JP2021015917A - Mounting device - Google Patents

Abstract

To provide a mounting device capable of inspecting positional deviation of an electronic component and a board after mounting, without compromising production efficiency.SOLUTION: A mounting device 30 for mounting an electronic component 2 on a board 3 has a bonding head 31 for transporting the electronic component 2 and mounting it on a board 3, a board stage 33 for placing the board 3, and an inspection unit 40 for inspecting positional deviation of the electronic component 2 and the board 3 after mounting. The inspection unit 40 has a height detector 41 provided in the bonding head 31 and detecting the height of the bonding head 31 when the electronic component 2 is mounted on the board 3 by means of the bonding head 31, imaging means 42 having a lens and imaging the electronic component 2 and the board 3 after being mounted, an imaging means lifting mechanism 43 for lifting the imaging means 42, and a control section for controlling the imaging means lifting mechanism 43 to adjust the height of the imaging means 42, on the basis of the height of the bonding head 31 detected by the height detector 41.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electronic component mounting device.

For mounting electronic components on a substrate, for example, flip chip mounting is performed. Flip-chip mounting is a method of mounting a substrate on which a conductive pattern is formed with the surfaces on which electrodes of electronic components such as semiconductor chips are formed facing each other. In flip-chip mounting, it is necessary to directly bond the fine electrodes of the electronic component to the fine terminals formed in the conductive pattern of the substrate, so the electronic component and the substrate must be positioned accurately.

Japanese Unexamined Patent Publication No. 10-125728

In recent years, the mounting accuracy has been improved by miniaturizing and increasing the density of circuits of electronic components such as semiconductor chips. Therefore, after mounting the electronic component, the alignment mark provided on the electronic component and the substrate is imaged by an imaging means, and the positional deviation between the electronic component and the substrate after mounting is inspected. A high magnification lens is used in this inspection. When the lens has a high magnification, the depth of field, which is the range in which the image is in focus, is very shallow. Therefore, if there are variations in the height of electronic components or the height of the substrate, the depth of field will deviate from the depth of field. In some cases, the captured image was out of focus and the misalignment could not be inspected with high accuracy.

Therefore, it is conceivable to measure the height of the mounted electronic component or substrate to be imaged with a laser displacement meter and adjust the height of the imaging means based on the height. However, in the measurement by the laser displacement meter, the height of the electronic component or the substrate after mounting must be measured separately, and the tact becomes worse.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a mounting device capable of inspecting a misalignment between an electronic component and a substrate after mounting without impairing production efficiency. To provide.

The mounting device of the present invention is a mounting device that mounts an electronic component on a substrate, and has a bonding head that conveys the electronic component and mounts the electronic component on the substrate, a substrate stage on which the substrate is placed, and the mounting. The electronic component and the inspection unit for inspecting the positional deviation from the substrate are provided, and the inspection unit is provided on the bonding head, and the electronic component is mounted on the substrate by the bonding head. An image pickup means that has a height detection unit that detects the height of the bonding head, has a lens, and images the electronic component and the substrate after the mounting, and an image pickup means elevating mechanism that raises and lowers the image pickup means. It has a control unit that controls the image pickup means elevating mechanism so as to adjust the height of the image pickup means based on the height of the bonding head detected by the height detection unit.

According to the present invention, it is possible to obtain a mounting device capable of inspecting the positional deviation between an electronic component and a substrate after mounting without impairing production efficiency.

It is a top view which shows the electronic component mounting system to which the mounting apparatus of embodiment is applied. It is a front view which shows the electronic component mounting system to which the mounting apparatus of embodiment is applied. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 2, which shows a state in which an imaging means is inserted between a bonding head and a substrate stage in order to image an electronic component and a planned mounting position on a substrate. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 2, which shows a state in which an electronic component held by a bonding head is mounted on a substrate. It is a functional block diagram of a control device. It is a figure which shows the state that the electronic component is mounted on the substrate by the face-down method. It is a figure which shows the state which the alignment mark of an electronic component and the alignment mark of a substrate are aligned. It is a figure which shows the state which the alignment mark of an electronic component and the alignment mark of a substrate are deviated. This is an example of an operation flowchart of an electronic component mounting system. It is a schematic diagram of the captured image taken by focusing on the alignment mark of the electronic component rather than the substrate. It is a schematic diagram of the captured image taken by focusing on the alignment mark of the substrate rather than the electronic component.

(Embodiment)
(Constitution)
An embodiment of the mounting device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an electronic component mounting system to which the mounting device of the embodiment is applied. FIG. 2 is a front view showing an electronic component mounting system to which the mounting device of the embodiment is applied.

The electronic component mounting system 1 is a system for mounting the electronic component 2 on the substrate 3. The electronic component 2 is, for example, a semiconductor chip made of silicon. In the present embodiment, the electronic component 2 is a semiconductor chip on which bumps, which are protruding electrodes, are formed of a solder material. The electronic component 2 is provided with an alignment mark. Assuming that the electronic component 2 has a rectangular shape, alignment marks are provided at the four corners or diagonal corners of the surface on which the bumps are formed.

The substrate 3 is a plate-like body on which the electronic component 2 is mounted. A conductive pattern to which bumps are connected is formed on the substrate 3. A mounting position for the electronic component 2 is provided on the surface of the substrate 3 on which the conductive pattern is formed. A plurality of planned mounting positions are provided here, and are arranged in an array. Alignment marks are provided at the planned mounting positions. For example, assuming that the electronic component 2 has a rectangular shape, the alignment marks are provided at the four corners or diagonal corners of the rectangular mounting scheduled position. After aligning the alignment marks of the electronic component 2 and the substrate 3, the electronic component 2 is mounted at the planned mounting position of the substrate 3.

The electronic component mounting system 1 includes a supply device 10, a pickup device 20, a mounting device 30, and a control device 50. The pickup device 20 picks up the electronic component 2 from the supply device 10 and mounts the electronic component 2. It is delivered to the device 30, and the electronic component 2 is mounted on the substrate 3 by the mounting device 30.

The supply device 10 is a device that supplies the electronic component 2. Specifically, the supply device 10 has a supply stage 11 on which the sheet 12 on which the electronic component 2 is placed is placed. The supply device 10 moves the supply stage 11 so that the electronic component 2 to be picked up comes to the supply position P1. The supply position P1 is a position where the electronic component 2 to be picked up by the pickup device 20 is scheduled to be picked up by the pickup device 20. For example, a camera 13 is provided above the supply position P1 so that the optical axis coincides with the supply position P1, and the supply device 11 has the electronic component 2 to be picked up at the image pickup center of the camera 13. The supply stage 11 is moved.

The sheet 12 on which the electronic component 2 placed on the supply stage 11 is placed is a wafer sheet here. The sheet 12 is an adhesive sheet, and electronic components 2 are arranged in a matrix on the sheet 12. The electronic component 2 may be arranged face-up with the bumps exposed upward, or may be arranged face-down with the bumps in contact with the sheet 12. In this embodiment, it is assumed that they are arranged face-up.

When the electronic component 2 is supplied to the pickup device 20, the supply device 10 pushes up the electronic component 2 on the supply position P1 via the sheet 12 with a needle-shaped pin provided below the supply position P1 to push up the electronic component 2 on the supply position P1. May be easily peeled off from the sheet 12.

The pick-up device 20 is a relay device that picks up the electronic component 2 from the supply device 10 and delivers the picked-up electronic component 2 to the mounting device 30. The pickup device 20 has a pickup head 21 and a head moving mechanism 22. The pickup head 21 holds the electronic component 2 and releases the holding state to release the electronic component 2. Specifically, the pickup head 21 has a tubular suction nozzle 21a. The inside of the suction nozzle 21a communicates with a negative pressure generating circuit such as a vacuum pump, and the electronic component 2 is sucked by the opening at the tip of the suction nozzle 21a by generating the negative pressure in the circuit. To hold. Further, by releasing the negative pressure, the electronic component 2 is separated from the suction nozzle 21a.

The head moving mechanism 22 reciprocates the pickup head 21 between the supply position P1 and the delivery position P2 of the electronic component 2 with the mounting device 30. As the head moving mechanism 22, for example, a ball screw mechanism driven by a servomotor can be used. The head moving mechanism 22 is provided on the support frame 23 so as to extend along the X-axis direction described later. The head moving mechanism 22 is provided with a suction nozzle 21a via a reversing mechanism. The reversing mechanism reverses the direction of the suction nozzle 21a. For example, when the electronic component 2 is sucked and held at the supply position P1 by the suction nozzle 21a whose opening end is directed downward, the head moving mechanism 22 positions the suction nozzle 21a at the delivery position P2. Then, the suction nozzle 21a is rotated by a reversing mechanism by 180 ° so that the open end holding the electronic component 2 faces upward, and the electronic component 2 is delivered to the mounting device 30.

In the present embodiment, the supply device 10 and the mounting device 30 are arranged side by side. The alignment direction of the supply device 10 and the mounting device 30, that is, the linear direction connecting the supply position P1 and the mounting position P3 is defined as the X-axis direction. Further, in the horizontal plane on which the supply stage 11 extends, the direction orthogonal to the X-axis direction is defined as the Y-axis direction, and the direction orthogonal to the X-axis and the Y-axis is defined as the Z-axis direction. In the present specification, the position in the Z-axis direction may be simply referred to as "height". For example, a specific reference position can be set and the distance in the Z-axis direction to the reference position can be set as a height, such as a position in the Z-axis direction of a specific position on the substrate stage 33 described later.

The mounting device 30 is a device that conveys the electronic component 2 received from the pickup device 20 to the mounting position P3 and mounts it on the substrate 3. The mounting position P3 is a position where the electronic component 2 is mounted on the substrate 3, and is set to a fixed place here.

The mounting device 30 includes a bonding head 31, a head moving mechanism 32, a substrate stage 33, a stage moving mechanism 34, an imaging means 35, and an inspection unit 40.

The bonding head 31 conveys the electronic component 2 and mounts it on the substrate 3. Specifically, the bonding head 31 receives the electronic component 2 from the pickup device 20 at the delivery position P2, and mounts the electronic component 2 on the substrate 3 at the mounting position P3. The bonding head 31 holds the electronic component 2, and after mounting, releases the holding state and releases the electronic component 2. Specifically, the bonding head 21 has a tubular suction nozzle 31a. The inside of the suction nozzle 31a communicates with a negative pressure generating circuit such as a vacuum pump, and the electronic component 2 is sucked by the opening at the tip of the suction nozzle 31a by generating a negative pressure in the circuit. To hold. Further, by releasing the negative pressure, the electronic component 2 is separated from the suction nozzle 31a.

The bonding head 31 reciprocates between the transfer position P2 and the mounting position P3, and moves up and down at the transfer position P2 and the mounting position P3. In other words, the head moving mechanism 32 has a slide mechanism 321 and an elevating mechanism 322.

The slide mechanism 321 linearly moves the bonding head 31 between the delivery position P2 and the mounting position P3. Here, the slide mechanism 321 has two rails 321a extending parallel to the X-axis direction and fixed to the support frame 323, and a slider 321b traveling on the rails 321a. Although not shown, the slide mechanism 321 has a slide mechanism that slides the bonding head 31 in the Y-axis direction. This slide mechanism can also be configured by a rail in the Y-axis direction and a slider running on the rail. When the slide mechanism 321 moves the suction nozzle 31a of the bonding head 31 to the delivery position P2, the suction nozzle 31a faces the suction nozzle 21a of the pickup head 21 located at the delivery position P2 via the electronic component 2. When the slide mechanism 321 moves the suction nozzle 31a holding the electronic component 2 to the mounting position P3, the suction nozzle 31a faces the planned mounting position positioned at the mounting position P3 of the substrate 3 via the electronic component 2. Further, the slide mechanism 321 moves the suction nozzle 32a to the inspection position P4 described later.

The elevating mechanism 322 elevates and elevates the bonding head 31. Here, the direction of raising and lowering is a direction parallel to the Z-axis direction. Specifically, as the elevating mechanism 322, a ball screw mechanism driven by a servomotor can be used. That is, the bonding head 31 moves up and down along the Z-axis direction by driving the servomotor.

The board stage 33 is a table on which the board 3 is placed. The substrate stage 33 slides on the XY plane.

The stage moving mechanism 34 slides the substrate stage 33 on the XY plane. Specifically, the stage moving mechanism 34 has an X-axis moving mechanism that moves the substrate stage 33 in the X-axis direction and a Y-axis moving mechanism that moves the substrate stage 33 in the Y-axis direction. The X-axis moving mechanism and the Y-axis moving mechanism are composed of, for example, a servomotor and a ball screw mechanism including a screw shaft, a nut, a guide rail, and a slider. The X-axis moving mechanism is provided so that its screw shaft and guide rail extend in the X-axis direction, and a nut is screwed onto the screw shaft. A board stage 33 is fixed to this nut via a slider, and by rotating the screw shaft by a servomotor, the slider moves along a guide rail extending in the X-axis direction, and the board stage 33 moves X. It moves linearly in the axial direction. The Y-axis moving mechanism is provided so that its screw shaft and guide rail extend in the Y-axis direction, and a nut is screwed onto the screw shaft. An X-axis movement mechanism is fixed to this nut via a slider, and by rotating the screw axis with a servomotor, the slider moves along a guide rail extending in the Y-axis direction, and the X-axis movement mechanism At the same time, the substrate stage 33 moves linearly in the Y-axis direction.

The imaging means 35 is a camera that images the alignment mark of the electronic component 2 and the alignment mark of the substrate 3 at the mounting position P3. The imaging means 35 is an upper and lower two-field camera. That is, as shown in FIG. 3, the imaging means 35 enters between the bonding head 31 and the substrate stage 33, and the alignment mark of the electronic component 2 held by the upper suction nozzle 31a and the lower substrate 3 The alignment mark at the planned mounting position at the mounting position P3 is imaged. As shown in FIG. 3, the imaging means 35 enters between the bonding head 31 and the substrate stage 33 before mounting the electronic component 2 on the substrate 3, and when mounted by the bonding head 31, FIG. 4 shows. As shown, it is retracted to a position where it does not interfere with the bonding head 31.

The inspection unit 40 inspects the misalignment between the electronic component 2 and the substrate 3 after mounting. The inspection unit 40 includes a height detector 41, an image pickup means 42, and an image pickup means elevating mechanism 43 (see FIGS. 1 and 2).

The height detector 41 is provided on the bonding head 31. The height detector 41 detects the height when the electronic component 2 is mounted on the substrate 3 by the bonding head 31. The height detection location detected by the height detector 41 is the height of the tip of the suction nozzle 31a. The height detector 41 can also detect the height of the substrate stage 33. That is, the height detector 41 detects the height of the object in contact with the suction nozzle 31a. As the height detector 41, it is preferable to combine a sensor that detects the amount of movement of the bonding head 31 and a sensor that detects the contact of the suction nozzle 31a with the object. For example, an encoder that detects the amount of movement of the bonding head 31 and a gap sensor that detects contact with an object by the relative movement of the suction nozzle 31a with respect to the bonding head 31 can be used. In this case, when the gap sensor detects the contact of the suction nozzle 31a with the object, the bonding head 31 moves slightly with respect to the suction nozzle 31a and stops. Then, the height of the object can be detected by subtracting the relative movement amount of the suction nozzle 31a detected by the gap sensor from the movement amount of the bonding head 31 detected by the encoder. A pressure sensor may be used as the sensor for detecting the contact. As the sensor used in the height detector 41, it is preferable to use an inexpensive sensor other than the laser displacement meter.

The imaging means 42 images the electronic component 2 and the substrate 3 after mounting. Specifically, the alignment mark of the electronic component 2 and the alignment mark of the substrate 3 after mounting are imaged. The imaging means 42 images at least two alignment marks for one electronic component 2. Further, the imaging means 42 images at least two alignment marks for each mounting location of the substrate 3. As the imaging means 42, an infrared (IR) camera, a CCD camera, or a CMOS camera can be used. In this embodiment, the imaging means 42 is an infrared camera. The imaging means 42 transmits infrared rays through the electronic component 2 to image the alignment mark of the electronic component 2 and the alignment mark of the substrate 3.

The imaging means 42 has a lens, and images the alignment marks of the electronic component 2 and the substrate 3 through the lens. This lens has a high magnification and a small depth of field. In this embodiment, the lens has a magnification of 20 and the depth of field is 10 μm or less.

The imaging means 42 is provided at the inspection position P4. That is, the image pickup means 42 is provided above the substrate stage 33 so that the optical axis of the camera coincides with the inspection position P4. The inspection position P4 is a positional deviation between the electronic component 2 and the substrate 3 by imaging the electronic component 2 and the substrate 3 after mounting by the imaging means 42, that is, the alignment mark of the electronic component 2 after mounting and the substrate 3 It is a position to inspect the misalignment with the alignment mark of. This misalignment is the misalignment when the alignment marks of the electronic component 2 and the substrate 3 are projected onto the XY plane. In the present embodiment, the inspection position P4 is a fixed position.

The image pickup means elevating mechanism 43 raises and lowers the image pickup means 42. Here, the ascending / descending direction is a direction parallel to the Z-axis direction, that is, a direction of advancing / retreating with respect to the mounted electronic component 2 located at the inspection position P4. As the image pickup means elevating mechanism 43, a ball screw mechanism driven by a servomotor can be used. That is, the image pickup means 42 moves up and down along the Z-axis direction by driving the servomotor.

The image pickup means elevating mechanism 43 moves the image pickup means 42 in the height direction based on the height of the bonding head 31 detected by the height detection unit 41. That is, the alignment mark of the electronic component 2 or the alignment mark of the substrate 3 after mounting is focused to the extent that it can be recognized by the imaging means 42. In other words, in the image pickup means elevating mechanism 43, the alignment mark of the mounted electronic component 2 or the alignment mark of the substrate 3 to be imaged is set based on the height of the bonding head 31 detected by the height detection unit 41. The height of the imaging means 42 is adjusted so as to be within the depth of field of the lens of the imaging means 42. This height adjustment is performed by the elevating mechanism control unit 57, which will be described later, controlling the imaging means elevating mechanism 43. The facing distance between the electronic component 2 mounted on the substrate 3 and the alignment mark of the substrate 3, that is, the separation distance in the height direction exceeds the depth of field of the lens of the imaging means 42. Therefore, the image pickup means elevating mechanism 43 switches the height of the image pickup means 42 when the alignment mark of the electronic component 2 is imaged and when the alignment mark of the substrate 3 is imaged.

The image pickup means elevating mechanism 43 takes an image based on the height of the bonding head 31 including the amount of height fluctuation of the electronic component 2 when the electronic component 2 at the mounting position P3 moves to the inspection position P4 by the stage moving mechanism 34. Adjust the height of the means 42.

The control device 50 controls the start, stop, speed, operation timing, and the like of the supply device 10, the pickup device 20, the mounting device 30, and the inspection unit 40. The control device 50 can be realized by, for example, a dedicated electronic circuit, a computer operating with a predetermined program, or the like. The control device 50 is connected to an input device for inputting instructions and information necessary for the operator to control, and an output device for checking the state of the device.

FIG. 5 is a functional block diagram of the control device 50. As shown in FIG. 5, the control device 50 includes a supply device control unit 51, a pickup head control unit 52, a bonding head control unit 53, a board stage control unit 54, a storage unit 55, a height calculation unit 56, and an elevating mechanism control unit. It has 57, an image pickup means control unit 58, and a determination unit 59.

The supply device control unit 51 controls the movement of the supply stage 11 so that the electronic component 2 to be supplied on the sheet 12 mounted on the supply stage 11 is located at the supply position P1.

The pickup head control unit 52 controls the operation of the pickup device 20. Specifically, the pickup head control unit 52 controls the negative pressure generation circuit communicating with the suction nozzle 21a, and controls the holding and detachment of the electronic component 2. Further, the pickup head control unit 52 controls the movement of the pickup head 21, that is, the operation of the head movement mechanism 22.

The bonding head control unit 53 controls the movement of the bonding head 31, that is, the operation of the head moving mechanism 32. The board stage control unit 54 controls the operation of the stage moving mechanism 34.

The storage unit 55 is a recording medium such as an HDD or SSD. Data and programs required for system operation are stored in advance in the storage unit 55, and data necessary for system operation is stored in the storage unit 55.

For example, the storage unit 55 stores the height of the bonding head 31 detected by the height detection unit 41. Further, the thickness of the electronic component 2 and the thickness of the substrate 3 are stored in advance in the storage unit 55. The thickness of the electronic component 2 may be a value obtained by measuring the thickness of the sample electronic component 2 in advance, or may be the average thickness of the plurality of electronic components 2. The thickness of the substrate 3 may be a value obtained by measuring the thickness of an arbitrary portion of the substrate 3, or may be the average of the thicknesses of a plurality of locations of the substrate 3. The storage unit 55 stores the magnification, focal length, depth of field, and the like of the lens of the imaging means 42.

The storage unit 55 stores the height of each position when each position on the substrate stage 33 is located at the mounting position P3. Each position on the board stage 33 means a position corresponding to a planned mounting position of the electronic component 2 mounted on the board 3 when the board 3 is mounted at a predetermined position on the board stage 33 (hereinafter, "" It is also called "the position corresponding to the planned mounting"). For example, when the board stage 33 is arranged parallel to the XY plane and the board 3 is arranged at a predetermined position on the board stage 33, the planned mounting position of the board 3 is set to the board stage 33. This is the position projected in the Z-axis direction.

For example, the method for measuring the position corresponding to the planned mounting is as follows. That is, the position corresponding to the planned mounting of the board stage 33 is moved to the mounting position P3, and the bonding head 31 located at the mounting position P3 is lowered to bring the tip (that is, the tip of the suction nozzle 31a) into contact with the board stage 33. The height of the bonding head 31 at the time of contact is detected by the height detecting unit 41. As described above, since this height is detected at the tip of the suction nozzle 31a, the height of the board stage 33 at the position corresponding to the planned mounting can be measured. By measuring the height of each planned mounting position on the board stage 33 by such a procedure, a height map of the board stage 33 in which the planned mounting position and the height of the board stage 33 at the position are associated with each other. Can be obtained. This height map is stored in the storage unit 55 as the height of each position when each position on the substrate stage 33 is located at the mounting position P3. This height map reflects the variation in the flatness of the substrate stage 33, more specifically, the undulation of the surface of the substrate stage 33 in the Z-axis direction. That is, the substrate stage 33 is supported by the stage moving mechanism 34, and the stage moving mechanism 34 includes, for example, a guide rail along the X-axis direction and a guide rail along the Y-axis direction. Such a guide rail may have waviness or distortion due to processing accuracy or assembly accuracy. In this case, the substrate stage 33 guided by this may fluctuate up and down during its movement. Generally, the magnitude of such vertical fluctuation tends to increase as the moving distance increases. That is, it is conceivable that the magnitude of the vertical fluctuation exceeds the depth of field (for example, 10 μm) of the imaging means 42 depending on the moving distance. Therefore, in the present embodiment, such a height map is created.

In the storage unit 55, the height fluctuation amount of the substrate stage 33 generated when each position on the substrate stage 33 moves from the mounting position P3 to the inspection position P4 is the height associated with each position on the substrate stage 33. The fluctuation map is stored in advance. Each position on the board stage 33 is a position corresponding to the planned mounting. For example, when the board stage 33 is arranged parallel to the XY plane and the board 3 is arranged at a predetermined position on the board stage 33, the planned mounting position of the board 3 is set to the board stage 33. This is the position projected in the Z-axis direction.

The height variation map can be measured as follows. That is, the planned mounting position of the electronic component 2 on the board stage 33 is positioned at the mounting position P3. Further, the bonding head 31 is positioned at the mounting position P3. Then, at the mounting position P3, the tip of the bonding head 31 (that is, the tip of the suction nozzle 31a) is brought into contact with the substrate stage 33. The height of the bonding head 31 at the time of contact (hereinafter, also referred to as “mounting position height”) is detected by the height detecting unit 41. Next, the substrate stage 33 is moved so that the mounting scheduled corresponding position comes to the inspection position P4. Further, the bonding head 31 is moved to the inspection position P4. Then, at the inspection position P4, the tip of the bonding head 31 (that is, the tip of the suction nozzle 31a) is brought into contact with the substrate stage 33. The height of the bonding head 31 at the time of contact (hereinafter, also referred to as “inspection position height”) is detected by the height detecting unit 41. The difference between the inspection position height and the mounting position height is the amount of height fluctuation due to the movement from the inspection position P4 to the mounting position P3. As described above, this height fluctuation amount is caused by the swell, distortion, and the like of the guide rail and the like of the stage moving mechanism 34 that moves on the XY plane. Ideally, the stage moving mechanism 34 moves in parallel with the XY plane, but it may deviate from the parallel movement on the XY plane due to, for example, vertical swelling or distortion of the guide rail or the like. As described above, the height variation map can be obtained by performing the above measurement for each position corresponding to the planned mounting. When the bonding head 31 detects the height of the inspection position at the inspection position P4, the imaging means 42 is raised and retracted from the bonding head 31. Alternatively, the height of the inspection position is detected by the bonding head 31 before the imaging means 42 is attached.

The height calculation unit 56 determines the height of the alignment mark of the electronic component 2 after mounting at the inspection position P4 and the alignment of the substrate 3 from the height of the bonding head 31 detected by the height detection unit 41 at the mounting position P3. Calculate the height of the mark. In this embodiment, as shown in FIG. 6, an example in which the electronic component 2 is face-down mounted on the substrate 3 will be described. As shown in FIG. 6, the alignment mark 2a of the electronic component 2 is provided on the surface on which the bump is provided, and faces the substrate 3 by face-down mounting. The alignment mark 3a of the substrate 3 is provided on the surface on which the electronic component 2 is mounted, which is the surface opposite to the substrate stage 33. By face-down mounting, the locations where the alignment marks 2a and 3a of the electronic component 2 and the substrate 3 are provided overlap each other in the Z-axis direction.

The height calculation unit 56 calculates the height of the alignment mark 2a of the electronic component 2 from the height of the bonding head 31 detected by the height detection unit 41 at the mounting position P3 and the thickness of the electronic component 2. Specifically, the height calculation unit 56 reads out from the storage unit 55 the height of the bonding head 31 and the thickness of the electronic component 2 at the mounting position P3 stored in the storage unit 55. As described above, the height of the bonding head 31 is, for example, the tip of the suction nozzle 31a, and is therefore equal to the height of the upper surface of the electronic component 2 to be sucked. Therefore, the height calculation unit 56 calculates the height of the alignment mark 2a by subtracting the thickness of the electronic component 2 from the height of the bonding head 31.

The height calculation unit 56 calculates the height of the alignment mark 3a of the substrate 3 from the height of the mounting schedule corresponding position on the substrate stage 33 located at the mounting position P3 and the thickness of the substrate 3. Specifically, the height calculation unit 56 reads out from the storage unit 55 the height of the mounting schedule corresponding position on the board stage 33 located at the mounting position P3 stored in the storage unit 55 and the thickness of the board 3. , The height of the alignment mark 3a is calculated by adding the latter to the former. When the height of the bump after mounting, that is, the distance between the upper surface of the substrate 3 and the lower surface of the electronic component 2 can be controlled to be constant at a desired value, the height of the bump is set to the bonding head 31. The height of the alignment mark 3a may be calculated by subtracting from the height of.

Further, when the height calculation unit 56 reads the height fluctuation map from the storage unit 55 and moves it to the height of the alignment marks 2a and 3a from the mounting position P3 read from the height fluctuation map to the inspection position P4. The height fluctuation amount of the resulting substrate stage 33 may be added. If the heights of the alignment marks 2a and 3a do not change (that is, if they move horizontally) even if they move from the mounting position P3 to the inspection position P4, or if they move, the heights of the alignment marks 2a and 3a are imaged. When the depth of field of the means 42 is within the range, it is not necessary to consider the amount of height variation of the substrate stage 33. For example, there is a case where the magnitude of the vertical fluctuation caused by the waviness of the substrate stage 33 is smaller than the depth of field of the imaging means 42.

The elevating mechanism control unit 57 is a control unit that controls the image pickup means elevating mechanism 43. For example, the elevating mechanism control unit 57 adjusts the height of the image pickup means 42 based on the heights of the alignment marks 2a and 3a calculated by the height calculation unit 56 by controlling the image pickup means elevating mechanism 43.

The image pickup means control unit 58 controls the operation of the image pickup means 42. For example, the start, stop, imaging, and imaging timing of the imaging means 42 are controlled.

The determination unit 59 determines the positional deviation of each of the alignment marks 2a and 3a from the imaging result of the alignment mark 2a of the electronic component 2 and the imaging result of the alignment mark 3a of the substrate 3 obtained by the imaging means 42. FIG. 7 is a diagram showing a state in which the alignment mark 2a of the electronic component 2 and the alignment mark 3a of the substrate 3 are aligned, that is, the positioning is normally performed. FIG. 8 is a diagram showing a state in which the alignment mark 2a of the electronic component 2 and the alignment mark 3a of the substrate 3 are misaligned.

As a method of determining the misalignment, for example, the determination unit 59 superimposes the imaging result of the alignment mark 2a of the electronic component 2 and the imaging result of the alignment mark 3a of the substrate 3 to determine the distance between the centers of the alignment marks 2a and 3a. calculate. If the calculated distance is within a predetermined threshold value, the determination unit 59 determines that the mounting is good in alignment, and if the calculated distance exceeds the predetermined threshold value, it determines that the mounting is poorly aligned. When it is determined that the alignment is poor, the worker is notified by a notification means such as a display device or a speaker connected to the control device 50.

(Action)
The operation of the electronic component mounting system and the mounting device 30 according to the embodiment will be described. FIG. 9 is an example of an operation flowchart of the electronic component mounting system. A sheet 12 in which the electronic components 2 are arranged in an array is mounted on the supply stage 11 in advance, and a substrate 3 to be mounted on the electronic components 2 is mounted on the substrate stage 33 in advance. Further, it is assumed that the electronic component 2 on the sheet 12 is placed in a face-up state in which the bumps face upward.

As shown in FIG. 9, first, the supply device 10 moves the electronic component 2 to be supplied on the sheet 12 to the supply position P1 (step S01). The head moving mechanism 22 moves the pickup head 21 to the supply position P1, picks up the electronic component 2 at the supply position P1 (step S02), and delivers the electronic component 2 to the bonding head 31 at the delivery position P2 (step S03). .. That is, when the pickup head 21 moves to the delivery position P2, the electronic component 2 is inverted by 180 ° by the inversion device. As a result, the bonding head 31 and the electronic component 2 face each other and are delivered. As a result, the electronic component 2 is held by the bonding head 31 with the alignment mark 2a facing downward.

The bonding head 31 is moved to the mounting position P3 by the slide mechanism 321 (step S04). On the other hand, the stage moving mechanism 34 moves the board stage 33 and moves the planned mounting position of the board 3 to the mounting position P3 (step S05).

In this way, after the planned mounting positions of the electronic component 2 and the board 3 are moved to the mounting position P3, the image pickup means 35, which is a vertical two-view camera, is advanced between the bonding head 31 and the board 3 and is located above. The alignment mark 2a of the electronic component 2 and the alignment mark 3a of the planned mounting position of the substrate 3 located below are imaged, and the alignment mark 3a of the electronic component 2 and the planned mounting position of the substrate 3 is aligned (step S06).

After the alignment, the bonding head 31 is lowered by the elevating mechanism 322, and the electronic component 2 is brought into contact with the planned mounting position of the substrate 3 for mounting (step S07). At the time of this mounting, the height of the bonding head 31 when the electronic component 2 is in contact with the substrate 3 is detected by the height detecting unit 41 (step S08). This height is stored in the storage unit 55. The bonding head 31 after mounting releases the holding of the electronic component 2 and returns to the delivery position P2 in order to receive the next electronic component 2. Since the bumps are crushed by the pressurization during mounting, the height of the bonding head 31 at the completion of mounting may be lower than when the electronic component 2 comes into contact with the planned mounting position. Therefore, more accurate height detection can be performed by measuring the height immediately before the mounting is completed and the bonding head 31 is raised. That is, in the above-mentioned detection of the height of the bonding head 31, the height immediately before the mounting is completed and the bonding head 31 is raised is measured.

After mounting the electronic component 2 on the substrate 3, the electronic component 2 at the mounting position P3 is moved to the inspection position P4 by the stage moving mechanism 34 (step S09). The height calculation unit 56 calculates the heights of the alignment marks 2a and 3a of the electronic component 2 and the substrate 3 (step S10).

That is, the height calculation unit 56 reads out the height of the bonding head 31 at the time of mounting from the storage unit 55, calculates the height of the alignment mark 2a of the electronic component 2 based on the height, and also stores the storage unit 2. The height of the alignment mark 3a of the substrate 3 is calculated by reading out the height of the mounting schedule corresponding position on the substrate stage 33 located at the mounting position P3 from 55 and the thickness of the substrate 3 and adding the height and the thickness. .. Further, in the present embodiment, the height calculation unit 56 reads the height fluctuation map from the storage unit 55, and at the heights of the alignment marks 2a and 3a, from the mounting position P3 read from the height fluctuation map to the inspection position P4. The height obtained by adding the height fluctuation amount of the substrate stage 33 generated when the substrate stage 33 is moved is defined as the height of the alignment marks 2a and 3a.

The heights of the alignment marks 2a and 3a may be calculated while the electronic component 2 is being moved from the mounting position P3 in step S09 to the inspection position P4.

Next, the elevating mechanism control unit 57 controls the imaging means elevating mechanism 43 based on the heights of the alignment marks 2a and 3a, adjusts the height of the imaging means 42 (step S11), and aligns the alignment marks 2a and 3a. Is imaged (step S12). As a result, the alignment marks 2a and 3a are within the depth of field of the lens and are in focus. However, since the distance between the alignment marks 2a and 3a exceeds the depth of field, the height adjustment of the imaging means 42 and the imaging of the alignment marks 2a and 3a are performed separately.

That is, when the image pickup means elevating mechanism 43 adjusts the height of the image pickup means 42 based on the height of the alignment mark 2a of the electronic component 2, the alignment mark 2a is in focus as shown in FIG. The alignment mark 3a is out of focus and a blurred image can be obtained. On the other hand, when the image pickup means elevating mechanism 43 adjusts the height of the image pickup means 42 based on the height of the alignment mark 3a of the substrate 3, as shown in FIG. 11, the alignment mark 3a is in focus and the alignment is aligned. The mark 2a is out of focus and a blurred image can be obtained.

The alignment marks 2a and 3a are imaged at at least two places for one electronic component 2. When the electronic component 2 has a rectangular shape, for example, the alignment marks 2a and 3a at diagonal positions are imaged. For example, in order to image the alignment mark 2a in the upper left corner when viewed from the viewpoint of the imaging means 42, the stage moving mechanism 34 ensures that the upper left corner of the target electronic component 2 after mounting comes to the inspection position P4. The substrate stage 33 is moved to, the height of the imaging means 42 is adjusted, and the alignment mark 2a is imaged. Then, the height of the imaging means 42 is adjusted by the imaging means elevating mechanism 43 based on the height of the alignment mark 3a paired with the alignment mark 2a, and the alignment mark 3a is imaged. Then, in order to image the alignment mark 3a in the lower right corner, the stage moving mechanism 34 moves the substrate stage 33 so that the lower right corner of the target electronic component 2 after mounting comes to the inspection position P4. .. As a result, the alignment mark 3a in the lower right corner falls within the depth of field, so that the image pickup means 42 takes an image. After that, in order to image the alignment mark 2a in the lower right corner, the height of the imaging means 42 is adjusted by the imaging means elevating mechanism 43 based on the height of the alignment mark 2a, and the alignment of the lower right corner by the imaging means 42. The mark 2a is imaged.

Next, from the obtained image, the determination unit 59 determines the positional deviation between the electronic component 2 and the substrate 3 after mounting (step S13). When it is determined that the misalignment is within an acceptable range, that is, the alignment is good (YES in step S13), the process returns to step S01 and the next step is to mount the electronic component 2. Steps S01 to S13 are repeated, and when the electronic component 2 on the supply stage 11 is exhausted, the operation of the system is stopped. On the other hand, when the determination unit 59 determines that the misalignment is unacceptable, that is, the alignment is poor (NO in step S13), the notification means notifies the worker, the system is stopped, and the system is terminated. The electronic component 2 having a poor alignment may be peeled off from the substrate 3 and reused.

(effect)
(1) A mounting device 30 for mounting an electronic component 2 on a substrate 3, wherein a bonding head 31 for transporting the electronic component 2 and mounting the electronic component 2 on the substrate 3 and a substrate stage 33 on which the substrate 3 is mounted are mounted. An inspection unit 40 for inspecting the positional deviation between the electronic component 2 and the substrate 3 afterwards is provided, and the inspection unit 40 is provided on the bonding head 31, and when the electronic component 2 is mounted on the substrate 3 by the bonding head 31. A height detection unit 41 that detects the height of the bonding head 31, an image pickup means 42 that has a lens and images the electronic component 2 and the substrate 3 after mounting, and an image pickup means elevating mechanism that raises and lowers the image pickup means 42. 43, and an elevating mechanism control unit 57 that controls the imaging means elevating mechanism 43 so as to adjust the height of the imaging means 42 based on the height of the bonding head 31 detected by the height detecting unit 41. I made it.

As a result, it is possible to inspect the misalignment between the electronic component 2 and the substrate 3 after mounting while improving the production efficiency. That is, since the height of the bonding head 31 is detected by the height detecting unit 41 provided on the bonding head 31 when the electronic component 2 is mounted on the substrate 3, it is not necessary to separately measure the height of the electronic component 2. .. Therefore, the production efficiency can be improved as compared with the case where the height of the electronic component 2 is separately measured by a laser displacement meter or the like. Further, since the height of the imaging means 42 is adjusted based on the detected height of the bonding head 31, the electronic component 2 and the substrate 3 can be contained in the depth of field to obtain a focused image. The misalignment between the electronic component 2 and the substrate 3 can be accurately inspected.

(2) A storage unit 55 is provided, and the storage unit 55 stores the height of the bonding head 31 detected by the height detection unit 41. As a result, the height of the bonding head 31 can be fed back to the height adjustment of the imaging means 42.

(3) The mounting position P3 on which the electronic component 2 is mounted on the substrate 3 by the bonding head 31, and the electronic component 2 and the substrate 3 are captured by imaging the electronic component 2 and the substrate 3 after mounting with the imaging means 42. The inspection position P4 for inspecting the misalignment of the board and the stage moving mechanism 34 for moving the substrate stage 33 are provided. The mounting position P3 and the inspection position P4 are fixedly provided at different places, and the stage moving mechanism 34 is provided. The board stage 33 is moved so that the electronic component 2 after mounting comes from the mounting position P3 to the inspection position P4.

As a result, it is possible to inspect the accurate positional deviation between the electronic component 2 and the substrate 3 after mounting, as compared with the case where the imaging means 42 is moved to the mounting position P3. That is, the image pickup means 42, particularly the image pickup means 42 having a high magnification of more than 10 times, has a delicate lens portion. When the imaging means 42 including such a lens portion is moved by a far larger distance than a minute amount of movement such as focus adjustment, such as movement between the mounting position P3 and the inspection position P4. , A large load is generated on the lens part. Unlike the substrate stage 33 and the like, which are configured on the premise of movement, the lens portion is liable to be damaged or have an error by repeatedly receiving a large load. As a result, accurate misalignment inspection may not be possible. On the other hand, by fixing the inspection position P4 by the imaging means 42 and moving the substrate stage 33 between the mounting position P3 and the inspection position P4, the above-mentioned problems can be avoided, so that the accurate positional deviation can be avoided. Can be inspected.

(4) The elevating mechanism control unit 57 is based on the height of the bonding head 31 including the amount of height fluctuation of the electronic component 2 when the electronic component 2 at the mounting position P3 is moved to the inspection position P4 by the stage moving mechanism 34. Therefore, the height of the imaging means 42 is adjusted. As a result, it is possible to inspect the accurate positional deviation between the electronic component 2 and the substrate 3 after mounting. That is, it is the stage moving mechanism 34 that moves the mounted electronic component 2 from the mounting position P3 to the inspection position P4. Even if the vertical waviness of each member constituting the stage moving mechanism 34 causes vertical fluctuations when moving in parallel with the XY plane, the height fluctuation is taken into consideration in the imaging means. Since the 42 is moved in the height direction, the electronic component 2 and the substrate 3 can be focused and imaged even by the imaging means 42 of the lens having a shallow depth of field, and the inspection of the misalignment can be made accurate. Can be done.

(5) The depth of field of the lens was set to 10 μm or less. As a result, it is possible to photograph the circuits of the electronic component 2 and the substrate 3 with high accuracy or high density.

(Other embodiments)
The present invention is not limited to the above embodiments, but also includes other embodiments shown below. The present invention also includes a combination of all or any of the above embodiments and the following other embodiments. Furthermore, various omissions, replacements, and changes can be made to these embodiments without departing from the scope of the invention, and modifications thereof are also included in the present invention.

(1) In the above embodiment, a height fluctuation map is created in advance in consideration of the height fluctuation amount of the substrate stage 33 when the mounted electronic component 2 located at the mounting position P3 is moved to the inspection position P4. However, the mounting position P3 and the inspection position P4 may be provided within 100 mm. According to the findings of the inventor of the present application, if the moving range of the substrate stage 33 is within 100 mm, the amount of height fluctuation of the substrate stage 33 can be suppressed to be small or small, that is, within 10 μm. The alignment marks of the electronic components 2 and the substrate 3 can be accommodated within the depth of field (10 μm) of the lens of the imaging means 42 to obtain an in-focus captured image. In other words, by providing the mounting position P3 and the inspection position P4 within a distance of 100 mm, even if the electronic component 2 after mounting is moved from the mounting position P3 to the inspection position P4 by the stage moving mechanism 34, the stage moving mechanism The vertical fluctuation due to 34 can be kept within the depth of field and is in a negligible range. This eliminates the need to measure the height variation map in advance, so that the device configuration of the mounting device 30 can be simplified.

(2) In the above embodiment, the imaging means 42 is provided at a fixed position on the XY plane, but the imaging means 42 may be movable in parallel with the XY plane. For example, the inspection position P4 may be matched with the mounting position P3. In this case, for example, after mounting the electronic component 2, the bonding head 31 retracts to receive the next electronic component 2 from the mounting position P3, then the imaging means 42 is moved to the mounting position P3, and the electronic component is moved to the mounting position P3. The alignment marks of 2 and the substrate 3 are imaged. In this case, regarding the movement of the imaging means 42, it is preferable to perform acceleration control while suppressing the load acting on the lens portion.

(3) In the above embodiment, the electronic component 2 is mounted on the substrate 3 by a face-down method, but in the mounting device 30, the surface on which the electrode formed by the bumps of the electronic component 2 is formed is different from the substrate 3. It may be mounted by a face-up method facing the opposite side.

(4) A flux having an adhesive action may be applied to the electronic component 2 before the electronic component 2 held by the pickup head 21 is delivered to the bonding head 31.
(5) In the above embodiment, regarding the acquisition of the height fluctuation map in consideration of the height fluctuation amount of the board stage 33 that occurs when each position on the board stage 33 moves from the mounting position P3 to the inspection position P4, each position. An example of a method in which the tip of the bonding head 31 is brought into contact with the substrate stage 33 in P3 and P4 for measurement is illustrated. However, the measurement method is not limited to this, and other measurement methods may be used for acquisition. For example, the mounting position P3 is measured by detecting the height position of the bonding head 31 when the tip of the bonding head 31 is brought into contact with the substrate stage 33, as described above. Regarding the inspection position P4, the height position of the imaging means 42 when the alignment mark attached on the measurement jig is in focus with the measurement jig mounted on the substrate stage 33. Is measured by detecting. Here, as the measuring jig, for example, a jig in which alignment marks are arranged on the upper surface of a flat glass substrate at predetermined intervals in each of the XY directions can be used. The glass substrate can be formed to such an extent that variations in thickness can be ignored. Further, the focusing of the imaging means 42 can be performed manually by the operator. The height position of the image pickup means 42 can be detected by using a position detector such as an encoder attached to the image pickup means elevating mechanism 43 that raises and lowers the image pickup means 42. In this way, the height of the substrate stage 33 can be obtained by subtracting the thickness of the glass substrate from the detected height position of the imaging means 42. The height position of the bonding head 31 detected at the mounting position P3 may be detected with the glass substrate, which is a measuring jig, mounted on the substrate stage 33. In this way, the detected values of both can be compared as they are without subtracting the thickness of the glass substrate from the height position of the imaging means 42. By doing so, the height variation map can be obtained without moving the bonding head 31 to the inspection position P4 or retracting the image pickup means 42 from the inspection position P4.

1 Electronic component mounting system 2 Electronic component 2a Alignment mark 3 Board 3a Alignment mark 10 Supply device 11 Supply stage 12 Sheet 13 Camera 20 Pickup device 21 Pickup head 21a Suction nozzle 22 Head movement mechanism 23 Support frame 30 Mounting device 31 Bonding head 31a Suction Nozzle 32 Head moving mechanism 321 Slide mechanism 321a Rail 321b Slider 322 Elevating mechanism 33 Board stage 34 Stage moving mechanism 35 Imaging means 40 Inspection unit 41 Height detector 42 Imaging means 43 Imaging means elevating mechanism 50 Control device 51 Supply device control unit 52 Pickup head control unit 53 Bonding head control unit 54 Board stage control unit 55 Storage unit 56 Height calculation unit 57 Elevating mechanism control unit 58 Imaging means control unit 59 Judgment unit P1 Supply position P2 Delivery position P3 Mounting position P4 Inspection position

Claims (6)

A mounting device that mounts electronic components on a board.
A bonding head that conveys the electronic components and mounts them on the substrate,
A board stage on which the board is placed and
An inspection unit that inspects the positional deviation between the electronic component and the substrate after the mounting, and
With
The inspection unit
A height detection unit provided on the bonding head and detecting the height of the bonding head when the electronic component is mounted on the substrate by the bonding head.
An imaging means having a lens and imaging the electronic component and the substrate after the mounting.
An image pickup means elevating mechanism for raising and lowering the image pickup means,
Having a control unit that controls the image pickup means elevating mechanism so as to adjust the height of the image pickup means based on the height of the bonding head detected by the height detection unit.
A mounting device characterized by. Equipped with a memory
The storage unit stores the height of the bonding head detected by the height detection unit.
1. The mounting apparatus according to claim 1. A mounting position for mounting the electronic component on the board by the bonding head, and
An inspection position for inspecting the positional deviation between the electronic component and the substrate by imaging the electronic component and the substrate after the mounting by the imaging means, and
A stage moving mechanism for moving the substrate stage and
With
The mounting position and the inspection position are fixedly provided at different locations.
The substrate stage is moved so that the mounted electronic component comes from the mounting position to the inspection position.
The mounting apparatus according to claim 1 or 2. The control unit
The height of the imaging means is adjusted based on the height of the bonding head including the amount of height fluctuation of the electronic component when the electronic component at the mounting position is moved to the inspection position by the stage moving mechanism. To do,
3. The mounting device according to claim 3. The distance between the mounting position and the inspection position shall be within 100 mm.
3. The mounting device according to claim 3. The depth of field of the lens shall be 10 μm or less.
The mounting apparatus according to any one of claims 1 to 5.