KR100783352B1 - System and method for inspect printed circuit board assembly using infrared thermography - Google Patents

Abstract

A system and a method for inspecting a pair of printed circuit board assemblies using an infrared thermography are provided to collectively inspect whether or not electronic components are mounted, whether or not a soldering abutment has an error, and whether or not the electronic components are normally operated. A system for inspecting a pair of printed circuit board assemblies(1a,1b) includes first to fourth chambers(10,20,30,40), a temperature equalizing unit, a heating unit, a temperature image acquiring unit, a controller(41), and an image processing unit(43). The PCB assembly sequentially passes through the first to the fourth chambers. The temperature equalizing unit is installed in the first chamber, and equalizes and maintains the temperature of the PCB assembly disposed in the first chamber. The heating unit equally heats a rear surface of the PCB assembly disposed at an inspection position after transferring the PCB assembly from the first chamber in the second chamber. The temperature image acquiring unit measures the temperature distribution for a front surface of the PCB assembly in the second chamber to provide the temperature distribution as a temperature image. The temperature equalizing unit is installed in the third chamber, and equalizes and maintains the temperature of the PCB assembly transferred from the second chamber.

Description

System and method for inspect printed circuit board assembly using infrared thermography

1 is a block diagram showing a PCB assembly inspection apparatus according to the present invention,

2a to 2c is a reference diagram for explaining the inspection principle of the present invention,

3 is a flowchart of a process of obtaining a reference image for PCB assembly inspection according to the present invention;

4 is a flow chart showing a PCB assembly inspection process according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1a: good quality PCB assembly 1b: inspection PCB assembly

10: first chamber 11: air shower device

20: second chamber 21: infrared heating device

22 infrared camera 30: third chamber

31: air shower device 40: fourth chamber

41 controller 42 infrared camera

43: image processing unit

The present invention relates to an apparatus and method for inspecting a PCB assembly using infrared thermal imaging, and more particularly, to measure a temperature distribution of a PCB assembly to be inspected using an infrared thermal imaging camera, and compare the same with PCB data of a good product. The present invention relates to a PCB assembly inspection apparatus and method using an infrared thermal image that can collectively inspect whether a component is mounted, a solder joint is defective, and whether an electronic component is normally operated (function failure occurs).

Today, as functions and components are complex and sophisticated electronics emerge, the printed circuit board assembly (PCB assembly) used for them is also increasingly large and complex and sophisticated.

The increase in the number of components mounted on a printed circuit board (hereinafter, referred to as a PCB) means that as the manufacturing cost increases, the probability of defects increases, the yield decreases, and error diagnosis becomes more difficult.

In particular, the smaller the component, the more difficult it is to accurately mount, while the limited access to soldered joints limits existing test / inspection methods in terms of efficiency in finding complex defects.

The most commonly used test / inspection procedures in Surface Mount Technology (SMT) are Manual Vision Inspection (MVI), In-Circuit Test (ICT) and Function Test (Function Test). ; FCT).

However, according to this conventional sequential inspection, it is true that the defect inspection range is quite wide for each test method, but there are also areas where the test methods overlap each other and fall short of the combined irradiation range.

And, if the defect inspection scope overlaps each other or fails to cover all defect types, the total test cost may increase.

 ICT, a typical test method, has its own drawbacks when applied to high-complexity boards because it is only possible to achieve a high level of defect inspection after a long time of high cost programming.

Moreover, the time required to produce the required jig can be quite long when the number of nodes is 3,000 or more.

In addition, if the board complexity is high, not only is the ICT fixture expensive, but it also increases the probability of contact problems with the fixture because it requires a larger number of test probes to access the reduced target point.

Problems like this provide a number of causes for retests, and also make it difficult to distinguish between real and true defects.

On the other hand, if there are defect types that are not included in the defect inspection scope, a low-quality product may be shipped, which means that the possibility of failure during use increases.

Detecting most of the short, open, and no component defects prior to performing the electrical test will significantly reduce test duplication.

Therefore, the present invention is invented to solve the above problems,

Measure the temperature distribution of the PCB assembly to be inspected using the infrared thermal imaging camera and compare it with the PCB assembly data of the good product to check whether the electronic component is mounted, whether the solder joint is defective, or whether the electronic component is operating normally ) Can be inspected in a batch, so that the scope of defect inspection can be comprehensively performed without depending on the equipment, thereby reducing the overall inspection cost, reducing the inspection time, and more accurately. It is an object of the present invention to provide a PCB assembly inspection apparatus and method for obtaining the inspection results.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention, the first to the fourth chamber to which the PCB assembly is sequentially passed through the transfer; Temperature equalization means installed in the first chamber to uniformize and maintain the temperature of the PCB assembly disposed in the first chamber; Heating means for uniformly heating the rear surface of the PCB assembly disposed at the inspection position after being transferred from the first chamber in the second chamber; Temperature image acquisition means for measuring a temperature distribution with respect to the front surface of the PCB assembly in the second chamber and providing a temperature image; Temperature equalization means installed in the third chamber to uniformly maintain and maintain the temperature of the PCB assembly transferred from the second chamber; A controller connected to the fourth chamber so as to supply power to the PCB assembly disposed at the inspection position after the transfer from the third chamber and to apply a control signal for the operation of the electronic component mounted on the PCB assembly; Temperature image acquisition means for measuring a temperature distribution with respect to the front surface of the PCB assembly in the fourth chamber and providing a temperature image; Provides a PCB assembly inspection apparatus comprising; an image processing unit for receiving and processing the image transmitted from each of the temperature image acquisition means, and stores and displays the received image and the result of the processing.

On the other hand, the present invention, PCB assembly inspection method, the temperature uniformity ensuring step of placing and maintaining the temperature of the PCB assembly to be inspected in the first chamber uniformly; Transferring the PCB assembly having a uniform temperature from the first chamber to the second chamber, and obtaining a temperature image 1 'representing the temperature distribution over the front surface of the PCB assembly using an infrared thermal camera; Recording / storing the temperature image 1 'transmitted from the infrared camera of the second chamber in the image processor, and obtaining a histogram of the temperature image 1' to check temperature uniformity; Evenly heating the back of the PCB assembly confirmed the temperature uniformity in the second chamber with an infrared heating device, and at the same time to obtain a temperature image 2 'representing the temperature distribution on the front surface of the PCB assembly using an infrared thermal camera. Steps; The image processor records / stores the temperature image 2 'transmitted from the infrared thermal camera of the second chamber, and the temperature image data obtained from the infrared thermal camera and the PCB assembly of good quality in advance under the same process and conditions. And comparing the acquired reference image data to determine whether the electronic component is mounted on the PCB assembly to be inspected, and providing the PCB assembly inspection method.

A temperature uniformity step of transferring the PCB assembly heated in the second chamber to the third chamber and making the temperature uniform and maintaining the temperature; Transferring the PCB assembly having a uniform temperature from the third chamber to the fourth chamber, and then obtaining a temperature image 3 'representing the temperature distribution over the front surface of the PCB assembly using an infrared thermal camera; Recording / storing the temperature image 3 'transferred from the infrared thermal camera of the fourth chamber in the image processing unit, and obtaining a histogram of the temperature image 3' to check temperature uniformity; Acquiring a temperature image 4 'representing the temperature distribution of the front surface of the PCB assembly using an infrared thermal camera while simultaneously applying power from the controller to the PCB assembly in which the temperature uniformity is confirmed in the fourth chamber; The image processing unit records / stores the temperature image 4 'transmitted from the infrared thermal camera of the fourth chamber, and the temperature image data obtained from the infrared thermal camera and the good PCB assembly under the same process and conditions in advance. And comparing the obtained reference image data to determine whether a solder joint of the PCB assembly to be inspected is defective.

In addition, in the fourth chamber, a control signal for operating an electronic component mounted on a PCB assembly is applied from a controller, and a temperature image 5 'representing a temperature distribution of the front surface of the PCB assembly is acquired using an infrared thermal camera. Making a step; The image processing unit records / stores the temperature image 5 'transferred from the infrared thermal camera of the fourth chamber, and the temperature image data obtained from the infrared thermal camera and the PCB assembly of good quality in advance under the same process and conditions. And determining whether the electronic component is normally operated with respect to the PCB assembly to be inspected by comparing the obtained reference image data.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The present invention relates to an apparatus and method for inspecting a PCB assembly using an infrared thermal image, and to improve the conventional problems, a temperature of a PCB assembly using an infrared thermal imager that detects infrared rays emitted from an object and provides a two-dimensional temperature image. Automated Thermography Inspection, which measures distribution and compares it with a normal state to inspect whether an electronic component is mounted, whether a solder joint is defective, or whether the electronic component is normally operated (function failure occurs); ATI) An apparatus and method are provided.

 1 is a block diagram showing a PCB assembly inspection apparatus according to the present invention, Figures 2a to 2c is a reference diagram for explaining the inspection principle of the present invention.

3 is a flowchart illustrating a process of acquiring a reference image for PCB assembly inspection according to the present invention, and FIG. 4 is a flowchart illustrating a PCB assembly inspection process according to the present invention.

In the present invention, the heat emitted from the PCB is detected using an infrared thermal imaging camera, and at this time, the temperature distribution is compared with the temperature distribution of the good product to determine whether it is defective, whether the electronic component is mounted or the solder joint is defective in this process. It is determined whether or not the electronic component is normally operated (function error occurs).

First, the principle of inspecting whether the electronic component is mounted will be described. As shown in FIG. 2A, heat is radiated from the infrared heat source (infrared heater) 4 disposed on the rear surface of the PCB assembly 1 to the rear surface of the PCB assembly. When incident, the temperature distribution detected by the infrared thermal imaging camera 5 is different due to the difference between the heat transfer coefficient of the electronic component 3 and the heat transfer coefficient of the PCB (substrate) 2.

That is, a temperature difference occurs for each part in the PCB assembly to be inspected according to whether the electronic component is inserted, and when the temperature difference is compared with the temperature distribution of the good product, it is possible to determine whether the electronic component is mounted.

In addition, the principle of inspecting whether the solder joint is defective will be described. As shown in FIG. 2B, when power is applied to the PCB assembly 1, the electronic component 3 generates heat corresponding to resistance. Heat generation is designed to maintain a constant temperature to ensure the safety of the product electronic components.

Therefore, when the electronic component 3 is not normally soldered to the PCB 2, since the power is not applied to the electronic component, the electronic device 3 does not generate constant heat, and the infrared thermal imaging camera 5 does not have the PCB assembly 1. By measuring the temperature distribution of), it is possible to know whether or not the corresponding part is heated. Through this, it is possible to know whether the power is applied and whether the solder joint is defective.

That is, whether or not heat is detected by the infrared thermal imaging camera 5 and compared with the good product 3a enables re-inspection of whether the electronic component is mounted together with detecting whether the solder joint is defective.

In addition, incomplete soldering between the solder joint and the PCB (interfacial separation, poor solder penetration, etc.) reduces the power supplied to the electronic component, thereby affecting the heat generation of the electronic component, and causing the solder to generate heat due to the increased resistance. do.

By comparing this heat generation change with a good product, incomplete solder joint detection becomes possible.

In addition, the principle of inspecting whether an electronic component operates normally or not (function failure) will be described. In the case of an electronic component whose function is changed according to a signal, it is conceived that the heating distribution is different between an operation and a non-operation. As shown in FIG. 2C, after inputting a control signal from the outside, the temperature distribution in the operating state and the non-operating state of the electronic component 3 is measured by the infrared thermal imaging camera 5 and compared with the good product 3a. It is possible to check whether the electronic component 3 performs a normal function.

Based on the inspection principle, the PCB assembly inspection apparatus proposed by the present invention will be described in detail with reference to FIG. 1.

First, four chambers 10, 20, 30, and 40 are partitioned, and a task is performed by sequentially moving the PCB assembly 1b, which is an object, along the chambers during the inspection.

In the present specification, for the sake of clarity, the four chambers will be referred to as the first chamber 10, the second chamber 20, the third chamber 30, and the fourth chamber 40, respectively, according to the movement order.

First, an air shower device 11 for injecting air to the front surface of the PCB assembly 1a, 1b is installed in the first chamber 10, and the air shower device 11 is inspected in the first chamber 10. In order to maintain a uniform temperature of the PCB assembly by injecting air to the front of the PCB assembly (1a, 1b) disposed in the position.

The air shower device 11 injects air adapted to the ambient temperature to the PCB assembly (1a, 1b) to ensure temperature uniformity.

Next, an infrared heater 21 for heating the rear surface of the PCB assembly 1a, 1b disposed at the inspection position after being transferred from the first chamber 10 to the second chamber 20 so that even heat is incident. Is installed, together with an infrared thermal imaging camera 22 for detecting infrared rays emitted from the front surfaces of the PCB assemblies 1a and 1b and providing them as two-dimensional temperature images.

The infrared thermal camera 22 is connected to the image processor 43 including an image processing processor so that the acquired image can be transferred, and the image processor 43 is an image transmitted from the infrared thermal camera 22. And store and display the transmitted image and processing results.

Next, the air shower device 31 is installed in the third chamber 30 in the same manner as in the first chamber 10, which is heated in the second chamber 20 and then transferred to the PCB assemblies 1a and 1b. It is installed to inject air to the front of).

The air shower device 31 plays the same role as the air shower device 11 in the first chamber 10, and is disposed on the front surface of the PCB assemblies 1a and 1b disposed at the inspection position in the third chamber 30. Air is blown to keep the temperature of the PCB assembly uniform.

The air shower device 31 injects air adapted to the ambient temperature to the PCB assembly to ensure temperature uniformity.

Next, the fourth chamber 40 receives power from a power supply unit (not shown) and supplies power to the PCB assemblies 1a and 1b that are transferred from the third chamber 30 and disposed at the inspection position. The controller 41 is connected and installed to apply a control signal for the operation of the electronic component mounted on the PCB assembly.

In addition, an infrared thermal camera 42 is installed to detect infrared rays emitted from the front surfaces of the PCB assemblies 1a and 1b and provide a two-dimensional temperature image.

The infrared thermal imaging camera 42 is connected to the image processor 43 so that the acquired image can be transferred.

And, in the PCB assembly inspection apparatus made as described above, the PCB assembly of the good and the PCB assembly of the inspection target of the first chamber 10, the second chamber 20, the third chamber 30, the fourth chamber 40 In order to be transported in order to go through the inspection process, a transfer means (not shown) for automatically transferring the PCB assembly along the chambers is installed.

The conveying means may be implemented as a conventional conveying means capable of conveying the PCB assembly (1a, 1b) along a predetermined path, for example, a conveyor device passing through the chambers (10, 20, 30, 40) and the like. have.

On the other hand, in the present invention by detecting a slight temperature difference or change in the PCB assembly in the inspection device made as described above to perform inspection by comparing the PCB assembly of the good and the PCB assembly of the inspection target in real time, the inspection according to the present invention The process is described in detail as follows.

Since the PCB assembly has a different configuration and structure of electronic components according to a product, a process of acquiring a reference image based on a good product should be preceded, and the process is shown in FIG. 3.

First, in order to secure temperature uniformity in the first chamber 10, the air shower device 11 sprays air adapted to the ambient temperature to the PCB assembly 1a of good quality to maintain the temperature of the PCB assembly uniformly. Transfer to the second chamber 20.

Subsequently, in the second chamber 20, the infrared thermal camera 21 acquires a temperature image 1 of the front surface of the PCB assembly 1a and transfers the temperature image 1 to the image processor 43. In this case, the temperature image 1 obtained at this time is received and recorded / stored, and a temperature distribution graph (histogram) of the temperature image 1 is obtained to check the temperature uniformity of the PCB assembly.

Here, the PCB assembly having no uniformity is transferred to the first chamber 10 again and then sprayed with air to the air shower device 11 to ensure uniformity, and then re-transmitted to the second chamber 20.

In addition, the rear surface of the PCB assembly is heated using the infrared heater 21 to the PCB assembly 1a that maintains a uniform temperature in the second chamber 20, and at this time, the temperature distribution on the front surface of the PCB assembly is infrared heat. Obtained through the image camera 22, the temperature image 2 at this time is transmitted to the image processing unit 43, and then recorded / stored.

The image processor 43 records / stores the relative temperature distribution image as the reference image 1 through a subtraction process of the temperature image 1 and the temperature image 2 (temperature image 2-temperature image 1).

Here, the finally obtained reference image 1 is used as a reference image in checking whether the electronic component of the PCB assembly, which is a test object, is mounted later.

Meanwhile, the PCB assembly 1a is again transferred from the second chamber 20 to the third chamber 30, and in the third chamber 30, as in the first chamber, the ambient temperature and the ambient temperature may be changed. Adapted air is injected into the PCB assembly 1a to ensure temperature uniformity of the PCB assembly, and the PCB assembly 1a is transferred to the fourth chamber 40 while maintaining a uniform temperature.

In the fourth chamber 40, the temperature uniformity is checked in the same manner as in the second chamber, and when the temperature uniformity is confirmed, the temperature image 3 having the uniform temperature distribution is recorded / stored.

Thereafter, the controller 41 applies power to the PCB assembly 1a, and acquires a temperature distribution on the front surface of the PCB assembly through the infrared thermal imager 42 while the power is applied. The image is transmitted to the image processor 43 and then recorded / stored.

The image processor 43 subtracts the temperature image 3 and the temperature image 4 (temperature image 4-temperature image 3), and records / stores the relative temperature distribution image obtained as the reference image 2.

The reference image 2 is used as a reference image for determining whether the solder joint of the electronic component is defective.

In addition, the fourth chamber 40 obtains a reference image for determining whether the electronic component is normally operating (function determination). When the electronic product receives a control signal, a minute voltage change occurs, and the controller 41 ) Applies a predetermined control signal to the PCB assembly 1a, and acquires a temperature distribution on the front surface of the PCB assembly through the infrared thermal camera 42 while the control signal is applied. It is transmitted to the processing unit 43 and then recorded / stored.

The image processor 43 subtracts the temperature image 3 and the temperature image 5 (temperature image 5-temperature image 4), and records / stores the relative temperature distribution image obtained as a reference image 3.

The reference image 3 is used as a reference image for determining whether the electronic component is normally operated (function error occurs).

As described above, three reference images of the PCB assembly of the good product are obtained before the inspection of the actual PCB assembly, and the defects are determined by comparing the reference images with the inspection images obtained from the PCB assembly of the inspection target.

In the state in which the reference image is obtained from the good PCB assembly as described above, the inspection is performed in the inspection apparatus shown in FIG. 1 with respect to the PCB assembly which is the actual inspection target. .

First, after placing the PCB assembly 1b to be inspected in the first chamber 10, the air shower device 11 injects air adapted to the ambient temperature to ensure good temperature uniformity to the good PCB assembly. The temperature of the PCB assembly is kept uniform and then transferred to the second chamber 20.

Subsequently, in the second chamber 20, the infrared thermal imaging camera 22 acquires the temperature image 1 ′ on the front surface of the PCB assembly 1b and transfers the temperature image 1 ′ to the image processor 43. In 43), the temperature image 1 'obtained at this time is received and recorded / stored, and a temperature distribution graph (histogram) of the temperature image 1' is obtained to check the temperature uniformity of the PCB assembly 1b.

Here, the PCB assembly having no uniformity is transferred to the first chamber 10 again and then sprayed with air to the air shower device 11 to ensure uniformity, and then re-transmitted to the second chamber 20.

Then, the rear surface of the PCB assembly is heated using the infrared heater 21 for the PCB assembly 1b maintaining the uniform temperature in the second chamber 20, and at this time, the temperature distribution on the front surface of the PCB assembly is infrared thermal image. Acquired through the camera 22, the temperature image 2 'at this time is transmitted to the image processor 43 and then recorded / stored.

The image processor 43 records / stores the relative temperature distribution image as the test image 1 through the subtraction process of the temperature image 1 'and the temperature image 2' (temperature image 2 '-temperature image 1').

In addition, the image processor 43 compares the previously obtained and stored reference image 1 with the inspection image 1 to determine whether the electronic component is mounted. Subtracts the inspection image 1 and the reference image 1 to obtain a temperature obtained at this time. If the histogram 1 of the distribution image 1 is constant, it is determined that all the electronic components are inserted into the PCB assembly 1b as in the inspection principle of FIG.

On the other hand, the PCB assembly (1b) passed in the electronic component mounting test is transferred to the third chamber 30, where the air and the air adapted to the PCB assembly (1b) by injecting the ambient temperature through the air shower device (31) The PCB assembly is transferred to the fourth chamber 40 while maintaining the temperature uniformity of the PCB assembly and maintaining the uniform temperature.

In the fourth chamber 40, the temperature uniformity is checked in the same manner as in the second chamber, and when it is confirmed that the temperature uniformity is secured, the temperature image 3 'having a uniform temperature distribution is recorded / stored.

Thereafter, the controller 41 applies power to the PCB assembly 1b, and acquires a temperature distribution on the front surface of the PCB assembly through the infrared thermal imaging camera 42 while the power is applied. The image is transmitted to the image processor 43 and then recorded / stored.

The image processor 43 subtracts the temperature image 3 'and the temperature image 4' (temperature image 4 '-temperature image 3'), and records / stores the relative temperature distribution image obtained as a test image 2.

In addition, the image processor 43 compares the reference image 2 previously obtained and stored with the inspection image 2 to determine whether the solder joint is defective. Subsequently, the inspection image 2 and the reference image 2 are subtracted. If the histogram 2 of the temperature distribution image 2 is constant, it is determined that the solder joint of the electronic component is good, as in the inspection principle of FIG.

Next, the fourth chamber 40 determines whether the electronic component is normally operated (function determination). The controller 41 applies a predetermined control signal to the PCB assembly 1b, and the control signal is applied. In this state, the temperature distribution on the front surface of the PCB assembly is obtained through the infrared thermal camera 42. At this time, the temperature image 5 'is transferred to the image processor 43 and recorded / stored.

The image processor 43 subtracts the temperature image 3 'and the temperature image 5' (temperature image 5 '-temperature image 3'), and records / stores the relative temperature distribution image obtained as a test image 3.

In addition, the image processor 43 compares the previously obtained and stored reference image 3 with the inspection image 3 to determine whether the electronic component is normally operated. Subsequently, the inspection image 3 and the reference image 3 are subtracted. If the histogram 3 of the obtained temperature distribution image 3 is constant, it is determined that the electronic component control function is good as in the inspection principle of FIG.

The PCB assembly is inspected through a series of reference image acquisition and inspection procedures in turn, and three reference images of the good PCB assembly are obtained before the actual PCB assembly is inspected. The defect is determined by comparing the inspection image obtained from the PCB assembly to be inspected.

In the present invention as described above, after the fourth chamber in the first chamber is arranged in succession, and each of the corresponding equipment for the inspection is installed in each chamber, the PCB assembly from the first chamber to the second chamber, the third While passing through the chamber, the fourth chamber may be subjected to the inspection process as described above collectively.

Eventually, the infrared thermal imaging camera is used to measure the temperature distribution of the PCB assembly under test and compare it with the PCB assembly data of the good product to determine whether the electronic component is mounted, whether the solder joint is defective, or whether the electronic component is normally operated (function It is possible to check whether an error occurs at once.

As described above, according to the apparatus and method for inspecting a PCB assembly using an infrared thermal image according to the present invention, an infrared thermal imaging camera is used to measure a temperature distribution of a PCB assembly to be inspected, and compare it with the PCB assembly data of a good product. It is configured to check whether the electronic parts are mounted, whether the solder joint is defective or not, and whether the electronic parts work normally (function failure occurs). As a result, the overall inspection cost can be reduced.

Also, it is suitable for the inspection of PCB assembly which is more highly integrated due to the characteristics of non-contact inspection, more accurate inspection results can be obtained, and it can make up for the problems of the existing contact inspection technology, and it can greatly contribute to the improvement of PCB assembly quality. It becomes.

In addition, it is possible to easily inspect the test time can be significantly shortened.

Claims (15)

First to fourth chambers through which the PCB assembly is sequentially passed; Temperature equalization means installed in the first chamber to uniformize and maintain the temperature of the PCB assembly disposed in the first chamber; Heating means for uniformly heating the rear surface of the PCB assembly disposed at the inspection position after being transferred from the first chamber in the second chamber; Temperature image acquisition means for measuring a temperature distribution with respect to the front surface of the PCB assembly in the second chamber and providing a temperature image; Temperature equalization means installed in the third chamber to uniformly maintain and maintain the temperature of the PCB assembly transferred from the second chamber; A controller connected to the fourth chamber so as to supply power to the PCB assembly disposed at the inspection position after the transfer from the third chamber and to apply a control signal for the operation of the electronic component mounted on the PCB assembly; Temperature image acquisition means for measuring a temperature distribution with respect to the front surface of the PCB assembly in the fourth chamber and providing a temperature image; An image processor for receiving and processing images transmitted from the temperature image obtaining means, and storing and displaying the received images and processing results thereof; PCB assembly inspection device comprising a. The method according to claim 1, The temperature homogenizing means is a PCB assembly inspection apparatus, characterized in that the air shower device to make the temperature of the PCB assembly uniform by injecting air to the PCB assembly. The method according to claim 1, PCB assembly inspection apparatus, characterized in that the heating means is an infrared heating device. The method according to claim 1, The temperature image acquisition means is a PCB assembly inspection apparatus, characterized in that the infrared thermal camera. PCB inspection method, Arranging a PCB assembly to be inspected in the first chamber to ensure temperature uniformity and to maintain the temperature uniformity; Transferring the PCB assembly having a uniform temperature from the first chamber to the second chamber, and obtaining a temperature image 1 'representing the temperature distribution over the front surface of the PCB assembly using an infrared thermal camera; Recording / storing the temperature image 1 'transmitted from the infrared camera of the second chamber in the image processor, and obtaining a histogram of the temperature image 1' to check temperature uniformity; Evenly heating the back of the PCB assembly confirmed the temperature uniformity in the second chamber with an infrared heating device, and at the same time to obtain a temperature image 2 'representing the temperature distribution on the front surface of the PCB assembly using an infrared thermal camera. Steps; The image processor records / stores the temperature image 2 'transmitted from the infrared thermal camera of the second chamber, and the temperature image data obtained from the infrared thermal camera and the PCB assembly of good quality in advance under the same process and conditions. Comparing the acquired reference image data to determine whether the electronic component is mounted on the PCB assembly to be inspected; PCB assembly inspection method comprising a. The method according to claim 5, The image processing unit records / stores the relative temperature distribution image obtained by subtracting the temperature image 1 'and the temperature image 2' as the test image 1, and then applies the same process and conditions to the test image 1 and the PCB assembly of good quality. PCB assembly inspection method characterized in that it is determined whether the electronic component is mounted on the PCB assembly to be inspected by comparing the reference image 1 obtained in advance. The method according to claim 6, And subtracting the inspection image 1 and the reference image 1 to determine that all the electronic components are mounted on the PCB assembly if the histogram of the temperature distribution image 1 is constant. The method according to claim 5, PCB assembly inspection method characterized in that to make and maintain a uniform temperature of the PCB assembly by injecting air to the PCB assembly using an air shower device in the first chamber. The method according to claim 5, A temperature uniformity securing step of transferring the PCB assembly heated in the second chamber to the third chamber and making the temperature uniform and maintaining the temperature; Transferring the PCB assembly having a uniform temperature from the third chamber to the fourth chamber, and then obtaining a temperature image 3 'representing the temperature distribution over the front surface of the PCB assembly using an infrared thermal camera; Recording / storing the temperature image 3 'transferred from the infrared thermal camera of the fourth chamber in the image processing unit, and obtaining a histogram of the temperature image 3' to check temperature uniformity; Acquiring a temperature image 4 'representing the temperature distribution of the front surface of the PCB assembly using an infrared thermal camera while simultaneously applying power from the controller to the PCB assembly in which the temperature uniformity is confirmed in the fourth chamber; The image processing unit records / stores the temperature image 4 'transmitted from the infrared thermal camera of the fourth chamber, and the temperature image data obtained from the infrared thermal camera and the good PCB assembly under the same process and conditions in advance. Comparing the obtained reference image data to determine whether a solder joint of the PCB assembly to be inspected is defective; PCB assembly inspection method comprising a further. The method according to claim 9, The relative temperature distribution image obtained by subtracting the temperature image 3 'and the temperature image 4' by the image processor is recorded / stored as the test image 2, and then the same process and conditions are applied to the test image 2 and the PCB assembly of good quality. Comparing the reference image 2 obtained in advance under the PCB assembly inspection method characterized in that it is determined whether the solder joint to the inspection of the PCB assembly. The method according to claim 10, And subtracting the inspection image 2 and the reference image 2 to determine that the solder joint of the electronic component is good if the histogram of the temperature distribution image 2 is constant. The method according to claim 9, PCB assembly inspection method characterized in that to maintain the temperature of the PCB assembly uniformly by injecting air to the PCB assembly using an air shower device in the third chamber. The method according to claim 9, Acquiring a control signal for the operation of the electronic component mounted on the PCB assembly from the controller in the fourth chamber and acquiring a temperature image 5 'representing the temperature distribution on the front surface of the PCB assembly using an infrared thermal camera; ; The image processing unit records / stores the temperature image 5 'transferred from the infrared thermal camera of the fourth chamber, and the temperature image data obtained from the infrared thermal camera and the PCB assembly of good quality in advance under the same process and conditions. Comparing the obtained reference image data to determine whether the electronic component is normally operated with respect to the PCB assembly to be inspected; PCB assembly inspection method comprising a further. The method according to claim 13, After recording / saving the relative temperature distribution image obtained by subtracting the temperature image 3 'and the temperature image 5' by the image processor as the test image 3, the same process and conditions are applied to the test image 3 and the good PCB assembly. PCB reference inspection method characterized in that it determines whether the normal operation of the electronic component for the PCB assembly to be inspected by comparing the reference image 3 obtained in advance. The method according to claim 14, And subtracting the inspection image 3 and the reference image 3 to determine that the electronic component control function is good if the histogram of the temperature distribution image 3 obtained at this time is constant.

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