KR101640936B1 - Method of Analyzing Defect in Printing Process and Computer Readable Media Storing The Same - Google Patents

Abstract

Disclosed is a method for poor analysis of a printing process and a computer-readable storage medium in which such methods are programmed and stored. The failure analysis method of the printing process includes the steps of setting a target condition for inspection on a solder paste attached to a printed circuit board, analyzing a failure type of the solder paste adhered to the printed circuit board, Selecting a type of defective according to the defective type, analyzing a defective phenomenon according to the selected defective type, correcting the defective due to the defective phenomenon, and analyzing the resultant value . Therefore, it is possible to improve the reliability of the failure analysis method of the printing process, systematize the cause of the defect according to the defect type, and easily take the defect remedial action.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method of analyzing a defect in a printing process and a computer-

The present invention relates to a failure analysis method of a printing process and a computer-readable storage medium in which the method is programmed and stored. More particularly, the present invention relates to a failure analysis method of a printing process in a surface mounting process, Lt; / RTI >

In general, many electronic products are formed by mounting various components on a printed circuit board (PCB). On the other hand, with miniaturization of electronic products, parts for forming electronic products have also been miniaturized. Accordingly, there is a possibility that defects may occur when mounting these components on a printed circuit board, Is being tested for defects.

That is, a surface mounting process (SMT) in which components are mounted on a printed circuit board includes a printing process for applying a solder paste onto a printed circuit board (PCB), a solder paste for inspecting the result of the printing process A solder paste inspection (SPI) process, a mounting process for disposing the device on the solder paste, a pre-optical inspection process (BOI) for inspecting the result of the mounting process, a solder paste And a post-optical inspection process (AOI: After Optical Inspection) for inspecting the result of the reflow process.

A printing process for applying a solder paste on a printed circuit board includes disposing a stencil, which is a frame plate having holes in a region corresponding to a pad region that is to be electrically contacted with the device, on a printed circuit board, After the upper part of the stencil is pressed by a blade (squeeze) and moved, a pad corresponding to the hole is formed.

Thereafter, through the solder paste inspecting process, for example, whether the solder paste is applied in the form of a pad (i.e., whether the solder paste has been applied over the entire planar shape of the hole), whether the volume of the solder paste is less than the volume of the pad (I.e., whether the solder paste has been applied to a thickness larger than the thickness of the stencil), or the like, or the like, if the volume of the solder paste is larger than the volume of the designed pad.

FIG. 1 is a diagram showing a setting example of a conventional target condition. Conventionally, a difference value between a maximum value and a minimum value specified by the standard as the average histogram tolerance value of the selected good sample data, that is, the range of the quality allowance in industrial mass production, is set as a target reference, Although optimization has been performed, there is a lack of standard setting and reliability, and a new method is required.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a failure analysis method of a printing process capable of improving such reliability.

Another problem to be solved by the present invention is to provide a computer-readable storage medium in which a failure analysis method of the printing process is programmed and stored.

According to an exemplary embodiment of the present invention, a failure analysis method for a printing process includes analyzing a failure type of a solder paste attached to a printed circuit board and displaying the analysis process, selecting a failure type according to the failure type Analyzing a failure phenomenon according to the selected failure type, displaying the analysis process, and displaying a failure check portion according to the failure phenomenon.

For example, the failure analysis method of the printing process may further include setting a target condition for the solder paste inspection before analyzing the failure type and displaying the analysis process.

For example, the failure type of the solder paste may include at least one of excessive, insufficient, positional, shape abnormal, bridging, and height.

If two or more of the defect types are generated, the defect having the maximum frequency may be treated as a representative defect. If two or more defect types are generated and the defect is generated in the same quantity, It can be treated as representative defective by priority.

For example, the defective phenomenon may include the position and deviation of the defects, the periodicity, and the occurrence frequency depending on the printing direction.

On the other hand, the defect check portions according to the excessive type, insufficient, position abnormal, shape abnormal, bridging and height are classified into categories and systemized .

The step of displaying the defect check part according to the defect phenomenon may display an improvement measure for at least one of hardware and software, and the hardware and software may be a measure for at least one of a printing process and a solder paste test .
The failure analysis method of the printing process may further include a step of performing an analysis of the defect check part after displaying the defect check part according to the defect phenomenon and then resetting the target condition according to the product group The method comprising the steps of:
According to another exemplary embodiment of the present invention, a failure analysis method for a printing process includes the steps of: selecting a failure type according to a failure type of a solder paste attached to a printed circuit board; analyzing a failure phenomenon according to the selected failure type; And displaying a defect check portion according to the defect phenomenon.
For example, the failure type of the solder paste may include at least one of excessive, insufficient, positional, shape, abnormal, bridging, and height. have.
The step of displaying the defect check part according to the defect phenomenon may display an improvement measure for at least one of hardware and software, and the hardware and software may be a measure for at least one of a printing process and a solder paste test .

According to the present invention, it is possible to improve the reliability of the failure analysis method of the printing process, to systematize the failure occurrence factors according to the failure type, and to easily take defective improvement measures.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that this invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprising" or "having ", and the like, are intended to specify the presence of stated features, integers, steps, operations, elements, parts, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

In addition, a component describing a function may mean a combination of components performing the process for performing the function, and may also be represented as one component by combining the functions of the components.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

2 is a flowchart of a failure analysis method of a printing process according to an embodiment of the present invention.

Referring to FIG. 2, according to the defect analysis method of the printing process according to the embodiment of the present invention, a target condition for inspection is set in the solder paste attached to the printed circuit board (step S101) The defective type of the solder paste attached to the circuit board is analyzed (step S102), a defect kind according to the defect type is selected (step S103), a defect phenomenon according to the selected defect kind is analyzed (step S104) After correcting the failure due to the bad phenomenon (step S105), analysis of the result is performed (step S106). Preferably, after the analysis of the result is performed, comparison analysis is performed before and after the improvement (step S107), and the target condition can be set again.

Hereinafter, a failure analysis method of the printing process according to the present invention will be described in detail.

First, as a target condition, a target condition that primarily conforms to the IPC standard is set (step S101). This setting can be automated. According to the IPC standard, the standard for the standard pad should be set as the primary target condition, thereby establishing some unclassified criteria of the customer and giving credibility and convenience to the setting of the standard.

Next, the defect type is analyzed so that the result of the accumulation of the defective quantity can be seen at a glance (step S102). In the conventional case, the presently implemented trend can be confirmed only for a single result. In the present invention, however, the cumulative result of the defective quantity can be grasped at a glance, and the tendency of defects can be grasped. For example, in the case of such a defective type, excessive solder paste is applied over a predetermined amount, insufficient solder paste is applied at a predetermined amount or less, position such as deflection of the solder paste, Bridging between the two pads, bridging between the two pads, and a height equal to or greater than the height of the solder paste and the height of the solder paste.

For example, when two or more defect types are generated, a defect having a maximum frequency is treated as a representative defect, and when two or more defect types are generated and generated in the same quantity, the priority set in the vision parameter It can be treated as a representative defect.

By monitoring the defects generated in the defect type analysis stage in real time by type, it is possible to analyze the present state by the defect type and whether it is a problem with the current model group.

FIG. 3 is a view showing a display screen in the failure type analysis process. As shown in FIG. 3, the accumulated data are shown according to the time of each failure type, namely, overdelivery, non-payment, deflection, shape abnormality, domination and low deposit. In the graph showing each defect, the X-axis shows the time, and the Y-axis shows the tolerance value, which can be set by the user.

Next, a defect type according to the defect type is selected (step S103). At this time, in order to grasp the general problem of the bad type data, the complexity of selecting the functions is reduced, and the selection type bad data and the analysis tool are accessed with one-click by selecting the bad statistics graph.

Next, the defective phenomenon according to the selected kind of defects is analyzed (step S104).

FIG. 4 is a view showing a display screen in the process of analyzing a failure phenomenon. As shown in FIG. 4, when the failure analysis method of the printing process of the present invention is programmed, it is preferable to select a PCB view and a histogram to conduct simultaneous analysis. In addition, it is preferable to reduce the hassle of function selection for defect analysis by simplifying the layout of the tool according to the function selection of the user.

In analyzing the bad phenomenon of overdue or non-paying, the bad data is calculated by the volume trend and volume histogram of the value trend, and the position and deviation of defects generated by dividing before and after printing, the periodicity, the printing direction of the solder paste And the frequency of occurrence according to age. Particularly, in the case of non-payment, it is necessary to select a specific pad and analyze only the selected portion intensively.

At the time of analyzing the defective phenomenon with respect to morphological abnormality, defective data is calculated in a three-dimensional shape and a two-dimensional shape, and the defective data is analyzed before and after printing to analyze whether there is a defect position and a pattern or periodicity. It also analyzes environmental factors, analyzes current temperature, print parameters, and operator habits and analyzes defective solder paste images.

In analyzing the failure phenomenon with respect to position error, the reference coordinate system of each printer is confirmed and set the same. The defective data is calculated by the offset trend X, Y and histogram, and the offset is corrected by dividing the data before and after printing. In addition, the two-dimensional image of the same selected pad should be divided before and after printing to always analyze the correction deviation.

In analyzing the bad phenomenon and height abnormality of the bridge, the bad data is calculated by the volume trend of the value trend and the volume histogram, and the position and deviation of defects generated by dividing before and after printing, periodicity, printing of the solder paste And the frequency of occurrence according to the direction. Particularly, in analyzing the height abnormality, it is preferable to analyze the average height using the SPC chart, and the point for the specific position is analyzed.

Thereafter, the defect according to the defective phenomenon is corrected (step S105). At this time, it is desirable to classify the defective type as an excessive, insufficient, position, shape abnormality, bridging and height improvement measures according to the category.

FIG. 5 is a view showing a display screen captured in the defect improvement measure process. Fig. 5 shows the case of, for example, overcharge. That is, in the case of overcharge, the hardware checkpoint first checks the flatness of the clamp and the table when the bad patterns of the overdischarge are shifted in the same direction, and checks whether the squeeze blade is damaged. Also, check the cleaning cycle, condition, or pressure if the software checkpoint is a periodic pattern of bad patterns.

In the case of non-payment, if bad patterns occur in BGA or QFP as a hardware checkpoint, make sure that the amount of vacuum, PCB and backup block position match. Also, with software checkpoints, if the bad pattern is periodic, check the cleaning cycle, condition or pressure, and check the printing speed of the solder paste and the separation speed of the stencil.

In case of abnormal shape, check the state of the solder paste at the checkpoint of the hardware and check the agitation according to the periodic time. Also check the print pressure of the solder paste and the print separation speed of the stencil with a software checkpoint. In addition, there is a need to check the temperature and humidity inside the printer due to environmental factors, and it is necessary to check whether the long time exposed printed solder residue is used without stirring.

In the case of a position fault, check the PCB clamping condition and the clamping condition of the stencil, if the bad check patterns occur sporadically. Also check the offset calibration status with software checkpoints.

In the case of bridging, check the flatness of the clamp and table if the defective patterns are biased in the same direction. Also, check the stencil for damage. In addition, checkpoints of the software, periodically check the cleaning cycle, condition, or pressure if the bad pattern is periodic.

Also, in the case of a bad height, check the hardware checkpoint to see if the squeeze is properly attached, and also check the stencil for damage. Also check the print speed of the solder paste and the separation speed of the stencil with a software checkpoint.

In this manner, the failure analysis method of the printing process performs an analysis on the result of the analysis, and then re-sets the target condition according to the product group by comparing before and after the improvement (step S107).

Meanwhile, the above-described series of processes can be stored in a computer-readable storage medium, which is programmed as shown in the drawings. Such storage media includes, but is not limited to, any type of floppy disk, optical disk, CD-ROMs, Marked Optic Disk, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, ASICs, Type media. The stored program can be read and operated by the inspection apparatus and directly stored in the inspection apparatus to drive the inspection apparatus.

The algorithms and operations described herein are not related to any particular computer or other system. Various general purpose systems may be used as the programs associated with the disclosure herein or may be more readily formed to perform more specialized systems to perform the required methods. The architecture required for the diversity of these systems will be apparent to those skilled in the art or similar technology. Moreover, the present invention has not been described with reference to any particular programming language. The invention described herein as various programming languages can be realized.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, the foregoing description and drawings are to be regarded as illustrative rather than limiting of the present invention.

FIG. 1 is a diagram showing a setting example of a conventional target condition.

2 is a flowchart of a failure analysis method of a printing process according to an embodiment of the present invention.

FIG. 3 is a view showing a display screen in the failure type analysis process.

FIG. 4 is a view showing a display screen in the process of analyzing a failure phenomenon.

FIG. 5 is a view showing a display screen captured in the defect improvement measure process.

Claims (13)

Analyzing the failure type of the solder paste attached to the printed circuit board and displaying the analysis process; Selecting a defect type according to the defect type; Analyzing a failure phenomenon caused by a printing process failure according to the selected failure type and displaying the analysis process; And And displaying a defect check portion of the printer according to the defect phenomenon. The method according to claim 1, Before the step of analyzing the defect type and displaying the analysis process And setting a target condition for the solder paste inspection. The method of claim 1, wherein the failure type of the solder paste includes at least one of excess, insufficient, position, shape, over, bridging, Wherein the printing method comprises the steps of: 4. The method according to claim 3, wherein when two or more of the defect types are generated, the defect having the maximum frequency is treated as representative defect. 5. The method according to claim 4, wherein if two or more of the defect types are generated and are generated in the same quantity, the representative defectives are processed according to the priority set in the vision parameter . The method according to claim 1, wherein the defect phenomenon includes a defect position, a deviation, a periodicity, and a frequency of occurrence according to a printing direction. Claim 7 has been abandoned due to the setting registration fee. 4. The method according to claim 3, wherein the defect check portion according to the defect type is insufficient, insufficient, abnormal position, shape abnormality, bridging and height, Wherein the printing method is classified into a printing method and a printing method. The method according to claim 1, The step of displaying the defect check portion of the printer according to the defect phenomenon may include: And displaying an improvement measure for at least one of hardware and software of the printer. The method according to claim 1, After the step of displaying the defect check portion of the printer according to the defect phenomenon Further comprising the step of resetting the target condition according to the product group after performing the analysis on the defect check part and comparing the before and after the improvement. A computer-readable storage medium on which a failure analysis method of a printing process according to any one of claims 1 to 9 is programmed and stored. delete delete delete

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