JP5209441B2 - Mounting component inspection apparatus and inspection method - Google Patents

Description

  The present invention relates to an inspection apparatus and an inspection method for a mounted state of an electronic component mounted on a substrate via an anisotropic conductive member.

  For example, a liquid crystal cell as a substrate is formed by facing the inner surfaces of two glass plates with deflecting plates attached to the outer surfaces and pasting them together with a sealant at a predetermined interval, and enclosing the liquid crystal between these glass plates. The

  A TCP (Tape Carrier Package) as a driving electronic component is mounted on the side portion of the liquid crystal cell. When TCP is mounted on the side of the liquid crystal cell, a tape-like anisotropic conductive member is attached to the side, and the TCP is temporarily pressure-bonded thereto, and then the TCP is heated and pressurized with a pressure-bonding tool. In this way, the anisotropic conductive member is melt-cured and subjected to final pressure bonding.

  Patent Document 1 discloses a mounting apparatus that performs main pressure bonding (mounting) on the side of the liquid crystal cell with an anisotropic conductive member.

  If TCP is finally pressure-bonded to the liquid crystal cell, it is inspected whether or not the mounting is reliably performed. The inspection of the mounting state of the TCP on the liquid crystal cell is performed by checking whether or not the metal particles contained in the anisotropic conductive member interposed between the TCP and the substrate are crushed, that is, the TCP and the liquid crystal cell by the metal particles. It is determined by whether or not these terminals are electrically connected securely.

  That is, if the TCP is mounted on the upper surface of the side portion of the liquid crystal cell, the mounted portion is imaged by the imaging camera from the lower surface side of the liquid crystal cell. Since the liquid crystal cell is formed of a transparent glass plate, the state of metal particles contained in the anisotropic conductive member interposed between the glass plate and the TCP can be observed through the glass plate. Thereby, the quality of the TCP mounting state can be determined.

  When the TCP mounting part is imaged by the imaging camera, the imaging camera is positioned and driven so that the focal position of the imaging camera matches the anisotropic conductive member between the liquid crystal cell and the TCP.

  The imaging camera has a high magnification so that the metal particles contained in the anisotropic conductive member are fine so that the metal particles can be observed reliably. For this reason, since the imaging camera has a shallow depth of focus and a narrow field of view, it may take a lot of time to adjust the focal position to the anisotropic conductive member interposed between the liquid crystal cell and the TCP.

In general, in order to adjust the focus position of an imaging camera to a subject, an active method in which the distance between the imaging camera and the subject is measured in advance by a measuring means, and the imaging camera is driven and positioned based on the result is called an active method. And a second method called a passive method in which an imaging camera sequentially captures an image within a predetermined range from one direction and positions the imaging camera at a position where the most out-of-focus image is obtained. It has been.
JP 2003-234373 A

  The active method has an advantage that the time required for alignment can be made relatively short because the movement amount of the imaging camera can be set in advance. However, since a measuring means for measuring the distance between the imaging camera and the subject is required, there is a demerit that the configuration is complicated and the cost is increased.

  Since the passive method does not require a measuring means, it can be configured at a lower cost than the active method. However, it may take time to search for a position where the focus position of the imaging camera matches the subject.

  Moreover, if the range in which the imaging camera is moved (drive range) is too large, it may take a long drive time until the focal position matches the subject. Conversely, if the drive range is narrowed, the subject is within the drive range. There is also a case where there is no focus position of the imaging camera that coincides with.

  It is an object of the present invention to provide a mounting component inspection apparatus and inspection method which can quickly and surely position the focal point of an imaging means at a predetermined position.

The present invention is an inspection apparatus for inspecting the mounting state of an electronic component mounted on a substrate,
Imaging means for imaging the mounting state of the electronic component mounted on the substrate;
Driving means for driving the image pickup means in a direction of coming into contact with and separating from the electronic component mounted on the substrate;
Determining means for determining whether the focus of the imaging means is in a predetermined position based on an image signal from the imaging means;
A drive control unit that operates the driving unit based on the determination of the determination unit to drive the imaging unit and adjust the focus of the imaging unit to a predetermined position;
Storage means for storing and storing the focal position of the imaging means by the driving means when the focus of the imaging means is adjusted to a predetermined position;
A setting unit configured to set a driving range of the imaging unit based on a focal position of the imaging unit stored and accumulated in the storage unit when the focus of the imaging unit is repeatedly aligned ;
The storage means stores and accumulates the focal position of the imaging means for each position of a plurality of electronic components mounted according to the type of board and the type of board.
When the focus of the image pickup means is aligned, the image pickup means is based on the focus position of the image pickup means stored and stored in the storage means divided into a plurality of electronic components mounted on the same position on the same type of substrate. The driving range of the mounting component inspection apparatus is set.

  The setting means obtains a standard deviation from an average value of a plurality of focal positions of the imaging means accumulated in the storage means, and sets a driving range of the imaging means within a range three times the standard deviation. Is preferred.

The electronic component is mounted on the side portion of the substrate by an anisotropic conductive member,
The imaging means preferably images the anisotropic conductive member interposed between the substrate and the electronic component through the substrate.

This invention is an inspection method for inspecting the mounting state of an electronic component mounted on a substrate,
Imaging the mounting state of the electronic component mounted on the substrate by an imaging means;
When imaging the mounting state of the electronic component, driving the imaging means in a direction to be in contact with and away from the electronic component mounted on the substrate to focus the imaging unit at a predetermined position;
Determining whether or not the imaging means is in focus at the predetermined position based on an image signal from the imaging means;
Driving the imaging means based on the determination to focus the imaging means on the predetermined position;
Storing and storing the focal position of the imaging means driven by the driving means when the imaging means is focused on a predetermined position;
The step of setting the drive range of the imaging means based on the stored focal position of the imaging means when repeatedly performing the focus alignment of the imaging means ;
The storage and accumulation of the drive position of the image pickup means is in an electronic component inspection method characterized by being classified according to the type of substrate and the position of the electronic component mounted on the substrate .

When a plurality of the electronic components are mounted on each of two or more side portions of the four side portions of the substrate, the drive range of the imaging unit is set on each side portion of the substrate. It is preferable to set the same value for each side part for a plurality of electronic components.
When a plurality of the electronic components are mounted on the side portion of the board, the drive range of the imaging means is set by obtaining a standard deviation from the stored and accumulated focal positions of the plurality of electronic components on the side portion. It is preferable to set based on the standard deviation.

  According to the present invention, when the imaging means is driven by the driving means and the focal position of the imaging means when the focus is adjusted to a predetermined position is stored and accumulated, and the focus alignment of the imaging means is repeatedly performed, The drive range of the imaging means is set based on the accumulation.

  For this reason, the driving range of the imaging unit is narrowed based on the stored and accumulated focal position, and the focal point of the imaging unit can be aligned within the driving range of the imaging unit. It can be done quickly and reliably.

  An embodiment of the present invention will be described below with reference to the drawings.

  The inspection apparatus of the present invention shown in FIG. 1 includes a drive mechanism 1 that drives and positions a substrate W such as a liquid crystal cell in the horizontal direction. The drive mechanism 1 has a base member 2, and an X table 3 that is movable in the X direction indicated by an arrow in FIG. The X table 3 is driven in the X direction by an X drive source 4 provided at one end of the base member 2.

  The X table 3 is provided with a Y table 5 that is movable along a Y direction orthogonal to the X direction. The Y table 5 is driven in a Y direction orthogonal to the X direction by a Y drive source 6 provided at one end of the X table 3.

  As shown in FIGS. 2 and 3, among the four sides of the substrate W, for example, one side is provided with a plurality of transparent metal terminals 11 having a width dimension of μm at predetermined intervals. 11, a plurality of TCPs 8 as electronic components, for example, eight TCPs 8 (each TCP is denoted by 8 a to 8 h) as shown in FIG. 2 are arranged at predetermined intervals via the tape-like anisotropic conductive member 12. Fully crimped.

  Before the final bonding of the TCP 8 to the side portion of the substrate W, the metal fine particles 13 contained in the anisotropic conductive member 12 are in a spherical state at a predetermined interval in the horizontal direction as shown in FIG. Is distributed. When the TCP 8 is finally press-bonded to the side portion of the substrate W, the metal fine particles 13 are crushed by the TCP 8 and the substrate W to become elliptical or non-circular as shown in FIG.

  Thereby, after the TCP 8 is finally pressure-bonded to the substrate W via the anisotropic conductive member 12, it is confirmed whether or not the metal fine particles 13 contained in the anisotropic conductive member 12 are sufficiently crushed. Thus, it is possible to determine whether or not the TCP 8 is securely bonded to the side portion of the substrate W.

The TCP 8 that is finally press-bonded to the substrate W is imaged from the lower surface side of the substrate W as will be described later by the imaging camera 15 as the imaging means disposed at the confirmation position of the base member 2 for the quality of the crimped state. It is confirmed. The mounting state of the TCP 8 is determined based on the above-described collapsed state of the metal fine particles 13 based on the imaging.

  As shown in FIG. 1, the imaging camera 15 is provided vertically on the upper surface of the vertical movable body 17 with the imaging window 15 a facing upward. The vertically movable body 17 is guided by the linear guide 16 and can move up and down. A feed screw 18 rotatably supported by the linear guide 16 is screwed to the vertical movable body 17. The feed screw 18 is rotationally driven by a vertical drive source 19 as drive means. As a result, the vertical movable body 17 provided with the imaging camera 15 is driven in the vertical direction.

  The imaging signal of the imaging camera 15 that images the TCP 8 main compression bonding state is output to the image processing unit 21 as shown in FIG. The image processing unit 21 converts the imaging signal of the imaging camera 15 from an analog signal to a digital signal and outputs the converted signal to the determination unit 23 provided in the control device 22.

  In the determination unit 23, whether or not the focus of the image captured by the imaging camera 15 matches a predetermined position in the height direction, that is, the height position of the anisotropic conductive member 12 interposed between the TCP 8 of the substrate W. Determine whether.

  That is, the determination is based on the imaging signal from the imaging camera 15 digitized by the image processing unit 21 with respect to the longitudinal direction of the metal terminal 11 provided on the side of the substrate W by the determination unit 23, for example. Are scanned along the width direction, and the white of the image at that time is set to (0), black is set to (1), the distribution state of (0) and (1) is examined, and the focus is determined by the result. It is determined whether or not.

  If the focus position of the imaging camera 15 matches the height position of the anisotropic conductive member 12 provided between the substrate W and the TCP 8, that is, the height position of the metal terminal 11 provided on the substrate W. The metal terminal 11 is determined as black (1), and the other portions are determined as white (0). Therefore, when the imaging camera 15 is focused on the height position of the metal terminal 11, the distribution state of (1) and (0) is such that the boundary between both ends in the width direction of the metal terminal 11 is shown in FIG. Since it is clearly divided, it becomes a state with a step vertically.

  On the other hand, when the focus of the imaging camera 15 is not aligned with the height position of the metal terminal 11, (1) and (0) at the boundary portions at both ends in the width direction of the metal terminal 11 as shown in FIG. ) Becomes unclear, and the boundary portion is a gentle curve.

  Therefore, for example, the imaging camera 15 is driven in a predetermined height range from the lower side to the upper side to scan the portion of the substrate W to which the TCP 8 is permanently bonded from the lower surface side. Then, the image that is not out of focus of the imaging camera 15 within the scanning range is determined by the determination unit 23, and the imaging camera 15 is moved to the height at that time. That is, the focus position of the imaging camera 15 is matched with the height position of the anisotropic conductive member 12.

  If the focus position of the imaging camera 15 is adjusted to the height position of the anisotropic conductive member 12, the operator determines the quality of the TCP 8 mounting state from the image at that position, and further the focus of the imaging camera 15 at that time. The position is stored in the storage unit 24 in association with the X and Y coordinates of the Y table 5. Note that the type of the substrate W at this time is stored in advance.

  As described above, eight TCPs 8a to 8h are mounted on one side portion of the substrate W. Therefore, when imaging each TCP 8a to 8h in association with the type of the substrate W and the X and Y coordinates of the Y table 5, the height position at which the focus of the imaging camera 15 coincides with the anisotropic conductive member 12 is the TCP 8a to 8h. Each time it is stored in the storage unit 24.

  In the storage unit 24, the data of the focal position of the imaging camera 15 for the eight TCPs 8a to 8h is accumulated a plurality of times, for example, about 10 times for each TCP 8a to 8h. The data accumulated in the storage unit 24 is sent to the setting unit 27. In the setting unit 27, an average value m of data for each TCP 8a to 8h is obtained, and a standard deviation σ for each TCP 8a to 8h is calculated from the average value m.

  FIG. 7 shows the state of the imaging camera 15 when the focal position of the imaging camera 15 coincides with the anisotropic conductive member 12, for example, when the focal position of the imaging camera 15 is performed 10 times for one TCP 8a. It is explanatory drawing when plotting a height position, calculating | requiring the average value m of those height positions, and also calculating | requiring the standard deviation (sigma).

  As described above, based on the focal position of the imaging camera 15 when the focus of the imaging camera 15 for imaging the TCPs 8 a to 8 h stored in the storage unit 24 is adjusted to the height of the anisotropic conductive member 12. When the setting unit 27 finishes obtaining the standard deviation σ of the height position of the imaging camera 15 for each TCP 8a to 8h, when imaging the next TCP 8, for example, the TCP 8 mounted on the next substrate W, The imaging camera 15 is driven by the drive control unit 26 in the vertical direction within the range of three times the standard deviation σ for each of the TCPs 8a to 8h, that is, within the range of 3σ.

That is, when the focusing of the imaging camera 15 is repeatedly performed on the TCPs 8a to 8h of the plurality of substrates W in order to determine the mounting state, the upper and lower sides of the imaging camera 15 are determined based on the standard deviation σ obtained by the setting unit 27. The direction scanning range is set to a range three times the standard deviation σ.

  Thereby, statistically, the focal position of the imaging camera 15 can be quickly and reliably aligned with the anisotropic conductive member 12 in which the eight TCPs 8a to 8h are mounted on one side of the substrate W. Therefore, the operator can efficiently and surely determine the mounting state of the eight TCPs 8a to 8h, that is, the degree of collapse of the metal fine particles 13 included in the anisotropic conductive member 12 with the naked eye.

  FIG. 8 is a flowchart illustrating the above-described operation. That is, in STEP 1, the substrate W is driven and positioned at a position for confirming the crimped state of the TCP 8. At the same time, the imaging camera 15 is positioned at the scanning start position.

  In STEP2, the imaging camera 15 is scanned from below to above. In STEP 3, after moving the imaging camera 15 to a position where an unfocused image can be obtained within the scanning range of the imaging camera 15, the mounting state of the TCP 8 is determined based on the image. At the same time, the height position of the imaging camera 15 at that time is accumulated.

  In STEP 4, the height position of the imaging camera 15 that is not out of focus with respect to all the TCPs 8 mounted on the substrate W is obtained and stored. In STEP 5, the scanning range of the imaging camera 15 with respect to the new substrate W is determined from the height position of the focus of the imaging camera 15 with respect to each accumulated TCP 8, and the TCP 8 mounted on the new substrate W is determined based on the determined scanning range. The above operation is repeated.

  As described above, when the mounting state of the eight TCPs 8a to 8h mounted on one side of the substrate W is imaged and determined by the imaging camera 15, each of the TCPs 8a to 8h is determined depending on the bending state of the substrate W or the like. Since the height may be different, it may be necessary to change the focus position of the imaging camera 15 according to the height and take an image.

  In that case, when the operator relies on his skill level and scans the imaging camera 15 in the vertical direction to focus, the imaging camera 15 is used with a narrow depth of focus and a narrow field of view. However, workability will be greatly reduced.

  However, if the quality of the substrate W is the same, such as when the same number of TCPs 8 are mounted, the TCP 8 is imaged if it is the same position in the X and Y directions of each substrate W. Therefore, it can be considered that the focal position of the imaging camera 15 is substantially the same or the deviation thereof is within a predetermined range, that is, within a range of three times the standard deviation σ.

  Therefore, as described above, at each TCP 8 position, the height position where the focus of the imaging camera 15 matches the anisotropic conductive member 12 is obtained a plurality of times, and the average value m and the standard deviation are obtained from the data of the plurality of times. If σ is calculated and the imaging camera 15 is scanned in the vertical direction within a range of three times the standard deviation σ, the focal position of the imaging camera 15 is anisotropically conductive within the scanning range in most cases. It becomes possible to match the member 12.

  In this way, if the scanning range in the vertical direction of the imaging camera 15 is within the range of three times the standard deviation σ, the driving range can be sufficiently narrowed, so that the focusing of the imaging camera 15 can be performed quickly and accurately. Can be performed.

Note that the substrate W may be two or more, respectively it side portions of the multiple TCP8 of the four side portions are mounted. In that case, as described above, the standard deviation σ of each of the plurality of TCPs 8 for each side is obtained, the standard deviation σ for each side is obtained from the standard deviation σ for each TCP 8, and the standard for each side is obtained. The scanning range in the vertical direction of the imaging camera 15 may be set to be the same for a plurality of TCPs 8 provided on one side portion based on the deviation σ.

  That is, the standard deviation σ may be set for each TCP 8, but the standard deviation σ is set for each side portion, and the vertical scanning range of the imaging camera 15 is set for each side. You may do it.

  Further, when a plurality of TCPs 8 are mounted on one side portion of the substrate W, one standard deviation σ is obtained from the standard deviation σ of the plurality of TCPs 8 for the entire TCP 8 on one side portion, and the standard is obtained. The vertical scanning range of the imaging camera 15 may be set for a plurality of TCPs 8 based on the deviation σ.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of the inspection apparatus which shows one embodiment of this invention. The top view which shows the one end part of the board | substrate with which TCP was mounted. The side view which expands and shows the one end part of the board | substrate with which TCP was mounted. (A) is a figure for demonstrating the state of the metal microparticle of the anisotropic conductive member when TCP mounting is uncertain, (b) is the anisotropic conductive member when TCP mounting is performed reliably The figure for demonstrating the state of the metal microparticle. (A) is explanatory drawing of the state of an image when the imaging camera is focused on the metal terminal, (b) is an explanatory diagram of the state of the image when the imaging camera is not focused on the metal terminal. The block diagram of a control system. Explanatory drawing in order to obtain | require the standard deviation when image | photographing TCP of the same position in multiple times with the imaging camera. The flowchart which shows the operation | movement of positioning of a board | substrate and imaging with an imaging camera.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drive mechanism, 11 ... Metal terminal, 12 ... Anisotropic conductive member, 13 ... Metal fine particle, 15 ... Imaging camera (imaging means), 19 ... Vertical drive source (drive means), 21 ... Image processing part, 22 ... Control unit, 23 ... determination unit (determination unit), 24 ... storage unit (storage unit), 26 ... drive control unit (drive control unit), 27 ... setting unit (setting unit).

Claims (6)

An inspection device for inspecting a mounting state of an electronic component mounted on a substrate,
Imaging means for imaging the mounting state of the electronic component mounted on the substrate;
Driving means for driving the image pickup means in a direction of coming into contact with and separating from the electronic component mounted on the substrate;
Determining means for determining whether the focus of the imaging means is in a predetermined position based on an image signal from the imaging means;
A drive control unit that operates the driving unit based on the determination of the determination unit to drive the imaging unit and adjust the focus of the imaging unit to a predetermined position;
Storage means for storing and storing the focal position of the imaging means by the driving means when the focus of the imaging means is adjusted to a predetermined position;
A setting unit configured to set a driving range of the imaging unit based on a focal position of the imaging unit stored and accumulated in the storage unit when the focus of the imaging unit is repeatedly aligned ;
The storage means stores and accumulates the focal position of the imaging means for each position of a plurality of electronic components mounted according to the type of board and the type of board.
When the focus of the image pickup means is aligned, the image pickup means is based on the focus position of the image pickup means stored and stored in the storage means divided into a plurality of electronic components mounted on the same position on the same type of substrate. An inspection apparatus for mounted parts, characterized in that a driving range is set.   The setting means obtains a standard deviation from an average value of a plurality of focal positions of the imaging means accumulated in the storage means, and sets a driving range of the imaging means within a range three times the standard deviation. The mounting component inspection apparatus according to claim 1. The electronic component is mounted on the side portion of the substrate by an anisotropic conductive member,
2. The mounting component inspection apparatus according to claim 1, wherein the imaging means images the anisotropic conductive member interposed between the substrate and the electronic component through the substrate. An inspection method for inspecting a mounting state of an electronic component mounted on a substrate,
Imaging the mounting state of the electronic component mounted on the substrate by an imaging means;
When imaging the mounting state of the electronic component, driving the imaging means in a direction to be in contact with and away from the electronic component mounted on the substrate to focus the imaging unit at a predetermined position;
Determining whether or not the imaging means is in focus at the predetermined position based on an image signal from the imaging means;
Driving the imaging means based on the determination to focus the imaging means on the predetermined position;
Storing and storing the focal position of the imaging means driven by the driving means when the imaging means is focused on a predetermined position;
The step of setting the drive range of the imaging means based on the stored focal position of the imaging means when repeatedly performing the focus alignment of the imaging means ;
The electronic component inspection method according to claim 1, wherein the storage and storage of the driving position of the imaging means is classified according to the type of the substrate and the position of the electronic component mounted on the substrate . When a plurality of the electronic components are mounted on each of two or more of the four side portions of the substrate, the driving range of the imaging unit is set on each side portion of the substrate. 5. The method of inspecting an electronic component according to claim 4, wherein the same is set for each side portion of the plurality of electronic components. When a plurality of the electronic components are mounted on the side portion of the board, the drive range of the imaging means is set by obtaining a standard deviation from the stored and accumulated focal positions of the plurality of electronic components on the side portion. 5. The electronic component inspection method according to claim 4, wherein the inspection is set based on the standard deviation.

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