TW201932859A - Method for checking the coated state of flux onto flip chip wherein the average light intensity value and the standard deviation are automatically set to check the reference light intensity value of the flux coating state of the flip chip - Google Patents

Abstract

The invention relates to a method for checking the coated state of flux onto a flip chip, comprising the steps of: light is illuminated on a bump of one side of a flip chip of a first flip chip group not coated with a flux to store the light intensity value of the bump as the first data; the flux is applied to the flip chip by immersing one side thereof on the disk containing the flux; and the bump of the flip chip of the second flip chip group coated with the flux is illuminated with light, and further the light intensity value of the bump is stored as the second data; the respective average light intensity values and standard deviations are obtained from the normal distribution of the first data and the second data; and the average light intensity value and the standard deviation are automatically set to check the checkup reference light intensity value of the flux coating state of the flip chip, wherein given that the range of the light intensity values of the normal distribution of the first data and the second data does not overlap, the checkup reference light intensity value is set to a value obtained by adding the average light intensity value of the second data to the standard deviation of the second data.

Description

Method for checking flux coating state of flip chip (second case)

The present invention relates to a method for inspecting the state of flux coating of a flip chip, and more particularly to a method for automatically setting a reference light intensity value for inspecting the state of flux coating of a flip chip; it has been approved as the first invention I 590401 another invention.

In recent years, with the development of electronic communication technology, various electronic devices have been further miniaturized and lightened. Therefore, electronic components such as semiconductor wafers that are built into various electronic devices must satisfy high integration and miniaturization.

Therefore, a surface mount technology for mounting a high-density, ultra-small surface mount device (SMD: Surface Mount Device) on a printed circuit board (PCB: Printed Circuit Board, hereinafter referred to as a " substrate " ) Research is actively underway.

As such a surface mount technology, instead of the conventional wire bonding technology, there is a flip chip which uses bumps to connect electrodes and substrates of a die of a semiconductor wafer to a substrate. (flip chip) process.

A flip-chip means a device capable of directly mounting an electronic device or a semiconductor wafer to a mounting pad of a substrate in a face-down manner.

When a flip chip is mounted on a substrate, electrical connection can be achieved by forming conductive bumps on the surface of the wafer, and when the wafer is mounted on the substrate, the wafer is mounted in an inverted state, so it is called flip chip Wafer.

Flip-chips do not require wire bonds, so the size of flip-chips is significantly smaller than that of chips that are typically subjected to a wire-bonding process. In addition, in wire bonding, the bonding between the bonding wire wafer and the substrate is performed one at a time. Conversely, in a flip chip, they can be performed simultaneously. Therefore, compared to a bonding wire wafer, flip chip The cost of the chip will be reduced, and the connection length of the flip chip will be shorter than wire bonding, so its performance will also be improved.

Hereinafter, a process for mounting a flip-chip on a substrate based on the above-mentioned flip-chip process will be briefly described.

First, a bumping process is performed, that is, after the wafer is separated from the wafer and taken out, the wafer is flipped to flip the positions of the upper and lower surfaces.

After that, a reflow process is performed, that is, the head of the placement machine is adsorbed by the inverted wafer and moved to a predetermined position, and And the surface containing the bumps is heated when necessary.

At this time, in order to improve the bonding performance between the substrate and the wafer, a fluxing process is performed, that is, flux is transferred to the bumps of the wafer.

After that, the following process is performed: using camera vision to identify the pads of the substrate as the predetermined positions where the wafer is to be mounted, thereby identifying the positions of the bumps, and making the bumps abut the pads for mounting Wafer.

Finally, heating is performed by reflow to bond the substrate and the wafer, and the wafer is protected by under filling with epoxy coating and curing by heat or the like.

In the flip-chip process as described above, when the flux transfer process of transferring the flux toward the bumps of the wafer is performed, it may happen that the flux cannot be normally applied to the bumps of the wafer. In this case, There is a large risk that the wafer is not normally bonded to the substrate, and accordingly, a problem of producing defective electronic components may be caused.

In view of this, in the prior art, various methods have been proposed for checking whether or not the flux is normally applied to the bumps of the wafer.

For example, there is a method of immersing a wafer in a container containing a flux, and then using a camera to photograph a bump mark of the flux in the container to check whether the flux is applied. However, in this method, since the flux is composed of a liquid, its traces disappear instantly, making it difficult to easily check the application of the flux to the bumps of the wafer. The question or not.

In addition, there has been proposed a method for checking whether or not the flux is applied to a wafer bump by capturing an image or an image obtained by photographing a state where the flux is applied to a wafer bump with a camera. However, it is difficult to easily set the flux. Problems with the best check parameters for repeated check jobs.

Advance technical literature

Patent Document 1: Korean Granted Patent No. 10-1377444 (2014.03.25)

The problem to be solved by the present invention is to provide a flux coating state inspection method for a flip chip that can automatically set an inspection reference light intensity value for inspecting the flux application state of the flip chip.

The subject of the present invention is not limited to the subjects described above, and those skilled in the art can easily understand other subjects not mentioned in the following description.

The method for inspecting the flux coating state of the flip chip according to the first embodiment of the present invention for solving the problem may include the step of applying the first flip chip formed on the flip chip to which no flux is applied. The bumps on one side of the flip chip of the group are irradiated with illumination light, and then the light intensity value of the bumps is stored as the first data; the one side is immersed in a disk containing a flux, so that The flip chip is coated with the flux; the bumps of the flip chip of the second flip chip group in which the flip chip is coated with the flux are irradiated with illumination light, and the bumps are further illuminated. Point of light The intensity values are stored as second data; the average light intensity values and standard deviations of the first data and the second data are obtained from the normal distributions of the first data and the second data, respectively; and using The average light intensity value and the standard deviation are automatically set as inspection reference light intensity values for inspecting a state where the flux is applied to the bumps of the flip chip, wherein, in the first data, When the normal distribution of the light intensity range of the second data does not overlap, the inspection reference light intensity value is set to the average light intensity value of the second data plus the The value obtained by describing the standard deviation of the second data.

Here, when the normal distribution of the first data and the range of the light intensity values of the normal distribution of the second data overlap, the inspection reference light intensity value may be set as follows from The value obtained by subtracting the standard deviation of the first material from the average light intensity value of the first material and the value obtained by adding the standard light deviation of the second material to the average light intensity value of the second material value.

In addition, the method for inspecting the state of flux coating of a flip chip may further include the steps of: irradiating the illumination light on the bumps of the inspection object coated with the flux to the bump of the flip chip of the inspection object, and then picking up a light intensity value, The picked-up light intensity value is compared with the inspection reference light intensity value that is automatically set, and then it is determined whether the flux coating state for the bumps of the flip chip is good.

Here, the light intensity of the flip chip when picking up the inspection object Before the value step, the method may further include the steps of: photographing a bump position of the flip chip of the inspection object; identifying the bump through the photographing step; and, if the bump is successfully identified, performing position correction so that The inspection object aligns the flip chip to a predetermined position.

Here, the method for inspecting the flux coating state of the flip chip may further include the following step: if the bump is not recognized normally, an error occurs.

In addition, the step of photographing the position of the bump may further include the step of irradiating a first illumination light for illuminating around the position of the bump of the inspection object flip-chip wafer.

Here, if the inspection reference light intensity value is greater than the picked up light intensity value, it can be determined that the flux coating state for the bumps of the flip chip is good.

In addition, if the inspection reference light intensity value is smaller than the picked-up light intensity value, it can be determined that the flux coating state for the bumps of the flip chip is poor.

In addition, the illumination light irradiated in order to pick up the light intensity values of the first material and the second material may be a light intensity value of the illumination light in a region having the bumps coated on the flip chip. The flux can be easily absorbed by the second illuminating light within a specific wavelength range of a specific region.

In addition, the first data and the second data may include A plurality of light intensity values measured for a plurality of flip-chip wafers included in the first flip-chip group and the second flip-chip group.

A method for inspecting a flux coating state of a flip chip according to a second embodiment of the present invention may include the following steps: photographing a bump position of a flip chip of an inspection object coated with a flux; identifying the said through the photographing step A bump; picking up the light intensity value of each of the bumps; calculating an average light intensity value of the light intensity value of each of the bumps, and setting the average light intensity value as a check reference light intensity value; comparing each of the sites The bump light intensity value and the inspection reference light intensity value; if the inspection reference light intensity value is less than each of the bump light intensity values, it is judged that the bump flux coating state of the flip chip is bad And if the defective area is more than a predetermined amount, it is determined that the flux coating state of the inspection object flip chip is poor, and if the defective area is less than a predetermined amount, it is determined that the inspection object is down. The wafer-mounted flux is in good condition.

Here, the area of the light intensity value of each of the bumps picked up may be the entire area of each of the bump balls.

10‧‧‧ Flip Chip

15‧‧‧ bump

100‧‧‧ First Flip Chip Set

110‧‧‧ first data

200‧‧‧Second Flip Chip Set

210‧‧‧second data

LI‧‧‧Light intensity value

Th‧‧‧Check the reference light intensity value

FIG. 1 is a flow chart showing a surface mounting step including a method for checking a flux coating state of a flip chip according to an embodiment of the present invention.

FIG. 2 is a flow chart showing a method for checking a flux coating state of a flip chip according to an embodiment of the present invention.

FIG. 3 is a diagram showing a state in which position correction of a flip chip is performed.

FIG. 4 is a flow chart showing a method for checking a flux coating state of a flip chip and judging whether the coating state is good according to a flow chart.

FIG. 5 is a flowchart showing a method for automatically setting and checking a reference light intensity value according to an embodiment of the present invention according to a flow chart.

FIG. 6 is a graph showing a case where a range of light intensity values included in the normal distribution of the first data and the normal distribution of the second data does not overlap according to the embodiment of the present invention.

FIG. 7 is a graph showing a case where the range of light intensity values included in the normal distribution of the first data and the normal distribution of the second data according to the embodiment of the present invention.

FIG. 8 is a flowchart showing a method for inspecting a flux coating state of a flip chip according to another embodiment of the present invention according to a flow chart.

With reference to the drawings and detailed embodiments, the advantages and features of the present invention, and the method for achieving the objectives will become clearer. However, the present invention is not limited to the embodiments disclosed below, and it can be implemented in different forms, but the purpose of providing this embodiment is to completely disclose the present invention and to make the technical field to which the present invention belongs has ordinary A skilled artisan can fully understand the scope of the present invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals denote the same constituent elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification can be taken as meanings generally understood by those having basic knowledge in the technical field to which the present invention belongs. In addition, the terms defined in commonly used dictionaries should not be condensed or excessively interpreted as long as there is no clear special definition.

The terminology used in this specification is used to illustrate embodiments and not to limit the present invention. In this specification, the singular form includes the plural form unless otherwise specified. In this specification, the use of " comprises " and / or " comprising " does not exclude the presence or addition of other constituent elements than the mentioned constituent elements.

In addition, an embodiment described in this specification will be described with reference to a cross-sectional view and / or a schematic diagram which is an ideal example diagram of the present invention. Therefore, the shape of the example drawings may be adjusted according to manufacturing technology and / or allowable errors. In addition, in each of the drawings shown in the present invention, considering the convenience of description, each constituent element may be enlarged or reduced to be displayed. Throughout the specification, the same reference signs refer to the same constituent elements, and " and / or " includes each of the mentioned elements and all combinations of more than one.

Spatially relative terms should be understood to include terms shown in the drawings and directions different from each other when constituent elements are used or operated. The constituent elements can be oriented in different directions, so terms that are spatially relative can be interpreted according to the orientation.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flow chart showing a surface mounting step including a method for checking a flux coating state of a flip chip 10 according to an embodiment of the present invention.

As shown in FIG. 1, the surface mount technology includes the steps of pick-up of a flip chip 10 mounted on a die shuttle board by a pick-up head having a nozzle; and A flux dipping step of coating a surface of the bump 15 with a flux.

The flux immersion step can apply a flux to the surface of the bump 15 formed on one surface of the flip chip 10 by immersing one surface of the flip chip 10 in a pan containing the flux.

If the flux is applied to the surface of the bumps 15 of the flip chip 10 by the flux dipping step, after the position correction of the flip chip 10 is performed, the flip chip 10 is bonded to the printed circuit board, thereby achieving the placement.

At this time, the flux coated on the surface of the bump 15 of the flip chip 10 performs a function of bonding the flip chip 10 to the substrate.

Therefore, if the flux cannot be applied to the bumps 15 of the flip-chip 10 well by the soldering step, the flip-chip cannot be bonded to the substrate, and eventually defective electronic components will be produced.

In order to solve the problem of producing defective electronic components as described above, the present invention proposes a method for inspecting the flux coating state of the flip chip 10 method.

FIG. 2 is a flowchart showing a method for checking a coating state of the flip chip 10 according to an embodiment of the present invention.

As shown in FIG. 2, the method for inspecting the flux coating state of the flip chip 10 according to the embodiment of the present invention may include the following steps: picking up the flip chip 10 with a plurality of bumps 15 formed on one side from the die shuttle board (S10); and dipping the bumps 15 of the picked up flip chip 10 with a flux, so that the flux is coated on the surface of the bumps 15 (S20).

In addition, the method may further include the steps of: using the illuminating part to illuminate the bumps 15 coated with the flux with the first illumination light, using a camera to photograph the positions of the bumps 15 (S30); The bump 15 is identified (S40).

FIG. 3 is a diagram showing a position correction of the flip chip 10.

When capturing the image of the bump 15 to identify the bump 15, the following steps may be included: if the bump 15 is not recognized normally, an error occurs (S50); if the bump 15 is successfully identified, then as shown in FIG. 3, The flip chip 10 is aligned to a preset position, thereby completing the position correction (S60).

In addition, after the correction of the position of the flip chip 10 (ie, the bump 15), the illumination portion irradiates the bump 15 with the second illumination light having a specific region wavelength range that the flux can easily absorb. In this state, Can include the following steps: the camera captures the second illumination light reflected by the bump 15 Reflected light (S70); and the coating state of the flux of the bump 15 is checked by the difference in light intensity of the photographed reflected light (S80).

Here, the first illuminating light irradiated by the illuminating part may be: light for improving the surrounding brightness when shooting by the camera in order to identify the bumps 15 of the flip chip 10; the second illuminating light may be a flux which can be easily The absorption of light in a specific wavelength range will be described in detail below.

The image or image obtained by photographing the reflected light of the above-mentioned second illumination light is read, so that the coating state of the flux can be checked (S80). The specific inspection method is described below with reference to FIG. 4 .

FIG. 4 is a flow chart showing a method for checking the flux coating state of the flip chip 10 and judging whether the coating state is good according to the flow chart.

Referring to FIG. 4, if the second illumination light having a wavelength range of a specific region that the flux can easily absorb is irradiated to the bumps 15 of the flip chip 10 by the illuminating section, and in this state, the camera captures the bumps 15 The reflected light of the reflected second illumination light can obtain a captured image or image (S810).

Thereafter, a step of identifying the area of the bump 15 may be performed (S820). As described above, since the second illumination light is light in a wavelength range having a specific region that the flux can easily absorb, part of it is absorbed by the flux coated on the bumps 15 of the flip chip 10.

For example, if the light intensity of the second illumination light is 100, then A part of the light is absorbed by the flux applied to the bumps 15 of the flip chip 10, and the intensity of light reflected from the bumps 15 of the flip chip 10 is reduced to 100 or less.

In contrast, when the bumps 15 of the flip chip 10 are not coated with flux, the light reflected from the bumps 15 of the flip chip 10 will remain at the original 100. Therefore, a region having a relatively low light intensity value can be identified as a bump 15 region from the captured image or image.

Next, a step of setting a check reference light intensity value may be performed (S830). Here, the reference light intensity value Th is a reference value used to determine whether the flux coating state of the flip chip 10 is good. In the embodiment of the present invention, although the step of identifying the bump 15 area (S820 ), But it can also be executed before it, and the sequence is not limited as long as it is executed before the step (S850) of comparing the picked-up light intensity value LI with the inspection reference light intensity value Th described below. this.

For example, a step of picking up the average light intensity value LI of the bumps 15 of the flip chip 10 corresponding to the identified areas of the bumps 15 may be performed (S840). As described above, the light intensity value LI of the bump 15 can be read to capture the reflected light that irradiates the second illumination light toward the bump 15 and reflects it, and the image or image obtained can be picked up, and the lighting section can be picked up. The second illuminating light may be irradiated from a light source having a wavelength range of a specific region where the flux coated on the bumps 15 of the flip chip 10 can be easily absorbed.

As mentioned above, the second illumination light can A light source in a specific wavelength range that is easy to absorb, irradiates the bumps 15 of the flip chip 10, and can pick up the average light intensity value LI of the reflected light reflected from the bumps 15 located in the region where the bumps 15 are identified (S840), and a step of comparing the picked-up light intensity value LI with the inspection reference light intensity value Th is performed (S850).

At this time, if it is read that the inspection reference light intensity value Th is greater than the average light intensity value LI picked up from the bump 15, it can be judged that the coating state of the flux is good (S860). Conversely, if read In order to check that the reference light intensity value Th is smaller than the average light intensity value LI picked up from the bump 15, it can be determined that the coating state of the flux is bad (S870).

Here, when it is read that the inspection reference light intensity value Th is larger than the average light intensity value LI picked up from the bump 15, it is explained that the flux is well coated on the bump 15 and the second illumination light is absorbed. Based on this, it can be judged that the coating state of the flux is good.

Conversely, when the reference light intensity value Th inputted as being read in advance and set is smaller than the average light intensity value LI picked up from the bump 15, it is shown that the flux is not well applied to the bump 15 and the second illumination light Since it is reflected directly, it can be judged that the coating state of the flux is bad.

Therefore, the method for inspecting the flux coating state of the flip chip 10 according to the embodiment of the present invention can automatically set the inspection reference light intensity value Th in the inspection reference light intensity value Th setting step (S830) described above.

Specifically, if the first flip chip group 100 and the second flip chip The light intensity value LI picked up by the bumps 15 of the flip chip set 200 has a normal distribution. According to the flux coating state inspection method of the flip chip 10 according to the embodiment of the present invention, the first flip chip set 100 and the second flip chip set 100 can be used. The average value and standard deviation of the respective normal distributions of the flip chip group 200 are automatically set to check the reference light intensity value Th.

Here, the first flip chip group 100 indicates a flip chip group 10 in a state before the surface of the bump 15 is coated with a flux, and the second flip chip group 200 indicates a flip chip 10 in which the bump 15 is formed. One side is immersed in a pan containing a flux, and the surface of the bump 15 is coated with a group of 10 flip-chip wafers in a flux state.

FIG. 5 is a flow chart showing a method for automatically setting and checking a reference light intensity value Th according to an embodiment of the present invention.

Referring to FIG. 5, according to the method for inspecting the flux coating state of the flip chip 10 according to the embodiment of the present invention, in order to automatically set the inspection reference light intensity value Th, the method may include the following steps: picking up the light intensity from the first flip chip group 100 The value LI is stored as the first data 110 (0); and the light intensity value LI picked up from the second flip chip set 200 is stored as the second data 210 (S8330).

In the step (S8310, S8330) of storing the first data 110 and the second data 210 corresponding to the light intensity value LI in the first flip chip group 100 and the second flip chip group 200, respectively, The plurality of flip-chips 10 included in each of the flip-chip group 100 and the second flip-chip group 200 are repeatedly executed, and furthermore, a plurality of lights including the plurality of flip-chips 10 can be stored. The first data 110 and the second data 210 of the intensity value LI.

First, a step of adjusting the light intensity value of the illuminating light by the illumination section in a wavelength range having a specific region where the flux coated on the bump 15 of the flip chip 10 can be easily absorbed by the illumination section (S8311) may be performed.

In addition, the following steps may be performed: a step of reading the image or image obtained by shooting the light reflected by the illumination section illuminating the bumps 15 of the first flip chip group 100 with illumination light and picking up the light intensity value LI ( S8312); and a step of storing the picked-up light intensity value LI as the first data 110 (S8313).

For the first flip chip group 100 without flux, after the first data 110 is stored, a step of dipping the flux may be performed on the first flip chip group 100 (S8320). As described above, the step of immersing the flux indicates the step of applying a flux to the surface of the bump 15 formed on one side of the flip-chip 10 by immersing one side of the flip-chip 10 in a pan containing the flux. .

If the first flip chip group 100 is subjected to the flux dipping step, the second flip chip group 200 in a state where the bumps 15 are coated with the flux is formed. Similarly, for the second flip chip group 200, it is possible to adjust the amount of the illumination light by the illuminating part in the wavelength range of the specific region where the flux having the bumps 15 coated on the flip chip 10 can be easily absorbed. Step of light intensity value (S8331). Here, the light intensity values of the illumination light irradiated to the first flip chip group 100 and the second flip chip group 200 by the illuminating section may be the same.

Next, as with the first flip chip group 100, the following steps may be performed: reading the image or image obtained by shooting the light reflected by the illumination section on the bumps 15 of the second flip chip group 200 with illumination light A step of picking up the light intensity value LI (S8332); and a step of storing the picked up light intensity value LI as the second data 210 (S8333).

The first data 110 and the second data 210 stored as described above have a normal distribution, and the steps of obtaining the average and standard deviation from the respective normal distributions of the first data 110 and the second data 210 can be performed (S8340).

Here, the step of determining whether the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 may be performed (S8350), and according to the first data 110 and the second data 210, If the normal distribution ranges overlap, a method of automatically setting and checking the reference light intensity value Th is applied.

If the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 does not overlap, set the inspection reference light intensity value Th as the average value of the second data 210 plus Step of obtaining the value obtained by the standard deviation of the second data 210 (S8360).

FIG. 6 is a graph showing a case where the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 does not overlap according to an embodiment of the present invention.

As shown in Figure 6, the normal distribution of the first data 110 and In the case where the ranges of the light intensity values LI included in the normal distribution of the second data 210 do not overlap, for example, if the average light intensity value LI according to the normal distribution of the second data 210 is 100 and the standard deviation is 20, then The inspection reference light intensity value Th is automatically set to a value of 120 as an average light intensity value LI of the second data 210 plus 20 as a standard deviation of the second data 210.

On the contrary, in the case where the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 overlaps, the inspection reference light intensity value Th can be set to be the average of the first data 110 A step of intermediate the value obtained by subtracting the standard deviation of the first data 110 from the light intensity value LI and the average light intensity value LI of the second data 210 plus the standard deviation of the second data 210 (S8370).

FIG. 7 is a graph showing a case where the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 overlaps according to an embodiment of the present invention.

As shown in FIG. 7, when the range of the light intensity value LI included in the normal distribution of the first data 110 and the normal distribution of the second data 210 overlaps, for example, based on the average light possessed by the normal distribution of the first data 110 The intensity value LI is 140 and the standard deviation is 40. According to the normal distribution of the second data 210, the average light intensity value LI may be 80 and the standard deviation is 40.

In this case, the inspection reference light intensity value Th may be automatically set as the average light intensity value LI 140 as the first data 110 minus as The median value between the value 100 obtained with the standard deviation 40 of the first data 110 and the average light intensity value LI 80 as the second data 210 plus the value 120 obtained with the standard deviation 40 of the second data 210 is 100 and The median of 120 is 110.

As described above, referring to FIG. 4 again, the second illumination light is irradiated onto the bumps 15 of the flip chip 10 by a light source having a wavelength range of a specific region that the flux can easily absorb, and can be picked up by being located The average light intensity value LI of the reflected light reflected by the bump 15 in the area of the bump 15 (S840), and a step of comparing the picked-up light intensity value LI with the inspection reference light intensity value Th is performed (S850).

At this time, if it is read that the inspection reference light intensity value Th is larger than the average light intensity value LI picked up from the bump 15, it can be judged that the coating state of the flux is good (S860). On the contrary, if it is read as inspection If the reference light intensity value Th is smaller than the average light intensity value LI picked up from the bump 15, it can be judged that the coating state of the flux is bad (S870).

If the flux coating state of the flip chip 10 is determined to be good by the inspection method of the above-mentioned inspection method, the flip chip 10 is transferred to the subsequent steps. On the contrary, if it is judged that the flux is applied If the coating state is not good, the soldering step for the flip chip 10 is performed again, so that the problem of mass-producing defective electronic components can be eliminated.

In addition, by automatically setting the inspection reference light intensity value Th, the work efficiency can be improved, and the flux of the flip chip 10 can be effectively judged. Whether the coating condition is good.

FIG. 8 is a flowchart showing a method for inspecting a flux coating state of a flip chip 10 according to another embodiment of the present invention according to a flow chart.

According to another embodiment of the present invention, the method for inspecting the coating state of the flip chip 10 can divide the entire area of the inspection object coated with the flux of the flip chip 10 into a region where the flip chip 10 has a good coating state and a defect. If the area with poor coating status is greater than the predetermined area, it is judged that the flux coating status of the flip chip 10 of the inspection object is poor. If the area with poor coating status is less than the predetermined area, it may be judged as the inspection object. The coating state of the flip chip 10 is good.

Referring to FIG. 8, the second illumination light having a wavelength range of a specific region that the flux can easily absorb is irradiated to the bumps 15 of the flip chip 10 by the illumination portion, and if the camera captures reflections from the bumps 15 in this state The reflected light of the second illumination light can acquire a captured image or image (S810).

Next, a step of identifying the area of the bump 15 may be performed (S820). As described above, a region having a relatively low light intensity value can be identified as a bump 15 region from a captured image or image (S820).

And, the step of picking up the light intensity value LI of each bump 15 of the flip chip 10 corresponding to the identified bump 15 area may be performed (S831). As described above, the light intensity value LI of the bump 15 can be obtained by reading an image obtained by photographing the reflected light that is reflected by irradiating the second illumination light toward the bump 15. Or the image is picked up, and the second illuminating light of the illuminating part may be irradiated from a light source having a wavelength range of a specific region that the flux applied to the bumps 15 of the flip chip 10 can easily absorb.

As described above, the second illumination light irradiates the bumps 15 of the flip chip 10, and picks up each light intensity value LI of the reflected light reflected at the position of each bump 15 located in the area of the identified bump 15 (S831 ), And then the average light intensity value LI of the light intensity value LI of each of the bumps 15 may be calculated (S841). Here, the average light intensity value LI becomes an inspection reference light intensity value Th.

Here, the region where each light intensity value LI of the reflected reflected light picked up at the position of each bump 15 may be the entire area of the bump 15 ball, or may be a part of the center portion of the bump 15 ball region.

Next, a step of comparing the inspection reference light intensity value Th with each light intensity value LI of the reflected light reflected at the position of each bump 15 is performed (S851).

At this time, if it is read that the inspection reference light intensity value Th is larger than each light intensity value LI picked up from the position of each bump 15, it can be judged as a region where the coating state of the flux is good (S871). On the contrary, if It is read that the inspection reference light intensity value Th is smaller than each light intensity value LI picked up from the position of each bump 15, and it can be determined that the area of the flux is poorly applied (S861).

Finally, if the area where the flux is poorly applied (read In order to check the case where the reference light intensity value Th is less than each light intensity value LI) is more than a predetermined amount, it can be judged that the solder coating state of the flip chip 10 of the inspection object is bad (S880). In the predetermined area, it can be judged that the coating state of the inspection object flip chip 10 is good (S890).

In addition, if the area where the flux is applied well (read as the inspection reference light intensity value Th is greater than the respective light intensity value LI) is less than a predetermined amount, it can be judged that the inspection object is the flux coating of the flip chip 10 of the inspection object. The coating state is bad (S880). If the area with a good coating state exceeds a predetermined area, it can be judged that the coating state of the inspection object flip chip 10 is good (S890).

According to the method for inspecting the flux coating state of the flip chip 10 according to another embodiment of the present invention as described above, the light intensity value LI at the position of each bump 15 and the The average light intensity value LI of the bumps 15 is compared, so that it can be judged whether the flux coating state of the flip chip 10 is good, and it can solve the recognition caused by changes in the external environment such as the shape, material and lighting brightness of the bumps 15 The problem of reduced reliability of parameters.

In the technical field to which the present invention belongs, anyone with basic knowledge can understand that the present invention can be implemented in other specific forms without changing its technical idea or necessary features. Therefore, it must be understood that the above-mentioned embodiments are illustrative and not restrictive in all aspects. this invention The scope of the patent is based on the scope of the patent application, and is not limited to the detailed description above, and all changes or changes derived from the meaning and scope of the scope of the patent application, as well as its equivalent concept, should be explained To be included in the scope of the present invention.

Although the present invention has described the preferred embodiment, various modifications or changes can be made without departing from the spirit and scope of the invention. Therefore, as long as it is the modification or change belonging to the gist of the present invention, it is included in the scope of the attached patent application.

Claims (13)

A method for inspecting a flux coating state of a flip chip includes the steps of: irradiating illumination light to a bump formed on one surface of the flip chip of the first flip chip group in which no flux is applied on the flip chip. And further storing the light intensity value of the bump as the first data; by dipping the side into a pan containing a flux, the flux is coated on the flip chip; The bumps of the flip chip of the second flip chip group coated with the flux are irradiated with illumination light, and the light intensity value of the bumps is stored as second data; Obtaining the normal light distributions of the first data and the second data, and obtaining the average light intensity value and the standard deviation of the first data and the second data respectively; and using the average light intensity value and the The standard deviation is automatically set to check a reference light intensity value for checking a state where the flux is applied to the bumps of the flip chip, wherein a normal distribution of the first data and the second data Range of the light intensity value of the normal distribution In the case of the stack, the inspection reference value is set to the light intensity of the average light intensity value of the second data preceded by the standard deviation of the second value obtained data. The method for inspecting the state of flux coating of a flip chip as described in item 1 of the scope of patent application, wherein the light intensity value range of the normal distribution of the first data and the normal distribution of the second data overlap In this case, the inspection reference light intensity value is set to a value obtained by subtracting a standard deviation of the first data from an average light intensity value of the first data and an average light of the second data. The median value obtained by adding the intensity value to the standard deviation of the second data. The method for inspecting the state of flux coating of a flip chip as described in item 1 of the scope of patent application, further comprising the step of: irradiating said illumination to the bumps of the flip chip of the inspection object coated with the flux Light, and then pick up the light intensity value, compare the picked-up light intensity value with the automatically set inspection reference light intensity value, and then judge the flux coating state for the bumps of the flip chip Is it good? The method for inspecting the flux coating state of a flip chip as described in item 3 of the patent application scope, wherein before the step of picking up the light intensity value of the flip chip of the inspection object, the method further includes the following steps: photographing the inspection The bump position of the flip chip of the object; the bump is identified through the photographing step; and if the bump is successfully identified, position correction is performed to align the flip chip of the inspection object to a preset position. Flux coating of flip-chips as described in patent application item 4 The status checking method further includes the following step: if the bump is not recognized normally, an error occurs. According to the method for inspecting the state of flux coating of a flip chip as described in item 4 of the scope of the patent application, the step of photographing the position of the bump further includes the step of irradiating the bump of the flip chip to illuminate the inspection object The first illumination light around the position. The method for inspecting the state of flux coating of a flip-chip as described in item 3 of the scope of patent application, wherein if the inspection reference light intensity value is greater than the picked-up light intensity value, it is judged to be for the flip-chip The solder coating state of the bumps is good. The method for inspecting the state of flux coating of a flip-chip as described in item 3 of the scope of patent application, wherein if the inspection reference light intensity value is smaller than the picked-up light intensity value, it is judged to be for the flip chip The solder coating state of the bumps of the wafer is poor. The method for inspecting the flux coating state of a flip chip according to item 1 of the scope of patent application, wherein the illumination light irradiated to pick up the light intensity values of the first data and the second data is the illumination The light intensity value of the light is adjusted as the second illumination light within a range of a wavelength range having a specific region where the flux coated on the bumps of the flip chip can be easily absorbed. Flux coating of flip-chips as described in patent application item 1 The state inspection method, wherein the first data and the second data include a plurality of light measured for a plurality of flip-chips included in the first flip-chip group and the second flip-chip group Intensity value. A method for inspecting a flux coating state of a flip chip, which includes the following steps: photographing a bump position of a flip chip of an inspection object coated with a flux; identifying the bumps by the photographing step; picking each The light intensity value of the bump; calculating an average light intensity value of the light intensity value of each of the bumps, and setting the average light intensity value as a check reference light intensity value; comparing the light intensity value of each of the bumps And the inspection reference light intensity value; if the inspection reference light intensity value is less than each of the bump light intensity values, it is determined to be an area where the bump flux coating state of the flip chip is poor; and If the defective area is more than a predetermined amount, it is judged that the flux coating state of the inspection object flip chip is poor. If the defective area is less than a predetermined amount, it is judged that the flux coating of the inspection object flip chip is flux. Cover is in good condition. The method for inspecting the flux coating state of a flip chip as described in item 11 of the scope of patent application, wherein the light intensity of each of said bumps picked up The area of values is the entire area of each of the bumps. According to the method for inspecting the flux coating state of a flip-chip according to item 11 of the scope of the patent application, a region for picking up a light intensity value of each of the bumps is a partial region of a center portion of each of the bump balls.