Inspection method and device

An inspection method is provided herein. The inspection method is adapted for an inspection device. The inspection method includes: optically scanning an examining target for generating a scanned image; reconstructing the scanned image for a reconstructed volume; adjusting a slicing direction associated with the examining target for slicing the reconstructed volume into a sliced image; inspecting the sliced image for analyzing one or more features of the examining target; and outputting an inspection result of the examining target.

BACKGROUND

Field of Invention

The present invention relates to inspection technique. More particularly, the present invention relates to method and device for inspection.

Description of Related Art

Conventional inline 3D AXI (Advanced eXtensible Interface) equipments usually use horizontally sliced images in the inspection algorithm. A scanned image of examining target may be captured for inspection.

In operation, if the examining target has no significant feature in the horizontal slice, it could lead to poor efficiency of inspection algorithm, and therefore the inspection result may be difficult to be reviewed in a repair station.

SUMMARY

In one aspect, the present disclosure is related to an inspection method including the following steps: optically scanning an examining target for generating a scanned image; reconstructing the scanned image for a reconstructed volume; adjusting a slicing direction associated with the examining target for slicing the reconstructed volume into a sliced image, wherein the slicing direction comprises a non-horizontal slicing direction; inspecting the sliced image for analyzing one or more features of the examining target; and outputting an inspection result of the examining target.

In another aspect, the present disclosure is related to an inspection device. The inspection device includes a scanning device and a computing device. The scanning device is configured to optically scan an examining target for generating a scanned image. The computing device is connected with the scanning device and comprises a processing unit and a storage unit. The processing unit is configured to execute the following instructions: reconstructing the scanned image for a reconstructed volume; adjusting a slicing direction associated with the examining target for slicing the reconstructed volume into a sliced image, wherein the slicing direction comprises a non-horizontal slicing direction; inspecting the sliced image for analyzing one or more features of the examining target; and outputting an inspection result of the examining target to an output device in which the storage unit is configured to store the scanned image, the reconstructed volume and the sliced image.

By applying the techniques disclosed in the present disclosure, a non-horizontal slice of an examining target can provide some characteristics and significant features of the examining target. Therefore, the inspection performance may be improved and the inspection result may be more easily reviewed in repair station.

DETAILED DESCRIPTION

FIG. 1is a schematic diagram illustrating an inspection device100according to one embodiment of the present disclosure. The inspection device100comprises a scanning device120, a computing device140, an input device160and an output device180. The scanning device120further includes an X-ray generator122, a substrate holding unit124and an X-ray detector126. The computing device140comprises a processing unit142and a storage unit144.

The substrate holding unit124holds an examining target128to be inspected. The X-ray generator122generates X-ray. The X-ray is controlled by, for example, an X-ray source control mechanism, and irradiates the examining target128. The examining target128is moved by the substrate holding unit124, and is arranged between the radiation ray generator122and the X-ray detector126.

The X-ray detector126is for detecting the X-ray outputted from the X-ray generator122and transmitted through the examining target128. The X-rays passing through the examining target128are photographed as an image by the X-ray detector126. Hence, a “scanned image” of the examining target128is generated by the X-ray detector126. In some embodiments, the X-ray detector126may be an image intensifier tube or a FPD (flat panel detector), but not limited thereto. The scanned image is sent to the computing device140and stored in the storage unit144.

The computing device140includes the processing unit142and the storage unit144. The processing unit142further includes a reconstruction portion152, a slicing portion154and an inspection portion156.

In order to efficiently inspect the examining target128, the inspection device100extracts some features from the examining target128. The processing unit142controls the reconstruction portion152to receive the scanned image outputted from the X-ray detector126and generates a “reconstructed volume” including, for example, a three-dimensional shape of the examining target128. In some applications, the reconstructed volume is also referred as “3D image”. In some embodiments, the method of reconstructing the scanned image for the reconstructed volume comprises shift-and-add or CT (computed tomography), but not limited thereto.

In addition, the processing unit142further controls the slicing portion154to slice the reconstructed volume into a “sliced image”. In some embodiments, the sliced image is a horizontal, vertical or arbitrary cross-section cut out from the reconstructed volume. The slicing direction of the sliced image is determined according to characteristics of the examining target128, which will be described later. The processing unit142then controls the inspection portion156to inspect the sliced image for analyzing one or more features of the examining target128so as to output the inspection results of the examining target128to the output device180.

The input device160is capable of accepting instructions and the like from user. The output device180is capable of outputting inspection results, scanned image, reconstructed volume, sliced image and the like to outside of the inspection device100. In some embodiments, the input device160is a keyboard, and the output device180is a monitor.

In some embodiments, the computing device140is a PC (Personal Computer). The storage unit144is configured to store the scanned image, reconstructed volume, sliced image, inspection result and the like. The storage unit144merely needs to be able to store data, and is configured by a storage device such as RAM (Random Access Memory) and HDD (Hard Disc Drive), but not limited thereto.

In some embodiments, the inspection portion156inspects the symmetry of the slice image and outputs an abnormal result when the symmetry of the sliced image is under a predetermined threshold value.

FIG. 2Ais a schematic diagram illustrating reconstructed volumes and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume220corresponds to a solder ball with head-in-pillow (HIP) defect, and reconstructed volume240corresponds to a solder ball without HIP defect. In addition, sliced image222is the horizontal slice of the reconstructed volume220, and sliced image242is the horizontal slice of the reconstructed volume240. As shown inFIG. 2A, it is hardly to distinguish HIP defect from a normal solder ball by the horizontal slices, since there is no clue in the horizontal slice.

FIG. 2Bis a schematic diagram illustrating reconstructed volumes and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume220corresponds to a solder ball with head-in-pillow (HIP) defect, and reconstructed volume240corresponds to a solder ball without HIP defect. In addition, sliced image224is the vertical slice of the reconstructed volume220, and sliced image244is the vertical slice of the reconstructed volume240.

Since the sliced image224and the sliced image244contain some vertical characteristics or information, so as to make HIP defect becomes more apparently. In other words, when the inspection device100inspects HIP defect of the examining target128, the processing unit142may control the slicing portion154to cut a vertical slice of the reconstructed volume so as to speed up the determination of HIP defect.

FIG. 3is a schematic diagram illustrating sliced images according to one embodiment of the present disclosure. In this embodiment, sliced image320corresponds to a connector with insufficient insertion defect, and sliced image340corresponds to a normal connector. It is noteworthy that both of the sliced image320and the slice image340are vertically sliced. As shown inFIG. 3, press-fit pins322,342are pressed into the PCB through-holes324,344by applying mechanical force, and it is not easy to measure the insertion depth unless measuring the pin length in vertical slice.

In other words, when the inspection device100inspects insufficient insertion defect of the examining target128, the processing unit142may control the slicing portion154to cut a vertical slice of the reconstructed volume so as to speed up the determination of insufficient insertion defect.

In some embodiments, the inspection portion156may use multiple vertical slices to evaluate solder quality of package component. For example, vertical slices represent solder thickness profile, and therefore the inspection portion156may use the thickness profile to extract proper features, such as gradient, curvature, shape descriptor, geometric characteristics and the like. With the features of the solder, it is possible to create some inspection rules for quality determination, so as to speed up the determination of solder quality. Hence, in one embodiment, the inspection portion156may output the inspection result to the output device180, such as in sufficient solder, open defect, excessive solder, good solder or NG solder. In another embodiment, the sliced images are displayed on the output device180for visual determination of solder quality by examiner.

FIG. 4Ais a schematic diagram illustrating reconstructed volumes and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume420corresponds to a component with open defect, and reconstructed volume440corresponds to a component without open defect. In addition, sliced image422is the horizontal slice of the reconstructed volume420, and sliced image442is the horizontal slice of the reconstructed volume440.

As shown inFIG. 4A, it is hardly to detect open defect from normal examining target by only using the horizontal slice, such as the sliced image422and the sliced image442, since there is no clue in the horizontal slice.

FIG. 4Bis a schematic diagram illustrating reconstructed volumes and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume420corresponds to a component with open defect, and reconstructed volume440corresponds to a component without open defect. In addition, sliced image424is the vertical slice of the reconstructed volume420, and sliced image444is the vertical slice of the reconstructed volume440.

For example, the inspection portion156may inspect open defect according to the shape of profile. As shown inFIG. 4B, if the shape is climbing from ground to the top like a hill, such as the edge of the sliced image444, it means that the solder connects with the component well, and the open defect does not exist.

FIG. 5is a schematic diagram illustrating a reconstructed volume and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume520corresponds to a component with non-wetting open defect. In addition, sliced images522A-522C are the horizontal slices of the reconstructed volume520, and sliced image524is the vertical slice of the reconstructed volume520.

As shown inFIG. 5, there is no significant feature in the horizontal slices522A-522C. Therefore, it is hard for the inspection portion156to determine non-wetting open defect according to the horizontal slices522A-522C.

However, as shown in the sliced image524, when non-wetting open defect occurs in the examining target128, there are two blobs of solder on vertical cross section. Therefore, the inspection portion156may detect non-wetting open defect with solder connectivity feature by using the vertical slice. In other words, when the inspection device100inspects non-wetting open defect of the examining target128, the processing unit142may control the slicing portion154to cut a vertical slice of the reconstructed volume so as to speed up the determination of non-wetting open defect.

FIG. 6is a schematic diagram illustrating a reconstructed volume and corresponding sliced images according to one embodiment of the present disclosure. In this embodiment, reconstructed volume620corresponds to a component with short defect. As shown inFIG. 6, solder ball622and solder ball624are shorted by redundant solder626. In addition, sliced image640is the horizontal slice of the reconstructed volume620, and sliced image660is the vertical slice of the reconstructed volume620.

It is difficult to inspect the short defect by using horizontal slice, especially when the redundant solder626is not located in the same height with the solder ball622and the solder ball624. However, vertical slice may directly reflect some significant features of short defect, so as to let the inspection portion156detect short defect successfully.

In some embodiments, the inspection device100further includes a drive mechanism130to transfer the examining target128. Hence, the inspection portion156inspects the sliced image so as to detect whether the examining target128is abnormal in real time during the examining target128on drive mechanism130.

Reference is now made toFIG. 7.FIG. 7is a flow chart of an inspection method in accordance with one embodiment of the present disclosure. The inspection method may be implemented by the inspection device100illustrated inFIG. 1, but is not limited in this regard. For convenience and clarity, it is assumed that the inspection method is implemented by the inspection device100illustrated inFIG. 1.

In step702, the scanning device120scans the examining target128so as to generate the scanned image. In step704, the processing unit142controls the reconstruction portion152so as to reconstruct the reconstructed volume from the scanned image. In step706, the processing unit142adjusts the slicing direction of the slicing portion154according to features of the examining target128, so as to slice the reconstructed volume into the sliced image.

In step708, the inspection portion156inspects the sliced image according to one or more features of the examining target128stored in the storage unit144, so as to generate the inspection result of the examining target128. In step710, the computing device140outputs the inspection result of the examining target128to the output device180.

By applying the techniques disclosed in the present disclosure, a non-horizontal slice of an examining target can provide some characteristics and significant features of the examining target. Therefore, the inspection performance may be improved and the inspection result may be more easily reviewed in repair station.