JPH08330790A - Bare chip mounter - Google Patents

Abstract

PURPOSE: To set a travel distance of a uniaxial table independent of a height difference between a bare chip and a board by a method wherein a table controller which controls a uniaxial table, which moves a suction nozzle in a vertical direction, comparing the detected pressure of a pressure detector with a reference pressure is provided. CONSTITUTION: This system comprises a first uniaxial table 6 which holds and guides a suction nozzle 2 in a vertical direction, a second uniaxial table 13 which holds and drives a bracket 7 in a vertical direction by a motor, and a table controller 14 which controls the motion of the uniaxial table 13 as connected to a pressure detecting section 12. A pressure outputted from a load cell 10 is detected by the pressure detecting suction 12 and compared with a prescribed reference pressure. The table controller 14 stops the uniaxial table 13 at the time when a pressure reaches the prescribed reference pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bare chip mounter, and more particularly to a bare chip mounter for mounting a bare chip on a print pattern of a printed wiring board while applying pressure.

[0002]

2. Description of the Related Art FIG. 2 is a side view showing an example of a conventional bare chip mounter. An example as shown in this figure is published in P187 to 188, a surface mounting technology reader (Nikkan Kogyo Shimbun), and is an example of a general conventional example in which a chip is mounted by controlling the position of a motor. A conventional bare chip mounter for mounting a bare chip on a print pattern of a printed wiring board (substrate) while applying pressure has a structure as shown in FIG. That is, the XY table 24 that mounts the substrate 3 on the upper surface and moves in a direction perpendicular to the horizontal plane, the suction nozzle portion 22 that is located above the XY table 24 and that sucks the upper surface of the bare chip 1, and the suction nozzle portion 22. A vacuum generator 25 that comes into contact with each other to perform vacuum suction of the bare chip 1, a first uniaxial table 26 that holds the suction nozzle unit 22 and guides its vertical movement, and a uniaxial table 2
6, a bracket 27 for holding 6, a compression spring 28 for pressing down the suction nozzle portion 22, and a compression spring 2 on the lower surface.
8, a second uniaxial table 32 for holding the bracket 27 and driving the bracket 27 up and down by a motor, and a table controller 33 for controlling the operation of the uniaxial table 32. .

When the bare chip 1 is mounted on the substrate 3 by the bare chip mounter thus constructed, the vacuum generator 25 is operated to suck the upper surface of the bare chip 1 by the suction nozzle portion 22, and the XY table 24 is moved to move the bare chip 1. 1 and the print pattern of the substrate 3 are aligned, and then the uniaxial table 32 is moved downward by the table controller 33 to mount the bare chip 1 sucked by the suction nozzle portion 22 on the print pattern of the substrate 3.

At this time, the uniaxial table 32 is moved by a pushing distance A more than the moving distance B before contact of the bare chip 1. This extra moving distance A
Are absorbed by the upward movement of the uniaxial table 26. Therefore, the compression spring 28 mounted between the suction nozzle portion 22 and the rod 29 is compressed by the pushing distance A. At this time, [compressive force of the compression spring 28 + self-weight of the suction nozzle 22 + self-weight of the movable portion of the uniaxial table 26] is the pressure applied to the bare chip 1.

[0005]

In the conventional bare chip mounter as described above, the pushing distance A is determined by the position control of the second uniaxial table 32 and the pressing force of the bare chip against the substrate is generated by the compression spring 28.
(1) It is necessary to change the setting of the moving distance of the second uniaxial table according to the thickness of the bare chip and the thickness of the substrate. (2) The pushing distance of the compression spring due to the variation in the thickness of the bare chip and the thickness of the substrate or the warp. (3) When the compression spring changes its characteristics due to deterioration or the like, there is a disadvantage that the pressing force changes even if the pushing distance is constant. In addition, when it is desired to mount the device with a small load, there is a disadvantage that [the own weight of the suction nozzle 22 + the own weight of the movable portion of the uniaxial table 26] acts and the device cannot be mounted with a load less than that.

[0006]

A bare chip mounter of the present invention mounts a printed wiring board on its upper surface and moves it in a direction perpendicular to a horizontal plane, and an upper surface of the bare chip located above the XY table. A suction nozzle portion for suctioning, a vacuum generator connected to the suction nozzle portion for vacuum suctioning the bare chip, a first uniaxial table for holding the suction nozzle portion and guiding the vertical movement thereof, A bracket that holds the first uniaxial table, a compression spring that presses down the suction nozzle portion, a rod that contacts the upper end of the compression spring on the lower surface, and a load cell that is held by the bracket and contacts the upper surface of the rod. And the movable part of the first uniaxial table is lifted so that the movable part of the uniaxial table has a weight equal to or more than its own weight in a direction opposite to the load direction of the compression spring. A tension spring for generating a heavy,
A pressing force detection unit connected to the load cell and outputting the detected pressure of the load cell, a second uniaxial table that holds the bracket and drives the vertical movement of the bracket by a motor, and is connected to the pressing force detection unit. And a table controller for controlling the operation of the second uniaxial table.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the present invention. The bare chip mounter shown in FIG. 1 includes an XY table 4 on which a substrate 3 is mounted on the upper surface and is moved in a horizontal direction at right angles, and an adsorption nozzle portion 2 which is located above the XY table 4 and adsorbs the upper surface of the bare chip 1. A vacuum generator 5 that is connected to the suction nozzle unit 2 to perform vacuum suction of the bare chip 1,
A first uniaxial table 6 that holds the suction nozzle unit 2 and guides its vertical movement, a bracket 7 that holds the uniaxial table 6, a compression spring 8 that presses the suction nozzle unit 2 downward, and a compression at the lower surface. The rod 9 that contacts the upper end of the spring 8, the load cell 10 that is held by the bracket 7 and that contacts the upper surface of the rod 9, and the movable portion of the uniaxial table 6 are lifted to move the uniaxial table 6 in the direction opposite to the load direction of the compression spring 8. Tension spring 11 for generating a load equal to or more than the own weight of the movable part, a pressure detection unit 12 connected to the load cell 10 for outputting the detected pressure of the load cell 10, and a bracket 7
And a second uniaxial table 13 for holding and driving the uniaxial table 13 by a motor to drive the uniaxial table 13 up and down, and a table controller 14 connected to the pressing force detection unit 12 to control the operation of the uniaxial table 13.

The bare chip mounter thus constructed operates as follows. That is, the vacuum generator 5 is operated to suck the upper surface of the bare chip 1 by the suction nozzle unit 2, the XY table 4 is moved to align the bare chip 1 and the print pattern of the substrate 3, and then the table controller 13 is used. The uniaxial table 13 is moved downward to mount the bare chip 1 sucked by the suction nozzle portion 2 on the printed pattern of the substrate 3.

At the same time, the pressing force detector 12 detects the pressing force output from the load cell 10 and compares it with a predetermined reference pressing force. The reference pressing force at this time is a value obtained by adding the load generated by the [compression spring 8 + tension spring 11] by the pushing distance A to the initial detection load detected by the load cell 10 before the suction nozzle unit 2 starts moving downward. And The load generated by the [compression spring 8 + tensile spring 11] due to the pushing distance A becomes the "loading pressure" when the bare chip 1 is mounted on the substrate 3. When the bare chip 1 contacts the substrate 3 and moves further by the pushing distance A, the pushing distance A is absorbed by the upward movement of the uniaxial table 6, the compression spring 8 is compressed by that amount, and the tension spring 11 is returned. Then, a predetermined pressing force is generated and detected by the pressing force detection unit 12. When the pressure reaches the reference pressure, the table controller 14 stops the operation of the uniaxial table 13. After stopping the uniaxial table 13, the vacuum generator 5 is stopped to release the suction of the bare chip 1 by the suction nozzle unit 2 to place the bare chip 1 on the substrate 3, and the uniaxial table 13 is moved upward to perform a series of operations. Complete the mounting operation of.

[0011]

As described above, the bare chip mounter of the present invention includes a load cell for detecting the mounting pressure applied to the bare chip when the bare chip is mounted on the substrate,
A pressure detection unit that inputs the output from this load cell to detect the pressure, and a uniaxial table that drives the vertical movement of the suction nozzle unit by comparing the pressure detected by the pressure detection unit and the reference pressure. By providing the table controller for controlling the operation, (1) it is not necessary to change the setting of the moving distance of the uniaxial table for driving the vertical movement of the suction nozzle unit according to the height of the bare chip with respect to the substrate. (2) There is no change in the pressing force due to variations in the thickness of the substrate and the bare chip or warpage, or a change in the pressing force due to a change in the characteristics of the compression spring, so that the mounting pressing force on the bare chip can always be kept constant ( 3) Lifting up with a tension spring cancels out the self-weight of the movable part of the first uniaxial table, and makes it the initial detection load of the load cell. There is an effect that can also be equipped with a load.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bare chip 2 Adsorption nozzle part 3 Substrate 4 XY table 5 Vacuum generator 6 Uniaxial table 7 Bracket 8 Compression spring 9 Rod 10 Load cell 11 Tension spring 12 Pressurizing force detection part 13 Uniaxial table 14 Table controller 22 Adsorption nozzle part 24 XY table 25 Vacuum Generator 26 Uniaxial table 27 Bracket 28 Compression spring 29 Rod 32 Uniaxial table 33 Table controller

Claims (1)

[Claims] 1. An XY table which mounts a printed wiring board on its upper surface and moves in a direction perpendicular to a horizontal plane, an adsorption nozzle portion which is located above the XY table and which adsorbs an upper surface of a bare chip, and said adsorption nozzle portion. A vacuum generator that is connected to a vacuum suction device for performing vacuum suction of the bare chip, a first uniaxial table that holds the suction nozzle unit and guides the vertical movement thereof, and a bracket that holds the first uniaxial table.
A compression spring that pushes down the suction nozzle portion, a rod that contacts the upper end of the compression spring on the lower surface, a load cell that is held by the bracket and that contacts the upper surface of the rod, and a movable portion of the first uniaxial table. A tension spring for lifting a load to generate a load equal to or more than its own weight of the movable portion of the uniaxial table in a direction opposite to the load direction of the compression spring, and a pressing force detection unit connected to the load cell and outputting a detected pressure of the load cell. And a second uniaxial table that holds the bracket and drives the motor to move up and down, and a table controller that is connected to the pressing force detector to control the operation of the second uniaxial table. Bare chip mounter characterized by the following.