JP2012099522A - Electronic component mounting device and mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress and prevent board deformation around an opening of a circuit board that can occur when an imaging element is mounted on the circuit board including the opening for imaging.SOLUTION: In an area in which the opening for imaging and a housing recess are partially lined up in a direction perpendicular to the circuit board, when the length of the area along the inner edge of the opening for imaging is assumed to be L, each Ln (n=1 to 9) satisfies 0<Ln≤4t (t is the board thickness in an imaging element mounting area of the circuit board).

Description

  The present invention relates to a mounting apparatus and a mounting method for mounting an electronic component on a circuit board using so-called ultrasonic vibration.

  Along with the downsizing and higher functionality of electronic devices, circuit boards used in the electronic devices are also being downsized and highly integrated. As a high integration method, an electronic component is mounted on both sides of a circuit board. In mounting electronic components on such a circuit board, first, electronic components are mounted on one surface of the circuit board. Next, the mounting of the electronic component on the other surface is performed using a flat plate-shaped mounting table in which a recess for accommodating the electronic component mounted on the one surface is formed in advance, with the circuit board supported by the mounting table. Is done.

  Here, in order to reduce the size and increase the integration of electronic components to be mounted, the fabrication of such a mounting table also requires fine processing, and the manufacturing cost of the mounting table is a major problem. For this reason, as disclosed in Patent Document 1 or 2, for example, a simple method for manufacturing a mounting table that can provide an appropriate mounting table has been proposed. In these manufacturing methods, a plastic or elastic member is used on the mounting table or the surface thereof, and the convex portions due to the electronic parts can be absorbed, thereby achieving both the elimination of the influence of the concave and convex portions and the support of other flat portions. ing.

Japanese Patent Laid-Open No. 02-010900 Japanese Patent No. 3895825

  Here, an imaging element such as a so-called CMOS or CCD may be mounted on the circuit board. In such an imaging element mounting circuit board, an imaging opening that penetrates the circuit board may be provided in the element mounting region. In this case, when an electronic component is disposed in the vicinity of the imaging opening, the inner edge of the imaging opening is not sufficiently supported when the imaging element is mounted, and the inner edge is deformed, making it difficult to mount appropriately. There is a case. With the recent increase in the density of electronic components mounted on circuit boards, such difficulty is considered to increase.

  In actual mounting of electronic components, the fixed positions of all electronic components with respect to the circuit board must match without error due to the effects of manufacturing errors of electronic components or circuit boards, displacement of mounting positions for each circuit board, etc. Is not possible. In the technique disclosed in Patent Document 1, the influence of such an error cannot be eliminated, and it is necessary to manufacture a mounting jig for each circuit board. Therefore, an increase in manufacturing process or manufacturing cost is inevitable. In addition, when the same mounting jig is used, unnecessary addition to the electronic component occurs due to contact between the jig and the electronic component, and if it is excessive, an appropriate circuit board support situation may occur. It can be difficult. Also in the technique disclosed in Patent Document 2, it is inevitable that a pressing force is applied to the electronic component, and improvement is required from the viewpoint of whether the circuit board can always be properly supported. That is, with the methods disclosed in Patent Documents 1 and 2, it is considered that the above-described deformation of the inner edge of the imaging opening of the circuit board cannot be sufficiently dealt with.

  The present invention has been made in view of the above situation, and suppresses and prevents deformation of the circuit board around the imaging opening provided in the circuit board when the image sensor is mounted on the circuit board. However, it is an object of the present invention to provide an actual apparatus or mounting method for electronic components that support the circuit board.

  In order to solve the above problems, a mounting apparatus according to the present invention is arranged on the back surface of an electronic component with respect to a terminal electrode formed on one surface of a substrate having a through hole penetrating from one surface to the other surface. A mounting apparatus for mounting an electronic component on a substrate by bonding the formed bump, and holding the electronic component and pressing the bump against the terminal electrode to provide a bonding force for bonding the bump and the terminal electrode A mounting nozzle, and a mounting table that supports the other surface of the substrate when the mounting nozzle provides a bonding force, and the mounting table accommodates other electronic components mounted on the other surface of the substrate. The length L of the housing recess along the inner edge of the through hole in the region having the recess and where the through hole and the housing recess are at least partially aligned in the direction perpendicular to the substrate is such that the electronic component of the board is mounted. The thickness of the region to be t When, and satisfies the 0 <L ≦ 4t.

  In order to solve the above problems, the mounting method according to the present invention provides a back surface of an electronic component with respect to a terminal electrode formed on one surface of a substrate having a through-hole penetrating from one surface to the other surface. A mounting method for mounting an electronic component on a substrate by bonding bumps arranged on the substrate, the substrate being supported from the other surface by the mounting table, the electronic component being held by the mounting nozzle, There is a step of bonding the bump of the electronic component and the terminal electrode of the substrate by pressing the bump against the terminal electrode on the supported substrate by a mounting nozzle, providing a bonding force for bonding the bump and the terminal electrode. When the mounting table supports the substrate, the mounting table accommodates other electronic components mounted on the other surface of the substrate by the accommodating recess provided on the support surface, and accommodates the through hole in a direction perpendicular to the substrate. The length L of the accommodating recess along the inner edge of the through hole in the region where the portion is at least partially aligned is 0 <L ≦ 4t, where t is the thickness of the region where the electronic component of the substrate is mounted Satisfied.

  According to the present invention, it is possible to suppress the deformation of the inner edge of the photographing opening described above, and to mount the image sensor on the circuit board without being affected by the deformation.

It is a top view of the mounting base which is the principal part in the mounting apparatus which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1 with respect to the mounting table illustrated in FIG. 1 and the circuit board mounted on the mounting table. It is a figure which shows the relationship between Ln in an accommodation recessed part, and a mounting yield. It is a figure which shows schematic structure of the mounting apparatus which concerns on one Embodiment of this invention. It is a figure which shows the relationship between Lsam in an accommodation recessed part, and a mounting yield.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a state where a mounting table, which is a main part of a mounting apparatus according to an embodiment of the present invention, is viewed from above. In the figure, an image pickup device and electrodes collectively referred to as bumps provided on the image pickup device are indicated by dotted lines, and an image pickup opening provided on the circuit board is indicated by a solid line frame. FIG. 2 is an outline of a configuration when a cross section taken along line 2-2 in FIG. 1 is viewed from the side, and shows a circuit board and a mounting table. In the present embodiment, the circuit board 1 to be placed is provided in the concave portion 1a on the circuit board that can accommodate the imaging device 3 and the concave portion 1a on the circuit board, and penetrates from the upper surface 1b to the lower surface 1c of the circuit board. An imaging opening 1d made of a through hole is provided. These recesses 1a on the circuit board are disposed on one surface of the circuit board, and the imaging opening 1d is formed in a manner penetrating from the one surface to the other surface. Further, the image sensor 3 is also mounted on the one surface.

  In the present embodiment, the imaging element 3 has a rectangular shape, and a plurality of bumps 3b are arranged on the back surface 3a at positions along each of a pair of opposing sides. The recess 1a on the circuit board has an internal width and depth that can accommodate the imaging device 3, and the terminal electrode 5 is disposed at a position corresponding to the bump 3b. The bumps 3b are electrically joined to the terminal electrodes 5, whereby the image pickup device 3 is mounted on the circuit board 1. The electronic component 7 is already mounted on the lower surface 1 c of the circuit board 1.

  In the mounting apparatus according to an embodiment of the present invention, the present invention has the feature in the mounting table 11 that supports the circuit board 1. The mounting table 11 is provided with an accommodation recess having a size capable of accommodating the electronic component 7 mounted on the circuit board 1. The mounting table 11 supports the other surface of the circuit board 1 on its surface. In this embodiment, the case where the 12 accommodation recessed parts 11-1 to 11-12 are provided is illustrated. Here, in the present invention, when viewed from the top (see FIG. 1), the accommodation recess is partially observable from the imaging opening 1c, and a second accommodation that cannot be observed. It is divided roughly into a recess. That is, the housing recesses 11-1 to 11-9 correspond to the first housing recess having a region overlapping the imaging opening 1 c in the direction perpendicular to the circuit board 1. In addition, the housing recesses 11-10 to 11-12 correspond to the second housing recesses that do not have the overlapping region. Since the periphery of the second housing recess can be supported by the circuit board support surface 11a of the mounting table 11, the deformation of the circuit board is not particularly affected. However, since there is a portion of the first housing recess that does not support the inner edge of the imaging opening 1c in the circuit board 1, the inner edge may be deformed.

  Here, let L be the length of the portion along the inner edge of the imaging opening 1c for each of the receiving recesses 11-1 to 11-9 in the first receiving recess. In other words, according to the present invention, in the direction perpendicular to the circuit board 1, each of the imaging opening 1c and the receiving recesses 11-1 to 11-9 is at least partially aligned with the imaging opening. Let L be the length of the region along the inner edge of the portion 1c. In this embodiment, it is assumed that the accommodating recesses 11-1 to 11-9 have recess lengths L1 to L9, respectively. When the present applicant examined, if each of these Ln (n = 1 to 9) satisfies 0 <Ln ≦ 4t, the deformation of the circuit board at the inner edge is suppressed, and the circuit board 1 is imaged in a suitable state. It was confirmed that the element 3 can be mounted. Here, t represents the thickness of the circuit board 1 in the concave portion 1a on the circuit board, that is, the thickness of the circuit board in the mounting region of the image sensor 3 on the circuit board, as shown in FIG. The 4t symbol represents 4 × t, and the following similar symbols also represent the same calculation formula.

  Here, there is a possibility that the influence of the housing recess 11 may change depending on the amount d (see FIG. 1) that protrudes from the imaging opening. FIG. 3 shows the correlation between Ln and inner edge deformation in consideration of the value of d. In the figure, the horizontal axis indicates the value of Ln, and the vertical axis indicates the yield when the obtained imaging apparatus is mounted. Further, d small schematically shows a case where the protruding width of the housing recess with respect to the imaging opening is small, d shows a case where the protruding width is medium, and d large shows a case where the protruding width is large. As the protrusion width decreases, the influence of the receiving recess becomes smaller, but it is understood that the yield decreases with a critical value of Ln = 4t. From the figure, it is more preferable to set the upper limit of Ln to 3t in order to maintain the yield higher reliably.

  Next, the influence of the total sum Lsam of the lengths of the housing recesses on each side of the inner edge of the imaging opening will be described. When the length of one of the four inner edges is R (see FIG. 1), as shown in FIG. 5, if 0 <Lsam ≦ 0.5R is satisfied, deformation at the inner edge is suppressed, and a suitable state is obtained. Thus, it was confirmed that the image pickup device 3 can be mounted on the circuit board 1. FIG. 5 shows the correlation regarding the relationship between Lsam and inner edge deformation. In the figure, the horizontal axis indicates the value of Lsam, and the vertical axis indicates the yield when the obtained imaging apparatus is mounted. Further, sam = 1 corresponds to the case where the electronic component is accommodated by one large accommodating recess on the side with the inner edge, sam = 3 corresponds to the case of 3, and sam = 9 corresponds to the individual electronic component as described above. The case where nine accommodation recessed parts are used is shown. Since the distribution of the receiving recesses is dispersed with the increase in the receiving recesses, the influence of the receiving recesses is reduced, but it is understood that the yield decreases with Lsam = 0.5R as a critical value. From the figure, it is more preferable to set the upper limit of Lsam to 0.3 R in order to maintain the yield more reliably.

  Next, a mounting apparatus that is an embodiment of the present invention using the mounting table 11 described above will be described. FIG. 4 is a diagram showing a schematic configuration of a main part of the mounting apparatus 100. The mounting apparatus 100 includes a substrate support unit 10 that supports the circuit board 1, a component supply table 20 that supports the imaging device 3 or the electronic component 7, and a component take-in unit that supports a take-out nozzle that takes out the electronic component 7 and the like from the component supply table 20. 30 and a mounting portion 50 for supporting a mounting nozzle for mounting the electronic component 7 and the like on the circuit board 1. The substrate support unit 10 includes the mounting table 11 that actually supports the circuit board 1 by vacuum suction or the like, the X-axis drive motor 13 that drives the mounting table 11 in the X direction indicated by an arrow in the figure, and the arrow Y direction. A Y-axis drive motor 15 that drives the mounting table 11 and a component recognition camera 17 for recognizing the posture and the like of the image sensor 3 held by the mounting nozzle are provided. The component recognition camera 17 is fixed to the mounting table 11 and always maintains a certain positional relationship with the mounting table 11.

  The component supply table 20 includes a table 21 on which the imaging device 3 and the like are placed, a drive motor (not shown) that drives the table 21 in the XY direction, and a rotation drive motor 23 that rotationally drives the table 21 in the XY plane. have. On the table 21, an element mounting substrate having a shape substantially equal to the shape of a so-called wafer on which the imaging element 3 or the electronic component 7 is spread is fixed by vacuum suction or the like. These image pickup devices 3 and the like are simply placed on a component mounting board, and can be easily taken out from the board. The component take-in unit 30 includes a take-out nozzle 33 that is rotatably supported by a rotary shaft 31 that is turned upside down, and a take-out nozzle lifting motor 35 that drives the rotary shaft 31 and the like up and down. These components are integrated as a capturing unit 39 and supported by a capturing unit base 37 so as to be driven in the X-axis direction by a driving motor (not shown). The component take-in unit 30 further includes a recognition camera 41 and a pre-alignment camera 43 such as the image pickup device 3, which are independent of the take-in unit 39 including the take-out nozzle 33 and the like, and a base 37. Fixed and supported by

  The pre-alignment camera 43 images the image sensor 3 and the like held by the take-out nozzle 33. The video obtained by the pre-alignment camera 43 is subjected to image processing, and the amount of deviation from the reference position and reference posture when the image sensor 3 is held is obtained. These deviation amounts are obtained for each of the X-axis direction, the Y-axis direction, and the rotation angle θ. These deviation amounts are calculated by a control device (not shown), and the control device, together with the prealignment camera 43, constitutes a deviation amount detection means. The mounting unit 50 includes a mounting nozzle 51, a θ rotation motor 53, and a mounting nozzle lifting / lowering motor 55. The mounting nozzle 51 has a function capable of mounting the imaging element 3 and the like on the circuit board 1 using, for example, ultrasonic vibration. The θ rotation motor 53 rotates the mounting nozzle 51 around an axis perpendicular to the XY plane. The mounting nozzle raising / lowering motor 55 drives the mounting nozzle 55 and the θ rotation motor 53 up and down. These components are integrated as a mounting unit 57, and are supported by a mounting portion base 59 so as to be driven in the Y-axis direction by a driving motor (not shown). A substrate mark recognition camera 61 is fixed to the mounting unit 57 independently of the mounting nozzle 51, the θ rotation motor 53, and the mounting nozzle lifting / lowering motor 55.

  The driving of each component in the X-axis direction and the Y-axis direction described above is executed by a combination of a ball screw shaft and a guide rail that are directly connected to the driving motor. With respect to these configurations, various configurations of the mounting apparatus do not constitute the main features of the present invention, and therefore description thereof is omitted here. In addition, the configuration used for these driving operations is publicly known, and is preferably changed as appropriate from other known configurations according to the required stop accuracy and driving speed. In this embodiment, the take-out nozzle moves in the X-axis direction and the mounting nozzle moves in the Y-axis direction. However, the take-out nozzle moves in the Y-axis direction and the mounting nozzle moves in the X-axis direction. It is also good.

  Next, a mounting process using the mounting apparatus 100 will be described. In the mounting process according to the embodiment of the present invention, the circuit board 1 is supported by the mounting table 11, the image sensor 3 is held by the mounting nozzle 51, the pressing force and the bonding force from the mounting nozzle 51 are applied, and the bumps of the image sensor 3. 3b and the terminal electrode 5 are joined. With these steps, in the present invention, the electronic component 7 other than the image sensor 3 is accommodated by the accommodating recess provided on the support surface 11a of the mounting table 11, and the circuit board 11 is supported on the support surface 11a. Support. At this time, as described above, in the direction perpendicular to the circuit board 1, the imaging openings 1c and the receiving recesses 11-1 to 11-9 are each imaged in an area at least partially aligned. Let L be the length of the region along the inner edge of the opening 1c. In this embodiment, when it is further assumed that the housing recesses 11-1 to 11-9 have the recess lengths L1 to L9, each of these Ln (n = 1 to 9) satisfies 0 <Ln ≦ 4t. It is characterized by that.

  In the above-described embodiment, a mode is described in which a plurality of bumps 3b are arranged along each of a pair of opposing sides of the rectangular imaging element 3. However, the relationship between the yield at the time of mounting described above and Ln and Lsam is not limited to this mode. A mode in which bumps are juxtaposed in a row along only one side of the image sensor, or bumps are arranged on all four sides. The same holds true for the mode to be performed. Further, even when the number of housing recesses is larger than that of the mounted electronic component, the deformation of the circuit board is suitably suppressed as long as the above relationship between Ln and Lsam and t and R is satisfied. Is possible. Therefore, the same mounting table can be used on the premise that the above relationship is satisfied even in a mounting operation using a combination of different circuit boards and image pickup devices. Therefore, the effect of suppressing the cost required for changing and forming the mounting table and the extension of the process time can be obtained.

  The present invention is directed to an apparatus and a mounting method for mounting an imaging element on a circuit board having an imaging opening. However, the concept of the present invention is not limited to this aspect, and a mounting apparatus for mounting an electronic component or the like by supporting a circuit board having a through hole penetrating from the upper surface to the lower surface or a portion corresponding to the strength from the lower surface side. It is applicable to the manufacturing method. The concept of the present invention applies not only to the mounting of electronic components, but also to the case where an electrode paste is applied to a circuit board with a squeegee, for example, and the previous through hole or the like exists in the circuit board. Applicable. Therefore, in the present invention, it is preferable to identify the imaging device as an electronic component and the circuit board as a substrate, and to grasp the present invention as a higher concept.

DESCRIPTION OF SYMBOLS 1: Circuit board 3: Imaging element 5: Terminal electrode 7: Electronic component 10: Board | substrate support unit 11: Mounting stand 13: X-axis drive motor 15: Y-axis drive motor 17: Component recognition camera , 20: parts supply table, 21: table, 23: motor for rotation drive, 30: parts take-in part, 31: rotating shaft, 33: take-out nozzle, 35: motor for raising / lowering nozzle, 37: take-in part base 39: take-in Unit: 41: camera, 43: pre-alignment camera, 50: mounting unit, 51: mounting nozzle, 53: θ rotation motor, 55: mounting nozzle lifting motor, 57: mounting unit, 61: substrate mark recognition camera

Claims (2)

The electronic component is bonded to the substrate by bonding a bump disposed on the back surface of the electronic component to a terminal electrode formed on the one surface of the substrate having a through hole penetrating from one surface to the other surface. A mounting device for mounting against
A mounting nozzle that holds the electronic component and presses the bump against the terminal electrode to provide a bonding force for bonding the bump and the terminal electrode;
A mounting table that supports the other surface of the substrate when the mounting nozzle provides the bonding force;
The mounting table has an accommodation recess capable of accommodating other electronic components mounted on the other surface of the substrate,
The length L of the housing recess along the inner edge of the through hole in a region where the through hole and the housing recess are at least partially aligned in a direction perpendicular to the substrate is determined by the electronic component of the board. A mounting apparatus characterized by satisfying 0 <L ≦ 4t, where t is a thickness of a region to be mounted. The electronic component is bonded to the substrate by bonding a bump disposed on the back surface of the electronic component to a terminal electrode formed on the one surface of the substrate having a through hole penetrating from one surface to the other surface. An implementation method that implements for
The substrate is supported from the other surface by a mounting table, and the electronic component is held by a mounting nozzle,
For the terminal electrode on the substrate supported by the mounting table, pressing the bump by the mounting nozzle, providing a bonding force for bonding the bump and the terminal electrode,
A step of bonding the bump of the electronic component and the terminal electrode of the substrate;
When the mounting table supports the substrate, the mounting table accommodates another electronic component mounted on the other surface of the substrate by a housing recess provided on the support surface,
The length L of the housing recess along the inner edge of the through hole in a region where the through hole and the housing recess are at least partially aligned in a direction perpendicular to the substrate is determined by the electronic component of the board. A mounting method characterized by satisfying 0 <L ≦ 4t, where t is a thickness of a region to be mounted.

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