentiation.

8 is a flowchart of a driving method of a variable output voltage charge pump device according to the present invention. 9 is a detailed flowchart of step S100 according to the present invention.

The present invention is a method for driving a variable output voltage charge pump device including a voltage level control unit 211, an oscillator 212 and a charge pump 213, wherein the voltage level control unit 211 has a division ratio n/N (1≤= An oscillator control signal that activates or deactivates the divided voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N according to the voltage selection signal specifying the natural number where n≤=N is compared with the reference voltage. S100 step of generating; Step S200 in which the oscillator 212 outputs a clock signal having a preset frequency when the oscillator control signal is activated; and a step S300 in which the charge pump 213 boosts a power supply voltage while the clock signal is applied from the oscillator 212 and outputs the variable output voltage.

Step S100 according to the present invention includes step S110 in which the voltage divider 2111 receives feedback of the variable output voltage of the charge pump 213 and generates N divided voltages distributed at predetermined voltage intervals; a step S120 in which the voltage selector 2112 selects an n-th division voltage corresponding to a division ratio n/N from among the N division voltages by the voltage selection signal and outputs the selected n-th division voltage; and a comparator 2113 compares the n-th divided voltage with the reference voltage, activates the operation of the oscillator 212 when the n-th divided voltage is lower than the reference voltage, and activates the oscillator 212 when the n-th divided voltage is equal to or higher than the reference voltage. Step S130 of generating the oscillator control signal to deactivate the operation of step 212.

The embodiments described in this specification and the accompanying drawings merely illustrate some of the technical ideas included in the present invention by way of example. Therefore, since the embodiments disclosed in this specification are intended to explain rather than limit the technical spirit of the present invention, it is obvious that the scope of the technical spirit of the present invention is not limited by these embodiments. All modified examples and specific examples that can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be construed as being included in the scope of the present invention.

10: substrate 20: chip cover
20a: first chip cover 20b: second chip cover
21: gas injection hole 30: housing cover
31: gas injection hole 40: filter unit
100: MEMS gas detection unit 110: compensation element
111: micro heater 120: detection element
121: micro heater 122: sensing material
130: voltage input terminal
200: signal processing unit 210: variable output voltage charge pump unit
211: voltage level controller 2111: voltage divider
2112: voltage selector 2113: comparator
212: oscillator 213: charge pump
220: detection signal detection unit 230: output signal amplification unit

Claims (20)

MEMS gas sensing unit provided on the printed circuit board;
a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; and
A gas injection hole is formed on one side and includes a chip cover provided on a printed circuit board to surround the MEMS gas sensing unit and the signal processing unit in a spaced apart state,
The MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that the signal processing unit includes a variable output voltage charge pump unit for supplying a variable voltage to the MEMS gas sensing unit. MEMS gas sensing unit provided on the printed circuit board;
a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board; and
A gas injection hole is formed on one side and includes a chip cover provided on a printed circuit board to surround the MEMS gas sensing unit in a spaced apart state,
The MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that the signal processing unit includes a variable output voltage charge pump unit for supplying a variable voltage to the MEMS gas sensing unit. According to claim 1 or claim 2,
The MEMS gas sensing unit
Compensation element with micro-heater; and
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it has a micro-heater and includes a sensing element on which a sensing material is formed on the micro-heater. The method of claim 3,
The signal processing unit
the variable output voltage charge pump unit;
a detection signal detection unit that detects a potential difference value from the detection circuit and outputs a detection signal; and
An MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it comprises an output signal amplifier for amplifying the detection signal (Vs) and outputting it to the outside as a gas sensor output signal. The method of claim 4,
The variable output voltage charge pump unit
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that the power supply voltage is boosted according to the voltage selection signal and the reference voltage according to the characteristics of the compensation element and the detection element of the MEMS gas sensing unit and output as a variable output voltage. The method of claim 5,
The variable output voltage charge pump unit
Activated according to the result of comparing the division voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N with the reference voltage according to the voltage selection signal specifying the division ratio n/N (a natural number of 1≤=n≤=N) or a voltage level control unit generating an oscillator control signal to be inactivated;
an oscillator outputting a clock signal having a predetermined frequency when the oscillator control signal is activated; and
A MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it comprises a charge pump for outputting the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator. The method of claim 6,
The voltage level controller
a voltage divider receiving feedback from the variable output voltage of the charge pump and generating N divided voltages divided at predetermined voltage intervals;
a voltage selector for selecting an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputting the selected n-th division voltage; and
The oscillator is controlled to compare the n-th divided voltage with the reference voltage, activate the operation of the oscillator when the n-th divided voltage is lower than the reference voltage, and deactivate the operation of the oscillator when the n-th divided voltage is equal to or higher than the reference voltage. MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it comprises a comparator for generating a signal. The method of claim 7,
The voltage divider is
An n-th division voltage corresponding to a division ratio n/N of the voltage divider is selected from among the N division voltages output from nodes of the N series-connected resistive elements or diodes by the voltage selection signal, and the selected An MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it operates to output an n-th distribution voltage. The method of claim 6,
The charge pump
The MEMS gas sensor chip package capable of supplying a variable output voltage, characterized in that it further comprises a low pass filter for removing a ripple component of the variable output voltage according to repeated activation and deactivation of the charge pump. MEMS gas sensing unit provided on the printed circuit board;
a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board;
a first chip cover having a gas injection hole formed on one side and provided on a printed circuit board to surround the MEMS gas sensing unit and the signal processing unit in a spaced apart state; and
A gas injection hole is formed on one side and includes a housing cover provided on the printed circuit board to surround the first chip cover in a spaced apart state,
The MEMS gas sensor device capable of supplying a variable output voltage, characterized in that the signal processing unit includes a variable output voltage charge pump unit for supplying a variable voltage to the MEMS gas sensing unit. MEMS gas sensing unit provided on the printed circuit board;
a signal processing unit electrically connected to the MEMS gas sensing unit on a printed circuit board;
a second chip cover having a gas injection hole formed on one side and provided on the printed circuit board to surround the MEMS gas sensing unit in a spaced state; and
A gas injection hole is formed on one side and includes a housing cover provided on the printed circuit board to surround the second chip cover and the signal processing unit in a spaced apart state,
The MEMS gas sensor device capable of supplying a variable output voltage, characterized in that the signal processing unit includes a variable output voltage charge pump unit for supplying a variable voltage to the MEMS gas sensing unit. According to claim 10 or claim 11,
A MEMS gas sensor device capable of supplying a variable output voltage, characterized in that a filter unit in the form of a thin film is provided in each gas injection hole. Activated according to the result of comparing the division voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N with the reference voltage according to the voltage selection signal specifying the division ratio n/N (a natural number of 1≤=n≤=N) or a voltage level control unit generating an oscillator control signal to be inactivated;
an oscillator outputting a clock signal having a predetermined frequency when the oscillator control signal is activated; and
and a charge pump configured to output the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator. The method of claim 13,
The voltage level controller
a voltage divider receiving feedback of the variable output voltage of the charge pump and generating N divided voltages divided at predetermined voltage intervals;
a voltage selector for selecting an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputting the selected n-th division voltage; and
The oscillator is controlled to compare the n-th divided voltage with the reference voltage, activate the operation of the oscillator when the n-th divided voltage is lower than the reference voltage, and deactivate the operation of the oscillator when the n-th divided voltage is equal to or higher than the reference voltage. A charge pump circuit capable of supplying a variable output voltage, comprising a comparator for generating a signal. The method of claim 14,
The voltage divider is
An n-th division voltage corresponding to a division ratio n/N of the voltage divider is selected from among the N division voltages output from nodes of the N series-connected resistive elements or diodes by the voltage selection signal, and the selected A charge pump circuit capable of supplying a variable output voltage, characterized in that it operates to output an n-th divided voltage. The method of claim 13,
The charge pump
The charge pump circuit capable of supplying a variable output voltage, further comprising a low pass filter for removing a ripple component of the variable output voltage caused by repeated activation and deactivation of the charge pump. A driving method of a variable output voltage charge pump device including a voltage level controller, an oscillator, and a charge pump,
The voltage level controller compares the divided voltage obtained by multiplying the variable output voltage of the charge pump by the division ratio n/N according to a voltage selection signal specifying the division ratio n/N (a natural number of 1≤=n≤=N) with the reference voltage. S100 step of generating an oscillator control signal to be activated or deactivated according to one result;
Step S200 of the oscillator outputting a clock signal having a preset frequency when the oscillator control signal is activated; and
and step S300 in which the charge pump outputs the variable output voltage by boosting a power supply voltage while the clock signal is applied from the oscillator. The method according to claim 17, step S100
Step S110 in which the voltage divider receives feedback of the variable output voltage of the charge pump and generates N divided voltages divided at predetermined voltage intervals;
a step S120 in which a voltage selector selects an n-th division voltage corresponding to a division ratio n/N among the N division voltages by the voltage selection signal and outputs the selected n-th division voltage; and
The comparator compares the n-th divided voltage with the reference voltage, activates the operation of the oscillator when the n-th divided voltage is lower than the reference voltage, and disables the operation of the oscillator when higher than or equal to the reference voltage. A method of driving a charge pump device capable of supplying a variable output voltage, comprising a step S130 of generating an oscillator control signal. The method according to claim 17, in step S110,
The voltage divider selects the n-th division voltage corresponding to the division ratio n/N of the voltage divider from among the N division voltages output from nodes of the N series-connected resistive elements or diodes by the voltage selection signal. and operating to output the selected n-th distribution voltage. The method according to claim 17, in step S300,
The charge pump driving method of a charge pump device capable of supplying a variable output voltage, characterized in that further comprising a low-pass filter for removing a ripple component of the variable output voltage caused by repeated activation and deactivation of the charge pump.

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