KR101609757B1 - Capacitive Sensor Apparatus, Fabrication Method and Operating Method Thereof - Google Patents

Abstract

A capacitive sensor device, a manufacturing method thereof, and an operation method are described.
A capacitive sensor device according to an embodiment of the present invention includes a printed circuit board on which a capacitive sensor IC is electrically coupled, a power terminal that is printed on a printed circuit board and is electrically connected to the capacitive sensor IC, A single input / output terminal and an injection structure for shielding the printed circuit board.

Description

Technical Field [0001] The present invention relates to a capacitive sensor device, a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device, and more particularly, to a sensor device of a capacitance type, a manufacturing method thereof, and an operation method thereof.

The sensor device is a device for measuring the state of the object to be measured by changing it to a known physical or chemical quantity. The object to be measured of the sensor varies greatly depending on the presence or absence of an object, position, displacement, angle, deformation, size, pressure, weight, approach, light, temperature, vibration and acceleration.

The sensor can be implemented in various ways such as an optical method, an ultrasonic method, and a capacitance method according to a method of measuring a state of an object to be measured.

The capacitance type sensor is a device that senses a change in capacitance caused when a dielectric comes in contact with or touches a sensing surface and outputs a signal corresponding thereto. The sensing device includes a touch pad, a touch screen, a touch key, a seating sensor, Sensors and so on.

Among the sensors of the capacitive type, for example, the seating sensor can be manufactured by the method shown in Fig.

1 is a view for explaining a method of manufacturing a general electrostatic capacity type sensor device.

First, a capacitive sensor IC (Integrated Chip) is manufactured, a printed circuit board (PCB) to be mounted thereon is manufactured, and the capacitive sensor IC is assembled with a PCB (S101). At this time, a process of soldering the cable extending to the outside can be performed.

Then, a case for mounting the PCB on which the capacitive sensor IC is mounted, that is, the sensor PCB, is prepared (S103), and the sensor PCB and the case are assembled (S105).

Subsequently, the assembled case is molded using a molding material such as epoxy resin (S107), and the molding material is solidified (S109).

Thus, the current capacitive sensor device is manufactured through a complicated process, and it takes a longer time than 6 hours to solidify the molding material.

Also, when the sensor PCB is closed by the molding material, an error or failure may occur depending on the external environment in which the sensor device is installed. For example, moisture can penetrate into the molding material in a high humidity environment such as a seat sensor or a water level sensor, so it is difficult to ensure a reliable operation and a guaranteed life span.

On the other hand, the capacitance sensor device generates parasitic capacitance depending on the external environment (temperature, humidity, noise, dielectric constant of the molding material, etc.) installed. This parasitic capacitance is a factor for changing the reference capacitance, which may result in malfunction of the capacitance sensor device.

Embodiments of the present technology provide a capacitance sensor device and a method of manufacturing the same that can simplify a process and shorten a process time.

Embodiments of the present technology provide a capacitance sensor device with high resistance to external environments and a method of manufacturing the same.

Embodiments of the present technology provide a capacitive sensor device and method of operation that are adaptable to changes in the external environment.

A capacitive sensor device according to an embodiment of the present invention includes a printed circuit board on which a capacitive sensor IC is electrically coupled; A power terminal, a ground terminal, and a single input / output terminal printed on the printed circuit board and electrically connected to the capacitance sensor IC; And an injection structure for shielding the printed circuit board.

A manufacturing method of a capacitive sensor device according to an embodiment of the present invention includes a sensor PCB having a power terminal, a ground terminal, and a single input / output terminal, to which a capacitive sensor IC is mounted and electrically connected to the capacitive sensor IC Producing; Forming a first injection molded product by injection molding the sensor PCB excluding the power terminal, the ground terminal, and the input / output terminal; Electrically connecting the power supply line, the ground line, and the input / output line to the power terminal, the ground terminal, and the input / output terminal, respectively; And the printed circuit board including the power supply terminal, the ground terminal, and the input / output terminal, and manufacturing the housing to shield the primary injection molding.

A method of operating a capacitive sensor device according to an embodiment of the present invention includes a capacitive sensor IC that performs sensing based on a difference between a reference capacitance and a variable capacitance, a power supply terminal, a ground terminal, and a single input / A method of operating a capacitive sensor device that is shielded by an injection structure, the method comprising: determining sensitivity of the capacitive sensor device after fabrication of the capacitive sensor device; Calculating a compensation value for the variable capacitance based on a predetermined sensitivity level required for the capacitance sensor device; And storing the compensation value in the capacitance sensor IC through the input / output terminal.

According to the present invention, the process and the process time of the electrostatic capacitance sensor device can be reduced by the injection method. Also, when the sensor PCB is manufactured by a double injection structure, a capacitance sensor device having high resistance to external environment such as humidity can be manufactured.

In addition, since one terminal of the sensor device is used as both the output terminal and the input terminal, the reference capacitance can be compensated for according to the environment in which the sensor device is attached, thereby improving the operational reliability. Further, since sensitivity can be set freely through the compensation process and the sensitivity setting process can be performed after the production of the sensor device is completed, sensitivity can be set for the purpose of collective production of the sensor device, .

1 is a view for explaining a manufacturing method of a general capacitance type sensor device,
FIG. 2A and FIG. 2B are diagrams showing a configuration of a capacitance sensor device according to an embodiment of the present invention,
3 is a flowchart illustrating a method of manufacturing a capacitive sensor device according to an embodiment of the present invention.
4 to 9 are conceptual diagrams for explaining a method of manufacturing a capacitive sensor device according to an embodiment of the present invention,
10 is a view for explaining an injection method according to an embodiment of the present invention,
11 is a configuration diagram of a capacitance sensor IC according to an embodiment of the present invention,
12 is a configuration diagram of a sensitivity adjusting unit according to an embodiment of the present invention;
13 is a flowchart illustrating an operation method of the capacitance sensor device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described more specifically with reference to the accompanying drawings.

2A and 2B are block diagrams of a capacitance sensor device according to an embodiment of the present invention.

2A, a capacitive sensor device 10 according to an exemplary embodiment of the present invention includes an injection structure 110 that is shielded by a sensor PCB and a plurality of cables (not shown) extending from the sensor PCB to the outside of the injection structure 110. [ (IO, VCC, GND).

The sensor PCB means a PCB on which a capacitive sensor IC is mounted. A cable connection terminal including an input / output terminal, a power supply terminal, and a ground terminal is provided at a designated position of the sensor PCB. Out of the plurality of cables, the input / output line IO is electrically connected to the input / output terminal and extends outside the injection structure 110. Among the plurality of cables, the power supply line VCC and the ground line GND are also electrically connected to the power supply terminal and the ground terminal, respectively, and extend outside the injection structure 110.

The input / output line IO consists of a single line, outputs the sensing signal of the capacitance sensor IC to the outside, and stores the compensation value received from the external device in the capacitance sensor IC. By storing the compensation value in the capacitance sensor IC, sensing operation adaptable to the external environment can be performed, which will be described later.

A manufacturing method of such a capacitive sensor device will be described in detail with reference to FIGS. 3 to 9. FIG.

FIG. 3 is a flowchart illustrating a method of manufacturing a capacitive sensor device according to an embodiment of the present invention. FIGS. 4 to 9 illustrate a method of manufacturing a capacitive sensor device according to an embodiment of the present invention. It is a conceptual diagram.

First, a PCB on which a capacitive sensor IC is mounted is fabricated, and a capacitive sensor IC is assembled on the fabricated PCB (S201). 4, a capacitive sensor IC 203 is mounted on a PCB 201, and a cable including a input / output terminal T_IO, a power supply terminal T_VCC, and a ground terminal T_GND is connected to a designated position of the PCB. It can be seen that a connection terminal is provided. Reference numeral 205 denotes an auxiliary circuit for allowing the electrostatic capacitance sensor IC to operate.

Next, the injection process is performed on the sensor PCB except for the cable connection terminal (S203), and the primary injection product 207 as shown in FIG. 5 is formed.

Then, the cable is assembled to the cable connection terminal (S205). That is, the input / output line IO, the power supply line VCC, and the ground line GND are electrically connected to the input / output terminal T_IO, the power supply terminal T_VCC, and the ground terminal T_GND, 6.

After the cable is assembled, the housing is manufactured so as to shield the cable connection terminal and the primary injection molding 207 (S207). The completed capacitive sensor device after fabricating the housing may have the form, for example, as shown in FIG.

In an embodiment of the present invention, the housing may be manufactured through an injection process. When the cable connection terminal and the primary injection object are secondarily injected to manufacture the injection structure 110 in a state in which the sensor PCB is closed by the primary injection object 207, the capacitance sensor device having more resistance to the external environment can be manufactured . In addition, since the sensor device is manufactured by injection molding without the need to carry out the case manufacturing, the molding process, and the molding re-solidification process for housing the sensor PCB, the process can be simplified and the process time can be greatly shortened have.

Meanwhile, the shape of the housing may include a fixing hole 112 as shown in FIG. 2B. The capacitance sensor device 10-1 can be easily attached to a desired object when the fixing hole 112 is included.

The manufacture of the housing is not limited to the injection molding method, and a separately manufactured housing may be used.

On the other hand, the PCB on which the capacitance sensor IC is mounted may have a shape as shown in FIG. Referring to FIG. 7, the PCB 201A has grooves corresponding to the number of cable connection terminals on one side, and cable connection terminals T_IO, T_VCC, and T_GND may be provided in the grooves.

In this case as well, it is needless to say that the injection molding process for the sensor PCB except for the cable connection terminal is performed as shown in FIG. 8 to mold the primary injection molding 207 as shown in FIG. 8, and the cable assembly process can be performed as shown in FIG. .

In the embodiment shown in Figs. 7 to 9, the PCB 201A has a groove in which a cable connection terminal is located. In this case, the end of each cable can be aligned in the groove, so there is an advantage that the cable can be connected by the automatic soldering process.

Meanwhile, it is preferable to use a pin point type gate in the injection process for molding the primary injection molded article 207, which will be described in detail with reference to FIG.

In the mold frame 301, the mold object, that is, the sensor PCBs 201 and 201A in the present invention, is seated. In the injection apparatus using the pin point type gate 303, the gate is disposed at the upper center portion of the mold frame, and therefore the flow resin is injected from the upper end of the object through the pin point gate 303 to fill the mold frame 301 .

At this time, a support rod 305 for supporting the sensor PCB 201 or 201A in a direction opposite to the direction in which the pin point gate 303 is installed may be provided.

When the injection process is performed with a side-type gate or the like, the sensor PCBs 201 and 201A can be driven by the pressure of the flow resin flowing through the gate. Even when a pin-point type gate is applied, it is difficult to completely eliminate such a warping phenomenon.

However, if the sensor PCBs 201 and 201A are pressed through the support bars 305 in the direction opposite to the flow resin injection direction as in the present invention, the injection process can be performed without bending the sensor PCBs 201 and 201A .

As described above, the capacitance sensor device according to an embodiment of the present invention includes an input / output line IO, and outputs a sensing signal of the capacitance sensor IC to the outside through the input / output line IO, Capacitive sensor IC. This will be described with reference to FIGS. 11 to 13. FIG.

11 is a configuration diagram of a capacitance sensor IC according to an embodiment of the present invention.

11, the capacitance sensor IC may include a sensing pad 401, a variable capacitor Cs, a reference capacitor Cr, a comparison unit 403, an input unit 405, and a sensitivity adjustment unit 407 have.

The sensing pad 401 serves as a sensing surface for sensing the approach or contact of the dielectric.

The variable capacitor Cs is connected between the sensing pad 401 and one input terminal of the comparator 403 and the capacitance is determined according to whether the dielectric is in contact with or contact with the sensing pad 401. [

The reference capacitor Cr is connected between the other input terminal of the comparator 403 and the ground terminal and has a predetermined capacitance.

The comparator 403 compares the capacitance of the variable capacitor Cs with the reference capacitance of the reference capacitor Cr and outputs a comparison signal through the input / output line IO.

The input unit 405 is connected to the input / output line IO and receives the compensation value.

The sensitivity adjustment unit 407 receives the compensation value through the input unit 405, stores the compensation value, and controls the detection level accordingly.

In the capacitance sensor IC, parasitic capacitances Cp1 and Cp2 exist in addition to the variable capacitor Cs and the reference capacitor Cr. These parasitic capacitances Cp1 and Cp2 have different values depending on the environment in which the capacitive sensor device is installed and serve as a factor for varying the capacitance of the reference capacitor Cr.

In the present invention, after the fabrication of the capacitance sensor device, the reference capacitance change amount according to the parasitic capacitances Cp1 and Cp2 is measured and the compensation value is determined based on the measured capacitance change amount. The determined compensation value may be input through the input / output line IO and stored in the sensitivity adjustment unit 407. Thereafter, a sensing operation may be performed considering the compensation value in the operation of the sensor device.

The sensitivity adjustment unit 407 may be configured to include a compensation unit 4071 and a storage unit 4073 as shown in FIG. 12, for example.

The compensation unit 4071 stores the compensation value received through the input unit 405 in the storage unit 4073. [ The storage unit 4073 may be an EEPROM, but is not limited thereto.

Meanwhile, the compensation unit 4071 is electrically connected to the sensing pad 401 to adjust the sensing sensitivity. Therefore, when the sensor device operates after the compensation value is stored in the storage unit 4073, the capacitance of the variable capacitor Cs which varies according to the state of the sensing pad 401 is compensated by the compensation value, To be compared with the capacitance caused by the capacitance.

An operation method considering the parasitic capacitance of the capacitance sensor device will be described with reference to FIG.

When the fabrication of the capacitive sensor device is completed (S301), the actual sensitivity of the sensor device is determined in an environment substantially identical to the environment in which the capacitive sensor device is installed (S303). At this time, all the parasitic capacitances Cp1 and Cp2 depending on characteristics such as temperature, humidity, thickness of the injection structure 110, air gap, etc. can be considered.

When the actual sensitivity is determined, the compensation value is calculated based on the predetermined sensitivity level required for the sensor device (S305). In general, the sensitivity level of the sensor device can be the difference between the reference capacitance and the variable capacitance, and the compensation value can be determined according to the required sensitivity level.

The calculated compensation value may be stored in the storage unit 4073 (S307). To this end, power is applied while the input / output line IO is connected to an external device to switch the capacitance sensor IC to the input mode. If the compensation value determined through the input / output line IO is provided, the compensation value is stored in the storage unit 4703 via the compensation unit 4071 via the input unit 405. [

In one embodiment of the present invention, it is desirable to input the compensation value within a predetermined time (several ms to several hundreds ms) after applying power to the input / output line. When the predetermined time has elapsed, the capacitive sensor IC is switched to the output mode.

Thereafter, the capacitive sensor device can detect the approach or contact of the dielectric with the compensated sensitivity according to the compensation value.

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

10: Capacitive sensor device
110: Injection structure
201, 201A: PCB
203: Capacitive Sensor IC
207: Primary Injection
301: mold frame
303: Pin point gate
305:

Claims (12)

A printed circuit board on which the electrostatic capacitance sensor IC is electrically coupled;
A power terminal, a ground terminal, and a single input / output terminal printed on the printed circuit board and electrically connected to the capacitance sensor IC; And
An injection structure for shielding the printed circuit board;
/ RTI >
The injection structure may include a primary injection molding material that shields the printed circuit board except for the power source terminal, the ground terminal, and the input / output terminal; And
A housing that shields the printed circuit board including the primary molded object, the power terminal, the ground terminal, and the input / output terminal;
Wherein the sensor device is a capacitive sensor device. delete The method according to claim 1,
Wherein the housing is formed by injection molding the printed circuit board including the primary molded product, the power supply terminal, the ground terminal, and the input / output terminal. The method of claim 3,
A capacitive sensor further comprising a power supply line extending outwardly from the housing and electrically connected to the power terminal, a ground line electrically connected to the ground terminal, and an input / output line electrically connected to the input / Device. The method according to claim 1,
Wherein the capacitance sensor IC includes: a storage unit for storing a compensation value provided to the input / output terminal; And
A compensation unit for adjusting sensing sensitivity according to a compensation value stored in the storage unit;
Wherein the sensor device is a capacitive sensor device. Fabricating a sensor PCB having a power supply terminal, a ground terminal, and a single input / output terminal, to which the capacitance sensor IC is mounted, and electrically connected to the capacitance sensor IC;
Forming a first injection molded product by injection molding the sensor PCB excluding the power terminal, the ground terminal, and the input / output terminal;
Electrically connecting the power supply line, the ground line, and the input / output line to the power terminal, the ground terminal, and the input / output terminal, respectively; And
The sensor PCB including the power terminal, the ground terminal, and the input / output terminal, and a housing for shielding the primary injection molding;
And a step of forming the capacitance sensor device. The method according to claim 6,
Wherein the housing is formed by injection molding. The method according to claim 6,
The step of fabricating the primary molded product may include: mounting the sensor PCB on a mold frame having a pin point type gate;
Supporting the sensor PCB through a support bar in a direction opposite to the pin point type gate; And
Injecting a flow resin through the pin point type gate;
And a step of forming the capacitance sensor device. A power supply terminal printed on the printed circuit board and electrically connected to the capacitive sensor IC, a power supply terminal electrically connected to the power supply terminal, and a power supply terminal electrically connected to the capacitive sensor IC, wherein the capacitive sensor is electrically connected to the capacitive sensor IC, A method of operating a capacitive sensor device having a terminal and a single input / output terminal and being shielded by an injection structure,
Wherein the injection structure includes a primary injection molding material that shields the printed circuit board except for the power supply terminal, the grounding terminal, and the input / output terminal, and a secondary injection molding material that includes the primary injection molding material, the printing terminal including the power supply terminal, A housing for shielding the circuit board,
Wherein the capacitance of the capacitance sensor is determined based on the temperature and humidity of the environment in which the capacitance sensor device is to be installed and the characteristics of the injection structure and the parasitic capacitance of the capacitance sensor IC, Determining the sensitivity of the capacitive sensor device;
Calculating a compensation value for the variable capacitance based on a predetermined sensitivity level required for the capacitance sensor device; And
Storing the compensation value in the capacitance sensor IC through the input / output terminal;
Wherein the capacitance sensor device comprises: delete 10. The method of claim 9,
The step of storing the compensation value includes: switching the capacitance sensor IC to an input mode; And
Inputting a compensation value through the input / output terminal;
Wherein the capacitance sensor device comprises: 12. The method of claim 11,
The step of switching to the input mode is a step of applying power through the input / output terminal,
Wherein the compensation value is controlled so as to be inputted within a predetermined time after the call in the input mode.

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