A method for determining an aging ambient temperature of a laser

Abstract

The application relates to the technical field of semiconductor device testing, and discloses a method for determining the aging environment temperature of a laser, wherein the method comprises the following steps: determining the wavelength temperature drift coefficient of the laser; acquiring the laser chip temperature corresponding to different step currents; determining the peak wavelength of the laser based on the step current and the chip temperature data; performing function fitting according to the peak wavelength of the laser and the step current to obtain a relationship between the peak wavelength of the laser and the step current, and determining a wavelength difference value; determining a temperature difference value according to the wavelength temperature drift coefficient and the wavelength difference value, and determining the junction temperature of the laser according to the initial environment temperature and the temperature difference value; and compensating the initial environment temperature according to the junction temperature of the laser to determine the aging environment temperature of the laser. The application has equipment compatibility while realizing accurate measurement of the aging environment temperature of the laser, directly utilizes existing equipment to complete junction temperature measurement and aging environment temperature backstepping, and significantly reduces the equipment cost and the modification difficulty of technology landing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor device testing, and particularly relates to a method for determining an aging environment temperature of a laser. BACKGROUND

[0002] In the production and manufacturing of semiconductor lasers, aging treatment is a key and effective means for quickly screening unqualified laser chip. Through aging treatment, potential failure problems caused by chip physical structure defects can be triggered in the early stage of the product "bath curve", and the failed chips can be removed in advance, thereby significantly improving the yield in the subsequent production process of the product. In the aging process of the laser chip, there are three important parameters, which are appropriate current, temperature and time. The parameter values cannot be too large, otherwise it will have a negative impact on the performance, service life and other key indicators of the chip; at the same time, the values cannot be too small, otherwise it will not achieve the purpose of effectively screening out bad chips, therefore, accurate measurement of these parameters plays a decisive role in the effect of aging treatment. The temperature mentioned here refers to the temperature of the PN junction region inside the semiconductor laser, which generally cannot be obtained by direct measurement.

[0003] At present, COC (Chip on Carrier, chip carrier) aging machines and COC test machines are generally equipped in factories, and the industry usually uses the temperature sensitivity of the wavelength of the semiconductor laser to indirectly measure the internal junction temperature of the laser, but in the actual application process, these two devices have certain limitations. On the one hand, although the COC aging machine can perform aging treatment on the COC under the set conditions, its function is limited to aging operation and does not have the ability to measure the junction temperature, so it cannot provide junction temperature data support for subsequent parameter adjustment and quality judgment; on the other hand, the COC test machine can indirectly measure the junction temperature by using the wavelength temperature drift phenomenon, however, the COC test machine is in an open environment and cannot simulate the real heat distribution in the relatively closed environment inside the aging machine, resulting in a significant deviation between the measured junction temperature data and the actual junction temperature of the chip in the aging process, and it is difficult to accurately reflect the temperature state of the chip in the real aging environment.

[0004] Furthermore, although existing patent technologies involve laser temperature control or wavelength stabilization methods, none of them proposes an effective solution to the accurate measurement of junction temperature during aging treatment. For example, Chinese patent document CN120855073A discloses a temperature adjustment method and device for a laser, with an IPC main classification number of H01S 5 / 068, which includes determining the second thermistor temperature based on the predetermined temperature compensation coefficient, the first environment temperature, the second environment temperature, and the first thermistor temperature, so that the temperature adjustment of the thermistor at the second environment temperature is the second thermistor temperature, thereby offsetting the influence of environmental temperature fluctuations on the actual temperature of the laser chip. However, this method relies on the feedback of the thermistor, and there is a location difference between the thermistor and the laser chip, so the measured temperature is not the direct junction temperature. Chinese patent document CN117673894A discloses a laser temperature control assembly and optical module, with an IPC main classification number of H01S 5 / 068, which includes connecting the thermistor and the laser pin through a connecting piece, and the thermoelectric cooler acts on the connecting piece to buffer the environmental temperature difference caused by the laser pin, so as to offset the influence of the environment temperature on the thermistor, and make the thermistor accurately detect the temperature of the laser die. Although this scheme improves the temperature detection accuracy, it still indirectly measures the junction temperature based on the thermistor and cannot directly obtain the junction temperature. Moreover, during the aging process, there is a temperature gradient between the heat sink and the junction area, and this method cannot adapt to the heat accumulation effect inside the aging machine, resulting in deviation in the estimation of the junction temperature. Chinese patent document CN107093839B discloses a semiconductor laser wavelength stabilization system and implementation method, with an IPC main classification number of H01S 5 / 068, which includes a control unit, a driving power supply, a heat sink, and a temperature sensor. The control unit is built-in with a mathematical model representing the relationship between the bias current and the heat sink temperature, which is used to calculate the required direct current bias current value based on the detected heat sink temperature value, so as to realize wavelength stabilization. This technology indirectly adjusts the junction temperature through the heat sink temperature, but there is a nonlinear gradient between the heat sink temperature and the junction temperature, and this gradient changes with the environment. In the closed environment of the aging machine, it is difficult for this model to accurately fit the real junction temperature, and it cannot meet the requirements of accurate measurement of the junction temperature during aging treatment. The present application proposes a method for determining the aging environment temperature of a laser, which belongs to the same field of laser output parameter stabilization and conforms to the classification number (H01S 5 / 068).

[0005] Due to the limitations of the above-mentioned existing technologies, it is difficult for factories to accurately control the aging parameters during laser chip aging treatment, which affects the accuracy and efficiency of defective chip screening and hinders the stable improvement of product quality. Therefore, there is an urgent need for a method that can accurately determine the junction temperature of a laser in a closed environment of an aging machine to optimize the aging process parameters and improve product yield and reliability. SUMMARY

[0006] (1) Technical problems to be solved

[0007] In view of the above-mentioned defects and deficiencies of the prior art, the present application provides a method for determining the aging environment temperature of a laser, which solves the technical problem that the aging environment temperature cannot be accurately set due to the complementary functional defects of the factory conventional COC aging machine and the COC test machine in the prior art method for determining the aging environment temperature of a laser.

[0008] (II) Technical solutions

[0009] To achieve the above-mentioned purpose, the main technical solution adopted by the present application includes:

[0010] The present application provides a method for determining the aging environment temperature of a laser, comprising the following steps: S1, determining the wavelength temperature drift coefficient of the laser; S2, at an initial environment temperature, obtaining the laser chip temperature corresponding to different step currents to determine a plurality of sets of step current and chip temperature data, wherein a thermistor is arranged at the laser chip to obtain the laser chip temperature; S3, determining a plurality of laser peak wavelengths based on each set of step current and chip temperature data; S4, performing function fitting according to the plurality of laser peak wavelengths and the plurality of step currents to obtain a relationship between the laser peak wavelength and the step current, and determining a wavelength difference value according to the relationship; S5, determining a temperature difference value according to the wavelength temperature drift coefficient and the wavelength difference value, and determining the junction temperature of the laser according to the initial environment temperature and the temperature difference value; S6, compensating the initial environment temperature according to the junction temperature of the laser to determine the aging environment temperature of the laser.

[0011] Optionally, in some embodiments of the present application, compensating the initial environment temperature according to the junction temperature of the laser comprises: in the case that the junction temperature of the laser does not reach a preset aging junction temperature, repeating steps S2-S5 after temperature compensation of the initial environment temperature, and in the case that the junction temperature of the laser reaches the preset aging junction temperature, taking the temperature-compensated environment temperature as the aging environment temperature of the laser.

[0012] Optionally, in some embodiments of the present application, the thermistor is arranged at the position of the laser chip mounted on the carrier, and the laser chips on which the thermistor is arranged are uniformly distributed at different positions of the aging clamp, so as to detect the real temperature in different areas of the aging oven.

[0013] Optionally, in some embodiments of the present application, obtaining the laser chip temperature corresponding to different step currents comprises: sequentially applying different step currents to each laser chip on which the thermistor is arranged , and obtaining the resistance value of the thermistor corresponding to each laser chip on which the thermistor is arranged corresponding to the same step current after temperature stabilization averaging to obtain different step currents corresponding thermistor average resistance values wherein n and m are both positive integers, the thermistor average resistance values for characterizing the laser chip temperature of each laser chip with the thermistor.

[0014] Optionally, in some embodiments of the present application, the different step currents The current difference between adjacent two step currents is equal, and each step current is greater than the light-emitting threshold current of the laser.

[0015] Optionally, in some embodiments of the present application, the different step currents The current difference between adjacent two step currents is equal, and the maximum step current is less than or equal to the specified aging current.

[0016] Optionally, in some embodiments of the present application, based on each group of the step currents and the chip temperature data, determining a plurality of laser peak wavelengths, comprising: sequentially applying different step currents to each laser chip with the thermistor, and adjusting the temperature to make the resistance value of each thermistor equal to the corresponding thermistor average resistance value when applying the same step current to each laser chip with the thermistor, and obtaining the laser peak wavelength of each laser chip with the thermistor at different step currents .

[0017] Optionally, in some embodiments of the present application, according to the plurality of laser peak wavelengths and the plurality of step currents, function fitting, comprising: for each laser chip with the thermistor, using the laser peak wavelength at different step currents and the different step currents , the relationship obtained by fitting is a polynomial related to n-order current.

[0018] Optionally, in some embodiments of the present application, according to the relationship, determining a wavelength difference, comprising: for each laser chip with the thermistor, based on the relationship, calculating a first wavelength and a second wavelength corresponding to a current of zero and a specified aging current, and calculating the difference between the first wavelength and the second wavelength; and performing mean value calculation on the difference corresponding to each laser chip with the thermistor to obtain the wavelength difference.

[0019] Optionally, in some embodiments of the present application, the wavelength temperature drift coefficient of the laser is determined, comprising: obtaining the peak wavelengths of a plurality of laser chips at different temperatures and different currents; calculating an average temperature difference and an average wavelength difference according to the peak wavelengths of the plurality of laser chips at different temperatures and different currents; and determining the wavelength temperature drift coefficient according to the ratio between the average wavelength difference and the average temperature difference.

[0020] (III) Beneficial Effects

[0021] The aging environment temperature determination method of the laser provided by the embodiments of the present application can utilize the original aging machine and test machine of the factory, and can accurately calculate the junction temperature of the laser in the simulated aging thermal environment by using the thermistor as a temperature transmission medium and combining the wavelength temperature drift characteristics of the laser, so that the environmental temperature to be set on the aging machine can be deduced by using the junction temperature of the laser without additionally increasing measuring equipment or jigs, thereby realizing accurate setting of the aging environment temperature of the laser, ensuring that the aging parameters can be accurately controlled when the laser chip aging process is performed in the factory, and improving the accuracy and efficiency of the selection of defective chips, and significantly improving the yield in the subsequent production process of the product. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 FIG. 1 is a flowchart of the aging environment temperature determination method of the laser according to an embodiment of the present application;

[0023] Figure 2 FIG. 2 is a flowchart of determining the wavelength temperature drift coefficient of the laser according to an embodiment of the present application;

[0024] Figure 3 FIG. 3 is a distribution diagram of the thermistor in the COC aging clamp according to an embodiment of the present application;

[0025] Figure 4 FIG. 4 is a COC diagram of the thermistor according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to better explain the present application and facilitate understanding, the present application is described in detail below by specific embodiments in combination with the accompanying drawings.

[0027] In related technologies, although COC aging machines can age COC under fixed current, fixed temperature and set time conditions, they do not have the ability to measure junction temperature. Therefore, they cannot provide junction temperature data support for subsequent parameter adjustment and quality judgment. COC testers can indirectly measure junction temperature by utilizing wavelength temperature drift. However, COC testers are in an open environment. This open environment cannot simulate the real heat distribution in the relatively closed environment inside the aging machine. As a result, the measured junction temperature data will deviate significantly from the actual junction temperature of the chip during the aging process, and cannot accurately reflect the temperature state of the chip in the real aging environment.

[0028] Furthermore, the COC aging machine is a relatively closed environment, and the heat distribution of COC varies in different locations. Under the same ambient temperature, the actual junction temperature of the laser in different locations may also be different, thus making it impossible to guarantee the consistency of aging conditions.

[0029] Therefore, when factories perform laser chip aging processes, it is difficult to accurately control the aging parameters, which affects the accuracy and efficiency of defective chip screening and hinders the stable improvement of product quality.

[0030] Therefore, the present application proposes a method for determining the aging environment temperature of a laser, which makes full use of the existing COC aging machine and COC testing machine in the factory. It can accurately set the aging environment temperature of the laser without the need to add special temperature measurement equipment or custom fixtures, effectively reducing production costs and avoiding production process adjustments and equipment compatibility issues caused by adding new equipment. It ensures that the factory can accurately control the aging parameters when performing laser chip aging treatment, improve the accuracy and efficiency of defective chip screening, and significantly improve the yield rate in subsequent production processes.

[0031] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application can be understood more clearly and thoroughly, and that the scope of this application can be fully conveyed to those skilled in the art.

[0032] The method for determining the aging environment temperature of a laser according to embodiments of this application will now be described with reference to the accompanying drawings.

[0033] Figure 1 This is a flowchart illustrating a method for determining the aging environment temperature of a laser according to an embodiment of this application. Figure 1 As shown, the method for determining the aging environment temperature of this laser includes the following steps:

[0034] S1, determine the wavelength temperature drift coefficient of the laser.

[0035] In some embodiments of the present application, the wavelength temperature drift coefficient of the laser can be calculated according to the formula TDC=Δλ / ΔT, wherein TDC is the wavelength temperature drift coefficient, Δλ is the wavelength difference, and ΔT is the temperature difference.

[0036] Specifically, as shown in Figure 2 determining the wavelength temperature drift coefficient of the laser includes:

[0037] S21, obtaining the peak wavelengths of the plurality of laser chips at different temperatures and different currents.

[0038] That is, at different temperatures, different excitation currents are applied to a certain laser chip to make it emit light, and then the wavelength of the laser chip is measured. For example, for each laser chip, different excitation currents are applied at the same temperature to measure a set of wavelength data. In this way, at different temperatures, a plurality of sets of wavelength data can be obtained, and the plurality of laser chips correspond to different sets of wavelength data.

[0039] S22, calculating the average temperature difference value and the average wavelength difference value according to the peak wavelengths of the plurality of laser chips at different temperatures and different currents.

[0040] For example, for a certain laser chip, a plurality of sets of wavelength data at a first temperature and a second temperature can be measured. The difference between the first temperature and the second temperature is referred to as a temperature difference. The average of the plurality of sets of wavelength data at the first temperature is referred to as a first average value, and the average of the plurality of sets of wavelength data at the second temperature is referred to as a second average value. The difference between the first average value and the second average value is referred to as a wavelength difference value. In this way, for a plurality of laser chips, a plurality of temperature differences and a plurality of wavelength difference values can be obtained, so as to calculate the average temperature difference value based on the plurality of temperature differences and calculate the average wavelength difference value based on the plurality of wavelength difference values.

[0041] S23, determining the wavelength temperature drift coefficient according to the ratio between the average wavelength difference value and the average temperature difference value.

[0042] That is, in the present embodiment, different current and temperature values can be set, and the peak wavelengths of a plurality of laser chips at different temperatures and different currents can be measured on a test machine. Then, the average temperature difference value and the average wavelength difference value are calculated according to the peak wavelengths of the plurality of laser chips at different temperatures and different currents. Finally, the ratio between the average wavelength difference value and the average temperature difference value is taken as the wavelength temperature drift coefficient.

[0043] In the test process, by measuring the data of a plurality of laser chips under a plurality of set conditions, the average value is taken to reduce random errors and improve the accuracy of calculating the wavelength temperature drift coefficient, thereby providing a reliable basis for subsequent junction temperature calculation.

[0044] S2, obtaining the temperature of the laser chip corresponding to different step currents at an initial ambient temperature to determine a plurality of sets of step currents and chip temperature data, wherein a thermistor is arranged at the laser chip to obtain the temperature of the laser chip.

[0045] Optionally, in some embodiments of the present application, as shown in Figure 3 and Figure 4 , a thermistor is arranged at the position of the laser chip mounted on the carrier, and the laser chips with thermistors are uniformly distributed at different positions of the aging fixture to detect the real temperature of different regions in the aging oven.

[0046] For example, the laser chips with thermistors are 6, and the distribution manner on the aging fixture is as shown in Figure 3 , so that the real temperature of different regions in the aging oven can be reflected, and the accuracy of temperature detection can be reflected. As shown in Figure 4 , a thermistor is mounted near the laser chip on the carrier and a lead wire is connected to realize temperature detection of the region. Since the heat distribution in the aging oven is uneven during aging, the COC with thermistors is uniformly distributed at different positions of the aging fixture to detect the real temperature of different regions of the COC.

[0047] Optionally, in some embodiments of the present application, the specific steps of obtaining the temperature of the laser chip corresponding to different step currents include: sequentially applying different step currents to each laser chip with a thermistor , and averaging the resistance values of the thermistors corresponding to each laser chip with a thermistor corresponding to the same step current after the temperature is stable to obtain the average resistance value of the thermistor corresponding to different step currents . , wherein n and m are positive integers, and the average resistance value of the thermistor is used to represent the temperature of each laser chip with a thermistor.

[0048] Specifically, an initial ambient temperature Ta is set for the aging machine, different step currents are sequentially applied to each laser chip with a thermistor , and each laser chip with a thermistor is operated, and then the resistance values of the thermistors corresponding to each laser chip with a thermistor corresponding to the same step current are averaged after the temperature is stable to obtain the average resistance value of the thermistor corresponding to different step currents . .

[0049] Optionally, in an embodiment of the present application, the different step currents ​​The current difference between two adjacent step currents is equal, and each step current is greater than the light-emitting threshold current of the laser.

[0050] That is, different step currents need to be greater than the light-emitting threshold current of the laser chip, and the interval between two adjacent step currents is preferably uniform, which can ensure that the laser chip is normally excited to emit light, ensure that the test data completely covers the aging scene of the laser chip, and facilitate the accuracy of the aging test.

[0051] In another embodiment of the present application, different step currents The current difference between two adjacent step currents is equal, and the maximum step current is near the specified aging current, which can be less than or equal to the specified aging current, ensuring that the data covers the key current interval of the aging scene, facilitating the averaging of the resistance values of the thermistors under the same current of multiple COCs, further reducing random errors, and improving the reliability of temperature data.

[0052] In the operation process, the thermistor is directly attached to the chip to accurately reflect the actual temperature of the chip and avoid the interference of the deviation between the environmental temperature and the chip temperature; the COCs are uniformly distributed at different positions of the aging fixture, which can detect the real temperature in different areas of the aging chamber and solve the problem of temperature measurement deviation caused by uneven heat distribution in the aging machine.

[0053] S3, determining the peak wavelengths of the multiple lasers based on each group of step currents and the chip temperature data.

[0054] Optionally, in some embodiments of the present application, the peak wavelengths of the multiple lasers are determined based on each group of step currents and the chip temperature data, specifically including:

[0055] Different step currents are sequentially applied to each laser chip provided with a thermistor , and when the same step current is applied to each laser chip provided with a thermistor, temperature adjustment is performed to make the resistance value of each thermistor equal to the average resistance value of the corresponding thermistor , and the peak wavelengths of the laser chips provided with the thermistor under different step currents are obtained.

[0056] It should be noted that the resistance value of the thermistor is corresponding to the current, for example: It is measured under the condition that , so and are a group of variables, denoted as , and the same applies to n groups of variables. The peak wavelength of the laser is measured under the condition that , denoted as , and the same applies to , … The laser peak wavelength corresponding to each group of variables is .

[0057] Specifically, when the same step current is applied to each laser chip provided with a thermistor, the resistance value of each corresponding thermistor provided for the laser chip is equalized by heating to the average resistance value of the corresponding thermistor, and then the laser peak wavelength of each laser chip provided with a thermistor under the excitation of the step current is measured, so that the laser peak wavelength of each laser chip provided with a thermistor under different step currents can be obtained.

[0058] Therefore, the current and temperature conditions of the aging machine are simulated on the test machine, both the wavelength measurement function of the test machine is utilized, and the defects of the open environment are avoided, the combination of "simulated aging thermal environment + precise wavelength measurement" is realized, accurate wavelength data is provided for subsequent fitting.

[0059] S4, function fitting is performed according to the plurality of laser peak wavelengths and the plurality of step currents, a relationship between the laser peak wavelength and the step current is obtained, and a wavelength difference value is determined according to the relationship.

[0060] Specifically, in an embodiment of the present application, the function fitting according to the plurality of laser peak wavelengths and the plurality of step currents comprises: for each laser chip provided with a thermistor, the laser peak wavelength under different step currents and the different step currents are used to fit the relationship, and the fitted relationship is a polynomial related to the n-order current.

[0061] For example, the laser peak wavelength under different step currents and the different step currents are used to fit the following polynomial of wavelength relative to current based on a linear fitting function:

[0062]

[0063] Wherein, y is the corresponding wavelength value, x is the corresponding current value, , and b is the polynomial coefficient.

[0064] Further, the wavelength difference value is determined according to the polynomial, specifically comprising:

[0065] For each laser chip provided with a thermistor, the first wavelength and the second wavelength corresponding to the current of zero and the specified aging current are calculated based on the relationship, and the difference between the first wavelength and the second wavelength is calculated.

[0066] The difference values corresponding to the laser chips provided with the thermistors are averaged to obtain the wavelength difference value.

[0067] Specifically, according to the above polynomial, the wavelength when the current is 0 is calculated first , and then the specified aging current is calculated. The corresponding wavelength is obtained by subtracting , so as to obtain the difference value corresponding to each laser chip provided with the thermistor, and then the average value is calculated to obtain the wavelength difference value Δλ.

[0068] If is equal to the specified aging current , then is directly subtracted to obtain the difference value corresponding to each laser chip provided with the thermistor.

[0069] The polynomial relationship between the wavelength and the current is established by linear function fitting, and the wavelength under any current can be calculated based on the polynomial relationship, which improves the efficiency and is more conducive to accurate measurement.

[0070] S5, according to the wavelength temperature drift coefficient and the wavelength difference value, the temperature difference value is determined, and according to the initial environment temperature and the temperature difference value, the laser junction temperature is determined.

[0071] Specifically, based on the determined temperature drift coefficient and wavelength difference value, the temperature difference value can be calculated by the above formula TDC=Δλ / ΔT, and then combined with the initial environment temperature Ta, the laser junction temperature Tj=Ta+ΔT can be calculated, realizing the indirect accurate measurement of the junction temperature, and solving the industry problem that the junction temperature cannot be accurately measured.

[0072] S6, according to the laser junction temperature, the initial environment temperature is compensated to determine the aging environment temperature of the laser.

[0073] Specifically, in one embodiment of the present application, the calculated laser junction temperature is judged, and in the case that the laser junction temperature reaches the preset aging junction temperature, the initial environment temperature is directly taken as the aging environment temperature of the laser.

[0074] If the calculated laser junction temperature does not reach the preset aging junction temperature, the initial ambient temperature is compensated for temperature, and the above steps S2-S5 are repeatedly executed until the laser junction temperature reaches the preset aging junction temperature. That is, compared with the preset aging junction temperature given by the laser chip manufacturer, if the current calculated laser junction temperature Tj does not reach the required preset aging junction temperature, the initial ambient temperature Ta is compensated accordingly (for example, after temperature adjustment according to the set step, it is recorded as Ta1), and the above steps S2-S5 are repeatedly executed until the measured laser junction temperature reaches the preset aging junction temperature required by the manufacturer. At this time, the compensated Ta1 is the aging ambient temperature of the laser.

[0075] Therefore, the present application can accurately set the aging ambient temperature of the laser, avoid the problem of damage to the chip due to too high temperature or ineffective screening of defective products due to too low temperature; at the same time, without adding special equipment during measurement, the existing COC aging machine and test machine in the factory are directly used, reducing the cost and difficulty of equipment modification.

[0076] In summary, according to the aging ambient temperature determination method of the laser provided by the embodiment of the present application, the original aging machine and test machine of the factory can be used, and through the thermistor as a temperature transfer medium, and combined with the wavelength drift characteristics of the laser, the junction temperature of the laser in the simulated aging thermal environment can be accurately calculated. Therefore, without adding additional measurement equipment or jigs, the ambient temperature to be set on the aging machine can be obtained by using the laser junction temperature, thereby realizing accurate setting of the aging ambient temperature of the laser, ensuring accurate control of the aging parameters when the factory performs laser chip aging processing, improving the accuracy and efficiency of defective chip screening, and significantly improving the yield rate in the subsequent production process of the product.

[0077] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0078] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connection", "fixed", and the like, should be construed broadly and can be understood as, for example, fixed connection, detachable connection, or integral; mechanical connection, or electrical connection; direct connection, or indirect connection via an intermediate medium; internal communication between two elements, or interaction between two elements. The specific meaning of the above terms in the present application can be understood according to the specific circumstances by those skilled in the art.

[0079] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature is "above", "over", and "on" the second feature, which can be directly above or obliquely above the second feature, or simply means that the first feature is higher in horizontal height than the second feature. The first feature is "below", "under", and "under" the second feature, which can be directly below or obliquely below the second feature, or simply means that the first feature is lower in horizontal height than the second feature.

[0080] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, different embodiments or examples described in the present application and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0081] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for determining the aging environment temperature of a laser, characterized in that, The method comprises the following steps: S1, determining a wavelength temperature drift coefficient of a laser; S2, obtaining laser chip temperatures corresponding to different step currents at an initial ambient temperature to determine a plurality of sets of step current and chip temperature data, wherein a thermistor is arranged at the laser chip to obtain the laser chip temperature; S3, determining a plurality of laser peak wavelengths based on each set of step current and chip temperature data; S4, performing function fitting according to the plurality of laser peak wavelengths and the plurality of step currents to obtain a relationship between the laser peak wavelength and the step current, and determining a wavelength difference value according to the relationship; wherein the determination of the wavelength difference value comprises: for each laser chip on which the thermistor is arranged, calculating a first wavelength and a second wavelength corresponding to a current of zero and a specified aging current based on the relationship, and calculating a difference value between the first wavelength and the second wavelength; and performing mean value calculation on the difference values corresponding to the respective laser chips on which the thermistor is arranged to obtain the wavelength difference value; S5, determining a temperature difference value according to the wavelength temperature drift coefficient and the wavelength difference value, and determining a laser junction temperature according to the initial ambient temperature and the temperature difference value; S6, compensating the initial ambient temperature according to the laser junction temperature to determine an aging ambient temperature of the laser.

2. The method of claim 1, wherein, The compensation of the initial ambient temperature according to the laser junction temperature comprises: in the case where the laser junction temperature does not reach a preset aging junction temperature, repeating steps S2-S5 after temperature compensation of the initial ambient temperature, until in the case where the laser junction temperature reaches the preset aging junction temperature, the temperature-compensated ambient temperature is taken as the aging ambient temperature of the laser.

3. The method of claim 1, wherein, The thermistor is arranged at a position of the laser chip mounted on a carrier, and the laser chips on which the thermistor is arranged are distributed at different positions of an aging clamp, so as to detect real temperatures in different regions of an aging oven.

4. The method of claim 3, wherein, The obtaining of the laser chip temperatures corresponding to different step currents comprises: Different stepped currents are applied sequentially to each laser chip in which the thermistor is located. After the temperature stabilizes, the resistance values ​​of the thermistors corresponding to the laser chips with the same step current are adjusted. Perform average calculations to obtain different step currents. The corresponding average resistance of the thermistor Where n and m are both positive integers, and the average resistance of the thermistor is... Used to characterize the temperature of each laser chip for which the thermistor is set.

5. The method of claim 4, wherein, Different step currents The current difference between adjacent two step currents is equal, and each step current is greater than the light emission threshold current of the laser.

6. The method of claim 4, wherein, Different step currents The current difference between adjacent two step currents is equal, and the maximum step current is less than or equal to the specified aging current.

7. The method of claim 4, wherein the laser's ambient temperature is determined by: The determination of the plurality of laser peak wavelengths based on each set of step current and chip temperature data comprises: applying different step currents to each of the laser chips provided with the thermistors and adjusting the temperature to make the resistance of each thermistor equal to the average resistance of the corresponding thermistor when applying the same step current to each of the laser chips provided with the thermistors and obtaining the laser peak wavelength of each of the laser chips provided with the thermistors at different step currents ​ 8. The method of claim 7, wherein, The function fitting according to the plurality of laser peak wavelengths and the plurality of step currents comprises: For each set of laser chips on which the thermistor is set, a different step current is used and a different step current , the resulting relationship is a polynomial related to the n-step current.

9. The method of claim 1-8, wherein, The determination of the wavelength temperature drift coefficient of the laser comprises: obtaining peak wavelengths of a plurality of laser chips at different temperatures and different currents; calculating an average temperature difference value and an average wavelength difference value according to the peak wavelengths of the plurality of laser chips at different temperatures and different currents; determining the wavelength temperature drift coefficient according to a ratio between the average wavelength difference value and the average temperature difference value.

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