WO2022097866A1

WO2022097866A1 - Method for measuring warpage degree of product, and apparatus for performing same

Info

Publication number: WO2022097866A1
Application number: PCT/KR2021/007283
Authority: WO
Inventors: 윤기욱; 김기태; 안정민
Original assignee: 라온피플 주식회사
Priority date: 2020-11-05
Filing date: 2021-06-10
Publication date: 2022-05-12
Also published as: KR20220060792A

Abstract

A method for measuring the warpage degree of a product comprises the steps of: measuring the height, excluding a region of one part, of the surface of a target product, and using the measured height to estimate the height of the region of one part excluded during height measurement; and measuring the warpage degree of the target product by using the measured height and the estimated height.

Description

A method for measuring the degree of warpage of a product and an apparatus for performing the same

Embodiments disclosed herein relate to a method and apparatus for measuring a warpage degree of a product through height measurement using a 3D line profiler.

This application claims priority based on November 05, 2020, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.

In the production of products such as PCB substrates and IC chips, it is important to keep the surface of the product flat in order to reduce the defect rate and increase reliability. Accordingly, the quality of the product can be managed by measuring the degree of warpage of each product during the production process and shipping the product only when the measured degree of warpage satisfies a certain standard.

For example, during a production process performed by placing a plurality of IC chips on a tray specified by the Joint Electron Device Engineering Council (JEDEC) as a standard, the degree of warpage of the surface of the IC chips using a 3D line profiler can be measured and whether to ship or not according to the measured degree of warpage.

As such, in measuring the degree of warpage of a plurality of products in the production process, if a technology capable of increasing the measurement speed while maintaining the accuracy at a high level is developed, production efficiency may be increased.

In relation to this, Japanese Patent No. 5073943, a prior art document, discloses a method of measuring the distortion distribution of a silicon wafer by receiving scattered light. Determination of the distortion distribution of the wafer surface from the energy distribution is disclosed.

On the other hand, the above-mentioned background art is technical information that the inventor possessed for the purpose of derivation of the present invention or acquired during the derivation process of the present invention, and it cannot be said that it is necessarily known technology disclosed to the general public before the filing of the present invention. .

Embodiments disclosed herein are intended to provide a method and apparatus capable of maintaining high accuracy while increasing the measurement speed in measuring the degree of warpage of a product through height measurement using a 3D line profiler.

As a technical means for achieving the above-described technical problem, according to one embodiment, the method of measuring the degree of warpage of the product measures the height except for a partial area with respect to the surface of the target product, and uses the measured height and estimating the height of the partial region excluded from measuring the height and measuring the degree of bending of the target product using the measured height and the estimated height.

According to another embodiment, as a computer-readable recording medium on which a program for performing a method of measuring the degree of warpage of a product is recorded, the method of measuring the degree of warpage of the product is performed except for a partial area on the surface of the product. Measuring the height, estimating the height of the partial region excluded from the height measurement using the measured height, and measuring the degree of bending of the target product using the measured height and the estimated height may include.

According to another embodiment, the computing device for measuring the degree of bending of the product receives the result of measuring the height with respect to the surface of the target product from the scanning device for measuring the height, and the result of measuring the degree of bending of the target product By executing the input and output unit for outputting a program and data for measuring the degree of warpage of the target product and a storage section and executing the program, to control the driving of the scanning device to measure the degree of warpage of the target product a control unit for controlling the scanning device to measure the height of the surface of the target product except for a partial area, and using the measured height to measure the height of the excluded partial area , and the degree of bending of the target product may be measured using the measured height and the estimated height.

According to any one of the above-mentioned problem solving means, by measuring the height of only a part of the surface of the target product and estimating the height of the remaining areas based on the measured height, the target product with high accuracy while increasing the measurement speed An effect that can measure the degree of warpage can be expected.

Effects obtainable in the disclosed embodiments are not limited to the above-mentioned effects, and other effects not mentioned are clear to those of ordinary skill in the art to which the embodiments disclosed from the description below belong. can be understood clearly.

1 is a view showing a bending degree measuring system according to an embodiment.

FIG. 2 is a diagram illustrating a detailed configuration of a computing device for measuring a degree of warpage of a product included in the system of FIG. 1 .

3 is a view for explaining a process of measuring and estimating the height of the surface of a target product, and calculating a height value for a reference point using the result according to an exemplary embodiment;

4 to 6 are flowcharts for explaining a method of measuring a degree of warpage of a product according to embodiments.

Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. The embodiments described below may be modified and implemented in various different forms. In order to more clearly describe the characteristics of the embodiments, detailed descriptions of matters widely known to those of ordinary skill in the art to which the following embodiments belong are omitted. In addition, in the drawings, parts irrelevant to the description of the embodiments are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a component is said to be "connected" with another component, it includes not only the case where it is 'directly connected', but also the case where it is 'connected with another component in between'. In addition, when a component "includes" a component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

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

1 is a view showing a bending degree measuring system according to an embodiment. Referring to FIG. 1 , the bending degree measuring system according to an embodiment may include a computing device 100 and a 3D line profiler 200 .

The 3D line profiler 200 is a device for measuring the height of the surface of the target product. According to an embodiment, the 3D line profiler 200 may measure the height by scanning a laser line on the surface of the target product line by line according to a predetermined scan direction. Of course, other types of devices capable of measuring the height of the product surface in a scan manner may be used.

1, the bending degree measuring system measures the degree of bending of the target products (11, 12, 13) in a state in which a plurality of target products (11, 12, 13) is placed on the tray (1). can In this case, the

target products

11 , 12 , and 13 may be electronic devices such as PCB chips or IC chips. The tray 1 on which the

target products

11, 12, 13 is placed is a mechanism for placing the

target products

11, 12, 13 at regular intervals for process automation, and the tray 1 contains the target products. (11, 12, 13) may be formed with a groove or guide projection for lifting in a fixed state. According to one embodiment, the tray 1 of the standard set by JEDEC may be used.

The 3D line profiler 200 determines the height of the surface of the

target products

11 , 12 , 13 in a state in which the

target products

11 , 12 , and 13 are placed on the tray 1 according to the control of the computing device 100 . measure A method for the 3D line profiler 200 to measure the height of the surface of the

target products

11, 12, 13 will be described in detail along with the configuration and operation of the computing device 100 with reference to FIGS. 2 and 3 below. do.

The computing device 100 controls the 3D line profiler 200 to measure the height of the surface of the

target product

11 , 12 , 13 , and receives the height measured from the 3D line profiler 200 and uses it Estimate the height and measure the degree of bending.

Hereinafter, it is assumed that the degree of bending of the target product 12 located in the center of the tray 1 is measured and a detailed process will be described.

The computing device 100 may set at least two reference points for measuring the degree of bending on the surface of the target product 12 , and referring to FIG. 1 , the computing device 100 is on the surface of the target product 12 . Four reference points (A1-A4) were established. 1 shows an example in which reference points A1-A4 are set one at the corners of the target product 12 , the computing device 100 is located at different locations in consideration of various situations such as the type of the target product 12 . Reference points can also be set.

The computing device 100 calculates a height value for each of the reference points A1-A4 through height measurement using the 3D line profiler 200, and compares the height values of the reference points A1-A4 with each other. It is possible to measure the degree of warpage of the target product (12).

According to an embodiment, the computing device 100 may measure (determine) the degree of bending based on a difference in height values between the reference points A1 to A4. For example, if the difference between the maximum value and the minimum value among the height values of the reference points A1-A4 exceeds a preset threshold, the computing device 100 determines that the degree of warpage is 'bad', otherwise the degree of warpage is It can be judged as 'good'. Or, for example, the computing device 100 calculates the average of the height values of the reference points A1-A4, and the absolute value of the difference between the calculated average and the height values of each of the reference points A1-A4 is preset. If the threshold is exceeded, the degree of warpage may be judged to be 'bad', otherwise, the degree of warpage may be determined to be 'good'. Or, for example, the computing device 100 measures the degree of horizontal bending by comparing the difference in height values between the left reference points A1 and A3 and the right reference points A2 and A4 with a preset threshold, and the upper reference point A1, The degree of vertical bending may be measured by comparing the difference in height between A2) and the lower reference points A3 and A4 with a preset threshold. In addition, the computing device 100 may measure the degree of bending of the target product 12 based on the height values of the reference points A1-A4 according to various standards or conditions.

A method in which the computing device 100 calculates height values for the reference points A1 to A4 will be described in detail below with reference to FIGS. 2 and 3 .

FIG. 2 is a diagram illustrating a detailed configuration of a computing device for measuring a degree of warpage of a product included in the system of FIG. 1 . Referring to FIG. 2 , the computing device 100 may include an input/output unit 110 , a control unit 120 , and a storage unit 130 .

The input/output unit 110 receives an input for control from the user or receives a height measurement result from the 3D line profiler 200 , and outputs a control command to the 3D line profiler 200 or a target product 12 to the user It is a configuration for outputting the measurement result of the degree of bending. The input/output unit 110 may include a configuration for receiving an input such as a keyboard, hard buttons, and a touch screen, a configuration for output such as an LCD panel, and a configuration for input/output such as a wired/wireless communication port.

The controller 120 is a configuration including at least one processor such as a CPU, and controls the overall operation of the computing device 100 . In particular, the control unit 120 may measure the degree of warpage of the target product 12 through the control of the 3D line profiler 200 by executing a program stored in the storage unit 130 to be described later. The control unit 120 measures the height of the surface of the target product 12 by controlling the 3D line profiler 200, and the specific process of measuring the degree of warpage of the target product 12 using the height measurement result will be described below. It will be described in detail with reference to FIG. 3 .

The storage unit 130 is a configuration in which data and programs can be stored, and may be configured to include at least one of various types of memories such as RAM, HDD, and SSD. A program for measuring the degree of warpage of the product may be stored in the storage unit 130 , and data such as a threshold value for determining the degree of warpage may be stored together.

Hereinafter, a process in which the computing device 100 and the 3D line profiler 200 measure the degree of warpage of the target product 12 will be described in detail with reference to FIGS. 1 to 3 .

As described above, the computing device 100 sets the four reference points A1-A4 on the target product 12 , and the height values for the reference points A1-A4 through the 3D line profiler 200 . can be calculated.

A process of calculating the height value for the reference point A1 will be described with reference to FIG. 3 .

Referring to FIG. 3 , the reference point A1 includes 5*5 pixels. In this case, it is assumed that the pixels correspond to the maximum resolution supported by the 3D line profiler 200 . That is, when the height of the surface of the target product 12 is scanned with the maximum resolution through the 3D line profiler 200 , the height of each of the pixels P1 - P25 may be measured. Setting the reference point A1 to include 5*5 pixels is only an example, and the controller 120 of the computing device 100 may set the number of pixels included in the reference point A1 differently according to the required accuracy or speed. there is.

If the 3D line profiler 200 assumes that the speed for scanning the height of the surface of the target product 12 at the maximum resolution is 50 mm/sec, the scan speed of the 3D line profiler 200 is doubled to 100 mm/sec. When raised, the height of pixels is scanned while skipping one row at a time. Referring to FIG. 3 , if the 3D line profiler 200 scans the height with respect to the reference point A1 at a speed of 50 mm/sec, the height can be measured for all pixels P1-P25, but the 3D line profile If the first row 200 scans at a speed of 100 mm/sec, the pixels P1-P5 included in the first row C1, the pixels P11-P15 included in the third row C3, and the fifth row Only the pixels P21 - P25 included in (C5) can be measured in height.

The control unit 120 controls the scan speed of the 3D line profiler 200 to measure the height of the surface of the target product 12 excluding some areas. For example, as described above, the controller 120 increases the scan speed of the 3D line profiler 200 to twice the speed corresponding to the maximum resolution, thereby measuring the height while skipping pixels included in the reference point A1 row by row. can make it Alternatively, the controller 120 may increase the scan speed of the 3D line profiler 200 to a higher level to measure the height while skipping two or more rows of pixels included in the reference point A1. As described above, by controlling the scan speed of the 3D line profiler 200 by the controller 120, the time required for height measurement can be reduced.

The control unit 120 receives the height data measured for a partial area (some pixels included in the reference point) of the surface of the target product 12 from the 3D line profiler 200, and the height is determined using the received height data. Heights of non-measured remaining regions (pixels whose height is not measured among pixels included in the reference point) may be estimated.

Referring to FIG. 3 , according to the example described above, pixels P6-P10 included in the second row C2 and pixels P6-P10 included in the fourth row C4 due to the control unit 120 adjusting the scan speed The height is not measured for (P16-20). The controller 120 may estimate the heights of the pixels P6-P10 and P16-P20 through an interpolation algorithm.

A method in which the controller 120 estimates heights of regions excluded from height measurement using an interpolation algorithm will be described in detail as follows.

The control unit 120 obtains an average of the heights of pixels with measured heights among pixels located within a predetermined distance from any one pixel of which height is not measured among pixels included in the reference point A1, and determines which height is not measured. It can be estimated as the height for one pixel. For example, if the height of the pixel P8 is estimated in FIG. 3 , the controller 120 may estimate the average of the heights measured for the pixels P3 and P13 positioned before and after the pixel P8 as the height for the pixel P8. . In addition, the controller 120 may estimate the height of pixels excluded from height measurement by using various interpolation algorithms.

When the height measurement and estimation of all pixels P1-P25 included in the reference point A1 is completed, the controller 120 may calculate a height value for the reference point A1 using the measured height and the estimated height. In this case, the 'height value for the reference point A1' means a height value representing the reference point A1. According to an embodiment, the controller 120 controls the average of the heights of all pixels P1-P25 included in the reference point A1. can be calculated as a height value with respect to the reference point A1.

When the control unit 120 completes calculating the height values for all the reference points A1-A4 according to the method described above, the degree of bending of the target product 12 by comparing the height values for the reference points A1-A4 with each other can be measured A specific method for the control unit 120 to measure the degree of warpage of the target product 12 by comparing the height values for the reference points A1 to A4 with each other is the same as described above with reference to FIG. 1 .

Hereinafter, a method of measuring the degree of warpage of a product using the computing device 100 and the 3D line profiler 200 as described above will be described. 4 to 6 are flowcharts for explaining a method of measuring a degree of warpage of a product according to embodiments. The method of measuring the degree of warpage according to the embodiments shown in FIGS. 4 to 6 includes steps that are time-series processed by the computing device 100 shown in FIGS. 1 and 2 . Therefore, even if omitted below, the content described above with respect to the computing device 100 shown in FIGS. 1 and 2 is also in the method for measuring the degree of warpage of a product according to the embodiments shown in FIGS. 4 to 6 . can be applied.

Referring to FIG. 4 , in step 401 , the computing device 100 controls the 3D line profiler 200 to measure the height of the surface of the target product except for a partial area, and uses the measured height to measure the height. Estimate the height for some excluded areas.

Detailed steps included in step 401 are illustrated in FIG. 5 .

Referring to FIG. 5 , in step 501 , the computing device 100 sets at least two reference points on the surface of the target product.

In operation 502 , the computing device 100 measures the heights of the remaining pixels except for at least some of the plurality of pixels included in each reference point. In this case, the plurality of pixels included in each reference point may correspond to the maximum resolution of the 3D line profiler 200 .

According to an embodiment, the computing device 100 may measure the height at a resolution lower than the maximum resolution by increasing the scan speed of the 3D line profiler 200 in measuring the heights of the remaining pixels in step 502 . can

In operation 503 , the computing device 100 may estimate the height of pixels whose height is not measured by using the height measured in operation 502 . According to an embodiment, the computing device 100 calculates an average of the heights of pixels with measured heights among pixels located within a predetermined distance from any one pixel whose height is not measured, and any one of which height is not measured. It can be estimated as the height in pixels of .

Returning again to FIG. 4 , in step 402 , the computing device 100 measures the degree of bending of the target product using the height measured and the estimated height in step 401 .

Detailed steps included in step 402 are illustrated in FIG. 6 .

Referring to FIG. 6 , in operation 601 the computing device 100 calculates a height value for each reference point using the height measured and the estimated height in operation 401 . For example, the computing device 100 may calculate an average of a height measured and an estimated height of a plurality of pixels included in each reference point as a height value for each reference point.

In step 602 , the computing device 100 measures the degree of bending of the target product by comparing height values for reference points with each other.

According to the embodiments described above, by measuring the height of only a portion of the surface of the target product and estimating the height of the remaining areas based on the measured height, the degree of bending of the target product with high accuracy while increasing the measurement speed can be expected to have a measurable effect.

The term '~ unit' used in the above embodiments means software or hardware components such as field programmable gate array (FPGA) or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Accordingly, as an example, '~' indicates components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program patent code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.

The functions provided in the components and '~ units' may be combined into a smaller number of elements and '~ units' or separated from additional components and '~ units'.

In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

The method for measuring the degree of warpage of the product according to the embodiments described through FIGS. 4 to 6 may be implemented in the form of a computer-readable medium for storing instructions and data executable by a computer. In this case, the instructions and data may be stored in the form of program codes, and when executed by the processor, a predetermined program module may be generated to perform a predetermined operation. In addition, computer-readable media can be any available media that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may be a computer recording medium, which is a volatile and non-volatile and non-volatile storage medium implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. It may include both volatile, removable and non-removable media. For example, the computer recording medium may be a magnetic storage medium such as HDD and SSD, an optical recording medium such as CD, DVD, and Blu-ray disc, or a memory included in a server accessible through a network.

In addition, the method for measuring the degree of warpage of the product according to the embodiments described with reference to FIGS. 4 to 6 may be implemented as a computer program (or computer program product) including instructions executable by a computer. The computer program includes programmable machine instructions processed by a processor, and may be implemented in a high-level programming language, an object-oriented programming language, an assembly language, or a machine language. . In addition, the computer program may be recorded in a tangible computer-readable recording medium (eg, a memory, a hard disk, a magnetic/optical medium, or a solid-state drive (SSD), etc.).

Accordingly, the method for measuring the degree of warpage of the product according to the embodiments described with reference to FIGS. 4 to 6 may be implemented by executing the computer program as described above by the computing device. The computing device may include at least a portion of a processor, a memory, a storage device, a high-speed interface connected to the memory and the high-speed expansion port, and a low-speed interface connected to the low-speed bus and the storage device. Each of these components is connected to each other using various buses, and may be mounted on a common motherboard or in any other suitable manner.

Here, the processor may process a command within the computing device, such as, for example, to display graphic information for providing a graphic user interface (GUI) on an external input or output device, such as a display connected to a high-speed interface. Examples are instructions stored in memory or a storage device. In other embodiments, multiple processors and/or multiple buses may be used with multiple memories and types of memory as appropriate. In addition, the processor may be implemented as a chipset formed by chips including a plurality of independent analog and/or digital processors.

Memory also stores information within the computing device. As an example, the memory may be configured as a volatile memory unit or a set thereof. As another example, the memory may be configured as a non-volatile memory unit or a set thereof. The memory may also be another form of computer readable medium, such as, for example, a magnetic or optical disk.

In addition, the storage device may provide a large-capacity storage space to the computing device. A storage device may be a computer-readable medium or a component comprising such a medium, and may include, for example, devices or other components within a storage area network (SAN), a floppy disk device, a hard disk device, an optical disk device, or a tape device, a flash memory, or other semiconductor memory device or device array similar thereto.

The above-described embodiments are for illustration, and those of ordinary skill in the art to which the above-described embodiments pertain can easily transform into other specific forms without changing the technical idea or essential features of the above-described embodiments. You will understand. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope to be protected through this specification is indicated by the claims described below rather than the detailed description, and it should be construed to include all changes or modifications derived from the meaning and scope of the claims and their equivalents. .

Claims

In the method of measuring the warpage degree of the product,

measuring the height of the surface of the target product except for a partial area, and estimating the height of the partial area excluded when measuring the height using the measured height; and

Using the measured height and the estimated height, the method comprising the step of measuring the degree of warping of the target product.
The method of claim 1,

The step of estimating the height is

setting at least two reference points on the surface of the target product;

measuring heights of pixels other than at least some of the plurality of pixels included in each of the two or more reference points; and

and estimating the heights of the at least some pixels excluded from the height measurement by using the heights measured with respect to the remaining pixels.
3. The method of claim 2,

A plurality of pixels included in each of the two or more reference points corresponds to a maximum resolution of a scanning device for height measurement.
4. The method of claim 3,

Measuring the heights of the remaining pixels includes:

By increasing a scan speed of a scanning device for measuring the height, the method of claim 1 , wherein the height is measured at a resolution lower than the maximum resolution.
3. The method of claim 2,

The step of estimating the heights of some of the pixels comprises:

It is characterized in that the average of the heights of pixels with measured heights among pixels located within a predetermined distance from any one pixel whose height is not measured is estimated as the height of any one pixel whose height is not measured. How to.
3. The method of claim 2,

The step of measuring the degree of warpage of the target product,

calculating a height value for each of the two or more reference points using the measured height and the estimated height; and

Method comprising the step of measuring the degree of warpage of the target product by comparing the height values for the two or more reference points with each other.
7. The method of claim 6,

The step of calculating the height value for each of the two or more reference points,

The method of claim 1, wherein the average of the measured heights and the estimated heights of the plurality of pixels included in each of the two or more reference points is calculated as a height value for each of the two or more reference points.
A computer-readable recording medium in which a program for executing the method according to claim 1 is recorded on a computer.
In the computing device for measuring the warpage degree of the product,

an input/output unit for receiving the result of measuring the height of the surface of the target product from the scanning device for measuring the height, and outputting the result of measuring the degree of bending of the target product;

a storage unit in which a program and data for measuring the degree of bending of the target product are stored; and

By executing the program, comprising a control unit for controlling the driving of the scanning device to measure the degree of warpage of the target product,

The control unit is

controlling the scanning device to measure the height of the surface of the target product except for a partial area, estimating the height of the partial area excluded when measuring the height using the measured height, and the measured height and A device for measuring the degree of bending of the target product using the estimated height.
10. The method of claim 9,

The control unit in estimating the height,

Setting at least two or more reference points on the surface of the target product, and controlling the scanning device to measure the height of the remaining pixels except for at least some pixels among a plurality of pixels included in each of the two or more reference points, and estimating the heights of the at least some pixels excluded from the height measurement by using the heights measured with respect to the remaining pixels.
11. The method of claim 10,

A plurality of pixels included in each of the two or more reference points corresponds to a maximum resolution of the scanning device.
12. The method of claim 11,

When the control unit measures the height of the remaining pixels,

The apparatus of claim 1, wherein the height is measured at a resolution lower than the maximum resolution by increasing the scanning speed of the scanning device.
11. The method of claim 10,

In estimating the height of the some of the pixels, the control unit,

It is characterized in that the average of the heights of pixels with measured heights among pixels located within a predetermined distance from any one pixel whose height is not measured is estimated as the height of any one pixel whose height is not measured. device to do.
11. The method of claim 10,

In measuring the degree of bending of the target product, the control unit

Calculate the height value for each of the two or more reference points using the measured height and the estimated height, and measure the degree of bending of the target product by comparing the height values for the two or more reference points with each other Device.
15. The method of claim 14,

When the control unit calculates the height value for each of the reference points,

and calculating an average of a height measured and an estimated height of a plurality of pixels included in each of the two or more reference points as a height value for each of the two or more reference points.