CN106876229B - Electrode lead unit, vacuum photoelectric device and manufacturing method thereof - Google Patents

Abstract

The invention belongs to the technical field of photoelectric devices, and relates to an electrode lead unit, a vacuum photoelectric device and a manufacturing method thereof. The electrode lead unit includes a glass substrate, a glass shell and a plurality of electrode leads; the glass shell is welded on the surface of the glass substrate; the electrode leads are distributed on the welding surface of the glass shell and the glass substrate, and one end of the electrode lead is located on the glass shell Inside, the other end of the electrode lead is located outside the glass envelope. The electrode lead unit produced by the invention is not limited by the diameter of the Kovar wire at the anode end, so a vacuum optoelectronic device with hundreds of readout channels can be produced. The minimum electrode size can reach tens of microns, which is conducive to the production of high-density electrode leads. It is suitable for various vacuum optoelectronic devices such as hybrid photodetectors and multi-anode photomultiplier tubes. It is used in high-energy physics, cosmic exploration, low-light night vision, It has broad application prospects in many fields such as medical instruments.

Description

Electrode lead unit, vacuum optoelectronic device and manufacturing method thereof

technical field

The invention belongs to the technical field of photoelectric devices, and relates to an electrode lead unit, a vacuum photoelectric device and a manufacturing method thereof.

Background technique

Due to its excellent performance, such as high sensitivity, fast time response, large effective area, low dark current and excellent environmental adaptability, vacuum optoelectronic devices are widely used in high-energy physics, astrophysics, medical equipment, laser radar, low-light night vision, It has important applications in many fields such as environmental monitoring and plasma diagnosis, and is an important branch of photodetection devices.

Vacuum optoelectronic devices are mainly composed of incident window, photocathode, electron optical system, electron multiplier and anode. Among them, the photocathode is attached to the incident window to convert the incident optical signal into an electrical signal; the electron optical system mainly realizes the functions of accelerating, focusing and deflecting electrons; the electron multiplier can generate a large electronic gain for Amplification of electrical signals; the anode is used to receive and read out the final signal.

Since the vacuum photoelectric device is a vacuum-sealed detection device, in order to connect with the external circuit for signal acquisition and processing, there must be electrode leads to connect the internal electrodes of the device and the external circuit, so the production of electrode leads is an important process for the preparation of vacuum photoelectric devices. process.

Fig. 1 is the structural representation of traditional microchannel plate photodetection device, comprises entrance window 11, photocathode 12, microchannel plate 13, anode 14, stem 15, electrode connection wire 16, tube shell 17 and welding on stem Kovar wire 18. Wherein the incident window 11, the tube shell 17 and the stem 15 are sealed by a vacuum sealing process, and the photocathode 12, the microchannel plate 13 and the anode 14 are all placed in a vacuum. The Kovar alloy wire is welded to the core column glass by high-temperature welding, one end of the Kovar alloy wire is placed inside the vacuum, and connected to each electrode of the photodetector device through the electrode connection line 16, and the other end of the Kovar alloy wire is placed in a vacuum External, it can be connected with external circuit for signal detection.

In patents CN101877297A, CN105424176A, CN103915311A, CN104733272A, and US6285018B1, the electrode leads of vacuum optoelectronic devices are connected through the stems at the bottom of the device, where the stems are used to support the electrode parts and lead out the electrodes, and the electrode leads are to conduct current . The specific implementation manner of making the electrode lead is as follows: first, forming a stem. The core column is made of glass and Kovar alloy wire welded at high temperature. The Kovar alloy wire is composed of iron-nickel-cobalt metal, with a diameter of about 1 mm, and its thermal expansion coefficient is similar to that of glass. At high temperature, the welding surface of the glass melts and softens and reacts with the oxide layer on the surface of the Kovar alloy wire to form a metallurgical joint surface, thereby obtaining a good hermetic sealing structure. Second, connect the electrode leads. One side of the electrode lead is connected to the electrode parts in the device, such as the cathode, electron multiplier, anode, etc., through metal spot welding, and the other side of the electrode lead is connected to the Kovar alloy wire in the core column by spot welding. The moving electrons are eventually exported through the lead and stem. Finally, the stem is sealed to the rest of the device to form a vacuum-tight environment.

This process for making electrode leads is relatively easy to implement and has low production costs, but there are several problems as follows:

1. The production of the core column needs to first form an oxide layer on the surface of the Kovar alloy wire and then weld it with the glass. These processes have strict requirements on the temperature, time and atmosphere of the process. Improper control of process parameters can easily lead to failure of welding Or the performance of the device is degraded due to slow air leakage during the subsequent use of the device, so the reliability is limited.

2. Due to the difference between the thermal expansion coefficient of Kovar alloy wire and glass, when the device is subjected to the photocathode activation process at high temperature, the stem will burst due to the inability to effectively release the thermal stress, resulting in the failure of the device fabrication. Therefore, the device preparation success rate cannot be guaranteed.

3. Due to the limitation of Kovar alloy wire diameter, if high-density electrode leads (such as more than 256 electrodes) are to be made, the volume of the stem will double, the weight of the device will increase, and it is difficult to Detection increases the difficulty and cost of device fabrication.

In summary, the manufacture of vacuum optoelectronic devices depends on efficient and reliable electrode lead fabrication methods; in some new vacuum optoelectronic devices, such as hybrid photodetectors or multi-anode microchannel photomultiplier tubes with high spatial and temporal resolution , requiring hundreds or even more electrode leads. Therefore, the existing fabrication methods of vacuum optoelectronic devices are difficult to meet the demand, especially cannot be used to fabricate multi-channel vacuum optoelectronic devices with high position resolution.

Contents of the invention

In order to solve the technical problem that the existing vacuum photoelectric device manufacturing method cannot meet the requirement of multi-electrode leads, the invention provides an electrode lead unit, a vacuum photoelectric device and a manufacturing method thereof.

The technical solution of the present invention is: an electrode lead unit, which is special in that it includes a glass substrate, a glass shell and a plurality of electrode leads; the glass shell is welded to the surface of the glass substrate; the electrode leads are distributed On the welding surface of the glass tube shell and the glass substrate, one end of the electrode lead wire is located inside the glass tube shell, and the other end of the electrode lead wire is located outside the glass tube shell.

Preferably, the above-mentioned electrode leads are strip-shaped metal thin films fabricated on a glass substrate using a semiconductor process.

Preferably, the above metal thin film is a single metal thin film or a stacked structure of multiple metal thin films.

The present invention also provides a method for manufacturing an electrode lead unit, which is special in that it includes the following steps:

1) Prepare the glass substrate;

2) Making electrode leads: using a semiconductor process to make electrode leads on a glass substrate; the electrode leads are a single metal film or a stacked structure of multiple metal films;

3) Welding glass shell: coating the installation part of the glass shell on the glass substrate with low-melting glass powder, the coating width of the glass powder is greater than the thickness of the glass shell and less than the length of the electrode lead; after the glass powder is heated and solidified Form the glass glue; place the glass shell on the glass glue, make one end of the electrode lead on the inside of the glass shell, and the other end of the electrode lead on the outside of the glass shell; heat the glass shell and the glass substrate through the glass in a vacuum furnace Glue together; take it out after cooling down, and complete the production of the electrode lead unit.

Preferably, the manufacturing method of the above-mentioned electrode lead unit further includes step 4) performing vacuum leak detection on the manufactured electrode lead unit.

The present invention also provides a vacuum photoelectric device based on the above-mentioned electrode lead unit, including an incident window, a cathode unit and an anode unit, and the special feature is that it also includes an electrode lead unit;

The electrode lead unit includes a glass substrate, a glass shell and a plurality of electrode leads; the glass shell is welded on the surface of the glass substrate; the electrode leads are distributed on the welding surface of the glass shell and the glass substrate; the electrodes One end of the lead wire is located inside the glass shell, and is connected to the anode unit through the electrode connecting wire; the other end of the electrode lead is located outside the glass shell;

The incident window is located on the top of the glass shell, and the incident window, the glass shell and the glass substrate together form a closed vacuum chamber, and the anode unit and the cathode unit are located in the vacuum chamber; the anode unit is fixed on the glass On the substrate, the cathode unit is fixed at the bottom of the incident window.

Preferably, the above-mentioned anode unit is an anode array fabricated on a glass substrate using a semiconductor process; a micro-channel plate is installed between the anode array and the photocathode.

Preferably, the above-mentioned anode unit is a semiconductor photodetection element fixed on a glass substrate.

The present invention also provides a method for manufacturing a vacuum photoelectric device based on the above-mentioned electrode lead unit, which is special in that it includes the following steps:

1) Prepare the glass substrate;

2) Making electrode leads: using a semiconductor process to make electrode leads on a glass substrate; the electrode leads are a single metal film or a stacked structure of multiple metal films;

3) Fabricate an anode array on a glass substrate using a semiconductor process;

4) Welding glass shell: Coating low melting point glass powder on the installation part of the glass shell on the glass substrate, the coating width of the glass powder is greater than the thickness of the glass shell and less than the length of the electrode lead; after the glass powder is heated and solidified Form the glass glue; place the glass shell on the glass glue, make one end of the electrode lead on the inside of the glass shell, and the other end of the electrode lead on the outside of the glass shell; heat the glass shell and the glass substrate through the glass in a vacuum furnace Glue together, take out after cooling down;

5) Using a wire bonding process to connect the anode array to the electrode leads;

6) After the micro-channel plate is installed, vacuum-seal the incident window with the photocathode attached to the upper end of the glass tube shell to form a multi-anode micro-channel plate vacuum photodetector.

The present invention also provides another method for manufacturing a vacuum photoelectric device based on the above-mentioned electrode lead unit, which is special in that it includes the following steps:

1) Prepare the glass substrate;

2) Making electrode leads: using a semiconductor process to make electrode leads on a glass substrate; the electrode leads are a single metal film or a stacked structure of multiple metal films;

3) fixing the semiconductor photodetection element on the glass substrate;

4) Using a wire bonding process to connect the semiconductor photodetection element with the electrode lead wire;

5) Welding glass shell: coating the installation part of the glass shell on the glass substrate with low-melting glass powder, the coating width of the glass powder is greater than the thickness of the glass shell and less than the length of the electrode lead; after the glass powder is heated and solidified Form the glass glue; place the glass shell on the glass glue, make one end of the electrode lead on the inside of the glass shell, and the other end of the electrode lead on the outside of the glass shell; heat the glass shell and the glass substrate through the glass in a vacuum furnace Glue together, take out after cooling down;

6) Vacuum sealing the incident window with the photocathode attached to the upper end of the glass tube shell to form a hybrid vacuum photodetector.

The beneficial effects of the present invention are:

(1) The production of the electrode lead unit in the present invention is realized by a mature semiconductor process, the process is simple, the cost is low, and it is easy to produce on a large scale, and it avoids the phenomenon of device bursting or slow air leakage caused by the mismatch of thermal expansion coefficients, making the vacuum The performance of the device is more reliable.

(2) Compared with using stems for electrode connection, the method for making electrode leads in the present invention does not have metal pins, so that the vacuum optoelectronic device made is small in size, light in weight and more compact.

(3) The electrode lead produced by the present invention is not limited by the diameter of the Kovar wire at the end of the anode, so a detector with hundreds of readout channels can be produced. The minimum electrode size can be tens of microns, which is conducive to the production of high-density electrode leads. It is suitable for various vacuum optoelectronic devices such as hybrid photodetectors and multi-anode photomultiplier tubes. The position resolution can be better than 50 microns. In high-energy physics , cosmic exploration, low-light night vision, medical equipment and other fields have broad application prospects.

Description of drawings

FIG. 1 is a schematic structural diagram of a traditional microchannel plate photodetection device.

FIG. 2 is a flow chart of a preferred implementation method for manufacturing an electrode lead unit according to the present invention.

FIG. 3 is a schematic diagram of a preferred distribution of electrode leads on a glass substrate in the present invention.

Fig. 4 is a schematic diagram of the welding position of the glass tube shell on the glass substrate in the present invention.

Fig. 5 is a schematic diagram of the electrode connection of the anode unit of the multi-anode microchannel plate vacuum photodetector in the first embodiment of the present invention.

FIG. 6 is a schematic diagram of the three-dimensional structure of the multi-anode microchannel plate vacuum photodetector in Embodiment 1 of the present invention.

Fig. 7 is a schematic diagram of the electrode connection of the anode unit of the hybrid vacuum photodetector in the second embodiment of the present invention.

FIG. 8 is a schematic diagram of a three-dimensional structure of a hybrid vacuum photodetector in Embodiment 2 of the present invention.

Detailed ways

Referring to Fig. 2, the preferred implementation method of the present invention for making the electrode lead unit mainly includes the following steps:

First, the preparation of the glass substrate. Usually the glass substrate is made of borosilicate glass with a thickness of 2 mm and a flat surface. The size of the glass substrate is larger than 20 mm × 20 mm. It is ultrasonically cleaned with a glass cleaner and dried at high temperature.

Second, the fabrication of electrode leads. Electrode leads are fabricated on glass substrates using standard semiconductor processes. The standard semiconductor process includes metal film deposition, photolithography, etching or corrosion or peeling, etc. The metal film can choose a single metal such as gold, silver or a stacked structure of multiple metal films such as titanium and platinum. The thickness of the metal film is greater than 500 nanometers. FIG. 3 is a typical distribution state of electrode leads formed on the glass substrate, and the electrode leads 21 are distributed on the surface edge of the glass substrate 22 . The size of the electrode leads can be changed according to the number of electrodes and the size of the glass substrate. In the case of a certain number of glass substrates and electrodes, the size of the electrode leads is required to be as large as possible in order to carry a large enough current. A typical electrode lead size is 1 mm x 6 mm, and the spacing between electrode leads is 0.5 mm.

Third, the welding of the glass substrate and the glass shell. The side length of a typical glass shell is the side length of the glass substrate minus 4 mm, the thickness of the glass shell is 2 mm, and the height of the glass shell is greater than 5 mm. First, apply low melting point glass powder on the edge of the glass substrate. The width of the glass powder coating is less than 3mm. After high temperature solidification to form glass glue, place the glass shell on the glass glue and send it into the vacuum furnace for heating. The heating temperature is Slightly higher than the melting temperature of glass glue. After the glass glue is melted, the glass tube shell is bonded with the glass substrate, and is taken out after cooling down. As shown in FIG. 4 , the glass shell 23 is welded on the glass substrate, the inner end of the electrode lead is inside the glass shell 23 , and the outer end of the electrode lead is outside the glass shell 23 . The other parts of the electrode leads 21 are covered by glass glue, which will not form a short circuit.

Fourth, carry out vacuum leak detection on the manufactured vacuum optoelectronic devices, and the leak rate must be less than 10 ^-10 Pa·m ³ /s.

The present invention also provides a vacuum photoelectric device based on the above electrode lead unit, that is, a multi-anode micro-channel plate vacuum photodetector.

Fig. 5 is a schematic diagram of the electrode connection of the anode unit of the multi-anode microchannel plate vacuum photodetector. The difference from FIG. 4 is that the current conduction channel composed of the anode unit 31 and the electrode connecting wire 32 is constructed on the glass substrate by using the same semiconductor manufacturing process as that used to make the electrode leads. Typically, each anode unit is a square structure with a size of 0.5 mm, and the interval between adjacent anode units is 0.5 mm, and the anode units are distributed in an array.

Fig. 6 is a schematic diagram of a three-dimensional structure of a multi-anode microchannel plate photodetector. On the basis of FIG. 5 , an incident window 33 , a photocathode 34 , a microchannel plate 35 , and a glass spacer 36 are added to form a multi-anode microchannel plate photodetector. The photocathode 34 is attached to the incident window 33 , and the microchannel plate 35 is insulated from the photocathode 34 and the anode unit 31 by a glass spacer 36 . The working principle of the device is: the incident light penetrates the incident window and interacts with the photocathode to generate photoelectrons, which convert the optical signal into an electrical signal. anode unit. Since the anode unit is connected to the electrode lead on the glass substrate through the electrode connection line, and the outer end of the electrode lead is placed outside the vacuum environment of the device, the signal can be read by connecting to the electrode at the outer end of the electrode lead, and finally realized detection of optical signals. One advantage of this device is that it realizes a multi-anode device structure. The device has high position resolution capability, and anode structures of different sizes can be made according to requirements. It is a vacuum photodetector device with high spatial resolution capability. , medical instruments and other fields have broad application prospects.

The present invention also provides a vacuum photoelectric device based on the above electrode lead unit, that is, a hybrid vacuum photodetector.

Fig. 7 is a schematic diagram of the connection of the anode unit electrodes of the hybrid vacuum photodetector. The difference from FIG. 5 is that this device uses a semiconductor photodetection element 41 instead of an array multi-anode structure. The semiconductor photodetection element is fixed in the center of the glass substrate, and each electrode 42 of the semiconductor photodetection unit is connected to the glass substrate through the electrode connection wire 43 of the wire bonding process, so as to realize the circulation of the current of each electrode. Among them, the semiconductor detection element can be selected from avalanche photodiode, charge-coupled device, active pixel sensor, silicon photomultiplier tube, etc.

FIG. 8 is a schematic diagram of a three-dimensional structure of a hybrid vacuum photodetector, which is composed of an incident window 44 and a photocathode 45 on the basis of FIG. 7 . The working principle of this device is: the incident light penetrates the incident window and interacts with the photocathode to generate photoelectrons, which convert the optical signal into an electrical signal, and the photoelectrons bombard the semiconductor detection element under the action of high voltage, thereby generating electron bombardment gain inside the semiconductor detection element , the electrical signal is amplified, and the signal reaches the outer end of the electrode lead outside the vacuum environment of the device after passing through the electrode of the semiconductor detection element, the electrode connection line and the electrode on the glass substrate, and then can be detected by an external circuit. The hybrid vacuum optoelectronic device made by the method of the invention can easily detect the signals of each electrode on the semiconductor detection element, the process is simple and reliable, and the manufacturing cost is low. The advantage of being compact. This vacuum optoelectronic device can perform single-photon imaging, and has potential application prospects in low-light night vision, astrophysics and other fields in the future.

The above only describes several preferred embodiments of the present invention, but the present invention is not limited thereto. Any improvement or deformation made by those skilled in the art without departing from the spirit of the present application shall be protected by the present invention. scope.

Claims (9)

1. a kind of contact conductor unit, it is characterised in that：Including glass substrate, glass shell and multiple electrodes lead；The glass Glass shell is fused to the surface of glass substrate；The contact conductor is distributed on the face of weld of glass shell and glass substrate, electricity Pole lead one end is located at the inside of glass shell, and the other end of contact conductor is located at the outside of glass shell；The contact conductor It is the metallic film of the strip made on the glass substrate of semiconductor technology.

2. contact conductor unit according to claim 1, it is characterised in that：The metallic film for single metallic film or The stacked structure of person's various metals film.

3. a kind of production method of contact conductor unit, it is characterised in that：Comprise the following steps：

1) glass substrate is prepared；

2) contact conductor is made：Contact conductor is made using semiconductor technology on the glass substrate；The contact conductor is single The stacked structure of metallic film or various metals film；

3) welding glass shell：The installation position coating glass powder with low melting point of glass shell on the glass substrate, glass dust Coating width is more than the thickness of glass shell and less than the length of contact conductor；Glass cement is formed after glass dust is heating and curing； Glass shell is positioned on glass cement, contact conductor one end is made to be located on the inside of glass shell, the other end of contact conductor is located at The outside of glass shell；Heating makes glass shell bond together with glass substrate by glass cement in vacuum drying oven；After cooling It takes out, completes the making of contact conductor unit.

4. the production method of contact conductor unit according to claim 3, it is characterised in that：Step 4) is further included to making Good contact conductor unit carries out vacuum leak hunting.

5. a kind of vacuum photoelectric device, including entrance window, cathode electrode unit and anode unit, it is characterised in that：Electrode is further included to draw Line unit；

The contact conductor unit includes glass substrate, glass shell and multiple electrodes lead；The glass shell is fused to glass The surface of glass substrate；The contact conductor is distributed on the face of weld of glass shell and glass substrate；Described contact conductor one end Positioned at the inside of glass shell, it is connected by electrode connecting line with anode unit；The other end of the contact conductor is located at glass The outside of shell；The contact conductor is the metallic film of the strip made on the glass substrate of semiconductor technology；

The entrance window is located at the top of glass shell, and the entrance window, glass shell and glass substrate surround closed jointly Vacuum chamber, the anode unit and cathode electrode unit are respectively positioned in vacuum chamber；The anode unit is fixed on glass substrate, described Cathode electrode unit is fixed on entrance window bottom.

6. vacuum photoelectric device according to claim 5, it is characterised in that：The anode unit is to adopt on the glass substrate The anode array made of semiconductor technology；Microchannel plate is installed between the anode array and photocathode.

7. vacuum photoelectric device according to claim 5, it is characterised in that：The anode unit is affixed to glass substrate On semiconductor optoelectronic detecting element.

8. a kind of production method of vacuum photoelectric device, it is characterised in that：Comprise the following steps：

1) glass substrate is prepared；

2) contact conductor is made：Contact conductor is made using semiconductor technology on the glass substrate；The contact conductor is single The stacked structure of metallic film or various metals film；

3) anode array is made using semiconductor technology on the glass substrate；

4) welding glass shell：The installation position coating glass powder with low melting point of glass shell on the glass substrate, glass dust Coating width is more than the thickness of glass shell and less than the length of contact conductor；Glass cement is formed after glass dust is heating and curing； Glass shell is positioned on glass cement, contact conductor one end is made to be located on the inside of glass shell, the other end of contact conductor is located at The outside of glass shell；Heating makes glass shell bond together with glass substrate by glass cement in vacuum drying oven, after cooling It takes out；

5) anode array is connected with contact conductor by conducting using lead key closing process；

6) after microchannel plate being installed, then the entrance window and the upper end vacuum sealing of glass shell that photocathode will be attached with, it is formed Multianode microchannel plate Vacuum Photoelectric Detectors.

9. a kind of production method of vacuum photoelectric device, it is characterised in that：Comprise the following steps：

1) glass substrate is prepared；

2) contact conductor is made：Contact conductor is made using semiconductor technology on the glass substrate；The contact conductor is single The stacked structure of metallic film or various metals film；

3) semiconductor optoelectronic detecting element is fixed on glass substrate；

4) semiconductor optoelectronic detecting element is connected with contact conductor by conducting using lead key closing process；

5) welding glass shell：The installation position coating glass powder with low melting point of glass shell on the glass substrate, glass dust Coating width is more than the thickness of glass shell and less than the length of contact conductor；Glass cement is formed after glass dust is heating and curing； Glass shell is positioned on glass cement, contact conductor one end is made to be located on the inside of glass shell, the other end of contact conductor is located at The outside of glass shell；Heating makes glass shell bond together with glass substrate by glass cement in vacuum drying oven, after cooling It takes out；

6) entrance window and the upper end vacuum sealing of glass shell that will be attached with photocathode forms mixed type vacuum photodetection Device.