JPH0979815A - Work position detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively detect a position at high speed with high accuracy. SOLUTION: A laser beam source 3 is arranged on one side of a position in which a positioning hole 2 of a work 1 is normally positioned, and a two-dimensional position detecting element 4 is arranged on the other side so as to be opposed to the laser beam source 3, and a spotlight 7 passing through the positioning hole 2 of the laser beam source 3 is received by the two-dimensional position detecting element 4, and operation processing is performed on four photoelectric currents Ix1 , Ix2 , Iy1 and Iy2 generated by the two dimensional position detecting element 4 by an operation circuit 12, and a dislocation quantity of the positioning hole 2 is calculated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for a work such as a lead frame or a tape carrier.

[0002]

2. Description of the Related Art For example, in a bonding apparatus,
It is necessary to position the bonding part of the work such as the lead frame or the tape carrier at the bonding position. Conventionally, as a method of positioning a work, a pattern detection method using a camera, a method of inserting a positioning pin into a positioning hole provided around the work, and the like are known.

[0003]

The pattern detection method using a camera is expensive because it uses a camera and a complicated image processing device. Further, since pattern matching is performed, the detection speed is relatively slow. Further, if there is the same pattern, there is a risk of false detection. The positioning pin insertion method has low accuracy because there is looseness (gap) between the positioning hole and the positioning pin. Further, if the diameter of the positioning hole changes, it is necessary to replace parts such as the positioning pin. Furthermore, it takes time to insert the positioning pin.

An object of the present invention is to provide a work position detecting device which can detect a position at low cost at high speed and with high accuracy.

[0005]

According to a first aspect of the present invention for achieving the above object, a light source is arranged on one side of a position where a positioning hole of a work is properly positioned, and the light source is on the other side. The semiconductor light receiving element is arranged so as to face the light source, the light passing through the positioning hole of the light source is received by the semiconductor light receiving element, and the four photocurrents generated by the semiconductor light receiving element are arithmetically processed by the arithmetic circuit to perform positioning. The feature is that the amount of deviation of the hole is calculated.

A second means of the present invention for achieving the above object is that the semiconductor light receiving element in the first means is
It is characterized by being a dimensional position detecting element or a four-division photodiode.

A third means of the present invention for attaining the above object is to dispose four light projectors on one side of a position where a positioning hole of a work is properly positioned and to face the light projector on the other side. 4 fiber sensors are arranged, the light passing through the positioning holes of the light source is received by the 4 fiber sensors, and the currents of the 4 fiber sensors are processed by a calculation circuit to shift the positioning holes. It is characterized by calculating an amount.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. A laser light source 3 is provided as a light source on one side of the position where the positioning hole 2 of the work 1 is properly positioned.
And a semiconductor light receiving element is arranged on the other side so as to face the laser light source 3. As the semiconductor light receiving element, the two-dimensional position detecting element 4 is used in the case of FIGS.
In this case, the four-division photodiode 20 is used. Further, in the case of FIG. 4, four light projectors 31A to 31A are provided on one side.
D is arranged, and four fiber sensors 30A to 30D are arranged on the other side so as to face the light projectors 31A to 31D. Then, the light passing through the positioning hole 2 of the light source is received by the dimensional position detecting element 4 or 20 or the fiber sensors 30A to 30D, and the semiconductor light receiving element 4 or 4 is received.
Split photodiode 20 or fiber sensor 30
The four photocurrents generated in A to 30D are arithmetically processed by the arithmetic circuit 12 or 25 to calculate the displacement amount of the positioning hole 2.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a laser light source 3 is arranged above a position where a positioning hole 2 of a work 1 such as a lead frame or a tape carrier is properly positioned, and a two-dimensional position is below the positioning hole 2. The central portion 5 of the detection element 4 is arranged. The two-dimensional position detecting element 4 is
P layer on the surface of flat silicon, N layer on the back surface, I in the middle
It is composed of three layers.

Then, the work 1 is sent to a predetermined positioning position by a transfer means (not shown), and the positioning hole 2 is positioned directly below the laser light source 3. When the laser light 6 is emitted from the laser light source 3, the laser light 6 passing through the positioning hole 2 becomes spot light 7 having the size of the positioning hole 2 and enters the two-dimensional position detecting element 4. When the spot light 7 is incident on the two-dimensional position detecting element 4, a charge proportional to the light energy is generated at the incident position. The generated charges pass as a photocurrent through the P layer on the surface, and the currents Ix ₁ and Ix are supplied from the electrodes 8x ₁ , 8x ₂ , 8y ₁ and 8y _{2 in} the XY directions.
_It outputs as ₂ , Iy ₁ and Iy ₂ . In this case, the current I
x ₁ , Ix ₂ , Iy ₁ and Iy ₂ are divided and taken out in inverse proportion to the distances from the center of the incident position of the spot light 7 to the electrodes 8x ₁ , 8x ₂ , 8y ₁ and 8y ₂ .

Now, as shown in FIG. 2, the photocurrent generated in the two-dimensional position detecting element 4 is I ₀ , the distance between the electrodes 8x ₁ and 8x ₂ is Lx, and the distance between the electrodes 8y ₁ and 8y ₂ is Ly, When the center 9 of the spot light 7 is incident at a position displaced from the central portion 5 of the two-dimensional position detecting element 4 by X ₀ , Y ₀ , the currents Ix ₁ , Ix
x ₂ , Iy ₁ , and Iy ₂ are represented by Formula ₁ . Also the current Ix
The ratio of ₁ , Ix ₂ , Iy ₁ , and Iy ₂ is expressed by the equation ₂ . Further, from Equation 2, the displacement amounts X ₀ and Y ₀ of the positioning hole 2 are expressed by Equation 3.

[Number 1] _{Ix 1 = (1/2) · (} 1 + 2X 0 / Lx) · I 0 Ix 2 = (1/2) · (1-2X 0 / Lx) · I 0 Iy 1 = (1/2) _{· (1 + 2Y 0 / Ly} ) · I 0 Iy 2 = (1/2) · (1-2Y 0 / Ly) · I 0

[Number 2] _{Ix 1 / Ix 1 = (Lx} + 2X 0) / (Lx-2X 0) Iy 1 / Iy 2 = (Ly + 2Y 0) / (Ly-2Y 0)

[Formula 3] X ₀ = (1/2) · (Ix ₁ + Ix ₂ ) / (I
x ₁ −Ix ₂ ) · Lx Y ₀ = (1/2) · (Iy ₁ + Iy ₂ ) / (Iy ₁ −I
y ₂ ) ・ Ly

The currents Ix ₁ , Ix ₂ , Iy ₁ and Iy ₂ are supplied to amplifiers 10x ₁ , 10x ₂ , 10y ₁ and 10y _{2, respectively.}
Signal processing circuits 11x ₁ and 11x, respectively.
D / A conversion is performed on x ₂ , 11y ₁ and 11y ₂ . Therefore, the signal processing circuits 11x ₁ , 11x ₂ , 11y ₁ and 11
From y _2, the current _{Ix 1, Ix 2, Iy 1} , Iy 2 voltage Vx ₁ that is proportional _{to, Vx 2, Vy 1, Vy} 2 outputs,
The voltages Vx ₁ , Vx ₂ , Vy ₁ , and Vy ₂ are calculated by the arithmetic circuit 1.
2 is input. The arithmetic circuit 12 has the voltages Vx ₁ and Vx ₂
Of the voltage Vy ₁ and Vy ₂ is calculated. This is converted by the A / D converter 13 to obtain the positional deviations X ₀ and Y ₀ of the positioning hole 2 and input to the control circuit 14.
The control circuit 14 drives the XY table of the bonding apparatus by using the positional deviations X ₀ and Y ₀ as the correction amounts at the time of bonding, or moves the work 1 to move the positioning holes 2 to two positions.
It is located at the central portion 5 of the dimensional position detecting element 4.

FIG. 3 shows a second embodiment of the present invention. This embodiment shows an example in which a four-division photodiode 20 having four elements 20A, 20B, 20C and 20D is used instead of the two-dimensional position detecting element 4 of the above-mentioned embodiment. In the case of this embodiment, the electrodes 21 of the elements 20A, 20B, 20C and 20D are used.
Currents Ia and I output from A, 21B, 21C and 21D
b, Ic, and Id are proportional to the amount of light to which the spot light 7 is applied (the areas where the spot light 6 hits the elements 20A, 20B, 20C, and 20D). That is, the current Ia is the area 22A of the element 20A, the current Ib is the area 22B of the element 20B, the current Ic is the area 22C of the element 20C, and the current Id.
Is proportional to the area 22D of the element 20D. This current Ia,
Ib, Ic, and Id are amplifiers 23A, 23B, 23C, and 2
The signal processing circuits 24A and 24 are amplified by 3D, respectively.
D / A conversion is performed on B, 24C, and 24D. Therefore, the voltage Va proportional to the amplified currents Ia, Ib, Ic, Id from the signal processing circuits 24A, 24B, 24C, 24D,
Vb, Vc, and Vd are output. This voltage Va, Vb, V
c and Vd are processed by the arithmetic circuit 25.

[0014] In the arithmetic circuit 25, in order to calculate the voltage corresponding to the deviation amount X _0, Y ₀ of the XY directions, are added in the addition circuit _{26x 1, 26x 2, 26y 1} , 26y 2,
After that, the subtraction circuits 27x and 27y perform subtraction. The adder circuit 26x ₁ adds the voltages Va and Vb to obtain the voltage Vx ₁
Is calculated, the adder circuit 26x ₂ calculates the voltage Vx ₂ by adding the voltage Vc and Vd, the adding circuit 26y _1, the voltage V
b and Vd are added to calculate the voltage Vy ₁ , and the addition circuit 26
For y ₂ , the voltage Vy ₂ is calculated by adding the voltages Va and Vc. If these are expressed by mathematical formulas, they are as shown in Formula 4. Next, the subtraction circuit 27x subtracts the voltages Vx ₁ and Vx ₂ to calculate the voltage difference Vx in the X direction, and the subtraction circuit 27y calculates the voltage Vx.
by subtracting y ₁ and Vy ₂ calculates a difference Vy of the Y-direction voltage. When this is expressed by a mathematical formula, it becomes as shown in Formula 5.

## EQU4 ## Vx ₁ = Va + Vb Vx ₂ = Vc + Vd Vy ₁ = Vb + Vd Vy ₂ = Va + Vc

[Number 5] _{Vx = Vx 1 -Vx 2 Vy =} Vy 1 -Vy 2

The voltages Vx and Vy calculated by the calculation circuit 25 are converted by the A / D converter 28 to output the positional deviation of the positioning hole 2 and input to the control circuit 29. The control circuit 29 drives the XY table of the bonding apparatus by using the positional deviations X ₀ and Y ₀ as the correction amounts at the time of bonding, or
Alternatively, the work is moved to position the positioning hole 2 at the central position of the two-dimensional position detecting element 4.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, four elements 20A, 20B, 20C and 20D of the four-division photodiode 20 of the second embodiment are replaced with four elements.
The individual fiber sensors 30A, 30B, 30C, 30D are used, and the fiber sensors 30A, 30B,
Four light projectors 31A, 31B, 31C, and 31D which face 30C and 30D and irradiate a spot light were used. Therefore, in the case of this embodiment, the projectors 31A, 31B, 31
The amount of light received by the fiber sensors 30A, 30B, 30C, and 30D that are emitted from C and 31D and that have passed through the positioning hole 2 is as follows:
2A, the fiber sensor 30B has a shaded area 32B,
Since the fiber sensor 30C does not receive light, the area is 0, and the fiber sensor 30D has a shaded area 32D. Therefore, also in the case of this embodiment, the fiber sensors 30A, 30B,
30C, 30D are likewise current Ia and the second embodiment in proportion to the amount of received light received, Ib, Ic, because Id is outputted, the shift amount is treated in the circuit of the second embodiment X _0, Y ₀
Can be requested.

In FIGS. 1 to 3, the laser light source 3 is used.
Is arranged above and the two-dimensional position detecting element 4 or the four-divided photodiode 20 which is a semiconductor light receiving element is arranged below, but they may be arranged in reverse. Although the laser light source 3 is used as the light source, another general light source may be used. FIG. 4
In the case of, the fiber sensors 30A, 30B, 30C, 3
The 0D and the light projectors 31A, 31B, 31C and 31D may be arranged in reverse. In addition, as in this embodiment, the four projectors 3
It is preferable to dispose 1A, 31B, 31C, 31D, but the number thereof is not particularly limited.

As described above, since the incident position of light or the amount of light is converted into an electric current and the electric current is processed to detect the positional deviation of the work 1, a camera is required as in the conventional pattern detection method using a camera. Moreover, since there is no need to store an image or perform pattern matching, it is possible to detect at low cost and at high speed. Moreover, the positioning pin in the conventional positioning pin insertion method is unnecessary, and the adjustment is easy and
It can be detected at high speed and with high accuracy.

[0019]

According to the present invention, the light source is arranged on one side of the position where the positioning hole of the work is properly positioned, and the semiconductor light receiving element is arranged on the other side so as to face the light source. The light passing through the positioning hole is received by the semiconductor light receiving element, and the four photocurrents generated in the semiconductor light receiving element are arithmetically processed by the arithmetic circuit to calculate the amount of deviation of the positioning hole, which is low cost and high speed. Moreover, the position can be detected with high accuracy. Further, four light projectors are arranged on one side of the position where the positioning hole of the work is properly positioned, and four fiber sensors are arranged on the other side so as to face the light projector, and the four fiber sensors are passed through the positioning holes of the light source. The same effect can be obtained by receiving the received light by the four fiber sensors and calculating the deviation amount of the positioning hole by calculating the current of the four fiber sensors by the calculation circuit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a work position detecting apparatus of the present invention.

FIG. 2 is a plan view of the two-dimensional position detecting element of FIG.

FIG. 3 is a block diagram showing a second embodiment of the work position detecting apparatus of the present invention.

4A and 4B show a third embodiment of the work position detecting apparatus of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a partially sectional front view.

[Explanation of symbols]

1 work 2 positioning hole 3 laser source 4 2-dimensional position detecting element 7 spot light _{11x 1, 11x 2, 11y 1} , 11y 2 signal processing circuit 12 calculation circuit 14 control circuit 20 quadrant photodiode 20A, 20B, 20C, 20D element 24A, 24B, 24C, 24D Signal processing circuit 25 Arithmetic circuit 30A, 30B, 30C, 30D Fiber sensor 31A, 31B, 31C, 31D Projector

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 5, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

The currents Ix ₁ , Ix ₂ , Iy ₁ and Iy ₂ are supplied to amplifiers 10x ₁ , 10x ₂ , 10y ₁ and 10y _{2, respectively.}
Signal processing circuits 11x ₁ and 11x, respectively.
The voltage is converted by x ₂ , 11y ₁ and 11y ₂ . Therefore,
The signal processing circuit _{11x 1, 11x 2, 11y 1} , 11y 2
From a current _{Ix 1, Ix 2, Iy 1} , Iy 2 voltage Vx ₁ that is proportional _{to, Vx 2, Vy 1, Vy} 2 outputs, the voltage _{Vx 1, Vx 2, Vy 1} , Vy 2 arithmetic circuit 12 is input. The arithmetic circuit 12 calculates the difference or ratio between the voltages Vx ₁ and Vx ₂ , and the difference or ratio between the voltages Vy ₁ and Vy ₂ . This is converted by the A / D converter 13 to obtain the positional deviations X ₀ and Y ₀ of the positioning hole 2 and input to the control circuit 14. The control circuit 14 drives the XY table of the bonding apparatus by using the positional deviations X ₀ and Y ₀ as correction amounts during bonding, or moves the work 1 to move the positioning hole 2 to the central portion 5 of the two-dimensional position detecting element 4. Located in.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

FIG. 3 shows a second embodiment of the present invention. This embodiment shows an example in which a four-division photodiode 20 having four elements 20A, 20B, 20C and 20D is used instead of the two-dimensional position detecting element 4 of the above-mentioned embodiment. In the case of this embodiment, the electrodes 21 of the elements 20A, 20B, 20C and 20D are used.
Currents Ia and I output from A, 21B, 21C and 21D
b, Ic, and Id are proportional to the amount of light with which the spot light 7 is applied (the areas where the spot light 6 hits the elements 20A, 20B, 20C, and 20D). That is, the current Ia is the area 22A of the element 20A, the current Ib is the area 22B of the element 20B, the current Ic is the area 22C of the element 20C, and the current Id.
Is proportional to the area 22D of the element 20D. This current Ia,
Ib, Ic, and Id are amplifiers 23A, 23B, 23C, and 2
The signal processing circuits 24A and 24 are amplified by 3D, respectively.
The voltage is converted by B, 24C, and 24D. Therefore, the signals Va, V proportional to the amplified currents Ia, Ib, Ic, Id from the signal processing circuits 24A, 24B, 24C, 24D.
b, Vc and Vd are output. This voltage Va, Vb, V
c and Vd are processed by the arithmetic circuit 25. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 18, 1995

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

[Fig. 2]

Claims (3)

[Claims] 1. A light source is arranged on one side of a position where a positioning hole of a work is properly positioned, and a semiconductor light receiving element is arranged on the other side so as to face the light source, and passes through the positioning hole of the light source. A position detecting device for a workpiece, wherein light is received by the semiconductor light receiving element, and four photocurrents generated by the semiconductor light receiving element are arithmetically processed by an arithmetic circuit to calculate a deviation amount of a positioning hole. 2. The position detecting device for a work according to claim 1, wherein the semiconductor light receiving element is a two-dimensional position detecting element or a four-division photodiode. 3. A light projecting device is arranged on one side of a position where a positioning hole of a work is properly positioned, and four fiber sensors are arranged on the other side so as to face the light projecting device, and the positioning hole of the light source is arranged. A position detecting device for a work, wherein the light passing through is received by the four fiber sensors, and the currents of the four fiber sensors are arithmetically processed by an arithmetic circuit to calculate the deviation amount of the positioning hole.