CN103808285B - Prealignment machine and the scaling method of mechanical hand relative coordinate system - Google Patents

Abstract

The invention discloses the scaling method of a kind of prealignment machine and mechanical hand relative coordinate system, described scaling method includes: the first, setting the coordinate system residing for prealignment machine is x ' o ' y ' coordinate system as xoy coordinate system, the coordinate system residing for mechanical hand；The second, utilize a wafer being in described xoy coordinate system to move radially relative to described x ' o ' y ' coordinate system, determine described x ' o ' y ' coordinate system attitude in described xoy coordinate system；3rd, described wafer is rotated relative to described x ' o ' y ' coordinate system, determine described x ' o ' y ' coordinate system position in described xoy coordinate system, i.e. obtain the relative position relation of described mechanical hand and described prealignment machine.The present invention can realize vacuum adsorption type mechanical hand being accurately positioned under vacuum adsorption type prealignment machine coordinate system, thus can be effectively improved the prealignment precision to wafer and transmission precision.

Description

Prealignment machine and the scaling method of mechanical hand relative coordinate system

Technical field

The present invention relates to mechanical hand manipulation technical field, particularly to the scaling method of a kind of prealignment machine Yu mechanical hand relative coordinate system, be mainly used in the relative position determining mechanical hand with being steered equipment, so that manipulation is more accurate.

Background technology

Mechanical hand be a kind of can imitate staff and arm some holding function, capture according to fixed routine, carrying object or the automatic pilot of operation instrument.At present, in production of integrated circuits technology, vacuum adsorption type single shaft prealignment machine is required for jointly completing the prealignment to wafer with mechanical hand, i.e. identifies the wafer center of circle and breach or trimming position and makes breach or trimming towards a certain default direction, and mostly using vacuum adsorption type mechanical hand.After prealignment machine identifies the wafer center of circle, wafer position should be adjusted by mechanical hand, make the rotating shaft of vacuum cup in prealignment machine pass through the wafer center of circle.If now not knowing the relative position information of prealignment machine and robot coordinate system, then system will be unable to refer to that wafer is made by it to mechanical hand and adjusts accurately, prealignment also cannot learn wafer accurate location on a robotic arm after terminating, and prealignment will lose meaning.The most now needing to demarcate, the task of demarcation determines that attitude (i.e. prealignment machine coordinate system and the relative rotation of robot coordinate system) and position (i.e. prealignment machine coordinate origin and the relative position of robot coordinate system initial point) of Two coordinate system.

During realizing the present invention, inventor finds that prior art at least there is problems in that the existing position determining and regulating mechanical hand and prealignment machine is to use artificial pilot teaching, make mechanical hand be difficult to the relative position of prealignment machine to determine or precision is the lowest, thus the alignment precision of wafer is substantially reduced.

Summary of the invention

In order to solve problem of the prior art, embodiments provide the scaling method of a kind of prealignment machine and mechanical hand relative coordinate system, the method is by demarcating the relative position information obtaining prealignment machine with robot coordinate system, realize arm end being accurately positioned in prealignment machine coordinate system, thus improve the precision to wafer prealigning.Described technical scheme is as follows:

A kind of prealignment machine and the scaling method of mechanical hand relative coordinate system, described scaling method includes:

S1, to set the coordinate system residing for prealignment machine be x ' o ' y ' coordinate system as xoy coordinate system, the coordinate system residing for mechanical hand；

S2, utilize a wafer being in described xoy coordinate system to move radially relative to described x ' o ' y ' coordinate system, determine described x ' o ' y ' coordinate system attitude in described xoy coordinate system；

S3, described wafer is rotated relative to described x ' o ' y ' coordinate system, determine described x ' o ' y ' coordinate system position in described xoy coordinate system, i.e. obtain the relative position relation of described mechanical hand and described prealignment machine.

Further, in step s 2, determine that described x ' o ' y ' coordinate system method of attitude in described xoy coordinate system includes:

S201, the center of circle of the described wafer being in described xoy coordinate system is transferred to a certain position B, draws the B point offset d=BO relative to described xoy coordinate origin；

S202, described mechanical hand is moved adjacent to a certain position A of B point, then by described mechanical hand together with described wafer along O ' A direction displacement d, write down the position A ' that described mechanical hand newly locates, position B ' that the described wafer center of circle is newly located；

S203, measure offset d '=B ' O, the most described x ' o ' y ' coordinate system attitude angle t=B ' BO in described xoy coordinate system of B ', try to achieve according to the cosine law:

$t=\arccos \left(\frac{2\·d^2-d^{\′2}}{2\·d^2}\right)=\arccos (1-\frac{1}{2}\·{\left(\frac{d^{\′}}{d}\right)}^2).$

Further, step S2 also includes the step of corrected parameter:

S204, demarcating after described x ' o ' y ' coordinate system attitude angle t in described xoy coordinate system, described mechanical hand is being coordinated with described prealignment machine described wafer bias is compensated, after compensation, again calculate the offset of described wafer；

If offset reading is in claimed range, the most generally less than CCD precision, then demarcate successfully；If offset reading is outside claimed range, then re-start demarcation.

Further, in step s3, determine that described x ' o ' y ' coordinate system method of position in described xoy coordinate system includes:

The initial position B in described xoy coordinate system of the wafer center of circle described in S301, labelling, mechanical hand initial position A in described xoy coordinate system described in labelling；

S302, by described mechanical hand together with described wafer around O ' rotational angle T, write down the position A ' that described mechanical hand newly locates, position B ' that the described wafer center of circle is newly located；

S303, according to position in described xoy coordinate system of B, B ', and the drift angle ∠ BO ' B '=T of isosceles triangle BO ' B ', calculate the O ' position in described xoy coordinate system, the most described x ' o ' y ' coordinate system position in described xoy coordinate system.

The technical scheme that the embodiment of the present invention provides has the benefit that

Vacuum adsorption type mechanical hand being accurately positioned under vacuum adsorption type prealignment machine coordinate system can be realized, and then wafer being accurately positioned under vacuum adsorption type prealignment machine and robot coordinate system can be implemented in combination in by vacuum adsorption type mechanical hand and vacuum adsorption type prealignment machine, thus the prealignment precision to wafer and transmission precision can be effectively improved.

Accompanying drawing explanation

For the technical scheme being illustrated more clearly that in the embodiment of the present invention, in describing embodiment below, the required accompanying drawing used is briefly described, apparently, accompanying drawing in describing below is only some embodiments of the present invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is that the prealignment machine that the embodiment of the present invention provides determines x ' o ' y ' coordinate system schematic diagram of attitude in xoy coordinate system in the scaling method of mechanical hand relative coordinate system；

Fig. 2 is that the prealignment machine that the embodiment of the present invention provides determines x ' o ' y ' coordinate system schematic diagram of position in xoy coordinate system in the scaling method of mechanical hand relative coordinate system.

In figure, xoy is prealignment machine coordinate system, and x ' o ' y ' is robot coordinate system, B is the initial position in the wafer center of circle, B ' move for wafer after home position, A is the initial position at manipulator clamping center, and A ' moves rear Clamping Center location for mechanical hand.

Detailed description of the invention

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.

Embodiment

Present embodiments providing the scaling method of a kind of prealignment machine and mechanical hand relative coordinate system, see Fig. 1 and Fig. 2, this scaling method includes:

S1, to set the coordinate system residing for prealignment machine be x ' o ' y ' coordinate system as xoy coordinate system, the coordinate system residing for mechanical hand 1.It is provided with CCD(Charge-CoupledDevice at the xoy coordinate system residing for prealignment machine；Chinese full name: charge coupled cell) camera.

S2, utilize a wafer 2 being in xoy coordinate system to move radially relative to x ' o ' y ' coordinate system, determine x ' o ' y ' coordinate system attitude in xoy coordinate system.Will be placed in xoy coordinate system by a wafer 2, the center of circle of this wafer 2 has certain offset with the initial point of xoy coordinate system, if the B point that the center of circle of this wafer 2 original state is in xoy coordinate system, the most now the offset d=BO in this wafer 2 center of circle；When this wafer 2 is radially moved into a new position B ' relative to x ' o ' y ' coordinate system together with mechanical hand 1, the most now this new position residing for wafer 2 center of circle has new offset d '=B ' O, the mechanical hand 1 attitude relative to xoy coordinate system, i.e. direction can be calculated accordingly.

S3, this wafer 2 is rotated relative to x ' o ' y ' coordinate system, determine x ' o ' y ' coordinate system position in xoy coordinate system, i.e. obtain the relative position relation of mechanical hand 1 and prealignment machine.Will be placed in xoy coordinate system by this wafer 2, the center of circle of this wafer 2 has certain offset with the initial point of xoy coordinate system, if the B point that the center of circle of this wafer 2 original state is in xoy coordinate system；When this wafer 2 turns an angle a new position B ' relative to the initial point of x ' o ' y ' coordinate system together with mechanical hand 1, according to B, the B ' position in described xoy coordinate system, and the angle rotated, x ' o ' y ' coordinate system position in xoy coordinate system can be calculated.

Preferably, in step s 2, determine that x ' o ' y ' coordinate system method of attitude in xoy coordinate system includes:

S201, the center of circle of the wafer 2 being in xoy coordinate system is transferred to a certain position B, draws the B point offset d=BO relative to xoy coordinate origin；

S202, mechanical hand 1 is moved adjacent to a certain position A of B point, then by mechanical hand 1 together with wafer 2 along o ' A direction displacement d, write down position A ' that mechanical hand 1 newly locates, position B ' that wafer 2 center of circle is newly located.Preferably, when being moved along o ' A direction together with wafer 2 by mechanical hand 1, being held up by wafer 2 with mechanical hand 1, further rise along o ' A direction displacement d, then mechanical hand 1 puts down wafer 2.

S203, measure offset d '=B ' O, the then x ' o ' y ' coordinate system attitude angle t=B ' BO in xoy coordinate system of B ', try to achieve according to the cosine law:

$t=\arccos \left(\frac{2\·d^2-d^{\′2}}{2\·d^2}\right)=\arccos (1-\frac{1}{2}\·{\left(\frac{d^{\′}}{d}\right)}^2).$

Preferably, step S2 also includes the step of corrected parameter:

S204, demarcating after x ' o ' y ' coordinate system attitude angle t in xoy coordinate system, mechanical hand 1 is being coordinated with prealignment machine wafer 2 bias is compensated, after compensation, again calculate the offset of wafer 2；If offset reading is in claimed range, the most generally less than CCD precision, then demarcate successfully；If offset reading is outside claimed range, then re-start demarcation.

Preferably, in step s3, determine that x ' o ' y ' coordinate system method of position in xoy coordinate system includes:

S301, marking wafer 2 center of circle initial position B in xoy coordinate system, the labelling mechanical hand 1 initial position A in xoy coordinate system.

S302, by mechanical hand 1 together with wafer 2 around O ' rotational angle T, and the length of mechanical hand 1 elongation is constant, writes down position A ' that mechanical hand 1 newly locates, position B ' that wafer 2 center of circle is newly located.In this step, mechanical hand 1 is driven mechanical hand 1 to drive wafer 2 to rotate predetermined angle by controller together with wafer 2 when O ' rotation.

S303, according to position in xoy coordinate system of B, B ', and the drift angle ∠ BO ' B '=T of isosceles triangle BO ' B ', calculate the O ' position in xoy coordinate system, i.e. x ' o ' y ' coordinate system position in xoy coordinate system.

In the present embodiment, the step demarcating x ' o ' y ' coordinate system attitude in xoy coordinate system can be exchanged with the sequence of steps demarcating x ' o ' y ' coordinate system position in xoy coordinate system, it is also possible to individually carries out.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all within the spirit and principles in the present invention, any modification, equivalent substitution and improvement etc. made, should be included within the scope of the present invention.

Claims (3)

1. a prealignment machine and the scaling method of mechanical hand relative coordinate system, it is characterised in that described scaling method includes:

S1, to set the coordinate system residing for prealignment machine be X ' O ' Y ' coordinate system as XOY coordinate system, the coordinate system residing for mechanical hand；

S2, utilize a wafer being in described XOY coordinate system to move radially relative to described X ' O ' Y ' coordinate system, determine described X ' O ' Y ' coordinate system attitude in described XOY coordinate system；

S3, described wafer is rotated relative to described X ' O ' Y ' coordinate system, determine described X ' O ' Y ' coordinate system position in described XOY coordinate system, i.e. obtain the relative position relation of described mechanical hand and described prealignment machine；

In step s 2, determine that described X ' O ' Y ' coordinate system method of attitude in described XOY coordinate system includes:

S201, the center of circle of the described wafer being in described XOY coordinate system is transferred to a certain position B, draws the B point offset d=BO relative to described XOY coordinate origin；

S202, described mechanical hand is moved adjacent to a certain position A of B point, then by described mechanical hand together with described wafer along O ' A direction displacement d, write down the position A ' that described mechanical hand newly locates, position B ' that the described wafer center of circle is newly located；

S203, measure offset d '=B ' O, the most described X ' O ' Y ' coordinate system attitude angle t=∠ B ' BO in described XOY coordinate system of B ', try to achieve according to the cosine law:

$t=\arccos \left(\frac{2\·d^2-d^{\′2}}{2\·d^2}\right)=\arccos (1-\frac{1}{2}\·{\left(\frac{d^{\′}}{d}\right)}^2).$

The scaling method of prealignment machine the most according to claim 1 and mechanical hand relative coordinate system, it is characterised in that step S2 also includes the step of corrected parameter:

S204, demarcating after described X ' O ' Y ' coordinate system attitude angle t in described XOY coordinate system, described mechanical hand is being coordinated with described prealignment machine described wafer bias is compensated, after compensation, again calculate the offset of described wafer；

If offset reading is in claimed range, then demarcate successfully；If offset reading is outside claimed range, then re-start demarcation.

Prealignment machine the most according to claim 2 and the scaling method of mechanical hand relative coordinate system, it is characterised in that in step s3, determine that described X ' O ' Y ' coordinate system method of position in described XOY coordinate system includes:

The initial position B in described XOY coordinate system of the wafer center of circle described in S301, labelling, mechanical hand initial position A in described XOY coordinate system described in labelling；

S302, by described mechanical hand together with described wafer around O ' rotational angle T, and the length of mechanical hand elongation is constant, writes down the position A ' that described mechanical hand newly locates, position B ' that the described wafer center of circle is newly located；

S303, according to position in described XOY coordinate system of B, B ', and the drift angle ∠ BO ' B '=T of isosceles triangle BO ' B ', calculate the O ' position in described XOY coordinate system, the most described X ' O ' Y ' coordinate system position in described XOY coordinate system.