A test system and method for thermal conduction response characteristics of a pump laser chip

Abstract

The present invention relates to the field of pump lasers, and specifically to a test system for the thermal conduction response characteristics of a pump laser chip, comprising: the thermal conduction test device comprises a refrigerator that carries or abuts against one end of the pump laser chip to be tested, and a temperature sensor that is arranged at the other end of the pump laser chip to be tested or at the farthest thermal conduction position; a driving unit that outputs a controllable current to control the operation of the refrigerator; the sampling unit respectively obtains the state information of the refrigerator and the sensing information of the temperature sensor; and the processing unit tests the thermal conduction response characteristics of the pump laser chip. It also relates to a test method based on a test system. The present invention obtains the thermal conduction performance of the pump laser chip through the test system for the thermal conduction response characteristics of the pump laser chip, thereby testing the thermal conduction response characteristics of the pump laser chip; and through the placement of the refrigerator and the temperature sensor, the thermal conduction response characteristics are accurately obtained, which is convenient for subsequent manufacturing.

Description

Technical Field

[0001] The invention relates to the field of pump lasers, and in particular to a testing system and a testing method for heat conduction response characteristics of a pump laser chip. Background Art

[0002] Pump lasers are widely used in the fields of optical amplifiers and fiber lasers. The chip is a semiconductor element with temperature sensitivity. At the same time, the manufacturing and assembly process (DieBounding) of its core component CoS (Chip on Submount) affects the product's thermal conduction response performance and thus affects the performance of the pump laser.

[0003] Specifically, the control of the Die Bounding process in the CoS manufacturing process, a key component of the pump laser, is related to the CoS thermal conductivity effect. At the same time, it is difficult to detect product defects through ordinary inspection methods due to the limitations of the Die Bounding process.

[0004] Among them, thermal conduction is the heat transfer phenomenon when there is no macroscopic movement in the medium. It can occur in solids, liquids and gases, but strictly speaking, pure heat conduction is only in solids. Even if the fluid is at rest, natural convection will occur in it due to the density difference caused by the temperature gradient. Therefore, thermal convection and heat conduction occur simultaneously in the fluid. Summary of the invention

[0005] The technical problem to be solved by the present invention is that, in view of the above-mentioned defects of the prior art, a test system and a test method for the thermal conduction response characteristics of a pump laser chip are provided to solve the problem that defects are easily generated during the manufacturing process due to the inability to obtain the thermal conduction effect of the core component CoS of the pump laser.

[0006] The technical solution adopted by the present invention to solve the technical problem is: to provide a test system for the heat conduction response characteristics of a pump laser chip, comprising: a heat conduction test device, the heat conduction test device comprising a refrigerator carrying or abutting against one end of a pump laser chip to be tested, and a temperature sensor arranged at the other end of the pump laser chip to be tested or at the farthest heat conduction position; a driving unit, the driving unit is connected to the refrigerator and outputs a controllable current to control the operation of the refrigerator; a sampling unit, the sampling unit is respectively connected to the refrigerator and the temperature sensor, and respectively obtains the state information of the refrigerator and the sensing information of the temperature sensor; a processing unit, which obtains the response value of the heat conduction of the pump laser chip to be tested according to the information adopted by the sampling unit, and tests the heat conduction response characteristics of the pump laser chip.

[0007] Among them, a preferred solution is: the refrigerator is placed horizontally, the pump laser chip to be tested is placed on the refrigerator, and the temperature sensor is arranged on the upper end surface of the pump laser chip to be tested.

[0008] Among them, a preferred solution is that the refrigerator is a semiconductor refrigerator.

[0009] Among them, a preferred solution is that the temperature sensor is a thermistor.

[0010] Among them, the preferred solution is: the processing unit includes a control module and a PC end, the control module, the driving unit and the sampling unit constitute a test board, the control module controls the test board to collect the adopted information and sends it to the PC end, the PC end obtains the response value of the thermal conduction of the pump laser chip to be tested according to the adopted information of the sampling unit, and tests the thermal conduction response characteristics of the pump laser chip.

[0011] Among them, a preferred solution is: the test board also includes a filtering unit to filter the adopted information.

[0012] Among them, a preferred solution is: the PC end includes a storage module to store the algorithm process for calculating the response value of heat conduction.

[0013] Among them, a preferred solution is: it also includes a control unit connected to the pump laser chip to be tested, and the control unit controls the pump laser chip to be tested to work during the test process.

[0014] Among them, a preferred solution is: it also includes a display unit connected to the processing unit and displaying the software graphical user interface.

[0015] Among them, a preferred solution is: the pump laser chip to be tested is a 980nm pump laser chip.

[0016] The technical solution adopted by the present invention to solve its technical problem is to provide a test method based on a test system, which is applied to the test system and includes the steps of: driving a refrigerator to work; collecting status information of the refrigerator and sensing information of a temperature sensor; according to an algorithm flow of a preset heat conduction response value, combining the status information and the sensing information, obtaining a response value of heat conduction of a pump laser chip to be tested, and testing the heat conduction response characteristics of the pump laser chip.

[0017] Among them, the preferred solution is: the temperature sensor is a thermistor, and the steps of the test method include: collecting multiple voltage values ​​of the refrigerator during the power-on process based on the same frequency, and collecting multiple voltage values ​​of the thermistor; obtaining the average voltage value formed by the maximum voltage value and the minimum voltage value of the array; and, when a voltage value V1 of the refrigerator satisfies that the difference between the Nth voltage value V2 and it is greater than the average voltage value, confirming that the time when the voltage value V2 is located is the power-on time T1 of the refrigerator; and, when the thermistor starts from a voltage value V3, there are M consecutive voltage values ​​that are all rising trends, and the Mth voltage value V4 satisfies that the difference between the voltage value V3 and it is greater than the preset voltage value, confirming that the time when the voltage value V4 is located is the dividing point T2; respectively, curve fitting is performed on the time periods indexed as T1 to T2, and T2 to X-T2, and the intersection of the two fitting curves is calculated, and used as the inflection point Ct of the thermistor, and Ct-T1 is the thermal response data.

[0018] The beneficial effects of the present invention are that, compared with the prior art, the present invention obtains the thermal conductivity performance of the pump laser chip through the test system of the thermal conductivity response characteristics of the pump laser chip, thereby testing the thermal conductivity response characteristics of the pump laser chip; and accurately obtains its thermal conductivity response characteristics through the placement of the refrigerator and the temperature sensor, which is convenient for subsequent manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0020] Figure 1 It is a structural schematic diagram of a test system for the heat conduction response characteristics of a pump laser chip according to the present invention;

[0021] Figure 2 It is a flow chart of a testing method based on a testing system of the present invention;

[0022] Figure 3 It is a structural schematic diagram of the control unit of the present invention;

[0023] Figure 4 It is a schematic structural diagram of the display unit of the present invention. DETAILED DESCRIPTION

[0024] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0025] like Figure 1 and Figure 2 As shown, the present invention provides a preferred embodiment of a testing system for the thermal conduction response characteristics of a pump laser chip.

[0026] A test system for the heat conduction response characteristics of a pump laser chip comprises a heat conduction test device, a driving unit 200, a sampling unit 300 and a processing unit 400, wherein the heat conduction test device comprises a refrigerator 110 bearing or abutting against one end of a pump laser chip 10 to be tested, and a temperature sensor 120 arranged at the other end of the pump laser chip 10 to be tested or at the farthest heat conduction position; the driving unit 200 is connected to the refrigerator 110 and outputs a controllable current to control the operation of the refrigerator 110; the sampling unit 300 is respectively connected to the refrigerator 110 and the temperature sensor 120 to respectively obtain the state information of the refrigerator 110 and the sensing information of the temperature sensor 120; the processing unit 400 obtains the response value of the heat conduction of the pump laser chip 10 to be tested according to the information adopted by the sampling unit 300, and tests the heat conduction response characteristics of the pump laser chip.

[0027] Preferably, the processing unit 400 includes a control module 410 and a PC terminal 420. The control module 410, the driving unit 200 and the sampling unit 300 constitute a test board 20. The control module 410 controls the test board 20 to collect the adopted information and sends it to the PC terminal 420. The PC terminal 420 obtains the response value of the heat conduction of the pump laser chip 10 to be tested according to the adopted information of the sampling unit 300, and tests the heat conduction response characteristics of the pump laser chip. Among them, the sampling unit 300 can transmit data to the PC terminal 420 through the control module 410, and can also directly transmit data to the PC terminal 420 under the control of the control module 410.

[0028] Further, and with reference to Figure 2 , a test method based on a test system is provided, which is applied to the test system, comprising the steps of:

[0029] Step S10, driving the refrigerator 110 to work;

[0030] Step S20, collecting status information of the refrigerator 110 and sensing information of the temperature sensor 120;

[0031] Step S30 , according to the preset algorithm flow of the thermal conduction response value, combined with the state information and the sensing information, the response value of the thermal conduction of the pump laser chip 10 to be tested is obtained, and the thermal conduction response characteristics of the pump laser chip are tested.

[0032] In this embodiment, the heat conduction test device is used as a heat conduction heat source and a sensing core for the heat conduction response of the pump laser chip 10 to be tested. There are several heat conduction schemes as follows:

[0033] Solution 1: The refrigerator 110 is used as a bearing platform, and the pump laser to be tested is placed on the bearing platform and fits with the refrigerator 110. The refrigerator 110 cools or generates heat to maintain a preset temperature, and transmits the heat from one end of the pump laser to be tested to the other end. The refrigerator 110 can be horizontally loaded (i.e. placed horizontally, which can be considered as a horizontal setting of the load surface), or non-horizontally loaded. Of course, in order to ensure that the pump laser to be tested fits with the refrigerator 110, especially in the case of non-horizontal loading, a fixed structure is required for fixing, or a limiting structure is required for limiting. Solution 2: The refrigerator 110 is used as a fitting structure to form a probe, which can be placed at different positions of the pump laser to be tested to maintain a preset temperature.

[0034] Among them, the temperature sensor 120 is also arranged on the pump laser to be tested, and is arranged in a close fit, and is preferably arranged on the other end face opposite to the refrigerator 110, such as the refrigerator 110 is arranged on the bottom face, and the temperature sensor 120 is arranged on the top face; of course, the current position relative to a refrigerator 110 can be obtained through algorithm calculation or experience summary, and its heat conduction position is the farthest position, which is used as the placement point of the temperature sensor 120, and the heat conduction response characteristics of the pump laser to be tested can be further fully obtained. Of course, in order to more accurately obtain the heat conduction response characteristics of the pump laser to be tested, multiple temperature sensors 120 can be set, and the mean or variance value of the temperature information at different positions can be taken to determine the overall heat conduction response characteristics of the pump laser to be tested.

[0035] Furthermore, the refrigerator 110 is preferably a semiconductor refrigerator 110. The conductor refrigerator 110 (Thermoelectric cooler) refers to a device that uses the thermal-electric effect of semiconductors to produce cooling, also known as a thermoelectric refrigerator 110. When two different metals are connected by a conductor and a direct current is connected, the temperature at one connection point decreases and the temperature at the other connection point increases. Of course, the refrigerator 110 can also be other refrigeration equipment.

[0036] Furthermore, the temperature sensor 120 is preferably a thermistor. Among them, thermistors are a type of sensitive components, which are divided into positive temperature coefficient thermistors (PTC) and negative temperature coefficient thermistors (NTC) according to different temperature coefficients. The typical feature of thermistors is that they are sensitive to temperature and show different resistance values ​​at different temperatures. The temperature information of the thermistor can be determined by obtaining the resistance value of the thermistor. Of course, the temperature sensor 120 can also be other temperature sensing modules.

[0037] In this embodiment, the sampling unit 300 obtains the status information of the refrigerator 110 and the sensing information of the temperature sensor 120 respectively, wherein obtaining the status information of the refrigerator 110 refers to obtaining the current working status of the refrigerator 110, such as on or off, or, refers to obtaining the cooling or heating information of the refrigerator 110, and its own temperature; and, obtaining the sensing information of the temperature sensor 120, such as the resistance value of the thermistor, are all sent to the control module 410; and, the above information also includes the detected time.

[0038] Alternatively, the real-time voltage across the refrigerator 110 is sampled, and a collection circuit composed of a sampling resistor is used to obtain the actual driving voltage change of the refrigerator 110 through the voltage change across the resistor, thereby obtaining the working status of the refrigerator 110.

[0039] Furthermore, the PC terminal 420 calculates the response value of the heat conduction of the pump laser chip 10 to be tested according to the working state of the refrigerator 110 and the change of the sensing information of the temperature sensor 120, as the heat conduction response characteristic of the pump laser chip 10 to be tested. Of course, the control module 410 can be a dedicated control circuit, including a processing chip and corresponding peripheral circuits. Further, the PC terminal 420 includes a storage module to store the algorithm flow for calculating the response value of heat conduction.

[0040] In this embodiment, the test system further includes a filtering unit disposed on the test board 20, and the filtering unit may be disposed between the sampling unit 300 and the control module 410, or between the sampling unit 300 and the PC terminal 420. The information collected by the acquisition unit is filtered by the filtering unit to improve the accuracy of the information and remove noise.

[0041] In this embodiment, the pump laser chip 10 to be tested is a 980nm pump laser chip, and of course it can be other wavelengths, such as a 1480nm pump laser chip. Why is the wavelength of the pump light source of the pump laser chip 10 to be tested selected at 980nm or 1480nm? In fact, the wavelength of the pump light source can be 520nm, 650nm, 980nm and 1480nm, but practice has proved that the pump light source with a wavelength of 1480nm has the highest laser efficiency, followed by the pump light source with a wavelength of 980nm, and the pump light source with a wavelength of 980nm has a lower noise coefficient.

[0042] like Figure 3 As shown, the present invention provides a preferred embodiment of a control unit.

[0043] The test system further includes a control unit 500 connected to the pump laser chip 10 to be tested, and the control unit 500 controls the pump laser chip 10 to be tested to work during the test process. Of course, the control unit 500 can also be integrated on the test board 20, and even the control unit 500 and the control module 410 can be the same circuit chip to achieve high integration.

[0044] The thermal conduction response characteristics of the test system are simulated to simulate the actual working process of the pump laser chip, which is an important part of the test system.

[0045] like Figure 4 As shown, the present invention provides a preferred embodiment of a display unit.

[0046] An algorithm formula and reference Figure 4 , including the steps of:

[0047] S31, collecting multiple voltage values ​​of the refrigerator during the power-on process, and collecting multiple voltage values ​​of the thermistor;

[0048] S321, obtaining an average voltage value formed by the maximum voltage value and the minimum voltage value of the array;

[0049] S322, and when a voltage value V1 of the refrigerator satisfies that the difference between the Nth voltage value V2 and the voltage value V1 is greater than the average voltage value, confirming that the time when the voltage value V2 is located is the power-on time T1 of the refrigerator;

[0050] S33, and when the thermistor starts from a voltage value V3, there are M voltage values ​​that are all in an upward trend, and the difference between the voltage value V3 and the Mth voltage value V4 is greater than the preset voltage value, confirm that the time when the voltage value V4 is located is the demarcation point T2;

[0051] S34, respectively, curve fitting is performed for the time periods indexed from T1 to T2 and from T2 to X-T2, and the intersection point of the two fitting curves is calculated and used as the inflection point Ct of the thermistor, and Ct-T1 is the thermal response data.

[0052] Preferably, the acquisition frequency is, N is 4, M is 5, X is 1500, and the preset voltage value is 0.1V.

[0053] Curve fitting refers to selecting an appropriate curve type to fit the observed data and using the fitted curve equation to analyze the relationship between two variables. In this embodiment, the relationship between the refrigerator and the thermistor is observed by curve fitting, thereby obtaining the intersection point as the thermal response data.

[0054] Among them, multiple voltage values ​​of the refrigerator during the power-on process and multiple voltage values ​​of the thermistor are collected based on the same frequency, preferably 1K samples per second. Of course, the test accuracy can be improved or adapted by collecting at the same frequency or a higher frequency.

[0055] In this embodiment, the test system further includes a display unit 600 connected to the processing unit 400 and displaying a software graphical user interface 610. The display unit 600 is preferably a display screen of the PC terminal 420, which can display the software graphical user interface 610 to achieve human-computer interaction.

[0056] The specific display contents include: the curve corresponding to the voltage value of the refrigerator; the curve corresponding to the voltage value of the thermistor; the power-on time T1 of the refrigerator; the dividing point T2 of the thermistor; the fitting curve from T1 to T2; the fitting curve from T2 to X-T2; and the inflection point Ct.

[0057] Through the display content of the software graphical user interface 610, the inflection point Ct is clearly obtained to obtain thermal response data, thereby realizing the test of the thermal conduction response characteristics of the pump laser chip.

[0058] The above is only the best embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes or modifications made according to the scope of the patent application of the present invention are covered by the present invention.

Claims

1. A test method based on a pump laser chip thermal conduction response characteristic test system, characterized in that: A pump laser chip thermal conduction response characteristic test system is used, and the pump laser chip thermal conduction response characteristic test system includes: A heat conduction test device, the heat conduction test device comprising a refrigerator that carries or abuts against one end of the pump laser chip to be tested, and a temperature sensor that is arranged at the other end of the pump laser chip to be tested or at the farthest heat conduction position; A driving unit, the driving unit is connected to the refrigerator and outputs a controllable current to control the operation of the refrigerator; A sampling unit, wherein the sampling unit is connected to the refrigerator and the temperature sensor respectively to obtain status information of the refrigerator and sensing information of the temperature sensor respectively; The processing unit acquires the response value of the heat conduction of the pump laser chip to be tested according to the information adopted by the sampling unit, and tests the heat conduction response characteristics of the pump laser chip; The method comprises the steps of: Drive the refrigerator to work; Collecting status information of the refrigerator and sensing information of a temperature sensor, wherein the temperature sensor is a thermistor, the status information includes multiple voltage values ​​of the refrigerator during power-on, and the sensing information includes multiple voltage values ​​of the thermistor; Get the average voltage value formed by the maximum voltage value and the minimum voltage value of the array; And, when a voltage value V1 of the refrigerator satisfies that the difference between the Nth voltage value V2 and the voltage value V1 is greater than the average voltage value, it is confirmed that the time when the voltage value V2 is located is the power-on time T1 of the refrigerator; And, when the thermistor starts from a voltage value V3, there are M voltage values ​​that are all in an upward trend, and the difference between the voltage value V3 and the Mth voltage value V4 is greater than the preset voltage value, the time when the voltage value V4 is located is confirmed to be the demarcation point T2; Curve fitting is performed for the time periods indexed from T1 to T2 and from T2 to X-T2, respectively, and the intersection of the two fitting curves is calculated and used as the inflection point Ct of the thermistor, and Ct-T1 is the thermal response data.

2. A test system for the thermal conduction response characteristics of a pump laser chip, used to implement the method of claim 1, characterized in that: include: The heat conduction test device includes a refrigerator that carries or is attached to one end of the pump laser chip to be tested, and a temperature sensor that is arranged at the other end of the pump laser chip to be tested or at the farthest heat conduction position; A driving unit is connected to the refrigerator and outputs a controllable current to control the operation of the refrigerator; The sampling unit is connected to the refrigerator and the thermistor respectively, and obtains the state information of the refrigerator and the sensing information of the temperature sensor respectively, wherein the state information includes a plurality of voltage values ​​of the refrigerator during the power-on process, and the sensing information includes a plurality of voltage values ​​of the temperature sensor, wherein the temperature sensor is a thermistor; The processing unit is connected to the sampling unit and is used to obtain the response value of the heat conduction of the pump laser chip to be tested according to the information adopted by the sampling unit, and test the heat conduction response characteristics of the pump laser chip, which specifically includes the following steps: Get the average voltage value formed by the maximum voltage value and the minimum voltage value of the array; And, when a voltage value V1 of the refrigerator satisfies that the difference between the Nth voltage value V2 and the voltage value V1 is greater than the average voltage value, it is confirmed that the time when the voltage value V2 is located is the power-on time T1 of the refrigerator; And, when the thermistor starts from a voltage value V3, there are M voltage values ​​that are all in an upward trend, and the difference between the voltage value V3 and the Mth voltage value V4 is greater than the preset voltage value, the time when the voltage value V4 is located is confirmed to be the demarcation point T2; Curve fitting is performed for the time periods indexed from T1 to T2 and from T2 to X-T2, respectively, and the intersection of the two fitting curves is calculated and used as the inflection point Ct of the thermistor, and Ct-T1 is the thermal response data.

3. The test system according to claim 2, characterized in that: The refrigerator is placed horizontally, the pump laser chip to be tested is placed on the refrigerator, the temperature sensor is arranged on the upper end surface of the pump laser chip to be tested, and the temperature sensor is a thermistor.

4. The test system according to claim 2 or 3, characterized in that: The refrigerator is a semiconductor refrigerator.

5. The test system according to claim 2, characterized in that: The processing unit includes a control module and a PC end. The control module, the driving unit and the sampling unit constitute a test board. The control module controls the test board to collect the adopted information and sends it to the PC end. The PC end obtains the response value of the heat conduction of the pump laser chip to be tested according to the adopted information of the sampling unit, and tests the heat conduction response characteristics of the pump laser chip.

6. The test system according to claim 5, characterized in that: The test board further comprises a filtering unit for filtering the adopted information.

7. The test system according to claim 5, characterized in that: The PC terminal includes a storage module to store an algorithm flow for calculating the response value of heat conduction.

8. The test system according to claim 2 or 5, characterized in that: It also includes a control unit connected to the pump laser chip to be tested, and the control unit controls the pump laser chip to be tested to work during the test process.

9. The test system according to claim 2 or 5, characterized in that: A display unit is also included which is connected to the processing unit and displays a software graphical user interface.

10. The test system according to claim 2, characterized in that: The pump laser chip to be tested is a 980nm pump laser chip.

Images