阅读说明：本技术 一种基于柔性衬底的带通滤波器及制作方法 (Band-pass filter based on flexible substrate and manufacturing method ) 是由 秦国轩 游子璇 于 2019-11-25 设计创作，主要内容包括：本发明公开了基于柔性衬底的带通滤波器及制作方法,具体结构为层式结构,自下而上依次GND金属层(4)、柔性衬底(3)以及高介电常数介质层(2)；其中,所述高介电常数介质层(2)上还设置有第一、第二微带线金属层(11)、(12)。采用一种新型的电路结构设计以及制备工艺,在柔性PET衬底上采用磁控溅射的方法涂上一层高介电常数钛酸钡介质层作为微带线介质层。通过HFSS设计优化带通滤波器结构参数,通过ADS仿真得到柔性带通滤波器的版图设计,采用磁控溅射高介电常数介质层,光刻后金属蒸发生长技术,从而实现一个较高频率下工作以及可弯曲工作的带通滤波器的制备。本发明的带通滤波器具有较好的性能以及较高的工作频率,在柔性射频集成电路的制作与智能穿戴领域具有广泛的应用前景。(The invention discloses a band-pass filter based on a flexible substrate and a manufacturing method thereof, wherein the specific structure is a layered structure, and a GND metal layer (4), the flexible substrate (3) and a high-dielectric-constant dielectric layer (2) are sequentially arranged from bottom to top; the high-dielectric-constant dielectric layer (2) is also provided with a first microstrip line metal layer (11) and a second microstrip line metal layer (12). A novel circuit structure design and a preparation process are adopted, and a high-dielectric-constant barium titanate dielectric layer is coated on a flexible PET substrate as a microstrip line dielectric layer by adopting a magnetron sputtering method. The structural parameters of the band-pass filter are optimized through HFSS design, the layout design of the flexible band-pass filter is obtained through ADS simulation, and the preparation of the band-pass filter working at higher frequency and capable of working in a bendable mode is achieved through magnetron sputtering of a high dielectric constant dielectric layer and a metal evaporation growth technology after photoetching. The band-pass filter has better performance and higher working frequency, and has wide application prospect in the fields of manufacturing of flexible radio frequency integrated circuits and intelligent wearing.)

1. A band-pass filter based on a flexible substrate is characterized in that the specific structure of the band-pass filter is a layered structure, and a GND metal layer (4), the flexible substrate (3) and a high-dielectric-constant dielectric layer (2) are sequentially arranged from bottom to top; the high-dielectric-constant dielectric layer (2) is also provided with a first microstrip line metal layer (11) and a second microstrip line metal layer (12).

2. A bandpass filter as claimed in claim, characterized in that a plurality of said bandpass filters (5) based on flexible substrates are connected in series, the series arrangement sharing the same bandpass filter input (6), bandpass filter output (7).

3. A method for manufacturing a band-pass filter based on a flexible substrate is characterized by comprising the following steps:

firstly, designing and adjusting structural parameters of a band-pass filter in HFSS, designing a basic schematic diagram of the band-pass filter in ADS simulation software, adopting common microstrip line tools in a microstrip circuit, such as a parallel coupling microstrip line, an arc microstrip line and a common microstrip line, as basic constituent units of the band-pass filter, completing wiring and design, initializing basic length and width parameters of the microstrip line, and designing a symmetrical network structure;

step two, calculating relevant parameters of the microstrip line: the thickness of the substrate is set to be 0.5mm, the relative dielectric constant of the microstrip line is 97.2, the conductivity of the microstrip line is 5.88E +7, the packaging height of the microstrip circuit is 1.0E +33mm, the thickness of the metal layer of the microstrip line is 500nm, the characteristic impedance of the input port is 50 omega, the characteristic impedance of the output port is 50 omega, and the basic length and width of the microstrip line are 998.784 mu m and 8.7451 mu m respectively through calculation;

step three, carrying out simulation and optimization with S parameters as targets on the microstrip line circuit diagram, adding an optimization control, setting 4.5-5.5 Ghz as a target working frequency interval and the numerical requirement of the S parameters in the interval, and finishing the optimization setting of each microstrip line unit;

step four, carrying out simulation to obtain a curve of the S parameter, comparing the curve with a target, and obtaining an optimal result after multiple times of optimization;

fifthly, generating a layout of the band-pass filter, performing simulation after layout optimization to obtain a simulation curve, and storing the layout;

preparing a mask according to the generated layout, and generating a 97.2 high-dielectric-constant dielectric layer on the flexible substrate through magnetron sputtering;

step seven, cleaning the flexible substrate in ultrasonic by using acetone and isopropanol, then carrying out spin coating on the substrate subjected to magnetron sputtering to obtain 1813 positive photoresist, wherein the spin coating speed is 4000r/min, the spin coating time is 30s, the spin coating temperature is 115 ℃, and the photoresist is subjected to prebaking at 90 ℃ for 3 minutes;

eighthly, carrying out alignment photoetching according to the generated mask plate to form a pattern of the band-pass filter;

and step nine, performing metal evaporation on the formed pattern to form a gold electrode metal layer with the thickness of 500nm, evaporating a layer of GND metal layer on the back surface, and removing the photoresist to finish the preparation of the device.

Technical Field

The invention belongs to the field of flexible radio frequency circuit design, and particularly relates to a design method and a preparation process of a radio frequency band-pass filter of a PET (polyethylene terephthalate) plastic substrate.

Background

Flexible electronics is a new electronic technology for manufacturing organic and inorganic electronic devices on flexible and ductile plastic or thin metal substrates, and has wide application in the fields of information, energy, medical treatment, national defense and the like. Such as printed RFID, surface mount for electronics, organic light emitting diodes OLED, flexible electronic displays, etc. The invention adopts a novel process, optimizes the structural parameters of the band-pass filter through HFSS design, obtains the layout design of the flexible band-pass filter through ADS simulation, adopts a magnetron sputtering high dielectric constant dielectric layer and a metal evaporation growth technology after photoetching, prepares a high-performance flexible radio frequency band-pass filter structure on a flexible substrate, and is expected to be widely applied in the aspects of wearable electronics, large-scale flexible integrated circuits and the like in the future.

Disclosure of Invention

The invention aims to provide a band-pass filter based on a flexible substrate and a manufacturing method thereof.

The band-pass filter based on the flexible substrate has the specific structure of a layered structure, and comprises a GND metal layer 4, a flexible substrate 3 and a high-dielectric-constant dielectric layer 2 from bottom to top in sequence; the high-dielectric-constant dielectric layer 2 is further provided with a first microstrip line metal layer 11 and a second microstrip line metal layer 12.

A plurality of band-pass filters 5 based on the flexible substrate are connected in series, and the series structure shares the same band-pass filter input end 6 and band-pass filter output end 7.

The invention relates to a band-pass filter based on a flexible substrate, which comprises the following steps:

firstly, designing and adjusting structural parameters of a band-pass filter in HFSS, designing a basic schematic diagram of the band-pass filter in ADS simulation software, adopting common microstrip line tools in a microstrip circuit, such as a parallel coupling microstrip line, an arc microstrip line and a common microstrip line, as basic constituent units of the band-pass filter, completing wiring and design, initializing basic length and width parameters of the microstrip line, and designing a symmetrical network structure;

step two, calculating relevant parameters of the microstrip line: the thickness of the substrate is set to be 0.5mm, the relative dielectric constant of the microstrip line is 97.2, the conductivity of the microstrip line is 5.88E +7, the packaging height of the microstrip circuit is 1.0E +33mm, the thickness of the metal layer of the microstrip line is 500nm, the characteristic impedance of the input port is 50 omega, the characteristic impedance of the output port is 50 omega, and the basic length and width of the microstrip line are 998.784 mu m and 8.7451 mu m respectively through calculation;

step three, carrying out simulation and optimization with S parameters as targets on the microstrip line circuit diagram, adding an optimization control, setting 4.5-5.5 Ghz as a target working frequency interval and the numerical requirement of the S parameters in the interval, and finishing the optimization setting of each microstrip line unit;

step four, carrying out simulation to obtain a curve of the S parameter, comparing the curve with a target, and obtaining an optimal result after multiple times of optimization;

fifthly, generating a layout of the band-pass filter, performing simulation after layout optimization to obtain a simulation curve, and storing the layout;

preparing a mask according to the generated layout, and generating a 97.2 high-dielectric-constant dielectric layer on the flexible substrate through magnetron sputtering;

step seven, cleaning the flexible substrate in ultrasonic by using acetone and isopropanol, then carrying out spin coating on the substrate subjected to magnetron sputtering to obtain 1813 positive photoresist, wherein the spin coating speed is 4000r/min, the spin coating time is 30s, the spin coating temperature is 115 ℃, and the photoresist is subjected to prebaking at 90 ℃ for 3 minutes;

eighthly, carrying out alignment photoetching according to the generated mask plate to form a pattern of the band-pass filter;

and step nine, performing metal evaporation on the formed pattern to form a gold electrode metal layer with the thickness of 500nm, evaporating a layer of GND metal layer on the back surface, and removing the photoresist to finish the preparation of the device.

Compared with the prior art, the invention has the positive technical effect that the dielectric layer with higher dielectric constant can be designed and prepared in a simpler process, thereby realizing large-scale integrated application of the band-pass filter.

Drawings

FIG. 1 is a schematic structural diagram of a band-pass filter based on a flexible substrate according to the present invention;

fig. 2 is a schematic structural diagram of an embodiment of a flexible substrate-based bandpass filter according to the present invention, (a) a side view, (b) a top view;

FIG. 3 is a schematic structural diagram of a second embodiment of a bandpass filter based on a flexible substrate according to the present invention;

FIG. 4 is a graph of the S-parameter of a flexible substrate based bandpass filter of the present invention;

reference numerals:

11. the flexible substrate-based band-pass filter comprises a first microstrip line metal layer, a second microstrip line metal layer, a high-dielectric-constant dielectric layer, a flexible substrate, a high-voltage Ground (GND) metal layer, a flexible substrate-based band-pass filter, a band-pass filter input end, a band-pass filter output end and a band-pass filter output end, wherein the first microstrip line metal layer is 12, the second microstrip line.

Detailed Description

The technical solution of the present invention is described in detail below with reference to the accompanying drawings and examples.

Fig. 1 and fig. 2 are schematic diagrams of a bandpass filter based on a flexible substrate according to the present invention. The structure is a layered structure and sequentially comprises a GND metal layer 4, a flexible substrate 3 (made of PET flexible plastics), a high-dielectric-constant dielectric layer 2 (serving as a microstrip line dielectric layer) and first and second microstrip line metal layers 11 and 12 from bottom to top.

The main working principle of the flexible power divider is that an input signal is connected through an input port of a band-pass filter, and the low impedance in a specific band and the high impedance outside the band are designed and finished by changing the structural parameters of the band-pass filter based on the basic theory of microstrip lines, so that the filtering function is realized. The invention completes the design of the band-pass filter on the flexible PET substrate for the first time, realizes the normal work of the circuit under different bending states, and provides possibility for the large-scale integration of the flexible radio frequency circuit.

Fig. 2 is a schematic structural diagram of an embodiment of a bandpass filter based on a flexible substrate according to the present invention. In one embodiment, the widths of the high-k dielectric layer 2, the flexible substrate 3 and the GND metal layer 4 may be varied. The positional relationship between the first microstrip line metal layer 11 and the second microstrip line metal layer 12 also has various modifications.

Fig. 3 is a schematic structural diagram of a second embodiment of a bandpass filter based on a flexible substrate according to the present invention. In the second embodiment, it can be seen that a plurality of bandpass filters 5 based on a flexible substrate are connected in series, and the series structure shares the same bandpass filter input end 6 and bandpass filter output end 7.

As shown in fig. 4, a graph of the S-parameter of a flexible substrate based bandpass filter of the present invention. Since the present invention has a symmetrical structure, S11 is the same as S22, S12 is the same as S21, and S11 and S22 are reflection coefficients, i.e., the ratio of the S parameter representing the signal input from the port to be reflected back to the port, and are represented as lg (P11/P1), where P1 is the input signal and P11 is the reflected back signal, and the unit is dB. S12 and S21 represent insertion loss, which represents the ratio of the signal output from the output terminal to the signal input from the input terminal, and is denoted by lg (P12/P1), where P1 is the input signal and P12 is the output signal. The S parameter optimization results comprise S11, S12, S21 and S22, wherein in the bandwidth of 4.5GHz-5.5GHz, S11 and S22 are smaller than-10 dB, and S12 and S21 are close to 0 so as to better transmit signals in the bandwidth. Outside the bandwidth, S11, S22 are close to 0, S12, S21 are less than-20 dB to block the transmission of signals.

The invention relates to a method for manufacturing a flexible substrate-based band-pass filter, which comprises the steps of plating a barium titanate dielectric layer with a high dielectric constant on a PET substrate by adopting a magnetron sputtering process, and then realizing the preparation of a metal layer by adopting a photoetching pattern forming and metal evaporation mode, thereby completing the preparation of the flexible band-pass filter designed in HFSS and ADS software. The manufacturing method comprises the following steps:

firstly, designing and adjusting structural parameters of a band-pass filter in HFSS, designing a basic schematic diagram of the band-pass filter in ADS simulation software, adopting common microstrip line tools in a microstrip circuit, such as a parallel coupling microstrip line, an arc microstrip line and a common microstrip line, as basic constituent units of the band-pass filter, completing wiring and design, initializing basic length and width parameters of the microstrip line, and designing a symmetrical network structure;

calculating relevant parameters of the microstrip line, wherein the thickness of the substrate is set to be 0.5mm, the relative dielectric constant of the microstrip line is 97.2, the conductivity of the microstrip line is 5.88E +7, the packaging height of the microstrip circuit is 1.0E +33mm, the thickness of a metal layer of the microstrip line is 500nm, the characteristic impedance of an input port is 50 omega, the characteristic impedance of an output port is 70 ohms, and the basic length and width of the microstrip line are 998.784 mu m and 8.7451 mu m respectively through calculation;

step three, carrying out simulation and optimization with S parameters as targets on the microstrip line circuit diagram, adding an optimization control, setting 4.5-5.5 Ghz as a target working frequency interval and the numerical requirement of the S parameters in the interval, and finishing the optimization setting of each microstrip line unit;

step four, carrying out simulation to obtain a curve of the S parameter, comparing the curve with a target, and obtaining an optimal result after multiple times of optimization;

fifthly, generating a layout of the band-pass filter, performing simulation after layout optimization to obtain a simulation curve, and storing the layout;

preparing a mask according to the generated layout, and generating a 97.2 high-dielectric-constant dielectric layer on the flexible substrate through magnetron sputtering;

cleaning a flexible substrate in ultrasonic by using acetone and isopropanol, then carrying out spin coating on the substrate subjected to magnetron sputtering to obtain 1813 positive photoresist, wherein the spin coating speed is 4000r/min, the spin coating time is 30s, the spin coating temperature is 115 ℃, and the photoresist is subjected to prebaking at 90 ℃ for 3 minutes;

eighthly, carrying out alignment photoetching according to the generated mask plate to form a pattern of the band-pass filter;

and step nine, performing metal evaporation on the formed pattern to form a gold electrode metal layer with the thickness of 500nm, evaporating a layer of GND metal layer on the back surface, and removing the photoresist to finish the preparation of the device.