Organic light emitting diode variable temperature testing device

Abstract

The application discloses a kind of organic light emitting diode variable temperature testing device, for testing the photoelectric performance of organic light emitting diode at low temperature, improve work efficiency and test accuracy, the device includes variable temperature testing module and liquid nitrogen refrigeration module;The variable temperature testing module includes device fixing device, temperature testing device, light measuring device, circuit device, for testing the photoelectric performance of organic light emitting diode at various temperatures;The liquid nitrogen refrigeration module includes cooling system, gas path, flow rate control system, and the temperature in variable temperature testing module is accurately controlled by controlling nitrogen flow rate.The application first proposes the structure device of combining testing module and refrigeration module, to solve the problem of organic light emitting diode variable temperature testing difficulty.

Description

Technical Field

[0001] The present invention belongs to the field of organic light emitting diode displays, and in particular relates to an organic light emitting diode temperature-varying test device. Background Art

[0002] The rapid development of information technology is placing increasing demands on display technology. Displays that are rich in color, low in energy consumption, environmentally friendly, lightweight, and even rollable are becoming the goal. Organic light-emitting diodes (OLEDs), with their advantages of low-voltage operation, high-efficiency light emission, rich colors, fast response, wide viewing angles, and ease of achieving ultra-thinness and lightness, meet these requirements and are poised to become an ideal display technology for the information age.

[0003] Due to the presence of charge traps within organic semiconductors, the transport of holes and electrons often differs by several orders of magnitude. This unbalanced charge transport results in the luminescent region being close to the electrode, which is prone to exciton quenching, reducing the device's luminous efficiency and lifetime. These inherent challenges limit the commercial prospects of OLEDs. Currently, the nature of the traps that affect charge transport and device efficiency remains unclear. Therefore, in-depth research on the nature of charge traps and carrier transport mechanisms to achieve high-performance OLEDs is crucial for the continued development of organic light-emitting displays.

[0004] A variable temperature spectrum testing device (CN202010161993.6), the cooling system includes a water tank and a water pipe. The water tank is connected to the temperature control device through the water pipe to form a water circulation system to lower the temperature of the temperature control device. There are certain limitations on the cooling of the organic light-emitting diode test environment.

[0005] Testing the optoelectronic performance (device current density, brightness) of organic light-emitting diodes at different temperatures is of great significance for studying the nature of charge traps and carrier transport mechanisms. However, there is currently no report on a complete set of variable-temperature testing equipment for organic light-emitting diodes. Summary of the Invention

[0006] The present invention provides an organic light-emitting diode (OLED) variable temperature testing device, combining a test module with a variable temperature module. This multi-functional device achieves precise temperature control by controlling the flow rate of cooling nitrogen gas, providing new impetus for the development of OLEDs. Liquid nitrogen is used to cool nitrogen gas to lower its temperature. The flow rate of the cooling nitrogen gas is precisely adjusted through dual control using a flow meter and a pressure reducing valve, achieving precise temperature control. This solves the current difficulty in low-temperature testing of OLED photoelectric devices in scientific research.

[0007] The present invention is achieved through at least one of the following technical solutions.

[0008] An organic light emitting diode variable temperature testing device comprises: a variable temperature testing module and a liquid nitrogen refrigeration module;

[0009] The variable temperature testing module comprises a fixing device and a circuit device;

[0010] The device fixing device comprises a bearing part for placing the testing component and a fixing part for pressing the device to be tested, the bearing part is arranged on the bottom plate through the height adjusting rod, and the fixing part is tightly pressed above the bearing part;

[0011] The temperature testing device is arranged in the bearing part, and the light measuring device is arranged in the fixing part;

[0012] The circuit device comprises a metal electrode embedded in the bearing part;

[0013] The nitrogen gas output by the liquid nitrogen refrigeration module after being cooled is used for cooling the component to be tested after entering the air inlet of the bearing part, and the nitrogen gas flows out through the air outlet of the bearing part.

[0014] Preferably, the bearing part has a groove on the surface, the component to be tested is located in the groove, and the metal electrode is located on the inner surface of the groove; the fixing part has a square hole for inserting the positioning block.

[0015] Preferably, the temperature testing device comprises a temperature probe and a temperature display connected with the temperature probe; the temperature probe is arranged in the bearing part and is used for testing the temperature change in the variable temperature process.

[0016] Preferably, the light measuring device comprises a fiber probe, a fiber spectrometer, a photodiode probe and an electrometer, which are used for detecting various indicators of the light emission of the organic light emitting diode device.

[0017] Preferably, the fixing part is provided with a positioning block, the fiber probe and the photodiode probe are fixed on the positioning block through a fiber matching head and a photodiode matching head respectively; the lower surface of the positioning block is provided with a protrusion, and the protrusion is matched with the square hole of the fixing part.

[0018] Preferably, the surface of the bearing part and the corresponding surface of the fixing part are both provided with a positioning magnet.

[0019] Preferably, the circuit device further comprises a digital source table, and the metal electrode is connected with the source table.

[0020] Preferably, the liquid nitrogen refrigeration module comprises a cooling system, an air path and a flow rate control system;

[0021] The cooling system comprises a nitrogen gas bottle, an air path and a liquid nitrogen tank;

[0022] The air path comprises a metal air path and air path switches, and the metal air path comprises a spiral metal air path;

[0023] The flow rate control system includes a pressure reducing valve and a flow meter. High-purity nitrogen flows out of the nitrogen bottle, flows to the pressure reducing valve through the metal gas path, is reduced in pressure by the pressure reducing valve, flows into the flow meter for controlling the flow rate, and then flows into the spiral metal gas path installed in the liquid nitrogen tank for cooling. The cooled nitrogen flowing out of the liquid nitrogen tank passes through the metal gas path and enters the variable temperature test module through the air inlet on the bearing component. After cooling the light-emitting diode, the nitrogen flows out through the air outlet on the bearing component of the fixing device and enters the exhaust system.

[0024] Preferably, except for the spiral metal gas path, the outer layers of other metal gas paths are covered with a heat-insulating plastic layer.

[0025] Preferably, the bearing component is tightly connected to the fixing component through a lock.

[0026] Compared with the existing technology, the beneficial effects of the present invention are:

[0027] This invention combines an OLED photoelectric testing system with a cooling system for the first time, using liquid nitrogen to cool high-purity nitrogen to perform variable-temperature testing on the OLEDs without damaging them. The nitrogen flow rate is precisely controlled by a pressure reducing valve and flowmeter to achieve precise temperature control. The device maintains a temperature stability deviation of plus or minus 0.2 degrees Celsius, fully meeting the scientific research requirements for variable-temperature testing of OLEDs, saving costs and improving research efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the present invention will become more apparent by describing in detail the embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0029] Figure 1 A flow chart of a liquid nitrogen refrigeration module according to an embodiment;

[0030] Figure 2 This is a main structural diagram of the variable temperature test module of the embodiment;

[0031] Figure 3 Detailed structural diagram of the variable temperature test module of the embodiment;

[0032] Figure 4 This is a distribution diagram of the electrodes, gas circuits, and temperature probes of the variable temperature test module of the embodiment;

[0033] Among them, 1-bearing component, 2-fixing component, 3-positioning block, 4-mating head, 5-locking buckle, 6-cooling nitrogen inlet, 7-cooling nitrogen outlet, 8-metal electrode, 9-positioning magnet, 10-temperature probe slot, 11-height adjustment rod. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0035] like Figure 2 、 Figure 3 、 Figure 4 The organic light-emitting diode variable temperature testing device shown includes: a variable temperature testing module and a liquid nitrogen refrigeration module; the variable temperature testing module is located in a glove box and includes a device fixing device, a temperature testing device, a light measuring device, and a circuit device;

[0036] The temperature testing device includes a temperature probe for testing the temperature of the variable temperature module and a temperature display for displaying the temperature. The flow rate control system described below is adjusted through the temperature displayed on the temperature display to achieve the temperature control purpose.

[0037] The light measuring device is a fiber optic probe combined with a fiber optic spectrometer, or a photodiode probe combined with an electrometer. The two combinations are selected as needed to detect various indicators of the luminescence of the organic light emitting diode device.

[0038] The circuit device includes a metal electrode 8 embedded in a carrier component, a circuit connected to the metal electrode 8, and a digital source meter.

[0039] The device fixing device comprises a carrying component 1 for placing the device under test, a fixing component 2 for pressing the device under test, a height adjustment rod 11 for placing the carrying component and the fixing component, and a lock 5 for tightly connecting the carrying component and the fixing component. Figure 2 As shown, a height adjustment rod 11 is fixed to the base plate, providing support for the entire device. The supporting components and the fixed components are fixed to the height adjustment rod 11 via nuts. The fixed component is provided with a positioning block 3, which has an opening for receiving a mating connector 4. The mating connector 4 is divided into a fiber optic mating connector and a photodiode mating connector, corresponding to the fiber optic probe and the photodiode probe. These connectors help secure the probe to the opening in the positioning block 3 and are used to detect various indicators of the OLED device's light emission.

[0040] A dark test cavity is formed between the carrying component and the fixing component, and the device to be tested is located in the test cavity.

[0041] like Figure 3As shown, the supporting component provides a support platform for the device to be tested and the fixing components; a groove is provided on one side of the supporting component, and the groove is used to place the device to be tested. The bottom of the supporting component is provided with an inlet and outlet for cooling nitrogen. The cooling nitrogen enters the test cavity through the air inlet 6 to cool the device to be tested, and then flows out of the test cavity through the air outlet 7 and enters the exhaust system.

[0042] The grooves are equipped with metal electrodes corresponding to the positive and negative electrodes of the device to be tested; the metal electrodes are connected to a digital source meter outside the test glove box for testing the electrical properties of the device; the metal electrodes are elastic, which facilitates the fixing of the device to be tested by the supporting components and the fixing components, and also prevents damage to the device to be tested.

[0043] The fixing part mainly plays a fixing role to prevent the cooling nitrogen from blowing up the device to be tested during the test, causing the test to be interrupted. Figure 3 As shown, the fixing component is located above the carrying component, one side of the fixing component is connected to the height adjustment rod 11, and the other side is provided with a square hole (the shape and size of the square hole are determined according to the shape of the device to be tested). The size of the opening is slightly smaller than the size of the test device carried by the carrying component. When the fixing component is closed and connected with the carrying component, the device to be tested is firmly fixed in the test cavity, which is convenient for further optoelectronic testing.

[0044] The lower surface of the positioning block 3 is provided with a protrusion, which cooperates with the square hole.

[0045] The inner side of the groove of the bearing component is provided with a temperature probe groove 10 and a hole for placing a metal electrode 8. The temperature probe is connected to the temperature display outside the glove box through a wire to monitor the temperature in the test cavity in real time, so as to adjust the flow rate of the cooling nitrogen and achieve the purpose of precise temperature control.

[0046] A positioning magnet is installed on the edge of the square opening, and a positioning magnet 9 is also installed at the corresponding position of the supporting component, so as to determine whether the supporting component and the fixing component are aligned through the positioning magnet 9, and to tightly connect the supporting component and the fixing component through the attraction of the magnet 9.

[0047] The fixing component and the supporting component must be tightly connected so that the cooling nitrogen can flow in from the air inlet at the bottom of the supporting component and out from the air outlet at the bottom. Otherwise, the cooling nitrogen will leak out from the gap between the supporting component and the fixing component, which will affect the cooling effect on the one hand and the gas atmosphere in the glove box on the other hand. Moreover, if the cooling nitrogen leaks from the gap between the supporting component and the fixing component, the gas pressure in the glove box will change, causing the glove box to be depressurized, further shortening the life of the glove box pressure relief device and reducing the service life of the glove box.

[0048] There is a height adjustment device at the connection position between the fixing component and the height adjustment rod 11. The height adjustment device is similar to a C-clip, which fastens the fixing component to the adjustment rod. The upper and lower heights of the fixing component can be adjusted using a knob to facilitate replacement of the device to be tested.

[0049] The lock 5 is located between the load-bearing component and the fixed component, and is in a closed state during the test process, so that the fixed component is tightly connected to the load-bearing component, preventing the fixed component from sliding during the test process, causing the device and the electrode to separate during the device test and cause a circuit break, thereby affecting the test results.

[0050] The positioning block 3 is a circular device located above the fixed component. It primarily positions the mating head, aligning it with the different light-emitting regions of the organic light-emitting diode (OLED) to facilitate the collection of light signals for detection by the fiber optic probe or photodiode probe. A mating head 4 is mounted on this circular device. The positioning block 3 not only blocks natural light, maintaining darkness within the test cavity, but also serves as a mating head 4.

[0051] The optical fiber probe is connected to the optical fiber spectrometer. When the organic light emitting diode is working, the optical fiber probe collects the light signal emitted by the organic light emitting diode and transmits it to the optical fiber spectrometer for spectral analysis.

[0052] The photodiode probe is connected to the electrometer. When the organic light emitting diode is working, the photodiode probe collects light signals and converts them into electrical signals, which are then transmitted to the electrometer for brightness analysis.

[0053] The pairing head 4 is located at the top of the entire test device. On the one hand, it fills the opening of the positioning block 3 to make the test cavity dark. On the other hand, it helps the two probes to be fixed on the positioning block to collect the light emitted by the device to be tested for optical testing.

[0054] Figure 4 This is a top view of the carrier component. Taking an organic light-emitting diode of a certain shape as an example to determine the position of the metal electrodes, the organic light-emitting diode is divided into four light-emitting areas, which correspond to the eight metal electrodes on the carrier component respectively.

[0055] The metal electrodes not only connect the organic light-emitting diodes (OLEDs), but also, due to their elasticity, support the device under test (DUT). This creates a gap between the DUT and the supporting component, ensuring that cooling nitrogen can enter the test cavity. The device is placed in the test cavity and connected to the sourcemeter via the metal electrodes embedded in the supporting component for electrical testing. A probe located on the fixed component transmits the collected electroluminescence signal to a fiber optic spectrometer or electrometer to characterize the DUT's electroluminescence characteristics.

[0056] Figure 4The positions of the air inlet and outlet on the carrier are clearly shown in the figure, as well as the opening position where the temperature probe enters the carrier. The sizes of the air inlet and outlet are determined according to different carriers, that is, they cannot be larger than the test cavity, nor too small, which will limit the cooling nitrogen flow rate.

[0057] It should be noted that the notch of the temperature probe must be tightly sealed with glue to prevent cooling nitrogen from leaking out of the notch. This will affect the cooling effect on the one hand, and the gas atmosphere in the glove box on the other hand. Moreover, if cooling nitrogen leaks from the gap between the load-bearing component and the fixed component, the gas pressure in the glove box will change, causing the glove box to depressurize, further shortening the life of the glove box pressure relief device and reducing the service life of the glove box.

[0058] The positioning magnet 9 can determine whether the bearing component and the fixing component are aligned, and the bearing component and the fixing component are tightly connected through the attraction of the magnet 9. Figure 4 Only exemplary positions of the components of the carrier are shown in FIG. 1 , and positions of the components shown can be changed to accommodate tests of various organic light emitting diodes.

[0059] The liquid nitrogen refrigeration module includes: a cooling system, an air circuit, and a flow rate control system.

[0060] The cooling system includes a nitrogen cylinder, a spiral metal gas circuit, and a liquid nitrogen tank; the gas circuit includes a metal gas circuit and switches for each gas circuit; the flow rate control system includes a pressure reducing valve and a flow meter. The nitrogen cylinder is connected to the air inlet 6 via the metal gas circuit.

[0061] like Figure 1 As shown, the liquid nitrogen refrigeration module and the variable temperature test module are combined. The arrow direction indicates the flow direction of nitrogen. The process is as follows:

[0062] (1) In the example shown in the figure, high-purity nitrogen is used as the working gas to cool the device under test. The high-purity nitrogen flows out of the gas cylinder and enters the metal gas path. At this time, the high-purity nitrogen pressure in the channel is relatively high;

[0063] (2) When the nitrogen gas flows into the regulating valve composed of a pressure reducing valve and a flow meter, the gas flow rate is precisely controlled, and the high-purity nitrogen gas flows out of the regulating valve and then enters the liquid nitrogen tank composed of a liquid nitrogen tank;

[0064] (3) A spiral metal gas path is provided in the liquid nitrogen tank. When the nitrogen flows into the spiral metal gas path, it is fully cooled by the liquid nitrogen in the liquid nitrogen tank. When it flows out of the liquid nitrogen tank, it is low-temperature high-purity nitrogen. At this time, the working gas truly plays a cooling role.

[0065] (4) The cooling nitrogen flows out of the spiral metal gas path and enters the next valve. At this time, the valve acts as an air inlet switch. The cooling nitrogen passes through the air inlet valve and enters the organic light-emitting diode variable temperature test module in the test glove box;

[0066] (5) An organic light-emitting diode device to be tested is placed in the test cavity formed by the supporting component and the fixing component, and the photoelectric performance of the organic light-emitting diode is tested at a corresponding temperature under the cooling effect of the cooling nitrogen;

[0067] (6) The cooling nitrogen flows out from the outlet of the bearing component after passing through the test cavity. Figure 1 The exhaust valve shown is used to control the discharge of cooling nitrogen. When not in operation, it is in a normally closed state to prevent air in the exhaust pipe from flowing back into the glove box and affecting its working atmosphere.

[0068] (7) The cooling nitrogen is discharged from the exhaust pipe after passing through the outlet valve.

[0069] A temperature probe is embedded in the bearing component and connected to a temperature display after being led out through a wire, so as to monitor the temperature change in the test cavity in real time and accurately control the temperature of the tested organic light emitting diode.

[0070] Example 2

[0071] All metal gas paths (excluding spiral metal gas paths) in this embodiment are covered with an outer layer of a thermal insulation plastic layer to reduce the heat transfer effect of the external temperature on the cooling nitrogen in the gas path, and to protect the metal gas path, preventing the water vapor in the environment from liquefying or even freezing due to the cooling nitrogen in the gas path, thereby reducing damage to the metal gas path caused by the environment.

[0072] The liquid nitrogen tank is equipped with a suitable tank cover to ensure normal addition of liquid nitrogen and reduce the influence of ambient temperature. At the same time, the tank cover is ensured to have moderate air tightness to avoid volatilization of liquid nitrogen in the liquid nitrogen tank due to excessive pressure in the tank causing explosion due to excessive air tightness, thereby ensuring test safety.

[0073] The air inlet valve and the air outlet valve are located inside and outside the glove box, that is, there is a valve inside and outside the glove box in the air inlet channel, and there is a valve inside and outside the glove box in the air outlet channel. This makes it easy to control the valves in any position when an emergency occurs, thereby increasing test safety.

[0074] The pressure reducing valve is located before the flow meter to ensure that the nitrogen flowing out of the nitrogen bottle is depressurized before adjusting its flow rate.

[0075] The temperature display is placed outside the glove box through a wire, which reduces the impact of the temperature display on the device test during operation and increases the test accuracy.

[0076] Furthermore, it should be understood that Figure 1 Only the basic structure of the entire testing device is shown. Other nitrogen flow rate control devices can be added between the various links shown to further improve the accuracy of the precise temperature control.

[0077] Example 3

[0078] The positioning block of this embodiment is in the shape of a circle with a flat bottom, and has the same shape of holes as the fiber pair head and the photodiode pair head, to facilitate the conversion between different pair heads during testing. The positioning block hole position is located in the organic light emitting diode light emitting area, and different positioning blocks are prepared for different light emitting devices.

[0079] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details and limit the application to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the specification. The specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. An organic light emitting diode temperature test device, characterized in that: include: Variable temperature test module and liquid nitrogen refrigeration module; The variable temperature test module includes a fixing device and a circuit device; The device fixing device includes a bearing component for placing the test component and a fixing component for pressing the device under test. The bearing component is arranged on the bottom plate through a height adjustment rod, and the fixing component is pressed tightly above the bearing component. The bearing component is provided with a temperature testing device, and the fixing component is provided with a light measuring device; a groove is formed on the surface of the bearing component, the device to be tested is located in the groove, and the metal electrode is located on the inner surface of the groove; the fixing component has a square hole for inserting a positioning block; the light measuring device includes a fiber optic probe, a fiber optic spectrometer, a photodiode probe, and an electrometer, and is used to detect various indicators of the light emission of the organic light emitting diode device; The circuit device includes a metal electrode embedded in the interior of the carrier component; The liquid nitrogen refrigeration module outputs cooled nitrogen gas which passes through the air inlet of the load-bearing component to cool the component to be tested, and the nitrogen gas flows out through the air outlet on the load-bearing component; the liquid nitrogen refrigeration module includes a cooling system, an air circuit, and a flow rate control system; The cooling system includes a nitrogen bottle, a gas line, and a liquid nitrogen tank; The gas circuit includes a metal gas circuit and gas circuit switches, and the metal gas circuit includes a spiral metal gas circuit; The flow rate control system includes a pressure reducing valve and a flow meter. High-purity nitrogen flows out of the nitrogen bottle, flows to the pressure reducing valve through the metal gas path, and after being reduced in pressure by the pressure reducing valve, flows into the flow meter for controlling the flow rate, and then flows into the spiral metal gas path installed in the liquid nitrogen tank for cooling. The cooled nitrogen flowing out of the liquid nitrogen tank passes through the metal gas path and enters the variable temperature test module through the air inlet on the supporting component. After cooling the light-emitting diode, the nitrogen flows out through the air outlet on the supporting component of the fixing device and enters the exhaust system. The temperature testing device includes a temperature probe and a temperature display connected to the temperature probe; the temperature probe is located in the bearing component and is used to test the temperature change during the temperature change process.

2. The organic light emitting diode temperature variation testing device according to claim 1, wherein: The fixing component is provided with a positioning block, and the optical fiber probe and the photodiode probe are fixed on the positioning block through an optical fiber matching head and a photodiode matching head respectively; a protrusion is provided on the lower surface of the positioning block, and the protrusion cooperates with the square hole of the fixing component.

3. The organic light emitting diode temperature variation testing device according to claim 1, wherein: Positioning magnets are provided on the surface of the bearing component and the corresponding surface of the fixing component.

4. The organic light emitting diode temperature variation testing device according to claim 1, wherein: The circuit device further comprises a digital source meter, and the metal electrode is connected to the source meter.

5. The organic light emitting diode temperature variation testing device according to claim 1, wherein: Except for the spiral metal gas circuit, the outer layer of other metal gas circuits is covered with a heat-insulating plastic layer.

6. The organic light emitting diode temperature-varying test device according to any one of claims 1 to 5, wherein: The bearing component is tightly connected to the fixing component through a lock.

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