阅读说明：本技术 一种白光led结温和荧光胶温度测量装置 (White light LED junction temperature and fluorescent glue temperature measuring device ) 是由 靳斌 王鹏 于 2021-08-03 设计创作，主要内容包括：本发明是关于白光LED结温和荧光胶温度测量装置,包括测温表、电流源、被测LED芯片,其特征在于其包括：Pt100铂电阻芯片,设置2圈互相绝缘的电极；微型热电偶,测点凝固在荧光胶中,测点不接触所述LED芯片；底板,其上设置2个互相绝缘的电极,底板的电极分别与所述铂电阻芯片的电极焊接,并保持电绝缘。本发明揭示的白光LED结温和荧光胶温度测量装置可直接测量且精度高于现有的方案。(The invention relates to a white light LED junction temperature and fluorescent glue temperature measuring device, which comprises a temperature meter, a current source and a measured LED chip, and is characterized by comprising: the Pt100 platinum resistor chip is provided with 2 circles of electrodes which are mutually insulated; the measuring points are solidified in the fluorescent glue, and are not in contact with the LED chip; and the bottom plate is provided with 2 mutually insulated electrodes, and the electrodes of the bottom plate are respectively welded with the electrodes of the platinum resistance chip and are kept in electric insulation. The device for measuring the junction temperature and the fluorescent glue temperature of the white light LED can directly measure and has higher precision than the prior scheme.)

1. The utility model provides a white light LED junction temperature and fluorescent glue temperature measuring device, includes current source, thermocouple thermometer, thermal resistance thermometer, is surveyed the LED chip, its characterized in that includes: the Pt100 platinum resistor chip is provided with 2 circles of mutually insulated electrodes, namely an electrode a and an electrode b; the measuring point is solidified in the fluorescent glue, and does not contact the LED chip to be measured; and a bottom plate, on which 2 mutually insulated electrodes are arranged, namely an electrode A and an electrode B, wherein the electrode A is welded with the electrode a, and the electrode B is welded with the electrode B and keeps A, B electrode insulation.

2. The white light LED junction temperature and fluorescent glue temperature measuring device as claimed in claim 1, wherein the electrodes of the Pt100 platinum resistor chip are formed by winding copper foil adhesive tapes on the platinum resistor chip.

3. The white LED junction temperature and fluorescent glue temperature measuring device as claimed in claim 1, wherein the electrodes provided on the Pt100 platinum resistor chip are formed by electroplating and depositing on the platinum resistor chip.

4. The white LED junction temperature and fluorescent glue temperature measurement device of claim 1, wherein the LED chip is a flip chip, and 2 electrodes of the flip chip are respectively soldered on 2 turns of mutually insulated electrodes of the platinum resistor chip.

5. The white LED junction temperature and fluorescent glue temperature measuring device of claim 1, wherein the LED chip is a front-mounted chip, the chip is fixed between 2 circles of mutually insulated electrodes of the platinum resistor chip by silver paste glue, and 2 electrodes of the platinum resistor chip are respectively connected to the 2 circles of mutually insulated electrodes of the platinum resistor chip by leads.

6. The white LED junction temperature and fluorescent glue temperature measuring device of claim 1, wherein the LED chip is a vertical structure chip, a bottom electrode of the chip is welded on one of 2 turns of mutually insulated electrodes of the platinum resistor chip, and a top electrode of the chip is connected on the other of the 2 turns of mutually insulated electrodes of the platinum resistor chip by a lead wire.

7. The white light LED junction temperature and fluorescent glue temperature measuring device as claimed in claim 1, wherein the base plate is a copper substrate, an aluminum substrate, a ceramic substrate, and is manufactured through a PCB process.

8. The white light LED junction temperature and fluorescent glue temperature measuring device of claim 1, wherein the bottom plate is made by arranging 2 circles of mutually insulated electrodes on the heat pipe.

9. The white light LED junction temperature and fluorescent glue temperature measuring device of claim 8, wherein one end of the heat pipe is welded with the platinum resistor chip, and the other end of the heat pipe is inserted into a container filled with ice and water.

Technical Field

The invention relates to the field of measurement of LED junction temperature and fluorescent glue temperature, in particular to the field of direct rather than indirect measurement of LED junction temperature and fluorescent glue temperature.

Background

In the service life of the LED in direct relation with the junction temperature of the LED, researches in recent years find that the junction temperature can be greatly improved due to the heating phenomenon of the fluorescent glue, so that the measurement of the junction temperature of the LED and the temperature of the fluorescent glue are very important.

The most common method for measuring the junction temperature of the LED is a direct measurement method of a pin, and the method has the problems that the pin is formed by connecting a PN junction with the pin through a thin metal wire (10 um level), the metal wire has large thermal resistance, the pin is welded with a printed board, errors are generated in the thermal resistance of the printed board, and the junction temperature measured by the method is obviously lower. There are also forward voltage method, infrared thermal imaging method, blue-white ratio method, these 3 methods are indirect measurement methods, the precision of which depends on the calibration process, the method and apparatus of which affect the precision, among which the forward voltage method is especially common, but the error is more than 2 ℃. The temperature measurement of the fluorescent glue is also similar to the infrared thermal imaging method, the spectrum method and the junction temperature measurement method, and is difficult to be used as a reliable measurement method.

The reliable temperature measurement is preferably directly measured by a standard temperature measuring element, the temperature of the measured object is interfered by the contact of the temperature measuring element and the measured object, so that the temperature measuring element as small as possible must be selected, the PN junction of the LED is a deposited InGaN-GaN film with the thickness of 2um and the area of less than 1mm²The volume of the fluorescent glue is also very small, and no interference thermal resistance and thermal capacity are introduced, which are the keys for ensuring the measurement precision.

The inventor finally creates the invention with practical value after continuous research and design and repeated trial production and improvement, and provides a white light LED junction temperature and fluorescent glue temperature measuring device with a novel structure.

Disclosure of Invention

The invention mainly aims to solve the problems of low measurement precision, low speed, complex operation and large measurement data fluctuation of the conventional white light LED junction temperature and fluorescent powder temperature, and provides a junction temperature device with a novel structure.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme. The invention provides a white light LED junction temperature and fluorescent glue temperature measuring device, which comprises a current source, a thermocouple temperature measuring meter, a thermal resistance temperature measuring meter and a tested LED chip, and is characterized by comprising the following components: the Pt100 platinum resistor chip is provided with 2 circles of mutually insulated electrodes, namely an electrode a and an electrode b; the measuring point is solidified in the fluorescent glue, and does not contact the LED chip to be measured; and a bottom plate, on which 2 mutually insulated electrodes are arranged, namely an electrode A and an electrode B, wherein the electrode A is welded with the electrode a, and the electrode B is welded with the electrode B and keeps A, B electrode insulation.

Further, the electrode arranged on the Pt100 platinum resistance chip is formed by winding a copper foil adhesive tape on the platinum resistance chip.

Further, the electrode arranged on the Pt100 platinum resistance chip is formed by electroplating and depositing on the platinum resistance chip.

Further, the LED chip is a flip chip, and 2 electrodes of the flip chip are respectively soldered to 2 turns of mutually insulated electrodes of the platinum resistor chip.

Further, the LED chip is a normal chip, the chip is fixed between 2 circles of mutually insulated electrodes of the platinum resistance chip by silver paste glue, and 2 electrodes are respectively connected to the 2 circles of mutually insulated electrodes of the platinum resistance chip by leads.

Further, the LED chip is a vertical structure chip, the bottom electrode of the chip is welded on one of the 2 circles of mutually insulated electrodes of the platinum resistance chip, and the top electrode of the chip is connected on the other of the 2 circles of mutually insulated electrodes of the platinum resistance chip by a lead wire.

Further, the base plate is made of a copper substrate, an aluminum substrate and a ceramic substrate through a PCB processing flow.

Furthermore, the bottom plate is made by arranging 2 circles of mutually insulated electrodes on the heat pipe.

Furthermore, one end of the heat pipe is welded with the platinum resistance chip, and the other end of the heat pipe is inserted into a container filled with ice and water.

According to the technical scheme, the device for measuring the junction temperature and the fluorescent glue temperature of the white light LED has the advantages that: the junction temperature measuring element is a standard Pt100 platinum resistor chip, has low price, high precision and small introduced thermal resistance heat capacity, and the measured value reflects a true value; the temperature of the fluorescent powder is measured by a standard micro thermocouple, the price is low, the precision is high, the introduced thermal resistance is small, the light is not blocked, and the measured value can reflect a true value; the electrode a and the electrode b which are made on the Pt100 platinum resistance chip are made of copper foil adhesive tapes or electroplating deposition, the self thermal resistance is low, and 2 electrodes of the flip chip are welded with the electrode a and the electrode b, so that the influence of air thermal resistance is overcome; similarly, the electrode A and the electrode B of the bottom plate are welded with the electrode a and the electrode B made on the Pt100 platinum resistance chip, so that the thermal resistance is minimized; the measuring points of the micro thermocouple are solidified in the glue and are not contacted with the LED chip to be measured, the temperature of the fluorescent glue is directly measured, the data is stable, and light blocking factors and thermal resistance and heat capacity interference factors are minimized.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a white LED junction temperature and fluorescent glue temperature measuring device according to the present invention.

Fig. 2 is a schematic diagram (flip chip-copper tape electrode) of a first embodiment of a measured sample of a white LED junction temperature and fluorescent glue temperature measuring device according to the present invention.

Fig. 3 is a schematic view (front chip-plating electrode) of a second embodiment of the measured sample of the white LED junction temperature and fluorescent glue temperature measuring device of the present invention.

Fig. 4 is a schematic view (vertical chip-plating electrode) of a third embodiment of a measured sample of the white LED junction temperature and fluorescent glue temperature measuring device of the present invention.

Fig. 5 is a schematic diagram of a fourth embodiment of the measured sample of the white LED junction temperature and fluorescent glue temperature measuring device (flip chip-copper tape-heat pipe base plate).

1. Constant current source 2, thermocouple thermometer 3, thermal resistance thermometer 100 and tested sample

110. Tested LED chip

120. A Pt100 platinum resistance chip 121, an a electrode 122 on the Pt100 platinum resistance chip, a b electrode 123 on the Pt100 platinum resistance chip, a electrode of the Pt100 platinum resistance chip, solder paste 124 coated on the b electrode, a platinum resistance wire 125 in the Pt100 platinum resistance chip, a two-connection terminal 126 of the Pt100 platinum resistance chip, silver paste glue

130. Bottom plate 131, A electrode 132 on the bottom plate, B electrode 133 on the bottom plate, solder paste coated on the A electrode and the B electrode

140. Fluorescent glue

150. Thermocouple

160. A container containing ice and water.

Detailed Description

FIG. 1 is a schematic diagram of the junction temperature and fluorescent glue temperature measuring device of the white light LED according to the present invention. The constant current source (1) is a programmable power supply and works in a constant current mode, and the power precision is 1%; the thermocouple thermometric indicator (2) is Ulried (UNI-T) UT320D and is used for measuring the temperature of the thermocouple (150); the thermal resistance temperature measurement meter (3) is a WSN-101 digital display meter, is connected with two connecting terminals (125) and is used for measuring the temperature of the Pt100 platinum resistance chip (120).

Fig. 2 is a schematic diagram of a first embodiment of a measured sample of the white light LED junction temperature and fluorescent glue temperature measuring device according to the present invention. The tested LED chip (110) was a three ampere S-75ABFSD flip-chip LED chip, 1.8 x 0.5mm in size. The Pt100 platinum resistor chip (120) is a German Schmidt film platinum resistor with the size of 5 x 2 x 1mm, a platinum resistance wire (124) is arranged inside, the platinum resistance wire is covered by glass glaze (not shown in the figure), a copper foil tape with the thickness of 0.05mm is wound on the platinum resistor chip (120) to form an a electrode (121) and a b electrode (122), tin paste (123) is coated on the a electrode (121) and the b electrode (122), the positive electrode of the tested LED chip (110) is welded on the a electrode (121) by a reflow soldering method, and the negative electrode of the tested LED chip (110) is welded on the b electrode (122). The bottom plate (130) is a copper plate with the size of 30 x 4 x 0.5mm, an electrode A (131) and an electrode B (132) are manufactured by winding a copper adhesive tape on the bottom plate (130), the electrode A (131) is insulated from the bottom plate (130), the electrode B (132) is conducted with the bottom plate (130), solder paste (133) is coated on the electrode A (131) and the electrode B (132), the electrode A (131) is communicated with the electrode a (121) by a reflow soldering method, and the electrode B (132) is communicated with the electrode B (122). The upper surface of the tested LED chip (110) is coated with fluorescent glue (140), the size of a point of a tip of the thermocouple (150) is 0.2mm in diameter, the point sinks into the fluorescent glue (140) and does not contact with the tested LED chip (110), the point is solidified in the fluorescent glue (140) through the tip of the dried thermocouple (150), and the fluorescent glue (140) completely covers the tested LED chip (110). The anode (not shown in the figure) of the constant current source (1) is connected with the electrode A (131), and the cathode (not shown in the figure) of the constant current source (1) is connected with the electrode B (132), so that power can be supplied to the tested LED chip (110). Two connecting terminals (125) of the Pt100 platinum resistance chip (120) are connected with a thermal resistance temperature measuring meter (3), a thermocouple (150) is connected with a thermocouple temperature measuring meter (2), and the temperature measured by the thermocouple (150) is the temperature of the fluorescent glue. The PN junction surface (the lower surface, namely the surface with the electrode) of the tested LED chip (110) is in close contact with the platinum resistance wire (124) of the Pt100 platinum resistance chip (120), and the measured temperature is the junction temperature.

FIG. 3 is a schematic diagram of a second embodiment of the present invention, a device for measuring junction temperature of white light LED and temperature of fluorescent glue. The tested LED chip (110) is a Cree SR-1321 normal LED chip with the size of 0.21 × 0.13 × 0.11 mm. The Pt100 platinum resistance chip (120) is a German forest minted film platinum resistance, the size is 5 x 2 x 1mm, a platinum resistance wire (124) is arranged inside, the platinum resistance wire is covered by glass glaze (not shown in the figure), an a electrode (121) and a b electrode (122) are made on the platinum resistance chip (120) by an electroplating method, and the LED chip (110) which is normally installed is adhered between the a electrode (121) and the b electrode (122) by silver paste glue (126). The positive electrode of the forward LED chip (110) is connected to the a electrode (121) by a bonding process, and the negative electrode of the forward LED chip (110) is connected to the b electrode (122) by a bonding process. The bottom plate (130) is a copper plate with the size of 30 x 4 x 0.5mm, an electrode A (131) and an electrode B (132) are manufactured by winding a copper adhesive tape on the bottom plate (130), the electrode A (131) is insulated from the bottom plate (130), the electrode B (132) is conducted with the bottom plate (130), solder paste (133) is coated on the electrode A (131) and the electrode B (132), the electrode A (131) is communicated with the electrode a (121) by a reflow soldering method, and the electrode B (132) is communicated with the electrode B (122). The upper surface of the tested LED chip (110) is coated with fluorescent glue (140), the size of a point of a tip of the thermocouple (150) is 0.2mm in diameter, the point sinks into the fluorescent glue (140) and does not contact with the tested LED chip (110), the point is solidified in the fluorescent glue (140) through the tip of the dried thermocouple (150), and the fluorescent glue (140) completely covers the tested LED chip (110). The anode (not shown in the figure) of the constant current source (1) is connected with the electrode A (131), and the cathode (not shown in the figure) of the constant current source (1) is connected with the electrode B (132), so that power can be supplied to the tested LED chip (110). Two connecting terminals (125) of the Pt100 platinum resistance chip (120) are connected with a thermal resistance temperature measuring meter (3), a thermocouple (150) is connected with a thermocouple temperature measuring meter (2), and the temperature measured by the thermocouple (150) is the temperature of the fluorescent glue. The PN junction surface (the upper surface, namely the surface with the electrode) of the tested LED chip (110) and the platinum resistance wire (124) of the Pt100 platinum resistance chip (120) are separated by the substrate of the LED chip (110) and the silver paste adhesive (126) to be in thermal contact, the measured temperature is junction temperature, but the temperature measurement precision is high without a flip chip.

FIG. 4 is a schematic diagram of a third embodiment of the measured sample of the white LED junction temperature and fluorescent glue temperature measuring device according to the present invention. The tested LED chip (110) is a Cree CT450UT170-Sxxxx-31 vertical LED chip with the size of 0.17 x 0.05 mm. The Pt100 platinum resistance chip (120) is a German forest minted film platinum resistance, the size is 5 x 2 x 1mm, a platinum resistance wire (124) is arranged inside, the platinum resistance wire is covered by glass glaze (not shown in the figure), and an a electrode (121) and a b electrode (122) are made on the platinum resistance chip (120) by an electroplating method. The negative electrode of the LED chip (110) to be tested is soldered to the a-electrode (122) by reflow soldering, and the positive electrode of the LED chip (110) to be tested is connected to the a-electrode (121) by a bonding process. The bottom plate (130) is a copper plate with the size of 30 x 4 x 0.5mm, an electrode A (131) and an electrode B (132) are manufactured by winding a copper adhesive tape on the bottom plate (130), the electrode A (131) is insulated from the bottom plate (130), the electrode B (132) is conducted with the bottom plate (130), solder paste (133) is coated on the electrode A (131) and the electrode B (132), the electrode A (131) is communicated with the electrode a (121) by a reflow soldering method, and the electrode B (132) is communicated with the electrode B (122). The upper surface of the tested LED chip (110) is coated with fluorescent glue (140), the size of a point of a tip of the thermocouple (150) is 0.2mm in diameter, the point sinks into the fluorescent glue (140) and does not contact with the tested LED chip (110), the point is solidified in the fluorescent glue (140) through the tip of the dried thermocouple (150), and the fluorescent glue (140) completely covers the tested LED chip (110). The anode (not shown in the figure) of the constant current source (1) is connected with the electrode A (131), and the cathode (not shown in the figure) of the constant current source (1) is connected with the electrode B (132), so that power can be supplied to the tested LED chip (110). Two connecting terminals (125) of the Pt100 platinum resistance chip (120) are connected with a thermal resistance temperature measuring meter (3), a thermocouple (150) is connected with a thermocouple temperature measuring meter (2), and the temperature measured by the thermocouple (150) is the temperature of the fluorescent glue. The PN junction surface (the upper surface, namely the surface with the electrode) of the tested LED chip (110) and the platinum resistance wire (124) of the Pt100 platinum resistance chip (120) are separated by the substrate of the LED chip (110) to be in thermal contact, the measured temperature is junction temperature, but the temperature measurement precision is high without a flip chip.

FIG. 5 is a schematic diagram of a fourth embodiment of the present invention, a device for measuring junction temperature of white light LED and temperature of fluorescent glue, of a sample to be measured. The tested LED chip (110) was a three ampere S-75ABFSD flip-chip LED chip, 1.8 x 0.5mm in size. The Pt100 platinum resistor chip (120) is a German Schmidt film platinum resistor with the size of 5 x 2 x 1mm, a platinum resistance wire (124) is arranged inside, the platinum resistance wire is covered by glass glaze (not shown in the figure), a copper foil tape with the thickness of 0.05mm is wound on the platinum resistance chip to form an a electrode (121) and a b electrode (122), tin paste (123) is coated on the a electrode (121) and the b electrode (122), the positive electrode of the tested LED chip (110) is welded on the a electrode (121) by a reflow soldering method, and the negative electrode of the tested LED chip (110) is welded on the b electrode (122). The bottom plate (130) is a flat heat pipe with the size of 200 x 6 x 2mm, one end of the heat pipe (130) is wound by a copper adhesive tape to manufacture an electrode A (131) and an electrode B (132), and a container (160) of ice and water is inserted into the other end of the heat pipe (130). The A electrode (131) is insulated from the base plate (130), the B electrode (132) is electrically connected to the base plate (130), solder paste (133) is applied to the A electrode (131) and the B electrode (132), the A electrode (131) is connected to the a electrode (121) by reflow soldering, and the B electrode (132) is connected to the B electrode (122). The upper surface of the tested LED chip (110) is coated with fluorescent glue (140), the size of a point of a tip of the thermocouple (150) is 0.2mm in diameter, the point sinks into the fluorescent glue (140) and does not contact with the tested LED chip (110), the point is solidified in the fluorescent glue (140) through the tip of the dried thermocouple (150), and the fluorescent glue (140) completely covers the tested LED chip (110). The anode (not shown in the figure) of the constant current source (1) is connected with the electrode A (131), and the cathode (not shown in the figure) of the constant current source (1) is connected with the electrode B (132), so that power can be supplied to the tested LED chip (110). Two connecting terminals (125) of the Pt100 platinum resistance chip (120) are connected with a thermal resistance temperature measuring meter (3), a thermocouple (150) is connected with a thermocouple temperature measuring meter (2), and the temperature measured by the thermocouple (150) is the temperature of the fluorescent glue. The PN junction surface (the lower surface, namely the surface with the electrode) of the tested LED chip (110) is in close contact with the platinum resistance wire (124) of the Pt100 platinum resistance chip (120), and the measured temperature is the junction temperature. The heat pipe is used as a bottom plate (130), the other end of the heat pipe is inserted into a container (160) filled with ice-water mixture, the purpose is to utilize the function of quick heat conduction of the heat pipe to quickly conduct heat generated by the tested LED to the container (160), and the A electrode (131) and the B electrode (132) are close to a fixed temperature (zero degree), so that the measurement of the temperature of the junction and the temperature of the fluorescent powder is not influenced by the ambient temperature.

As described above, the present invention is only a few embodiments, and not limited to any form, and those skilled in the art can make many modifications and equivalent variations to the above-described embodiments without departing from the scope of the present invention, and all the modifications, equivalent variations and modifications of the above-described embodiments based on the technical essence of the present invention are within the scope of the present invention.