JP2725702B2 - Electronic component mounting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic component mounting method for flip-chip flipping a flip chip to mount it on a substrate.

(Prior Art) As an electronic component, a flip chip in which a bump (protruding electrode) is provided on a die by soldering or the like is known. 4th
The figure shows a conventional method of mounting this type of flip chip on a substrate. A flip chip 102 is provided on the lower surface of a wafer 101 with a surface on which a bump 103 is formed as a front surface. Is held in hand, and while visually recognizing the working point by the microscope 105, the chip 102 is pushed down by the pins 106 and mounted on the substrate 107.

(Problems to be Solved by the Invention) However, since the above-mentioned conventional method is a manual operation, there is a problem that mounting efficiency and mounting accuracy are not improved.

Accordingly, an object of the present invention is to provide an electronic component mounting method capable of mounting a flip chip mounted on a wafer or the like with a bump forming surface on a substrate at high speed and with high accuracy.

(Means for Solving the Problems) At the first level, a plurality of flip chips mounted on the chip supply unit are moved in the horizontal direction with the bump forming surface facing up, and one of them is selected, and the flip chip is selected from the first level. High second
An electronic component mounting method for mounting on a substrate positioned at the level. The flip chip in the chip supply unit is sucked up by the suction unit to take up, and the flip chip is rotated by the surface reversing device to turn the flip chip up and down. A step of raising the first level from the first level to approach the second level while inverting, and a step of causing a nozzle of the mounting head to perform an up / down operation to attract a flip chip to a lower end portion of the nozzle to take up; Observing the flip chip with a camera to detect the displacement of the flip chip in the X, Y, and θ directions; and driving the horizontal moving device based on the detection result to move the mounting head relative to the substrate. Correcting the positional deviation in the X direction and the Y direction by horizontally moving in a horizontal direction; The de of the nozzle in terms of correcting the positional deviation of the θ direction by rotating about its axis, and a step of mounting the flip chip to the substrate.

(Operation) In the above configuration, the suction unit sucks the flip chip mounted on the chip supply unit such as a wafer on the bump forming surface, and takes up the flip chip so that the flip chip is turned upside down. Raise to the second level. Next, the nozzle of the mounting head sucks the bump-free surface of the flip chip, which has been turned upside down, at the second level and takes up from the suction part, and the camera displaces the flip chip in the X, Y, and θ directions. To detect. Next, the horizontal movement device and the θ direction driving device are driven to correct the positional deviation in the X direction, the Y direction, and the θ direction, and then the flip chip is mounted on the substrate positioned at the positioning portion.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an electronic component mounting apparatus.
Is a table, and 2 is a main body box installed on the table. Reference numeral 3 denotes a transport path for a substrate 4 formed of an endless chain, and the substrate 4 on which electronic components are mounted is carried into the table 1, and
It will be removed from here. Reference numeral 14 denotes a positioning portion of the substrate 4 provided in the transport path 3, which is formed of a clamp plate.
Reference numeral 5 denotes a wafer serving as a chip supply unit disposed on a base 13 in front of the conveyor 3, and a large number of flip chips are provided on the upper surface thereof. The level at which the wafer 5 is provided is called a first level L1.

Reference numeral 6 denotes a mounting head, from which a nozzle 6a for sucking a flip chip is projected. Reference numerals 8 and 9 denote XY direction moving devices as horizontal moving devices for horizontally moving the mounting head 6 in the X and Y directions, and reference numerals 10 and 11 denote driving motors thereof. Numeral 18 denotes a θ-direction driving device mounted on the mounting head 6, which comprises a motor 18a and a belt 18b,
Is rotated in the θ direction about its axis. Reference numeral 17 denotes a camera integrally mounted on the mounting head 6.
And observes the displacement of the print pattern on the substrate 4 and the like. Reference numeral 7 denotes a die ejector disposed below the wafer 5, and reference numeral 7a denotes a pin thereof. The flip chip on the wafer 5 is pushed up by the pin 7a. Reference numeral 20 denotes a box on the side of the wafer 5 in which the flip-chip reversing device is stored, 21 denotes a visual inspection device,
Next, these will be described in detail with reference to FIG.

Reference numeral 22 denotes a front / back reversing device disposed inside the box 20, reference numeral 23 denotes a fan-shaped gear, reference numeral 24 denotes a gear that meshes with the gear 23 and rotates along the gear, and reference numeral 25 denotes a rotating rod. 26
Is an arm extending from the gear 24, and a suction part 27 is attached to the tip of the arm. F denotes a flip chip mounted on the wafer 5, B denotes a bump thereof, and the flip chips F are arranged side by side on the wafer 5 of the first level L1 with the bump forming surface facing the surface. The nozzle 6a of the mounting head 6 approaches the flip chip F which has been turned upside down by the upside down device 22 and adsorbs on the bump non-formed surface to take it up.

The visual inspection device 21 includes a camera 21a, an eyepiece 21b having a reflecting mirror 211b, and a light source 21c. The mounting head 6, which has taken up the flip chip F, is driven by the XY direction moving devices 8, 9 to move onto the eyepiece 21b, temporarily stops there, observes the flip chip F from below by the camera 21a, and Detects displacements in the X, Y, and θ directions. 30 is a control device such as a computer,
It is connected to each of the cameras 17, 21a, and controls each of the motors 10, 11, 18a as a position shift correcting device so as to correct the position shift of the flip chip F based on the observation result.

The present electronic component mounting apparatus has the above configuration, and the operation will be described next. First, the XY direction moving devices 8 and 9 are driven to move the camera 17 above the substrate 4 positioned by the positioning unit 14, and the positional deviation of the print pattern printed on the substrate 4 is detected. Next, in FIG.
When the arm 26 is rotated clockwise by the driving of the device and the suction portion 27 at the tip thereof approaches the wafer 5, the pin 7a of the lower die ejector 7 protrudes and pushes up the flip chip F on the wafer 5, and the suction is performed. The part 27 sucks up the bump formation surface and takes it up (reference numeral in the figure). Next arm
Numeral 26 rotates counterclockwise to the position shown by the chain line, and raises the flip chip F from the first level L1 to the second level L2 while turning the flip chip F upside down (sign). So the mounting head 6
The nozzle 6a approaches the nozzle 6a and sucks up the flip chip F to take up (sign). In this case, since the flip chip F is turned upside down as described above, the flip chip F is sucked by the nozzle 6a with the bump forming surface facing down.

As described above, at the first level L1, the flip chip F is sucked up by the suction portion 27 and taken up, and the arm 26 is rotated in the counterclockwise direction from the solid line position to the position indicated by the dashed line, whereby the flip chip F is moved. The flip chip F is raised and lowered from the first level L1 to the second level L2, which is higher than the first level L2, and transferred to the mounting head 6 at the second level L2. The distance is gained by the height difference H. Accordingly, the vertical stroke for the nozzle 6a of the mounting head 6 waiting above to take up the flip chip F can be shortened, and the tact time can be shortened accordingly.

Next, the mounting head 6 moves to the visual inspection device 21 to move the eyepiece unit.
After temporarily stopping above 21b, the displacement of the flip chip F adsorbed by the nozzle 6a in the X, Y, and θ directions is observed (indicated by,). Next, the mounting head 6 moves onto the substrate 4 positioned by the positioning section 14, where the nozzle 6a moves up and down to move the flip chip F to the substrate 4.
(Sign). In this case, among the positional deviation of the flip chip F detected by the visual inspection device 21 and the positional deviation of the printed pattern of the substrate 4 detected in advance by the camera 17, the positional deviation in the X direction and the Y direction is as follows.
The mounting head 6 is corrected by moving the mounting head 6 horizontally by driving the XY direction moving devices 8 and 9, and the positional deviation in the θ direction is driven by driving the θ direction driving device 18 to rotate the nozzle 6a about its axis. After the correction, the flip chip F
Is mounted on the substrate 4.

As described above, according to the present method, the flip chip F mounted on the wafer 5 with the bump formation surface facing upside down can be flipped upside down to correct the position, and then mounted on the substrate 4 with high accuracy. Note that the chip supply unit may be a tray provided with flip chips F as shown in FIG.

(Effects of the Invention) According to the present invention, a flip chip mounted on a chip supply unit with a bump forming surface facing upward is sucked up by a suction unit and taken up, and the flip chip is turned upside down from the first level to approach the second level. At the second level to take up by adsorbing to the lower end of the nozzle of the mounting head, so that the vertical stroke of the nozzle of the mounting head can be shortened, and the tact time can be shortened accordingly. In addition, the displacements in the X, Y, and θ directions detected by the camera are as follows:
Since the horizontal movement device and the θ-direction drive device are driven for correction, little or no time is required for positional deviation correction, and therefore the flip chip is mounted on the board at high speed and with high positional accuracy can do.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an electronic component mounting apparatus according to one embodiment of the present invention, FIG. 2 is a developed view showing a working state in this embodiment, and FIG. 3 is another embodiment of a supply unit in this embodiment. FIG. 4 is a side view of the conventional means. 4 Substrate 5, 28 Chip supply unit 6 Mounting head 8, 9 XY-direction moving device 14 Positioning unit 22 Front-back reversing device 27 Suction unit B Bump F Flip Chips

Claims (1)

(57) [Claims] 1. A plurality of flip chips mounted on a chip supply unit are moved in a horizontal direction with a bump forming surface facing upward at a first level, and one of the flip chips is selected, and a second level higher than the first level is selected. This is an electronic component mounting method for mounting on a substrate positioned at a position where the flip chip of the chip supply unit is sucked up by the suction unit and taken up, and the flip unit is turned upside down by rotating this suction unit by the surface reversing device. Raising the nozzle from the first level to approach the second level while causing the nozzle of the mounting head to move up and down to attract a flip chip to the lower end of the nozzle to take up; A step of observing the chip with a camera to detect a displacement of the flip chip in the X, Y, and θ directions; Correcting the positional deviation in the X direction and the Y direction by driving a moving device to move the mounting head horizontally relative to the substrate; and driving the θ direction driving device to drive the nozzle of the mounting head. And a step of correcting the positional shift in the θ direction by rotating the flip chip about the axis thereof, and then mounting the flip chip on a substrate.