JPH09239627A - Tool end height position controlling device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely transfer conductive resin paste to a bump at the time when a bare chip holding tool is expanded and contracted by measuring the minute change in the tool tip and controlling the tool tip position according to the measuring result. SOLUTION: Since in the process to transfer conductive resin paste 5 to the bump of the bare tip part 1 adsorbedly held at the tip of a tool 3, the tool 3 is expanded by length δ due to thermal expansion, the travel amount of the tool 3 from standard height must not be considered to be L2, initial setting amount, but to be L2-δ. Accordingly, when a control section 9 controls a motor 6 for vertically moving the tool 3 to correct the travel amount of the tool 3 from the standard height when transferring the conductive resin paste 5 to L2-δ, the conductive resin paste 5 can normally be transferred to the bump of the bare tip part 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for controlling the tip position of a tool for holding a bare chip component attached to a chip bonder to a constant height, and more particularly, to a conductive paste for a surface mount type component or the like. The present invention relates to an apparatus and method for controlling the position when transferring.

[0002]

2. Description of the Related Art As a method of mounting a bare chip component such as an IC element on a printed circuit board of an electronic device, there is a method called flip chip mounting, which is a top perspective view of FIG. 4A and a bottom surface of FIG. The bumps 2, 2 are provided on the electrodes provided on the outer surface of the bare chip component 1 as shown in the perspective view.
Is provided, and the bumps 2, 2, ... Are further coated with a conductive resin paste described later and connected and fixed to a printed circuit board.

As described above, flip-chip mounting of bare chip components on a printed circuit board is generally performed by a mounting device such as a chip bonder. The apparatus is provided with a tubular tool 3 made of a metal and having a hollow inside as shown in FIG. 5, and the bare chip component 1 is suction-held on the tip of the tool 3 by sucking the inside with a vacuum pump or the like. Then, by causing the tool 3 to move in a desired manner, a conductive resin paste is applied to the bump surface of the bare chip component 1 described later, the bare chip component 1 is mounted on a printed circuit board, and the tool 3 is heated to move the conductive resin. A series of operations is performed until the paste is cured.

FIG. 6 shows a flow chart for flip-chip mounting bare chip components on a printed circuit board. That is, a bare chip component having bumps formed on the outer surface is held by suction on the above-mentioned tool tip (step 1), and a conductive resin paste that is cured by heating is applied to the bump surface (step 2), and then the bare chip The component is placed on the printed circuit board (step 3), and the tool is heated (step 4) to cure the conductive resin paste to electrically connect the bare chip component and the electrode pattern of the printed circuit board.

FIGS. 7 (a) and 7 (b) show a transfer method, which is one means of applying a conductive resin paste to the bumps of the conventional bare chip component, and FIG. It is the A section enlarged view of a). That is, the transfer stage 4 is provided with a required amount of the conductive resin paste 5, the tip of the tool 3 holds the bare chip component 1 by suction, and the tool vertical movement motor 6 lowers the tool 3. A method of transferring the conductive resin paste 5 to the bumps 2, 2, ... Is shown.

The control for moving the tool 3 is performed by inputting a set value. For example, the tool 3 is provided with a sensor 7 such as a load cell, and the tool 7 is moved up and down until a desired load is applied to the sensor 7. The tool 3 can be controlled by arranging the motor 6 to move. Alternatively, if the tool up-and-down moving motor 6 is composed of a stepping motor, the tool 3 can be controlled by the rotation speed thereof. Therefore, when the tool 3 is moved by the length L2 from the reference height based on the set value, the conductive resin paste 5 is normally transferred to the surfaces of the bumps 2, 2, ... Of the bare chip component 1.

[0007]

However, as described above, the bare chip component is mounted on the printed circuit board while being sucked and held on the tip of the tool, and the tool is heated to cure the conductive resin paste to thereby leave the bare chip component. , The tool thermally expands by a length δ by heating. That is, by heating,
The conductive resin paste is transferred to the bumps of the bare chip component while the tool is extended by the length δ.
As shown in (a) and (b), when the tool 6 for moving the tool up and down is driven to control the tool 3 to move by the length L2 from the reference height, the tip portion of the tool 3, that is,
The bare chip component 1 is equivalent to moving the length L2 + δ.

Therefore, the bare chip component 1 is deeply embedded in the conductive resin paste 5 in the transfer stage 4 by the length δ, and the conductive resin paste 5 is bumped by the bumps 2,
2, ... There was a drawback that it was not possible to transfer normally to only the surface.

Further, since the bare chip component 1 is buried in the conductive resin paste 5, the conductive resin paste 5 also adheres to the outer surface thereof, so that the conductive resin paste 5 is bumped to the bumps of the bare chip component 1. 2, 2, ...
, Or the bumps 2, 2, ... And the terminals to be insulated of the electrode pattern of the printed circuit board are short-circuited.

Furthermore, when the length of the tool 3 is extended due to thermal expansion or the like and the movement amount is set, and then the length of the tool 3 is shortened due to a change in the temperature of the outer circumference of the tool 3 or the like. , Bumps 2, 2, ... Can not be transferred to the conductive resin paste 5, so that it is impossible to mount the bare chip component on the printed circuit board.

[0011]

An object of the present invention is to eliminate the above-mentioned drawbacks when transferring the conductive resin paste to the bumps of the bare chip component, and to form the bump on the bump when the tool for holding the bare chip component expands and contracts. An object of the present invention is to provide a tool tip height position control device and method for reliably transferring a conductive resin paste.

[0012]

In order to achieve the above-mentioned object, a tool tip height position control device according to the present invention is a control device for controlling a position of a tool tip for fixing a component to a constant value. The apparatus has a function of measuring a change, a function of storing the measurement result, and a function of controlling the position of the tool tip based on the measurement result.

Further, the method is a control method in which the position of the tool tip for fixing a component is controlled to be constant, a minute change in the tool tip is measured, and the measurement result is fed back to the control of the tool vertical movement motor. This is a method of controlling the position of the tool tip.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment.

FIG. 1 is a block diagram of a tool tip height position control device showing an embodiment of the present invention. That is, in the device that controls the position of the tip of the tool 3 that fixes the bare chip component 1, a function that measures a minute change in the length of the tool 3 and a function that controls the movement amount of the tool 3 based on the measurement result. It is characterized by having.

The function for measuring the extended length of the tool 3 includes a leveling table 8, a sensor 7 such as a load cell for measuring the pressure generated when the tool 3 is moved, and a controller 9. The tool 3 is pressed against the leveling table 8 in a state where the tip of the tool 3 is suction-held on the tip of the tool 3, the load generated at that time is measured by the sensor 7, and the control unit is based on the measurement result. 9 calculates the length of thermal expansion of tool 3,
Further memorize.

The function of controlling the amount of movement of the tool for transferring the conductive resin paste is composed of a control section and a sensor 7 such as a load cell for measuring the pressure generated when the tool 3 is moved. , The control unit 9 calculates the movement amount of the tool 3 based on the calculation result of the extended length of the tool 3, and normally transfers the conductive resin paste to the bump of the bare chip component 1 held at the tip of the tool 3. It is configured in. The control of the movement amount of the tool 3 is performed while measuring the load by the sensor 7.

That is, in order to keep the height of the bare chip component 1 constant, if the length of the tool 3 changed by thermal expansion is measured, the leveling process is performed, and then the movement amount of the tool 3 is controlled based on the measurement result. By doing so, the conductive resin paste 5 is controlled to be transferred to the bumps of the bare chip component.

In the operation of the apparatus according to the present invention, the leveling process is performed by pressing the tool 3 with the tip of the bare chip component 1 sucked and held onto the leveling table 8. At that time, a sensor 7 such as a load cell is provided so as to measure the movement amount of the tool 3, and the sensor 7
Measure the load on. At that time, the control unit 9 calculates and stores the movement amount L1 of the tool 3 from the reference height based on the measurement result of the sensor 7.

Thereafter, the bare chip component 1 is sucked and held on the tip portion of the tool 3 as it is, and the bare chip component 1 is held.
The conductive resin paste 5 provided on the transfer stage 4 is normally transferred to the bumps 2, 2, ..., And the load applied to the sensor 7 provided on the tool is measured. Based on the measurement result, the control unit 9 calculates and stores the movement amount L2 from the reference height of the tool 3 that transfers the conductive paste to the bump of the bare chip component.

Thereafter, with the tip of the tool 3 holding the bare chip component 1 by suction, while holding the bare chip component on a printed circuit board (not shown), the tool 3 is heated and the conductive resin paste 5 is applied. Cure
The bare chip component 1 is held on the printed board and electrically connected to the wiring pattern provided on the printed board.

After that, the tool 3 sucks and holds another bare chip component at its tip and then mounts it on the printed circuit board.
At this time, as described above, the tool 3 expands by the length δ due to the heating for hardening the conductive resin paste. Therefore, as shown in FIG. 2, in the leveling process of the tool 3, the movement amount of the tool 3 from the reference height is L1-δ.

At this time, the control unit 9 calculates the extended length δ of the tool 3 based on the measurement result of the sensor 7 provided in the tool 3 and the measurement result of the previous leveling process.

Next, in the step of transferring the conductive resin paste to the bumps of the bare chip component which is suction-held at the tip of the tool 3, the tool 3 is stretched by the length δ due to thermal expansion. The amount of movement from the reference height must be L2-δ, not L2 which is the initial setting.
Therefore, as shown in FIG. 3, the control unit 9 controls the tool vertical movement motor 6 to set the movement amount of the tool 3 from the reference height when transferring the conductive resin paste 5 to L2-δ. As a result, the conductive resin paste 5 can be normally transferred to the bumps of the bare chip component 1, and the bare chip component 1 can be reliably mounted on the printed board.

That is, the tool tip height position during the leveling process when the conductive resin paste transfer condition is good and the tool tip height position during the conductive resin paste transfer are stored, and the leveling of the tool that has been further thermally expanded is stored. By detecting the height position of the tool tip in the process, the length of extension of the tool can be detected, and the movement amount of the tool 3 can be controlled. Therefore, it is possible to prevent defective mounting on the printed circuit board due to defective transfer of the conductive resin paste to the bumps of the bare chip component, which improves the yield of the printed circuit board.

As described above, if the tool up / down moving motor 6 for moving the tool 3 is composed of a stepping motor during the leveling process or the transfer of the conductive resin paste, the length of the tool 3 which has been thermally expanded is determined from the number of rotations thereof. Calculation is possible, and further, when transferring the conductive resin paste, the movement of the tool 3 can be controlled by the rotation speed thereof.

The present invention has been described above with respect to an apparatus and method for mounting a bare chip component on a printed board, but the present invention is not limited to this, and an apparatus and a device for mounting a general electronic component on the printed board. It is applicable to the method, and the electronic component can be surely mounted on the printed circuit board of the electronic device.

Further, since the bumps conventionally provided on the bare chip component have manufacturing variations such as size and height, the transfer of the conductive resin paste may be defective. However, by applying the present invention, it is possible to measure the manufacturing variation of the bump as well as the extension of the tool, so that it is possible to reliably transfer the conductive resin paste to the bump.

[0029]

Since the present invention is configured as described above, when the conductive resin paste is transferred to the electrodes (bumps) of the electronic component by storing the settings in advance, the conductive resin paste is applied only to the bumps. Since it can be applied, it is possible to prevent defective application of the conductive resin paste and to exert a remarkable effect in mounting the electronic component on the printed board.

[Brief description of drawings]

FIG. 1 is a block diagram of a tool tip height control device according to the present invention.

FIG. 2 is a diagram showing a leveling process of the tool tip height control device according to the present invention.

FIG. 3 is an explanatory view showing control of a tool tip height of a tool tip height control device according to the present invention.

4A and 4B are a top perspective view and a bottom perspective view of a bare chip component.

FIG. 5 is a structural diagram of a tool of a mounting apparatus

FIG. 6 is a flow chart for mounting bare chip components of a mounting apparatus.

7A and 7B are a block diagram of a tool tip height control device and a magnified view of part A showing a conventional method for mounting bare chip components.

8 (a) and 8 (b) are configuration diagrams of a tool tip height control device and an enlarged view of a portion A showing a method for mounting components in a state where the tool is thermally expanded.

[Explanation of symbols]

 1 ... Bare chip part 2 ... Bump 3 ... Tool 4 ... Transfer stage 5 ... Conductive resin paste 6 ... Tool vertical movement motor 7 ... Sensor 8 ... Leveling table 9 ... Control unit

Claims (2)

[Claims] 1. A control device for controlling a position of a tool tip for fixing a component to be constant, a function of measuring a minute change of the tool tip, a function of storing the measurement result, and a position of the tool tip based on the measurement result. A tool tip height position control device having a function of controlling. 2. A control method for controlling a position of a tool tip for fixing a component to be constant, measuring a minute change of the tool tip and feeding back the measurement result to the control of a tool up-and-down moving motor to obtain the tool tip. A tool tip height position control method characterized by controlling a position.