1. A method for detecting defects of silica gel at a light-emitting side leakage point of an optical coupler is characterized by comprising the following steps:

the current source applies a first input current to the input end of the optical coupler to be tested, the voltage source applies a first voltage to the output end of the optical coupler to be tested and measures a first conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR1 between the first conduction current and the first input current;

applying a large current larger than the first input current to the current source to electrify the optocoupler to be tested for a period of time for aging;

the current source applies a second input current to the input end of the optical coupler to be tested, the voltage source applies a second voltage to the output end of the optical coupler to be tested and measures a second conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR2 between the second conduction current and the second input current;

and comparing the attenuation percentage change of the CTR1 and the CTR2 to achieve the purpose of screening.

2. The method for detecting the silica gel defect at the light-emitting side leakage point of the optical coupler as claimed in claim 1, wherein the comparison result shows that the product is good when the attenuation percentage variation of CTR1 and CTR2 is less than 5%, and the product is poor when the attenuation percentage variation is more than or equal to 5%.

3. The method for detecting the defect of the silica gel on the light-emitting side leakage point of the optical coupler as claimed in claim 2, wherein the step of applying a large current larger than the first input current to the optical coupler to be tested by the current source to electrify the optical coupler to be tested for a period of time for aging comprises the following steps: the current source applies a large current which is 10 times of the first input current to electrify the optical coupler to be tested for a period of time for aging.

4. The method for detecting the defect of the silica gel on the light-emitting side leakage point of the optical coupler as claimed in claim 3, wherein before and after the current source applies a large current which is 10 times of the first input current to electrify the optical coupler to be detected for a period of time for aging, the method comprises the following steps: the values of the first input current and the second input current which are applied to the optocoupler to be tested in the front-back mode are consistent, the values of the first voltage and the second voltage which are applied to the optocoupler to be tested in the front-back mode are consistent, and the values of the ambient temperatures in the front-back mode are consistent.

5. The method for detecting the silica gel defect at the light-emitting side leakage point of the optical coupler as claimed in claim 1, wherein the comparison of the attenuation percentage variation of CTR1 and CTR2 for screening purposes comprises: and calculating the attenuation percentage variation of each group of CTR1 and CTR2 by adopting a circuit with an operation function, and judging the magnitude of the attenuation percentage variation by an intuitive numerical value to achieve the purpose of screening.

6. The utility model provides a detect device of luminous side leakage point silica gel defect of opto-coupler which characterized in that includes:

the current source module is used for applying a first input current and a second input current to the input end of the optical coupler to be tested and applying a large current larger than the first input current to electrify the optical coupler to be tested for aging;

the voltage source module is used for applying a first voltage and a second voltage to the output end of the optical coupler to be tested;

and the operation circuit module is used for calculating the current transmission ratio and the attenuation percentage variation before and after aging.

7. The device for detecting the silica gel defect of the light-emitting side leakage point of the optical coupler as claimed in claim 6, wherein two ends of the current source module are respectively connected with two pins of the input end of the optical coupler to be detected, two ends of the voltage source module are respectively connected with two pins of the output end of the optical coupler to be detected, and two ends of the operation circuit module are both connected with the input end and the output end of the optical coupler to be detected so as to calculate the current transmission ratio and the attenuation percentage variation before and after aging.

8. The apparatus according to claim 7, wherein the operational circuit module, the current source module and the voltage source module are integrated into a test instrument.

9. The device for detecting the silica gel defect of the light-coupling light-emitting side leakage point of the optical coupler as claimed in claim 7, wherein the operation circuit module, the current source module and the voltage source module are in the form of separate and independent circuits.

10. An apparatus for detecting defects of silica gel on a light emitting side of an optical coupler, comprising a power module, an interface circuit module, and further comprising a memory and a processor, wherein the power module is connected to the processor through the interface circuit module, the processor is connected to the memory, and the memory stores a program, and when the program is executed by the processor, the processor is enabled to execute the steps of the method according to any one of claims 1 to 5.

Background

An Optical Coupler (OCEP) is also called a photo isolator or a photo coupler for short, and is a device for transmitting an electrical signal by using light as a medium, and generally an infrared light emitting device (an infrared light emitting diode) and an infrared light receiving device (a phototriode) are packaged in the same tube shell, as shown in a figure 1, the working principle of the optical coupler is to realize conversion and transmission of electricity-light-electricity, specifically, to transmit an analog voltage or current signal, and to generate a corresponding optical signal along with the change of the intensity of an input signal, so that the output voltage or current of the phototriode changes accordingly. The input end of the infrared light receiving device is provided with an infrared light emitting device, the output end of the infrared light receiving device is correspondingly provided with an infrared light receiving device, the input end and the output end of the infrared light receiving device are filled with insulating media, signals are transmitted from the input end to the output end in a one-way mode through the transmission media, and therefore electrical isolation is achieved.

The optical coupler belongs to an industrial grade product, and the failure rate requirement is high (generally less than 10 ppm, the smaller the better); the production process flow of the optical coupler is complex, each process has quality defects, most of the process defects can be screened out in the testing process by an electrical parameter measuring method, but the defects in the point gluing process are very special, and defective products cannot be selected out by a common electrical parameter measuring method. The concrete description is as follows: as shown in fig. 1, the input end of the optical coupler is an infrared light emitting device, and silica gel is required to be dotted in the production process to protect the infrared light emitting device, and meanwhile, the optical coupler also has the functions of light transmission and heat dissipation; because the precise control difficulty of the process of dispensing the silica gel is very high, the production process is difficult to avoid leaking the silica gel, and zero defects cannot be realized, the conventional detection and screening method uses X-ray equipment to manually perform perspective detection on each product after the product is packaged, and selects defective products, and the detection and screening method has the defects of long time consumption and high cost.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method, a device and equipment for detecting the defect of the silica gel at the light-emitting side leakage point of the optical coupler, which replace manual perspective detection with an electrical test method and greatly improve the production efficiency.

In order to achieve the purpose, the invention provides a method for detecting the defect of silica gel at a leak point on a light-emitting side of an optical coupler, which comprises the following steps: the current source applies a first input current to the input end of the optical coupler to be tested, the voltage source applies a first voltage to the output end of the optical coupler to be tested and measures a first conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR1 between the first conduction current and the first input current; applying a large current larger than the first input current to the current source to electrify the optocoupler to be tested for a period of time for aging; the current source applies a second input current to the input end of the optical coupler to be tested, the voltage source applies a second voltage to the output end of the optical coupler to be tested and measures a second conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR2 between the second conduction current and the second input current; and comparing the attenuation percentage change of the CTR1 and the CTR2 to achieve the purpose of screening.

Preferably, the comparison between CTR1 and CTR2 shows that the product is good when the attenuation percentage variation is less than 5%, and the product is not good when the attenuation percentage variation is greater than or equal to 5%.

Preferably, the current source applies a large current larger than the first input current to energize the optocoupler to be tested for a period of time for aging, and the aging process includes: the current source applies a large current which is 10 times of the first input current to electrify the optical coupler to be tested for a period of time for aging.

Preferably, before and after the current source applies a large current 10 times of the first input current to energize the optocoupler to be tested for a period of time for aging, the method includes: the values of the first input current and the second input current which are applied to the optocoupler to be tested in the front-back mode are consistent, the values of the first voltage and the second voltage which are applied to the optocoupler to be tested in the front-back mode are consistent, and the values of the ambient temperatures in the front-back mode are consistent.

Preferably, the comparison of the percentage change of attenuation between CTR1 and CTR2 for screening purposes comprises: and calculating the attenuation percentage variation of each group of CTR1 and CTR2 by adopting a circuit with an operation function, and judging the magnitude of the attenuation percentage variation by an intuitive numerical value to achieve the purpose of screening.

Based on the same technical concept, the invention also provides a device for detecting the silica gel defect of the light-emitting side leakage point of the optical coupler, which comprises the following steps: the current source module is used for applying a first input current and a second input current to the input end of the optical coupler to be tested and applying a large current larger than the first input current to electrify the optical coupler to be tested for aging; the voltage source module is used for applying a first voltage and a second voltage to the output end of the optical coupler to be tested; and the operation circuit module is used for calculating the current transmission ratio and the attenuation percentage variation before and after aging.

Preferably, the both ends of current source module are connected with two pins of the input of the opto-coupler that awaits measuring respectively, the both ends of voltage source module are connected with two pins of the output of the opto-coupler that awaits measuring respectively, the both ends of operation circuit module are all connected with the input and the output of the opto-coupler that awaits measuring to current transmission ratio and decay percentage change volume before the calculation is ageing.

Preferably, the operation circuit module, the current source module and the voltage source module are integrated in a test instrument.

Preferably, the operation circuit module, the current source module and the voltage source module are in the form of separate and independent circuits.

Based on the same technical concept, the invention also provides equipment for detecting the defect of the silica gel at the light-emitting side leakage point of the optical coupler, which comprises a power supply module, an interface circuit module, a memory and a processor, wherein the power supply module is connected with the processor through the interface circuit module, the processor is connected with the memory, the memory stores a program, and when the program is executed by the processor, the processor executes the steps of the method.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a method, a device and equipment for detecting the defect of silica gel at a light-emitting side leakage point of an optocoupler, solves the problem of detecting the defect of silica gel at the light-emitting side leakage point of the optocoupler in the production process, solves the problems of overlong time consumption and high cost of the existing detection and screening products, improves the working efficiency of detection and screening in the production process of the optocoupler, and has the advantages of simple connection of hardware circuits, convenient operation, reliability and high efficiency by adopting a high-current impact method for detection.

Drawings

In order to more clearly illustrate the solution of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive labor.

FIG. 1 is a schematic flow chart of a first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a second embodiment of the present invention;

fig. 3 is a block diagram of the third embodiment of the present invention.

Description of reference numerals:

1. a current source module; 2. a voltage source module; 3. an arithmetic circuit module; 4. a power supply module; 5. an interface circuit module; 6. a processor; 7. a memory.

Detailed Description

The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

The terms "comprising" and "having," and any variations thereof, in the description and claims of this invention and the description of the above figures, are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and in the claims, or in the drawings, are used for distinguishing between different objects and not necessarily for describing a particular sequential order. In the description and claims of the present invention or the drawings, directional terms such as "upper", "lower", "left", "right", "front", "rear", "side", and the like are used for relative positional description of the drawings, and are not used to describe a specific order of actual products.

For convenience of understanding, the following explains noun terms referred to in the embodiments of the present application.

The optocoupler to be tested: the input end of the photoelectric coupler to be tested is a light emitting diode, and the output end of the photoelectric coupler is a photosensitive triode. The function of the optical fiber coupler is that the input end converts an electric signal into an optical signal, and the output end converts the optical signal into the electric signal, so that input-output physical isolation is realized. The technical parameters of the photoelectric coupler mainly include forward voltage drop VF of the light emitting diode, forward current IF, current transfer ratio CTR, insulation resistance between an input electrode and an output electrode, reverse breakdown voltage V (BR) CEO of a collector electrode and an emitter electrode, and saturation voltage VCE (sat) of the collector electrode and the emitter electrode. The current Transfer ratio ctr (current Transfer radio) is a key index and an important parameter of the optical coupler, and is usually expressed by a direct current Transfer ratio. When the output voltage is kept constant, it is equal to the percentage of the dc output current IC and the dc input current IF, that is, the ratio of the output current of the phototriode to the input current of the light emitting diode, multiplied by 100%, and its formula is: CTR = IC/IF 100%.

Referring to fig. 1, a first embodiment of the present invention provides a method for detecting a defect of a silica gel on a light emitting side leakage point of an optical coupler, which includes the following steps:

step S1: the current source applies a first input current to the input end of the optical coupler to be tested, the voltage source applies a first voltage to the output end of the optical coupler to be tested and measures a first conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR1 between the first conduction current and the first input current.

The current source applies a first input current to the input end of the optical coupler to be measured, for example, the first input current is 5mA, and the current source has a precision measurement function and adopts a current adding and pressure measuring mode. Similarly, the voltage source applies a first voltage to the output end of the optocoupler to be measured, for example, the first voltage is applied to 5V, and since the voltage source also has the function of precision measurement, the first on-current of the output end of the optocoupler to be measured is measured at the same time, and a pressurizing current measuring mode is adopted. And the circuit with the operation function calculates the current transmission ratio CTR1 between the first conduction current and the first input current, and the step is a test before the optical coupler to be tested is aged.

Step S2: and the current source applies a large current larger than the first input current to electrify the optocoupler to be tested for a period of time for aging.

After step S1, the optocoupler to be tested may be aged, for example, the current source applies a large current 10 times the first input current to energize the optocoupler to be tested for a period of time for aging. Specifically, the current source applies a large current of 50mA to electrify the optocoupler to be tested for 1min for aging.

It should be noted that, in the aging process of the optocoupler to be tested, the time length can be adjusted according to the actual product characteristics, and the current in the aging process can also be adjusted according to the actual product characteristics, as long as the current larger than the first input current is applied to impact the optocoupler to be tested.

Step S3: the current source applies a second input current to the input end of the optical coupler to be tested, the voltage source applies a second voltage to the output end of the optical coupler to be tested and measures a second conduction current, and the circuit with the operation function calculates and records a current transmission ratio CTR2 between the second conduction current and the second input current.

The current source applies a second input current to the input end of the optical coupler to be measured, for example, the second input current is 5mA, and the current source has a precision measurement function and adopts a current adding and pressure measuring mode. Similarly, the voltage source applies a second voltage to the output end of the optocoupler to be measured, for example, the voltage source applies the second voltage of 5V, and since the voltage source also has the function of precision measurement, the second on-current of the output end of the optocoupler to be measured is measured at the same time, and a pressurizing current measuring mode is adopted. And the circuit with the operation function calculates the current transmission ratio CTR2 between the second conduction current and the second input current, and the step is the test after the optical coupler to be tested is aged.

In order to ensure the accuracy before and after detection, the values of the first input current and the second input current which are applied to the optical coupler to be detected are consistent, the values of the first voltage and the second voltage which are applied to the optical coupler to be detected are consistent, and the environmental temperatures are consistent.

Step S4: and comparing the attenuation percentage change of the CTR1 and the CTR2 to achieve the purpose of screening.

The circuit with the operation function is adopted to calculate the attenuation percentage variation of each group of CTR1 and CTR2, the size of the attenuation percentage variation is judged through visual numerical values to achieve the purpose of screening, when the attenuation percentage variation of the optical coupler to be tested is less than 5%, the optical coupler to be tested is qualified, namely, when the attenuation percentage variation of the optical coupler to be tested is more than or equal to 5%, the optical coupler to be tested is defective, namely, the optical coupler to be tested has the defect of point leakage silica gel on the light-emitting side.

It should be noted that the formula of the attenuation percentage change is as follows:

(after aging CTR-before aging CTR)/before aging CTR 100%

In conclusion, the method solves the problem of detecting the defect of the silica gel on the light-coupling light-emitting side leakage point in the production process, solves the problems of overlong time consumption and high cost of the existing detection and screening products, and improves the working efficiency of detection and screening in the production process of the optical coupler.

Based on the same technical concept, the second embodiment of the present invention further provides a device for detecting a defect of silica gel at a light emitting side leakage point of an optocoupler, which includes a current source module 1, configured to apply a first input current and a second input current to an input end of the optocoupler to be tested, and apply a large current larger than the first input current to energize the optocoupler to be tested for aging; the voltage source module 2 is used for applying a first voltage and a second voltage to the output end of the optical coupler to be tested; and the operation circuit module 3 is used for calculating the current transmission ratio and the attenuation percentage variation before and after aging. As shown in fig. 2, two ends of the current source module 1 are respectively connected with two pins of the input end of the optical coupler to be tested, two ends of the voltage source module 2 are respectively connected with two pins of the output end of the optical coupler to be tested, and two ends of the operation circuit module 3 are both connected with the input end and the output end of the optical coupler to be tested so as to calculate the current transmission ratio and the attenuation percentage variation before and after aging.

Optionally, the operation circuit module 3, the current source module 1 and the voltage source module 2 are integrated in a testing instrument, or may be in a form of separate and independent circuits, and are connected by external wires, and the attenuation percentage variation is obtained by manual operation, reading, calculation and the like, and then the magnitude of the attenuation percentage variation is judged by an intuitive value to achieve the purpose of screening.

By adopting the device of the second embodiment and the method of the first embodiment, the invention takes the model QX-817 optical coupler as the optical coupler sample to be tested, and experimental verification proves that a group of data is provided as follows:

through the data table, under the conditions that the ambient temperatures before and after aging are consistent, the values of the first input current and the second input current applied to the optocoupler to be tested before and after aging are consistent, and the values of the first voltage and the second voltage applied to the optocoupler to be tested before and after aging are consistent, the optocoupler to be tested is IF =0.5A under the aging condition, and after 1min, the attenuation percentage variation of the sample 1# to 5# is within 5%, the optocoupler to be tested is a qualified sample, the attenuation percentage variation of the sample 6# to 10# is greater than 5%, that is, the defect of the silica gel with a leakage point exists, that is, the defective sample is selected through detection, the screening purpose is completed, the experiment is verified through the inspection of an X-RAY device, and the fact that the attenuation percentage variation of the sample 6# to 10# is greater than 5% is a defective input-side optocoupler, and judging the product as a defective product.

Based on the same technical concept, a third embodiment of the present invention further provides an apparatus for detecting a defect of a silica gel on a light emitting side of an optical coupler, as shown in fig. 3, which includes a power module 4, an interface circuit module 5, a memory 6 and a processor 7, where the power module 4 includes a current source module 1 and a voltage source module 2, the power module 4 is connected to the processor 6 through the interface circuit module 5, the processor 6 is connected to the memory 7, the memory 7 stores a program, and when the program is executed by the processor 6, the processor 6 executes the steps of the method. The equipment solves the problems of overlong time consumption and high cost of screening products for the defects of the light coupling light-emitting side leakage point silica gel in the production process.

It should be understood that the above experimental data are only used as a verification reference, and are influenced by sample selection, experimental instruments, circuit design, environment, human factors and the like, and have certain experimental tolerance errors, which do not mean that the experimental data are identical every time.

The above description is only for the purpose of illustrating the technical solutions of the present invention and is not intended to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; all the equivalent structures or equivalent processes performed by using the contents of the specification and the drawings of the invention, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.