CN213455880U - MEMS infrared temperature measurement sensor based on CSP packaging technology - Google Patents

Abstract

The utility model relates to an infrared temperature sensor has the effect that the function is integrated, the application scene is extensive. The utility model discloses a based on CSP packaging technology MEMS infrared temperature measurement sensor, including the PCB substrate, be provided with MEMS thermopile, NTC resistance, resistance-capacitance and ADC on the PCB substrate, the ADC is used for converting the voltage signal of MEMS thermopile into digital signal, PCB substrate overcoat is equipped with the resin shell, set up the opening that is located directly over the MEMS thermopile on the resin shell, the resin shell inlays and is equipped with and covers open-ended long infrared lens that leads to. By means of the cooperation of the CSP packaging technology and the ADC, the integrated arrangement of the ADC and the MEMS thermopile is realized, and the application range of the infrared temperature measurement sensor is expanded.

Description

MEMS infrared temperature measurement sensor based on CSP packaging technology

Technical Field

The utility model relates to an infrared temperature sensor, more specifically say, it relates to a based on CSP packaging technology MEMS infrared temperature sensor.

Background

Non-contact infrared temperature measurement, also called radiation temperature measurement, generally uses a pyroelectric or photoelectric detector as a detection element. The temperature measuring system is simple, can realize large-area temperature measurement, and can also be used for measuring the temperature of a certain point on a measured object.

At present, an infrared sensor only has a single temperature measurement function in a TO46 packaging mode, an MEMS thermopile chip is contained inside the infrared sensor, an NTC (negative temperature coefficient) resistor is used for temperature compensation, a 5.5um long-pass filter can only output an analog signal, the anti-interference capability is poor, an ADC (analog-TO-digital converter) is still required TO be additionally arranged at a client side for analog-TO-digital conversion, the cost and the hardware design difficulty are increased, and the space of part of application scenes.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model aims to provide a based on CSP packaging technology MEMS infrared temperature sensor has the effect that function integration, application scene are extensive.

In order to achieve the technical purpose, the utility model provides a following technical scheme: the utility model provides an infrared temperature sensor of MEMS based on CSP packaging technology, includes the PCB substrate, be provided with MEMS thermopile, NTC resistance, resistance-capacitance and ADC on the PCB substrate, the ADC is used for converting the voltage signal of MEMS thermopile into digital signal, PCB substrate overcoat is equipped with the resin shell, set up the opening that is located directly over the MEMS thermopile on the resin shell, the resin shell inlays and is equipped with and covers open-ended long-pass infrared lens.

By adopting the technical scheme, the MEMS thermopile consists of a plurality of thermocouples, and when the infrared light irradiation temperature in the detection range of the sensor changes at a certain value, the thermocouples generate charges, namely weak voltage difference is generated between two electrodes. The MEMS thermopile sensor detects the changed temperature, and the changed temperature is converted into a voltage signal through photoelectric conversion, and the voltage signal is converted into a digital signal through the ADC so as to be provided for the MCU to perform algorithm processing. The ADC is directly arranged on the PCB substrate, the ADC is not additionally arranged at a client side, the flexibility of the infrared temperature measuring sensor is improved, and the application range is widened.

Preferably, the ADC includes a reference voltage output, a multiplexer, a 4-64X programmable operational amplifier, a 24-bit digital-to-analog converter, a digital filter and a DSP, and supports 12C and SPI interfaces.

By adopting the technical scheme, the electric signals transmitted by the MEMS thermopile are sequentially amplified, converted and filtered by means of the matching of the converter, the amplifier and the filter, so that the influence of the environment on temperature measurement is avoided, the consistency of output signals of the sensor is ensured, and the temperature measurement precision is improved.

Preferably, the NTC resistor and the ADC are fixed on the PCB substrate through silver glue, and the long-pass infrared lens is fixed on the resin shell through glue.

Through adopting above-mentioned technical scheme, fix electronic components on the PCB substrate with the help of glue, guaranteed the structural stability, improved the life of sensor.

To sum up, the utility model discloses following effect has been gained:

1. by means of the cooperation of the CSP packaging technology and the ADC, the integrated arrangement of the ADC and the MEMS thermopile is realized, and the application range of the infrared temperature measurement sensor is expanded;

2. by means of a calibration circuit in the ADC, sensor signals are unified and high in precision.

Drawings

FIG. 1 is a schematic view for showing the overall structure in the present embodiment;

FIG. 2 is a schematic diagram for showing the overall control process in the present embodiment;

fig. 3 is a schematic diagram for showing a calibration circuit in the ADC according to this embodiment.

In the figure, 1, a PCB substrate; 2.a MEMS thermopile; 3. an NTC resistor; 4. resistance-capacitance; 5. an ADC; 6. a resin housing; 7. a long pass infrared lens.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Example (b): the utility model provides an infrared temperature sensor of MEMS based on CSP packaging technology, as shown in fig. 1 and fig. 2, including PCB substrate 1, be provided with MEMS thermopile 2 on the PCB substrate 1, NTC resistance 3, resistance-capacitance 4 and ADC5, ADC5 is used for converting the voltage signal of MEMS thermopile 2 into digital signal, PCB substrate 1 overcoat is equipped with resin housing 6, set up the opening that is located MEMS thermopile 2 directly over on the resin housing 6, resin housing 6 inlays and is equipped with and covers open-ended long-pass infrared lens 7.

The MEMS thermopile 2 is composed of a plurality of thermocouples, and when the infrared light irradiation temperature in the detection range of the sensor changes at a certain value, the thermocouples generate charges, namely weak voltage difference is generated between two electrodes. The MEMS thermopile 2 sensor detects the changed temperature, and the changed temperature is converted into a voltage signal through photoelectric conversion, and the voltage signal is converted into a digital signal through the ADC5 to be processed by the back-end MCU through an algorithm. The ADC5 is directly arranged on the PCB substrate 1, and the ADC5 is not required to be additionally arranged at a client side, so that the flexibility of the infrared temperature measurement sensor is improved, and the application range is widened.

As shown in fig. 3, ADC5 includes a reference voltage output, a multiplexer, a 4-64X programmable op-amp, a 24-bit digital-to-analog converter, a digital filter, and a DSP, and ADC5 supports 12C and SPI interfaces. By means of the cooperation of the converter, the amplifier and the filter, the electric signals transmitted by the MEMS thermopile 2 are sequentially amplified, converted and filtered, the influence of the environment on temperature measurement is avoided, the consistency of output signals of the sensor is ensured, and the temperature measurement precision is improved.

The NTC resistor 3 resistance value calculation formula involved in the ADC5 is:

and the MEMS thermopile 2 voltage is measured using the following equation:

the NTC resistor 3 and the ADC5 are fixed on the PCB substrate 1 through silver glue, and the long-pass infrared lens 7 is fixed on the resin shell 6 through glue. The electronic components on the PCB substrate 1 are fixed by glue, so that the structural stability is ensured, and the service life of the sensor is prolonged.

A production process of an MEMS infrared temperature measurement sensor based on a CSP packaging process comprises the following steps:

s1, mounting a chip, namely mounting a resistance-capacitance device 4 on a PCB substrate by using a chip mounter; s2, ASIC die bonding, namely, using an automatic equipment suction chip (ADC5, NTC), and fixing the NTC and the ADC5 on the PCB substrate 1 through silver glue; s3, baking, namely putting the PCB substrate 1 attached with the chip into a baking oven at 150 ℃; s4, bonding, namely welding a gold wire to a bonding pad between the chip and the PCB substrate 1 by using ultrasonic waves by using automatic equipment to complete the electrical connection of the chip; s5, plasma cleaning is carried out to remove organic matters on the surface of the product and avoid bubbles between the resin shell 6 and the PCB substrate 1; s6, performing injection molding on the MOLDING EMC to form a product shell and protect the ASIC; s7, solidifying the MEMS thermopile 2, sucking the MEMS thermopile 2 by using automatic equipment, fixing the MEMS thermopile 2 on the PCB substrate 1 by using silver glue, and baking and curing; s8, bonding, namely welding a gold wire to a bonding pad between the MEMS thermopile and the PCB by using ultrasonic waves by using automatic equipment;

s9, bonding the lens, namely bonding the long-pass infrared lens 7 to the resin shell 6 by using glue; s10, dividing the whole substrate into single temperature sensing elements by using an automatic cutting machine through a thin diamond blade rotating at 30000 revolutions per minute; and S11, detecting, namely automatically sucking the element to detect the photoelectric property and the electric property, automatically finishing BIN by the element, and removing defective products.

The whole process is realized by using automatic equipment to automatically produce and detect electronic components, manual participation is not needed, the sealing property and cleanliness of products are guaranteed, meanwhile, the automatic equipment can be produced for 24 hours, the position does not need to be measured, and the production efficiency is improved.

Claims (3)

1. A MEMS infrared temperature measurement sensor based on CSP packaging technology is characterized in that: including PCB substrate (1), be provided with MEMS thermopile (2), NTC resistance (3), resistance-capacitance (4) and ADC (5) on PCB substrate (1), ADC (5) are used for converting the voltage signal of MEMS thermopile (2) into digital signal, PCB substrate (1) overcoat is equipped with resin shell (6), set up the opening that is located directly over MEMS thermopile (2) on resin shell (6), resin shell (6) inlay and are equipped with and cover open-ended long-pass infrared lens (7).

2. The MEMS infrared temperature measurement sensor based on the CSP packaging process is characterized in that: the ADC (5) comprises a reference voltage output, a multiplexer, a 4-64X programmable operational amplifier, a 24-bit digital-to-analog conversion, a digital filter and a DSP, and the ADC (5) supports a 12C interface and an SPI interface.

3. The MEMS infrared temperature measurement sensor based on CSP packaging technology of claim 2, wherein: NTC resistance (3) and ADC (5) are fixed on PCB substrate (1) through the silver-colored glue, long lead to infrared lens (7) and pass through glue and fix on resin housing (6).

Images