JP2003270390A - Electron beam irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a using efficiency of an electron beam and to reduce a power loss of a device by reducing the quantity of the electron beam lost by being shielded by a mask, regardless of the size of the irradiation width of the electron beam to an irradiating object. <P>SOLUTION: This electron beam irradiation device is equipped with a mask driving device 36 for moving the mask 22 and changing its opening width WM, and a control device 30 having a function for performing following controls based on set values of the irradiation width WI and an irradiation dose D of the electron beam 6 to the irradiation object 26, and an acceleration voltage VA of the electron beam 6: (a) a function for controlling the mask driving device 36 in order to control the opening width WM of the mask to satisfy a relation that WM is approximately equal to WI; (b) a function for controlling a scanning power source 20 in order to control a scanning current IS outputted therefrom to satisfy IS=K<SB>1</SB>×VA×(WI+α), wherein K<SB>1</SB>is a constant and α is the scanning marginal width; and (c) a function for controlling a filament power source 16 in order to control a current IE of the electron beam generated from a filament 4 to satisfy IE=K<SB>2</SB>×D×WI, wherein K<SB>2</SB>is a constant. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
It is used for bridges, polymerization, curing, sterilization, modification, etc.
A scanning electron beam irradiation device that scans an electron beam,
More specifically, the irradiation width of the electron beam to the irradiation target is determined.
Reduce the amount of electron beam wasted due to the mask
Therefore, the efficiency of electron beam utilization is improved, and the power loss of the equipment is reduced.
Means for enabling reduction. [0002] 2. Description of the Related Art A conventional example of this type of electron beam irradiation apparatus is shown in FIG.
Shown in This electron beam irradiation device emits light from the electron beam accelerator 2.
The emitted electron beam 6 passes through the opening 24 of the mask 22.
To the irradiation object 26 in an irradiation atmosphere (for example, the atmosphere).
It is configured to irradiate. In this example, the electron beam accelerator 2 comprises an electron beam 6
And electron beam 6 which accelerates
The accelerating tube 8 and the accelerated electron beam 6
A scanning coil 10 for reciprocating scanning in Y)
A divergent scanning tube 12 for guiding the scanned electron beam 6;
Of the scanning tube 12
Outside atmosphere (inside is vacuum atmosphere, outside is the irradiation atmosphere
And a window foil 14 for separating the electron beam 6
It has. The output part of the electron beam accelerator 2 (specifically,
Is the scanning width of the electron beam 6 in the window foil 14)._SWhen
I do. [0004] The filament 4 is heated by heating
Power for emitting wire 6 is supplied from filament power supply 16
Is done. The accelerator tube 8 (and the filament 4) contains electrons
DC acceleration voltage V for the acceleration on line 6_AIs the accelerating power supply 18
Is applied. The scanning coil 10 has the electron beam 6
Scanning current I for scanning_SAre supplied from the scanning power supply 20.
Scan current I_SHas a waveform close to a triangular wave. The output portion of the electron beam accelerator 2 (specifically, a window foil
14) between the electron beam accelerator 2 and the irradiation target 26.
Both ends of the emitted electron beam 6 in the scanning direction Y are blocked and
The irradiation width W of the electron beam 6 irradiated to the irradiation object 26_IDetermine
A movable mask 22 is provided. [0006] As shown by an arrow H, the mask 22
Two masks that can reciprocate along the scanning direction Y of the slave wire 6
The opening width W of the opening 24 is made of a plate 22a._MIs variable
It is. The mask 22 physically blocks the electron beam 6,
On the irradiation target 26, (a) the irradiation area of the electron beam 6
Shape the shape. (B) Irradiation area and non-irradiation area of electron beam 6
It is provided for the purpose of clearly separating the border from the area.
You. The above-mentioned scanning width in a conventional electron beam irradiation apparatus
W_S, Opening width W_MAnd irradiation width W_IIs related to
It is a cage. [0008] [Equation 1] W_M≒ W_I [0009] [Equation 2] W_S> W_M The object 26 is scanned by the electron beam 6, for example.
Transport in the direction X (which is called the transport direction) orthogonal to the direction Y
Sent. In the above-mentioned electron beam irradiation apparatus, the object to be irradiated 2
6 irradiation width W of electron beam 6_IWhen changing the
Scan width W of slave line 6_SAnd the current of the electron beam 6 (this is
Line current) I_EIs kept constant, and the mask 22
Opening width W_MIs adjusted to obtain the desired irradiation width W._I
Was realized. More specifically, the mask 2 is stopped while the apparatus is stopped.
2 by manually sliding the opening width W_MHas been adjusted
Was. However, the irradiation width W_IIs changed, the scanning power supply 20
Scan current I supplied to the scan coil 10 from the_S(More specific
The maximum value was kept constant. Filament 4
Beam current I generated from_EWas also constant. However, the acceleration voltage V_AIs the scanning width W_SAffect
The scanning width W_SIn order to achieve
Speed voltage V_AScanning current I_SNeed to change
The scanning current I_SCalculation control and the irradiation object 26
Beam current I according to the irradiation dose D of the electron beam 6_EPerformance
The control device 28 is used to perform arithmetic control. [0014] SUMMARY OF THE INVENTION The above-described conventional electric
In the child beam irradiation device, the scanning width W of the electron beam 6_SIs constant
Therefore, the maximum possible irradiation width W_IThe above equation 1
And can satisfy the relationship of Equation 2
Large scanning width W_SNeeds to be realized. As a result, the irradiation width W_IThe smaller the
Area S where electron beam 6 is wasted because it is blocked by mask 22
₁(That is, the amount of waste) increases, and the electron beam 6 is used.
Efficiency decreases. As a result, unnecessary power is consumed by the device.
Power loss of the device. Accordingly, the present invention provides a method for controlling an electron beam on an object to be irradiated.
Regardless of the irradiation width of the line, it is blocked by the mask and wasteful
To improve the efficiency of electron beam utilization.
To reduce the power loss of the equipment
Aim. [0017] An electron beam irradiation apparatus according to the present invention is provided.
The mask is moved by moving the mask to open the opening W._MChange
Mask driving device and the irradiation width W_I, The acceleration voltage V
_AAnd the irradiation dose D of the electron beam to the object to be irradiated is set.
And the following controls (a) to (c) are performed based on them.
Control device having a control function for performing
It is a sign. (A) By controlling the mask driving device,
Opening width W of the mask_MSo that substantially the following equation is satisfied.
Aperture width control function to control. [0019] [Equation 3] W_M≒ W_I (B) controlling the scanning power supply and then
The scanning current I to be output_SSatisfies the following equation
Scan current control function. Where K₁Is the accelerating power
Pressure V _AAnd α is a predetermined scanning margin width. [0021] ## EQU4 ##_S= K₁・ V_A・ (W_I+ Α) (C) controlling the filament power supply to
The current I of the electron beam generated from the filament_ETo
Electron beam current controller that controls to substantially satisfy the following equation
Noh. Where K_TwoIs the transport speed of the irradiation target and the structure of the device.
Constant determined according to the structure. [0023] ## EQU5 ##_E= K_Two・ D ・ W_I According to the above configuration, the opening width W of the mask is obtained.
_MIs, as shown in Equation 3, the irradiation of the irradiation target with the electron beam.
Range W_IIs automatically controlled according to the set value of. Scan current I output from scan power supply_SWell, number
As shown in FIG. 4, the irradiation width W of the electron beam to the irradiation object_I
Is automatically controlled according to the set value of. The result
As a result, the scanning width W of the electron beam_SAlso the irradiation width W_IAccording to
Controlled automatically. It is assumed that the scanning current I_S(Ie scan width
W_S) Irradiation width W_IJust change it to something according to
The electron beam current I_EIs constant, the scanning width W
_SThe electron beam density changes in response to changes in
Inspection width W_SBecomes smaller, the electron beam density becomes larger).
The irradiation dose of the electron beam to the irradiation object changes. This
In the present invention, to prevent
Generated electron beam current I_EAs shown in Equation 5
The irradiation width W of the electron beam on the object_IDepending on the set value of
It is controlled automatically. This allows the electronic
Line irradiation width W_IConsequently, the scanning width W_SIs changed,
A constant irradiation dose D can be realized. As a result, according to the present invention, the object to be irradiated
Regardless of the size of the irradiation width of the electron beam to the
It is possible to reduce the amount of wasted electron beams. So
As a result, the efficiency of electron beam utilization is improved, and the power
Loss can be reduced. Moreover, it is applied to the irradiated object.
It can be realized while maintaining the irradiation dose at a predetermined value.
Wear. [0028] FIG. 1 shows an electron beam illuminator according to the present invention.
It is a figure which shows an example of a shooting device. Same as the conventional example shown in FIG.
The same reference numerals are given to one or corresponding parts, and
The differences from the conventional example will be mainly described. This electron beam irradiation apparatus uses the mask 22
Move the opening width W_MDriving device 3 that changes
6 and a control device 30 in place of the control device 28
ing. In this example, the mask driving device 36
Each of the two mask plates 22a constituting the mask 22
Reciprocatingly driving in the direction along the arrow H
Opening width W_MAnd two motors 32
32 and a motor controller 34 for driving and controlling
You. Both motors 32 are, for example, servo motors. Mo
The controller 34 is, specifically, an opening from the controller 30.
Width W_MBoth motors receive the command value of
32. The control device 30 controls the filament power supply 1
6, scanning power supply 20 and mask driving device 36 (specifically,
Controls the motor controller 34). this
The control device 30 includes, for example, an external
Desired irradiation width W of electron beam 6 with respect to_I, The acceleration power source 1
8 to the desired acceleration voltage V applied to the acceleration tube 8_AAnd before
The desired irradiation dose D of the electron beam 6 to the irradiation target 26 is
Is set. [0032] The control device 30 is based on the setting information.
And has a control function for performing the following controls (a) to (c).
I have. (A) The mask driving device 36 (specifically,
Controls the motor controller 34) so that the mask 22
Opening width W_MIs controlled so as to substantially satisfy Equation 3 above.
Aperture width control function. In FIG. 1, for convenience of illustration, W_M<W_INo
Although it looks like, in an actual device, the scanning coil 10
(That is, the center of scanning of the electron beam 6; the same applies hereinafter)
Compared to the distance between the mask 22 and the mask 22,
Since the distance between the mask 26 and the object 26 is small,
The spread of the electron beam 6 with the object 26 due to the scanning is small.
Therefore, the mask is set so as to substantially satisfy Equation (3).
22 to control the irradiation width W that has been set._IAchieve
Can be By the above control, the opening width W of the mask 22 is obtained.
_MIs the irradiation width W of the electron beam 6 on the irradiation target 26._ISetting
It is automatically controlled according to the fixed value. (B) controlling the scanning power supply 20 to
The scanning current I output from the scanning coil 10 and supplied to the scanning coil 10
_SIs controlled so as to substantially satisfy Equation 4 above.
Flow control function. More specifically, the scanning current I_SIs actually three
Since it has a waveform close to an angular wave, the scanning current I_SMost
Control is performed so that the large value satisfies the above equation (4). Equation 4 is derived from the following relationship.
is there. That is, the scanning width W of the electron beam 6_SAnd opening of mask 22
Width W_MIs controlled so as to satisfy the following equation. [0039] [Formula 6] W_S= W_M+ Α The above α is an alignment of the electron beam 6 by the mask 22.
In order to ensure the shape, the electron beam 6 is applied to the opening width of the mask 22.
W_MIt is a scan margin width that scans a little extra than
It is about 5 to 10 cm. In FIG. 1, for convenience of illustration, W_S<W
_MAlthough it looks like
Window foil 14 compared to the distance between the center of the
Since the distance between the mask 14 and the mask 22 is small,
Between the mask and the mask 22 by the scanning of the electron beam 6.
Therefore, by satisfying the above Expression 6, the electron beam 6
Is the opening width W_MYou can scan a little bit more than that. On the other hand, the scanning current I_SIs the scanning width W_STo
If expressed using, it is controlled so as to satisfy the following equation. [0043] ## EQU7 ## I_S= K₁・ V_A・ W_S The above K₁Is the acceleration voltage V_ADetermined according to
It is a constant. That is, the acceleration voltage V_AIs the scanning width W_SAffects
And the scanning current I_SIs constant, the acceleration voltage V
_ABecomes larger, the scanning width W_SBecomes smaller. Paraphrase
If the scanning width W_SIn order to realize, the acceleration voltage V
_AScanning current I_SNeeds to be changed. this
Acceleration voltage V_AAnd scanning width W_SAnd scanning current I_SRelationship with
Is the acceleration voltage V_AWithin a predetermined operating range of₁so
It can be expressed by approximating a proportional relationship. This constant K₁of
Values must be determined in advance for the electron beam irradiation device.
If it is stored in the control device 30, for example,
good. Such a constant K₁Is used, the scanning current I_STo
Since it can be expressed by a simple expression such as Equation 7, the control device
Scan current I by the device 30_SControl becomes simple. The relationship of Equations 6 and 3 is substituted into Equation 7 above.
Then, the relationship of Equation 4 is obtained. With the above control, the output from the scanning power supply 20 is output.
Scanning current I_SIs also the value of the electron beam
6 irradiation width W_IIs automatically controlled according to the set value of
It is. As a result, the scanning width W of the electron beam 6_SAlso the irradiation width W_I
Is automatically controlled according to As a result, the irradiation width
W_IAnd opening width W_MIs changed, but it is blocked by the mask 22
Area S of electron beam 6 which is wasted_TwoSmall and useless
The amount of the electron beam 6 can be reduced. (C) controlling the filament power supply 16
The current I of the electron beam generated from the filament 4
_EIs controlled so as to substantially satisfy Expression 5.
Current control function. The constant K of the above equation (5)_TwoTransports the irradiation target 26
Depends on the feed speed and the structure of the electron beam irradiation device
It is a constant. More specifically, the device-specific constant is k,
Assuming that the transport speed of the irradiation object 26 is v, a constant K_TwoIs
expressed. [0049] [Equation 8] K_Two= Kv As described above, the filament 4
Electron beam current I_EWith the electron beam 6 with respect to the irradiation target 26.
Irradiation width W_IControl automatically according to the set value of
Thereby, the irradiation width W of the electron beam 6 is obtained._IConsequently, the scanning width W
_SCan achieve a predetermined irradiation dose D even if
it can. As described above, according to this electron beam irradiation apparatus,
For example, the irradiation width W of the electron beam 6 on the irradiation target 26 is_IBig and small
Regardless, the electron beam 6 that is blocked by the mask 22 and wasted
Area S_TwoTo reduce the amount of wasted electron beam 6
I can do it. As a result, the use efficiency of the electron beam 6 is improved.
In addition, the power loss of the device can be reduced. Moreover
The irradiation dose D to the irradiation target 26 is set to a predetermined value.
It can be realized while keeping it. [0052] As described above, according to the present invention, the irradiation
Regardless of the size of the irradiation width of the electron beam to the object, with a mask
It is possible to reduce the amount of electron beams that are blocked and wasted.
As a result, the efficiency of electron beam utilization is improved, and the power
The loss can be reduced. In addition, it is
Can be achieved while maintaining the prescribed irradiation dose at a predetermined value.
it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an example of an electron beam irradiation device according to the present invention. FIG. 2 is a diagram showing an example of a conventional electron beam irradiation device. [Description of Signs] 2 Electron beam accelerator 4 Filament 6 Electron beam 8 Acceleration tube 10 Scanning coil 12 Scanning tube 14 Window foil 16 Filament power supply 18 Acceleration power supply 20 Scanning power supply 22 Mask 26 Irradiated object 30 Control device 36 Mask driving device

Claims (1)

[Claims] A filament for generating an electron beam;
A filament power supply for heating a plurality of filaments;
An accelerating tube for accelerating the electron beam generated by the filament.
Acceleration voltage V_AAcceleration power supply for applying
A scanning coil that scans the electron beam accelerated by the speed tube,
Scan current I_SA scanning power supply for supplying
A divergent scanning tube for guiding an electron beam scanned by a scanning coil
And provided at the tip of the scanning tube,
Window foil that separates the atmosphere inside and outside and allows electron beams to pass through
Between the window foil and the object to be irradiated
Irradiation width W of electron beam irradiated on object_IMovable to determine
In an electron beam irradiation apparatus including a mask, By moving the mask, its opening width W_MChanging mass
Drive unit, The irradiation width W_I, The acceleration voltage V_AAnd the object to be irradiated
The irradiation dose D of the electron beam is set for
And has a control function for performing the following controls (a) to (c).
An electron beam irradiation device, comprising: a control device.
Place. (A) controlling the mask driving device to open the mask;
Mouth width W_MIs controlled to substantially satisfy the following equation:
Width control function. W_M≒ W_I (B) controlling the scanning power supply and outputting the control signal from the scanning power supply;
Scan current I_SIs controlled to substantially satisfy the following equation:
Scan current control function. Where K₁Is the acceleration voltage V _AAccording to
Is a predetermined scanning margin width. I_S= K₁・ V_A・ (W_I+ Α) (C) controlling the filament power supply to control the filament
Current I of the electron beam generated from the_EIs substantially equal to
Electron beam current control function to control to satisfy. here,
K_TwoIs determined according to the transport speed of the irradiation target and the structure of the device.
The whole constant. I_E= K_Two・ D ・ W_I