Camera module assembly apparatus capable of measuring the weight of applied photocurable adhesive using a vision-camera

Abstract

A camera module assembly device according to one aspect of the present invention photographs a photocurable adhesive applied along the upper edge of a PCB to which a lens housing is to be attached using a vision camera, calculates the left and right slopes of the cross-section of the applied photocurable adhesive using the brightness of the image from the captured image, calculates the cross-sectional area using this, and calculates the weight of the applied photocurable adhesive by multiplying the calculated cross-sectional area by a pre-calculated weight constant.

Description

Technology Field

[0001] The present invention relates to a camera module assembly device, and more specifically, to a camera module assembly device capable of determining the possibility of product defects by measuring the weight of a photocurable adhesive applied to a PCB, etc., to attach a lens housing. Background Technology

[0002] In the manufacturing process of camera modules, particularly ultra-miniaturized ones, optical alignment and precision optical positioning are extremely demanding and time-consuming tasks. Even a slight misalignment between components during optical element assembly significantly impacts performance, leading to product defects.

[0003] In the camera module manufacturing process, the batch process affects not only the image quality of individual camera modules but also the consistency of image quality among identical camera modules manufactured in mass production units. It is important to minimize variations between units and ensure consistent quality for each camera unit during the manufacturing process.

[0004] Active alignment is a critical process in the manufacturing of camera modules, involving the placement of a lens onto an image sensor. Active alignment minimizes the tilt and rotation of the image sensor and aligns the center of the sensor with the lens optical axis. This is achieved through real-time analysis and adjustment of the image plane during the placement process.

[0005] Active alignment is performed after applying photocurable adhesive to the image sensor PCB and attaching the lens housing thereto. If the amount of photocurable adhesive applied to the image sensor PCB is inconsistent, product defects may occur during the active alignment process. The problem to be solved

[0006] The present invention aims to provide a camera module assembly device capable of preventing product defects in advance by using a vision camera to photograph a photocurable adhesive applied to a PCB, etc., using the brightness of the captured image to determine the left and right slopes of the cross-section of the applied photocurable adhesive, and using this to determine whether the amount of application is appropriate. means of solving the problem

[0007] A camera module assembly device according to one aspect of the present invention includes an adhesive part, a vision camera part, and a weight calculation part.

[0008] A photocurable adhesive is applied to the adhesive area along the upper edge of the PCB to which the lens housing is to be attached or along the upper edge of the lens housing to which the lens module is to be attached.

[0009] The vision camera unit captures an image of the photocurable adhesive applied along the upper edge of the PCB or the upper edge of the lens housing.

[0010] The weight calculation unit calculates the weight of the photocurable adhesive applied to the entire coating section in the captured image, by determining the number of pixels of the width of the photocurable adhesive applied for each unit section, determining the left and right coating slopes from the brightness change in the width direction of the corresponding unit section, calculating the area of ​​the cross-section in the width direction of the corresponding unit section based on the number of pixels of the photocurable width and the left and right coating slopes, multiplying this by a previously calculated weight constant of the photocurable adhesive to calculate the weight of the photocurable adhesive for the unit section, and then summing the weights of all unit sections to calculate the total weight of the applied photocurable adhesive.

[0011] A camera module assembly device according to an additional aspect of the present invention may further include a weight constant derivation unit.

[0012] The weight constant derivation unit derives the weight constant of the photocurable adhesive by calculating the area of ​​the photocurable adhesive from the image captured by the vision camera unit and the measured weight of the photocurable adhesive applied at the height of a unit section, and then dividing the measured weight by the calculated area.

[0013] A camera module assembly device according to an additional aspect of the present invention may further include a coating uniformity determination unit.

[0014] The coating uniformity determination unit determines the coating uniformity of the photocurable adhesive from the calculated weight of the photocurable adhesive applied per unit section derived by the weight calculation unit.

[0015] The coating uniformity judgment unit can generate an alarm based on the additionally judged coating uniformity of the photocurable adhesive.

[0016] A camera module assembly device according to an additional aspect of the present invention may further include an alarm generating unit.

[0017] The alarm generating unit generates an alarm when the weight of the applied photocurable adhesive calculated by the weight calculation unit deviates from the set error range relative to the set reference weight. Effects of the invention

[0018] According to the present invention, a photocurable adhesive applied to a PCB, etc. is photographed using a vision camera, and the left and right slopes of the cross-section of the applied photocurable adhesive are determined using the brightness of the captured image. By using this, it is possible to determine whether the amount of application is appropriate and thereby prevent product defects in advance. Brief explanation of the drawing

[0019] Figure 1 illustrates the concept of calculating the volume of a photocurable adhesive applied to an image sensor PCB using a vision camera. FIG. 2 is a block diagram including a configuration added to a camera module assembly device for measuring the weight of a photocurable adhesive applied according to one aspect of the present invention. Figure 3 illustrates the concept of calculating the cross-sectional area of ​​a photocurable adhesive. Specific details for implementing the invention

[0020] The foregoing and additional aspects are embodied in the embodiments described with reference to the attached drawings. It is understood that the components of each embodiment may be combined in various ways within the embodiment unless otherwise stated or contradictory. Each block in the block diagram may represent a physical part in some cases, but in others, it may be a logical representation of a part of the function of a single physical part or a function spanning multiple physical parts. Sometimes, the entity of a block or part thereof may be a set of program instructions. These blocks may be implemented in whole or in part by hardware, software, or a combination thereof.

[0021] Figure 1 illustrates the concept of calculating the volume of a photocurable adhesive applied to an image sensor PCB using a vision camera. (a) illustrates capturing an image of the photocurable adhesive applied to the image sensor PCB using a vision camera. (b) is an image of a unit section showing the width and the slopes at both ends of the applied photocurable adhesive in the width direction. The number of pixels of the left and right width of the photocurable adhesive is measured for each unit section in the captured image. (c) illustrates a cross-section of the photocurable adhesive in the width direction. In the cross-section (cross-section cut in the width direction) of the applied photocurable adhesive in the corresponding unit section, the first slope on the left and the second slope on the right are determined using image brightness, and the area of ​​the cross-section is calculated using these values. The weight of the photocurable adhesive applied to the unit section is calculated by multiplying the calculated area by a previously determined weight constant. The total weight of the applied photocurable adhesive is calculated by summing the weights for all unit sections.

[0022] FIG. 2 is a block diagram including a configuration added to a camera module assembly device for measuring the weight of a photocurable adhesive applied according to one aspect of the present invention. A camera module assembly device (10) according to one aspect of the present invention includes an adhesive part (11), a vision camera part (12), and a weight calculation part (13).

[0023] The camera module assembly device (10) is a device for assembling a lens housing and an image sensor PCB by aligning the optical axis, and may include, in addition to the adhesive part (11), the vision camera part (12), and the weight calculation part (13), a loading platform, a lens housing carrier part, a lens housing clamp part, an image sensor PCB alignment part, a handler part, and a control part, although not shown.

[0024] A stack loads multiple lens housings and multiple image sensor PCBs. At this time, one or more lenses are mounted in each lens housing, and an image sensor is mounted on each image sensor PCB.

[0025] The lens housing carrier transports the lens housing transferred from the loading platform to the alignment area.

[0026] The lens housing clamp is placed in the alignment area and clamps the lens housing transported by the lens housing carrier.

[0027] The image sensor PCB alignment unit transfers the image sensor PCB transferred from the loading platform to the alignment area and aligns the image sensor PCB with respect to the lens housing clamped in the lens housing clamp using an active alignment method.

[0028] The adhesive part (11) applies a photocurable adhesive to the image sensor PCB before actively aligning the lens housing to the image sensor PCB, and after active alignment by the image sensor PCB alignment part, cures the photocurable adhesive to bond the lens housing and the image sensor PCB.

[0029] The handler transfers the lens housing loaded on the loading platform to the lens housing carrier, transfers the image sensor PCB loaded on the loading platform to the image sensor PCB alignment unit, and receives the camera module with the lens housing and image sensor PCB bonded from the lens housing clamp and transfers it to the loading platform.

[0030] The control unit controls the lens housing carrier, lens housing clamp, image sensor PCB alignment unit, bonding unit, handler, etc.

[0031] The camera module assembly device (10) can increase assembly efficiency by automating a series of processes for assembling the lens housing and the image sensor PCB into a camera module by aligning the optical axes. In addition, since the camera module assembly device (10) can precisely align the optical axes between the lens and the image sensor, it can assemble a high-performance camera module with high reliability.

[0032] The adhesive part (11) includes a dispenser capable of applying a photocurable adhesive, and applies the photocurable adhesive along the upper edge of the image sensor PCB to which the lens housing is to be attached or along the upper edge of the lens housing attached to the image sensor PCB. The photocurable adhesive applied by the adhesive part (11) may be a UV-curing adhesive, and epoxy, acrylic, silicone, urethane, etc. may be used. The dispenser is controlled to maintain a constant amount of photocurable adhesive, so as to dispense a constant amount along the upper edge of the image sensor PCB or the upper edge of the lens housing.

[0033] The vision camera unit (12) is a type of industrial camera that photographs a photocurable adhesive applied to an image sensor PCB or lens housing from top to bottom. Depending on the aspect of the invention, the vision camera unit (12) may convert the captured image into a grayscale image.

[0034] The weight calculation unit (13) calculates the weight of the photocurable adhesive applied to the entire coating section in the captured image. The weight calculation unit (13) repeatedly calculates the weight of the photocurable adhesive applied for each unit section, and then calculates the weight of the photocurable adhesive applied for all unit sections by summing the weights of the photocurable adhesive applied for all unit sections.

[0035] The weight calculation unit (13) calculates the number of pixels of the width of the photocurable adhesive applied per unit section. That is, the weight calculation unit (13) calculates the width of the adhesive from the captured image, and calculates the width of the adhesive as the number of pixels. The horizontal distance per pixel can be calculated using the specification information of the image sensor PCB or lens housing and the number of pixels in the width direction of the image sensor PCB or lens housing in the image.

[0036] The weight calculation unit (13) calculates the left and right coating slopes from the brightness change in the width direction of the unit section, and calculates the area of ​​the cross-section in the width direction of the unit section based on the number of pixels of the photocuring width and the left and right coating slopes.

[0037] The weight calculation unit (13) calculates the slope of the cross-section in the width direction from the change in brightness in the width direction in the unit section image. When the photocurable adhesive is applied, parts marked as slope 1 and slope 2 in Fig. 1 occur, and a cross-section in the width direction appears as in (c). The parts corresponding to slope 1 and slope 2 are parts where brightness changes significantly, and there is a correlation between brightness and slope, which can be measured step by step.

[0038] The brightness E(d, θ) according to the light intensity I of the vision camera, the distance d between the vision camera and the applied photocurable adhesive, and the inclination θ of the photocurable adhesive reflective surface is Although it can be calculated as such, the change in d is very small compared to the value of d (approx. 100 mm), so the amount of change in E due to this change is relatively very small compared to the amount of change in E due to the change in θ, so it can be assumed to be a constant k, and thus E(θ) can be expressed as E(θ) = kcosθ, and the image brightness value Y = F(E) = F(kcosθ). From the image brightness value (Y), θ can be calculated as follows.

[0039]

[0040] The weight calculation unit (13) calculates the slope 1 and slope 2 shown in Figure 1 in pixel units and uses them to calculate the cross-sectional area in the width direction.

[0041] Figure 3 illustrates the concept of calculating the cross-sectional area of ​​a photocurable adhesive. h n is the height of the applied photocurable adhesive corresponding to the order of pixels along the width direction, and d p represents the horizontal distance corresponding to 1 pixel, and θ n represents the photocurable adhesive gradient of the corresponding pixel. S n represents the cross-sectional area of ​​the photocurable adhesive at the n-th pixel position. For the image sensor PCB, the 1-pixel horizontal distance can be obtained by determining the total length from the specifications of the image sensor PCB and from the number of pixels in the width direction of the image sensor PCB (same as the width direction of (b) in Fig. 1) in the captured image.

[0042] h in Fig. 3 n , S1, S2 is , , It can be calculated as follows. If we call the last pixel of the interval corresponding to slope 1 the n-th pixel, is. The cross-sectional area of ​​the section corresponding to slope 1 is S total If you say... It can be calculated as follows. The section corresponding to slope 2 can be calculated in the same way, and the middle section can be calculated by treating it as a rectangle. In this case, the height of the rectangle, h of the section corresponding to slope 1 k The sum and h of the interval corresponding to slope 2 k The higher value of the sum can be used. The cross-sectional area of ​​a unit section can be calculated by adding the cross-sectional area of ​​the section corresponding to slope 1, the cross-sectional area of ​​the section corresponding to slope 2, and the cross-sectional area of ​​the middle section.

[0043] The weight calculation unit (13) calculates the weight of the photocurable adhesive in a unit section by multiplying the cross-sectional area of ​​the unit section by the weight constant of the photocurable adhesive calculated in advance.

[0044] The weight calculation unit (13) calculates the weight of the photocurable adhesive for all unit sections and calculates the sum of these to calculate the total weight of the applied photocurable adhesive.

[0045] A camera module assembly device (10) according to an additional aspect of the present invention may further include a weight constant derivation unit (14).

[0046] The weight constant derivation unit (14) derives the weight constant of the photocurable adhesive by measuring the weight of the photocurable adhesive applied at the height of a unit section and the area of ​​the photocurable adhesive in an image captured through the vision camera unit (12), and then dividing the measured weight by the measured area.

[0047] The weight constant derivation unit (14) can obtain the weight of the applied photocurable adhesive by subtracting the weight of the sample PCB without the photocurable adhesive applied from the weight of the sample PCB with the photocurable adhesive applied.

[0048] Additionally, the weight constant derivation unit (14) can calculate the applied area by obtaining the surface area of ​​the applied photocurable adhesive in pixels from an image of a sample PCB coated with photocurable adhesive captured through a vision camera unit (12) and converting it. The weight constant derivation unit (14) can also obtain the horizontal distance per pixel using the specification information of the sample PCB and the number of pixels in the width direction of the sample PCB in the image, and convert this into a surface area.

[0049] The weight constant derivation unit (14) can derive the weight constant of the photocurable adhesive by dividing the calculated weight by the calculated area.

[0050] According to an aspect of the invention, the camera module device (10) may further include an electronic scale unit (not shown), and the weight may be measured by transferring the sample PCB to the electronic scale unit through the image sensor PCB alignment unit only when deriving the weight constant.

[0051] A camera module assembly device (10) according to an additional aspect of the present invention may further include a coating uniformity determination unit (15).

[0052] The coating uniformity determination unit (15) determines the coating uniformity of the photocurable adhesive from the calculated weight of the photocurable adhesive applied per unit section derived by the weight calculation unit (13).

[0053] Since photocurable adhesive is controlled to be dispensed in a constant amount, the weight should be constant across the entire coated section, but the actual coated weight may not be constant depending on the amount of adhesive remaining in the dispenser, etc.

[0054] Accordingly, the coating uniformity judgment unit (15) can determine that there is a problem, such as when the weight of the photocurable adhesive measured by the weight calculation unit (13) per unit section is larger or smaller than the weight of another section than the set error range, i.e., when the coating is not uniform, or when there is not much remaining adhesive left in the dispenser.

[0055] Depending on the aspect of the invention, the coating uniformity judgment unit (15) may additionally generate an alarm based on the coating uniformity of the photocurable adhesive. When this alarm is generated, the operator may inspect the dispenser, check the remaining amount of photocurable adhesive, and then proceed with replacement, etc.

[0056] A camera module assembly device (10) according to an additional aspect of the present invention may further include an alarm generating unit (16).

[0057] The alarm generating unit (16) generates an alarm when the weight of the applied photocurable adhesive calculated by the weight calculation unit (13) deviates from the set error range with respect to the set reference weight.

[0058] When the alarm occurs, the operator determines that there is a high probability that the camera module being assembled is defective and takes appropriate action. In addition, when this alarm occurs, the operator can inspect the dispenser to check the remaining amount of adhesive.

[0059] The various embodiments disclosed in this specification and drawings are provided merely as specific examples to aid understanding and are not intended to limit the scope of the various embodiments of the invention.

[0060] Accordingly, the scope of the various embodiments of the present invention should be interpreted as including all modifications or variations derived based on the technical concept of the various embodiments of the present invention, in addition to the embodiments described herein. Explanation of the symbols

[0061] 10: Camera module assembly device 11 : Adhesive part 12: Vision Camera Department 13: Weight calculation section 14: Weight Constant Derivation Section 15: Coating uniformity judgment unit 16: Alarm generator

Claims

Claim 1 A camera module assembly device comprising: an adhesive unit for applying a photocurable adhesive along the upper edge of a PCB to which a lens housing is to be attached or along the upper edge of a lens housing to which a lens module is to be attached; a vision camera unit for capturing an image of the photocurable adhesive applied along the upper edge of the PCB or the upper edge of the lens housing; and a weight calculation unit for calculating the weight of the photocurable adhesive applied for the entire application section from the captured image, wherein the weight calculation unit calculates the number of pixels of the photocurable adhesive width applied for each unit section, calculates the left and right application slopes by inverse calculation based on a brightness relationship formula according to the light intensity of the vision camera, the distance to the adhesive, and the slope of the adhesive reflection surface from the brightness change in the width direction of the corresponding unit section, calculates the area of ​​the cross-section in the width direction of the corresponding unit section based on the number of pixels of the photocurable width and the left and right application slopes, calculates the weight of the photocurable adhesive for the unit section by multiplying it by a previously calculated weight constant of the photocurable adhesive, and then calculates the total weight of the photocurable adhesive applied by summing the weights of all unit sections. Claim 2 A camera module assembly device further comprising: a weight constant derivation unit that derives a weight constant of a photocurable adhesive by dividing the measured weight of the photocurable adhesive applied at the height of a unit section and the area of ​​the photocurable adhesive in an image captured through a vision camera unit, and then dividing the measured weight by the calculated area. Claim 3 A camera module assembly device according to claim 1, further comprising: a coating uniformity determination unit that determines the coating uniformity of a photocurable adhesive from the calculated weight of the photocurable adhesive applied per unit section derived by the weight calculation unit. Claim 4 A camera module assembly device according to claim 1, further comprising an alarm generating unit that generates an alarm when the weight of the applied photocurable adhesive calculated by the weight calculation unit deviates from a set error range with respect to a set reference weight. Claim 5 A camera module assembly device according to claim 3, which generates an alarm based on the uniformity of the application of a photocurable adhesive determined by the uniformity of the application of the application of the photocurable adhesive determined by the uniformity of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the photocurable adhesive determined by application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the application of the

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