JP2001024316A - Method and device for controlling dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the gap between the nozzle of a dispenser and object to a set value with high accuracy with a simple circuit configuration, without using high-accuracy high-speed A/D converters. SOLUTION: For controlling the gap between the nozzle of a dispenser and a substrate to be coated to a set value, a sample-and-hold circuit 24 holds and outputs a surface level VB detected by means of a sensor 4 corresponding to the height position of the nozzle, when the nozzle reaches the surface of the substrate and a window comparator 25 prepares a non-detected level region VB±VW including the level VB and compares the area VB±VW with an output signal Vi of the sensor 4 corresponding to the height position of the nozzle. When the level of the output signal Vi of the sensor 4 lies outside of the non- detected level region VB±VW, the comparator 25 determines that the gap between the nozzle and substrate reached the set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a semiconductor assembling apparatus provided with a dispenser for applying a flux to a substrate, and a dispenser control method for controlling a height of a nozzle of the dispenser to a predetermined value. And its device.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a dispenser control device.

A nozzle 3 of a dispenser is supported on a base 1 via a guide 2 so as to be vertically movable. The vertical movement of the nozzle 3 is performed, for example, by the operation of an actuator (not shown). Further, the nozzle 3 is provided integrally with a target 5 for detecting a height position of the nozzle 3 by a sensor 4.

In such a dispenser, a coating agent is ejected from the nozzle 3 to apply a flux to the substrate 6, and at this time, the nozzle g is set so that the gap g between the nozzle 3 and the substrate 6 becomes a set value. Height control 3 is performed.

[0005] The height of the nozzle 3 is controlled by detecting the position of a target 5 provided integrally with the nozzle 3 by a sensor 4, whereby a gap g between the nozzle 3 and the substrate 6 is detected.
Is managed.

FIG. 6 is a block diagram of a circuit for detecting the position of the target 5.

A sample and hold circuit 8 is connected to an output terminal of the sensor 4 via an amplifier 7, and an output signal of the sensor 4 is amplified by the amplifier 7 and introduced to the sample and hold circuit 8.

The sample and hold circuit 8 includes a sensor 4
Is sampled and held at a constant cycle, and the output is sent to the A / D converter 9. The A / D converter 9 converts the sample / hold output into a digital signal, and sends a digital signal for each hold to the control circuit 10.

The control circuit 10 captures digital signals for each hold, monitors the changes in these digital signals to determine the height position of the nozzle 3, and
The target distance 1 is determined from the sensor mounting position s from the reference plane 11 and the gap g between the nozzle 3 and the substrate 6, and the output signal of the sensor 4 at the target distance 1 is stored in advance as a reference value, and the nozzle 3 is gradually moved. The nozzle 3 is moved to detect that the output signal of the sensor 4 at this time has reached a previously stored reference value, the nozzle 3 is stopped, and the gap g is controlled to be constant.

[0010] Except for the sensor 4 and the amplifier 7, all are mounted on a printed circuit board and housed in a control housing.

[0011]

However, in order to control the gap g between the nozzle 3 and the substrate 6 with high accuracy by the detection circuit, a high-precision A / D converter 9 must be used. Not in

In order to speed up the control of the gap g, the sample / hold period of the A / D converter 9 must be extremely short, and a high-speed A / D converter 9 must be used. Must.

Since the A / D converter 9 must be a high-precision and high-speed A / D converter, the detection circuit becomes expensive.

On the other hand, since the control circuit 10 compares the height position of the nozzle 3, ie, the output signal of the sensor 4, with the reference value, when the control circuit 10 performs control for a plurality of gaps g, The load on the computer in the circuit 10 increases, which may affect other processes.
For example, there is a possibility that a waiting time is generated before moving to the next sequence.

Further, when the mounting position of the sensor 4 is changed due to a change in setup in semiconductor assembly, etc., the nozzle 3
Cannot be controlled to a desired gap g, even if is positioned at the target distance 1 with high accuracy. This is because if the mounting position of the sensor 4 changes, the gap g cannot always be kept at a constant position, and it is necessary to re-align the sensor 4 so as to have extremely high accuracy or to obtain the target distance l again. is there.

Accordingly, the present invention provides a dispenser control method and apparatus capable of controlling a nozzle and an object to a fixed gap with high accuracy with a simple circuit configuration without using a high-precision and high-speed A / D converter. The purpose is to provide.

[0017]

SUMMARY OF THE INVENTION A dispenser control method according to the present invention controls a gap between a nozzle of a dispenser and an object to be coated to a set value, and controls a gap when the nozzle reaches a surface of the object. Creating a non-detection level area including the level of the output signal from the sensor according to the height position of the nozzle, and comparing the non-detection level area with the output signal level according to the height position of the nozzle from the sensor. hand,
Determining that the gap between the nozzle and the object has reached a set value when the output signal level of the sensor is outside the non-detection level region.

In such a dispenser control method, the non-detection level area includes an upper limit value and a lower limit value obtained by adding or subtracting a sensor output difference designating signal level to a sensor output signal level when the nozzle reaches the surface of the object. And is created in the area.

A dispenser control device according to the present invention controls a gap between a nozzle of a dispenser and an object to be coated to a set value, and a sensor for obtaining an output signal corresponding to a height position of the nozzle; Means for taking in the output signal of the sensor when the nozzle reaches the surface of the object, creating a non-detection level area including the output signal level of the sensor, and the non-detection level area created by this means and the output of the sensor Means for comparing with the signal level to determine that the gap between the nozzle and the object has reached a set value when the output signal level of the sensor is outside the non-detection level region.

In such a dispenser control device, a non-detection level region is determined from an upper limit value and a lower limit value obtained by adding or subtracting a sensor output difference designating signal level with respect to a sensor output signal level when a nozzle reaches a surface of an object. It has a function to create an area.

The dispenser control device according to the present invention controls a gap between a nozzle of the dispenser and an object to be coated to a set value, and includes a sensor for obtaining an output signal corresponding to a height position of the nozzle; A sample-and-hold circuit that samples and holds the output signal of the sensor in response to a sampling start signal when the nozzle reaches the surface of the object, and takes in the output signal of the sensor that is held and output from the sample-and-hold circuit and obtains the output signal level. And a window comparator that outputs a detection signal when the output signal level of the sensor is out of the non-detection level area by comparing the non-detection level area with the output signal level of the sensor. The gap between the nozzle and the object is set based on the detection signal output from this window comparator. Equipped with a gap determining means for determining that it has reached.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The same parts as those in FIG. 5 are denoted by the same reference numerals.

FIG. 1 is a block diagram of a dispenser control device according to the present invention.

A base 1 is erected on a gantry 20. A nozzle 3 of a dispenser is attached to the base 1 via a guide 2 so as to be vertically movable by, for example, an operation of an actuator.

A target 5 is provided integrally with the nozzle 3, and a sensor 4 is provided below the target 5. The sensor 4 obtains an output signal corresponding to the height position of the nozzle 3 by detecting the target 5, and is, for example, an eddy current displacement sensor, a position sensor, a thermocouple, a speed sensor, an acceleration sensor, or the like.

The output terminal of the sensor 4 is connected to a nozzle height detection circuit 21 via an amplifier 7, and the input / output terminals (IN, OUT) of the nozzle height detection circuit 21 It is connected to the control unit 23.

The nozzle height detecting circuit 21 is a small unit
And the nozzle 3 reaches the surface of the substrate 6
Output signal from the sensor 4 (the surface detection level V_B)
Non-detection level area V as center value_B± V_WCreate this
Non-detection level region V_B± V _WAnd the output signal level of sensor 4
Output signal level of sensor 4 is not detected
Level area V_B± V_WWhen it is outside, the detection signal OT is raised.
It has a function of outputting to the position control unit 23.

FIG. 2 is a specific configuration diagram of the nozzle height detection circuit 21.

A window comparator 25 is connected to an output terminal of the sample and hold circuit 24, and a control circuit 26 is connected to the sample and hold circuit 24 and the window comparator 25.

The sample and hold circuit 24 samples and holds the output signal Vi of the sensor 4 when receiving the sampling start signal SH from the control circuit 26 when the nozzle 3 reaches the surface of the substrate 6. window comparator 2 output signal Vi of the sensor 4 immediately after the nozzle 3 reaches the surface of the substrate 6 as a surface detection level V _B
5 has a function of outputting a hold signal.

The window comparator 25 includes a sump
The nozzle 3 output from the hold circuit 24
The output signal of the sensor 4 when it reaches the surface of the substrate 6 (surface detection)
Outgoing level V_B) And the surface detection level V_BIncluding
Non-detection level region V_B± V _WAnd this unchecked
Outgoing level area V_B± V_WAnd the output signal Vi of the sensor 4
And the level of the output signal Vi of the sensor 4 is
Non-detection level area V_B± V_WHigh level (H
(Level) detection signal OT.
Note that V_WIs the sensor output difference designating voltage and the variable resistance
It is set by the circuit 27.

FIG. 3 is a specific circuit configuration diagram of the window comparator 25.

[0033] The window comparator 25, an adder circuit 28 and subtraction circuit 29 for setting the non-detection level region _{V B} ± _{V W,} the level of the output signal Vi of the non-detection level region _{V B} ± _{V W} and the sensor 4 Comparison circuit 30 for comparing
It is composed of

The adder circuit 28 includes the sample hold circuit 2
4 by adding the sensor output difference specified voltage V _W on the face detection level V _B is held outputted from the upper limit value Vref1 of the non-detection level region V _B ± V _W as indicating the addition output 4 (=
And outputs it to the comparator circuit 29 as _{V B} + V _W).

The subtraction circuit 29 includes the sample hold circuit 2
4 subtracts the sensor output difference specified voltage V _W on the face detection level V _B is held outputted from the lower limit value Vref2 of the non-detection level region V _B ± V _W as shown the subtraction output in FIG. 4 (=
And outputs it to the comparator circuit 29 as V _B -V _W).

The comparison circuit 30 includes a pair of comparators 3
1 and 32, and an OR circuit 33 for performing an OR operation on the outputs of the comparators 31 and 32. Among the comparator 31 receives the output signal Vi of the upper limit value Vref1 and the sensor 4 of the non-detection level region V _B ± V _W from the adder circuit 28, generates a detection signal OT of H level when the Vref1 <Vi It has become something.

The comparator 32 receives the output signal Vi of the lower limit value Vref2 and the sensor 4 of the non-detection level region _{V B} ± _{V W} from the subtraction circuit 29, generates a detection signal OT of H level when the Vref2> Vi It is something to do.

Accordingly, the H-level detection signal OT generated by the comparators 31 and 32 is sent to the control circuit 26 through the OR circuit 33.

The control circuit 26 sends the sample hold start signal SH to the sample hold circuit 24 immediately upon receiving the surface detection signal ST from the host control unit 23, and detects the H level output from the window comparator 25. It has a function as gap determination means for receiving the signal OT and determining that the gap g between the nozzle 3 and the substrate 6 has reached a set value.

Next, the operation of the device configured as described above will be described.

In spraying the coating agent from the nozzle 3 to apply the flux to the substrate 6, when the nozzle 3 detects the surface of the substrate 6, the host controller 23 receives the detection of the surface of the substrate 6 by the nozzle 3. Then, a surface detection signal ST is sent to the control circuit 26.

The control circuit 26 sends a sample hold start signal SH to the sample hold circuit 24 immediately after receiving the surface detection signal ST.

At this time, the sensor 4 detects the target 5 and outputs a signal Vi corresponding to the height position of the nozzle 3.
Is output, the sample and hold circuit 24 outputs the signal from the sensor 4 when the sample and hold start signal SH is received.
Outputs hold the output signal Vi as a surface detection level V _B.

The hold output (surface detection level V _B ) of the sample hold circuit 24 is supplied to the window comparator 2
5 and the output signal Vi of the sensor 4 is also sent to the window comparator 25.

[0045] In the window comparator 25, the adder circuit 28 adds the sensor output difference specified voltage V _W, which is set by the variable resistor circuit 27 from the sample hold circuit 24 to the face detection level V _B is hold output, the addition outputs the output to the comparison circuit 29 as the upper limit value _{Vref1 (= V B + V W} ) of the non-detection level region _{V B} ± _{V W} as shown in FIG.

At the same time, the subtraction circuit 29 provides the surface detection level V _{B held and} output from the sample hold circuit 24.
To subtract the sensor output difference specified voltage _{V W,} and outputs the comparison circuit 29 and the subtraction output as the lower limit value Vref2 of the non-detection level region _{V B ± V W (= V} B -V W) as shown in FIG. 4 .

[0047] In the comparison circuit 30, one of the comparator 31, the non-detection level region _{V B} ± from the adder circuit 28
The output signal Vi of the upper limit value Vref1 and the sensor 4 of V _W, Vref1 <detection signal OT of H level occurs when the Vi, the other comparator 32, the non-detection level region V _B from the subtracting circuit 29 the output signal Vi of the lower limit value Vref2 and the sensor 4 ± V _W, generates a detection signal OT of H level when the Vref2> Vi.

The H level detection signal OT generated by the comparators 31 and 32 is sent to the control circuit 26 through the OR circuit 33.

Upon receiving the H-level detection signal OT output from the window comparator 25, the control circuit 26 determines that the gap g between the nozzle 3 and the substrate 6 has reached the set value.

At the same time, when the control circuit 26 determines that the gap g between the nozzle 3 and the substrate 6 has reached the set value,
A stop signal SP for stopping the rising of the nozzle 3 is sent to the host controller 23.

When receiving the stop signal SP from the control circuit 26, the host control section 23 controls the rising of the nozzle 3 to stop. As a result, the gap g between the nozzle 3 and the substrate 6 becomes
It is always controlled to a set value.

As described above, in one embodiment,
To control the gap g between the dispenser nozzle 3 and the substrate 6 to be coated to a set value, a surface detection level from the sensor 4 according to the height position of the nozzle 3 when the nozzle 3 reaches the surface of the substrate 6 non-detection level region _{V B} ± _{V W} containing V _B
Create and the non-detection level region _{V B} ± _{V W} and the sensor 4
By comparing the level of the output signal Vi in accordance with the height position of the nozzle 3 from the nozzle 3 when the level of the output signal Vi of the sensor 4 is out of non-detection level region V _B ± V _W substrate 6
Is determined to have reached the set value, it is possible to continuously monitor the output signal Vi of the sensor 4 in the window comparator 25, and thereby a high-speed sample-hold circuit and a high-precision Fast A /
Even without using a D converter, the nozzle 3 and the substrate 6 can be controlled to a fixed gap g with high accuracy with a simple circuit configuration.

[0053] Also, the positive, since the set by adjusting the sensor output difference specified voltage V _W in the negative direction, the sensor 4 of the nozzle 3 the non-detection level region V _B ± V _W around the face detection level V _B A type in which the output signal level increases in response to the upward movement or a type in which the output signal level decreases in the opposite direction can be used in the same manner. For example, as long as the output signal level of the sensor 4 changes according to the value of the gap g between the nozzle 3 and the substrate 6, any sensor can be used regardless of the direction of the change.

With such a dispenser control device, the height position of the nozzle 3 can be controlled to be a constant gap g even if the mounting position of the sensor 4 is slightly changed due to a change in setup in semiconductor assembly or the like. . Thereby, the alignment of the sensor 4 may be rough, and the working efficiency is improved.

[0055] Further, the nozzle height detection circuit 21, since it is formed into small units, the output signal level and the non-detection level region V _B ± V _W of easily various analog sensors simply be placed close to the sensor 4 Can be compared, and the function can be easily expanded.

In particular, when used for high-accuracy or high-speed positioning control, etc., a high-performance sample-hold circuit and A /
High-accuracy or high-speed positioning control can be performed without using a D converter, and cost can be reduced.

The present invention is not limited to the above embodiment, but may be modified as follows.

For example, the non-detection level region V _B ± V _W is
Although set by adjusting the sensor output difference specified voltage V _W as the center value of the upper limit value Vref1 and the lower limit value Vref2 surface detection level V _B, without the center value of the surface detection level V _B, face detection level V adds each sensor output difference specified voltage V _W having different respective values from _B, the upper limit value Vref1 and subtraction and the lower limit value Vre
f2 may be set.

[0059]

As described above in detail, according to the present invention, a nozzle and an object can be precisely formed in a fixed gap with a simple circuit configuration without using a high-precision and high-speed A / D converter. A controllable dispenser control method and device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a dispenser control device according to the present invention.

FIG. 2 is a specific configuration diagram of a nozzle height detection circuit in the apparatus.

FIG. 3 is a specific configuration diagram of a window comparator in the nozzle height detection circuit.

FIG. 4 is a schematic diagram showing a non-detection level area.

FIG. 5 is a configuration diagram of a conventional dispenser control device.

FIG. 6 is a configuration diagram of a target position detection circuit in the apparatus.

[Description of Signs] 1: Base, 2: Guide, 3: Nozzle, 4: Sensor, 5: Target, 6: Substrate, 7: Amplifier, 20: Mount, 21: Nozzle height detection circuit, 22: Control housing , 23: host control unit, 24: sample hold circuit, 25: window comparator, 26: control circuit, 27: variable resistance circuit, 28: addition circuit, 29: subtraction circuit, 30: comparison circuit, 31, 32: comparator, 33: OR circuit.

Continued on the front page F term (reference) 4D075 AA04 AA85 DA06 DC21 4F041 AA02 AA05 AB01 BA23 5E319 AC01 CD22 CD27 5F047 BA21 BB11 BB16 FA22 FA77

Claims (5)

[Claims] 1. A dispenser control method for controlling a gap between a nozzle of a dispenser and an object to be coated to a set value, wherein the nozzle corresponds to a height position of the nozzle when the nozzle reaches a surface of the object. Creating a non-detection level area including the level of the output signal from the sensor; comparing the non-detection level area with an output signal level corresponding to the height position of the nozzle from the sensor; Judging that the gap between the nozzle and the object has reached a set value when the output signal level is outside the non-detection level region. 2. The non-detection level area includes an upper limit value and a lower limit value obtained by adding or subtracting a sensor output difference designating signal level with respect to an output signal level of the sensor when the nozzle reaches a surface of the object. The dispenser control method according to claim 1, wherein the dispenser control method is created in an area. 3. A dispenser control device for controlling a gap between a nozzle of a dispenser and an object to be coated to a set value, wherein: a sensor for obtaining an output signal corresponding to a height position of the nozzle; Means for taking in the output signal of the sensor when it reaches the surface of the sensor and creating a non-detection level area including the output signal level of the sensor; and the output signal of the sensor and the non-detection level area created by this means. Means for determining that the gap between the nozzle and the object has reached a set value when the output signal level of the sensor is outside the non-detection level area. Dispenser control device. 4. The non-detection level area region is determined from an upper limit value and a lower limit value obtained by adding or subtracting a sensor output difference designating signal level to an output signal level of the sensor when the nozzle reaches the surface of the object. 4. The dispenser control device according to claim 3, wherein the dispenser control device has a function of creating. 5. A dispenser control device for controlling a gap between a nozzle of a dispenser and an object to be coated to a set value, wherein: a sensor for obtaining an output signal corresponding to a height position of the nozzle; A sample and hold circuit that samples and holds the output signal of the sensor in response to a sampling start signal when the signal reaches the surface of the sensor, captures the output signal of the sensor that is output from the sample and hold circuit, and includes the output signal level A window comparator that creates a non-detection level area, compares the non-detection level area with the output signal level of the sensor, and outputs a detection signal when the output signal level of the sensor is outside the non-detection level area Receiving the detection signal output from the window comparator and Dispenser control apparatus characterized by comprising a gap determining unit, the it is determined that the gap reaches the set value of the.