Abstract:
In an optical pickup head of an optical recording reproducing apparatus, a fabrication method thereof, a lubricant-coated optical pickup head of an optical recording reproducing apparatus and a method for coating lubricant onto an optical pickup head, by using a MEMS (micro electro mechanical system) technique used for designing, fabricating and application of a microstructure, it is possible to miniaturize an optical pickup head of an optical recording reproducing apparatus and reduce a fabrication cost thereof.

Description:
This nonprovisional application claims priority under 35 U.S.C. § 119(a) on patent application Nos. 10-2002-0066654 and 10-2002-0072861 filed in KOREA on Oct. 30, 2002 and Nov. 21, 2002, respectively, the entire contents of which are herein incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an optical pickup head of an optical recording reproducing apparatus, a fabrication method thereof, a lubricant-coated optical pickup head of an optical recording reproducing apparatus and a method for coating lubricant onto an optical pickup head, and in particular to an optical pickup head of an optical recording reproducing apparatus capable of reading information recorded on an optical disk by irradiating light from an optical system onto a surface of the optical disk, a fabrication method thereof, a lubricant-coated optical pickup head of an optical recording reproducing apparatus and a method for coating lubricant onto an optical pickup head. 
     2. Description of the Related Art 
     The conventional magnetic recording apparatus includes a slider for ascending a head from a magnetic recording medium; a suspension for supporting the head; and a coil, etc. for generating a magnetic force, because of those construction parts, the apparatus is big and heavy, and accordingly there is a limit to miniaturize the apparatus. 
     In addition, in case of an optical recording reproducing apparatus using a rotating optical disk as an recording medium, due to flatness of an optical disk and mechanical vibration and eccentric error caused by a driving unit for rotating the optical disk, signal to noise ratio of an optical signal for recording and reproducing may be deteriorated, readable and recordable unit bit size may be restricted by that, and accordingly misreading and mis-recording may occur. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-mentioned problem, it is an object of the present invention to provide an optical pickup head of an optical recording reproducing apparatus capable of being miniaturized and reducing a fabrication cost by using a MEMS (micro electro mechanical system) technique used for designing, fabricating and application of a microstructure, a fabrication method thereof, a lubricant-coated optical pickup head of an optical recording reproducing apparatus and a method for coating lubricant onto an optical pickup head. 
     In order to achieve the above-mentioned object, an optical pickup head of an optical recording reproducing apparatus includes a slider installed so as to be slidable along the surface of an optical disk and having a convergence lens for focusing light at a side; and a micro-actuating means installed so as to be laminated with the slider in order to adjust an optic axis of the convergence lens minutely. 
     An optical pickup head of an optical recording reproducing apparatus includes a slider installed so as to be slidable along the surface of an optical disk and having a convergence lens at a side for focusing light; and a micro-actuating means installed so as to be laminated with the slider in order to adjust an optic axis of the convergence lens minutely. 
     A method for fabricating an optical pickup head of an optical recording reproducing apparatus includes step of preparing a mother material on which an insulating layer is arranged and a silicon layer is laminated on both sides of the insulating layer; forming a lower body having a lower fixed electrode at a side of the mother body by using a certain semiconductor device fabricating processes, forming an upper body having an upper fixed electrode at the other side and forming a moving body installed between the upper and lower fixed electrodes so as to be movable and have a moving electrode alternately arranged between the upper and lower fixed electrodes; joining the body obtained by the preparing step to a slider; and combining a convergence lens with the body. 
     A lubricant-coated optical pickup head of an optical recording reproducing apparatus includes a slider installed so as to be slidable along the surface of an optical disk, having a convergence lens at a side for focusing light and having a lubricant-coated air bearing surface at the bottom; and a micro-actuating means installed so as to be laminated with the slider in order to adjust an optic axis of the convergence lens minutely. 
     A method for coating lubricant on an optical pickup head includes steps of coating lubricant onto upper and lower fixed electrodes, a moving electrode and an air bearing surface of a slider by dipping an optical pickup head into the lubricant; and eliminating the rest lubricant not coated on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head in a toluene solvent. 
     A method for coating lubricant on an optical pickup head includes steps of coating lubricant onto upper and lower fixed electrodes, a moving electrode and an air bearing surface of a slider by installing an optical pickup head in a flow channel in which the lubricant flows; and eliminating the rest lubricant not coated onto the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by making a toluene solvent flow in the flow channel. 
     A method for coating lubricant on an optical pickup head includes steps of forming a silicon dioxide film onto upper and lower fixed electrodes, a moving electrode and an air bearing surface of a slider by dipping an optical pickup head into hydrogen peroxide; eliminating the rest hydrogen peroxide on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head in a toluene solvent; coating lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head in the lubricant; and eliminating the rest lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head in a solvent. 
     A method for coating lubricant on an optical pickup head includes steps of forming a hydrogen peroxide film onto upper and lower fixed electrodes, a moving electrode and an air bearing surface of a slider by installing an optical pickup head in a flow channel in which hydrogen peroxide flows; eliminating the rest hydrogen peroxide on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by making a toluene solvent flow in the flow channel; coating lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by making the lubricant flow in the flow channel; and eliminating the rest lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by making a toluene solvent flow in the flow channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
       In the drawings: 
         FIGS. 1˜11  illustrate an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention; 
         FIG. 1  is an exploded-perspective view illustrating an optical pickup head; 
         FIG. 2  is a longitudinal-sectional view illustrating an optical pickup head; 
         FIG. 3  is a plane view illustrating an optical pickup head; 
         FIG. 4  is a sectional view taken along a line A-A in  FIG. 3 ; 
         FIG. 5  is a bottom-perspective view illustrating an example of wiring; 
         FIG. 6  is a bottom-perspective view illustrating another example of wiring; 
         FIG. 7  illustrates an example of an elastic-supporting portion; 
         FIG. 8  illustrates another example of an elastic-supporting portion; 
         FIG. 9  illustrates yet another example of an elastic-supporting portion; 
         FIGS. 10 and 11  illustrate focal length error compensation; 
         FIG. 12  is a flow chart illustrating a fabrication method of an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention; 
         FIGS. 13˜15  illustrate a lubricant-coated optical pickup head of an optical recording reproducing apparatus in accordance with the present invention; 
         FIG. 13  is an exploded-perspective view illustrating an optical pickup head; 
         FIG. 14A  illustrates an example of an elastic-supporting portion; 
         FIG. 14B  is a longitudinal-sectional view illustrating a lubricant-coated optical pick up head an optical recording reproducing apparatus in accordance with the present invention; 
         FIG. 15  illustrates a lubricant-coated surface of a slider; 
         FIGS. 16˜20  are flow charts illustrating a coating process of a lubricant-coated optical pickup head in accordance with the present invention; 
         FIG. 16  is a flow chart illustrating an example of a coating process; 
         FIG. 17  illustrates a lubricant coating apparatus; 
         FIG. 18  is a flow chart illustrating another example of a coating process; 
         FIG. 19  is a flow chart illustrating yet another example of a coating process; and 
         FIG. 20  is a flow chart illustrating still another example of a coating process. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, the preferred embodiment of an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention will be described with reference to accompanying  FIGS. 1˜11 . 
       FIGS. 1˜11  illustrate an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention;  FIG. 1  is an exploded-perspective view illustrating an optical pickup head;  FIG. 2  is a longitudinal-sectional view illustrating an optical pickup head;  FIG. 3  is a plane view illustrating an optical pickup head;  FIG. 4  is a sectional view taken along a line A-A in  FIG. 3 ;  FIG. 5  is a bottom-perspective view illustrating an example of wiring;  FIG. 6  is a bottom-perspective view illustrating another example of wiring;  FIG. 7  illustrates an example of an elastic-supporting portion;  FIG. 8  illustrates another example of an elastic-supporting portion;  FIG. 9  illustrates yet another example of an elastic-supporting portion; and  FIGS. 10 and 11  illustrate focal length error compensation. 
     As depicted in  FIGS. 1˜11 , the optical pickup head  100  of the optical recording reproducing apparatus in accordance with the present invention includes a slider  110  installed so as to be slidable along the surface of an optical disk  10  and having a convergence lens  111   a  at a side; a lower fixed body  120  installed at the top of the slider  110  so as to adjust an optic axis of the convergence lens  111   a  minutely; a lower fixed body  120  installed at the top of the slider  110  so as to adjust an optic axis of the convergence lens  111   a  minutely and having plural lower fixed electrodes  121  on the inner circumference at regular intervals; an insulating layer  140  interposed between the lower fixed body  120  and the upper fixed body  130 ; a moving body  150  corresponded to the lower and upper fixed bodies  120 ,  130  so as to be moved in the optical axis direction and having a moving electrode  151  arranged alternately between the lower and upper fixed electrodes  121 ,  131 ; and plural electrode pads  137 ,  138 ,  139  for supplying power to the lower fixed body  120 , the upper fixed body  130  and the moving body  150  in order to drive the moving body  150 . 
     So as to transmit light, the slider  110  is made of a transparent material and has a plate shape. At a side corresponded to the optical disk  10 , namely, at the bottom surface of the slider  110 , an air bearing surface  111  is formed so as to be ascended from the surface of the optical disk  10  in rotating (operating) of the optical disk  10 . 
     An insertion groove  112  is formed at the bottom surface of the slider  110 , and a magnetic coil  113  for magnetizing the optical disk  10  is formed at the insertion groove  112 . Filler  115  having at least one of SIO 2  and SI 3 N 4  is charged around the circumference of the magnetic coil  113 . The magnetic coil  113  is electrically connected with a side electrode pad  116 . 
     As described-above, the optical pickup head  100  includes the fixed bodies  120 ,  130 ,  140 ; the moving body  150  arranged as a corn shape on the fixed body so as to be movable up and down according to power apply; and the slider  110  joined to the bottom of the fixed body. 
     The fixed body consists of the insulating layer  140 ; the lower fixed body  120  and the upper fixed body  130  laminated on the both side of the insulating layer  140 ; and the lower fixed electrode  121  and the upper fixed electrode  131  are respectively arranged on the lower and upper fixed bodies  120 ,  130 . 
     By being corresponded to the lower and upper fixed electrodes  121 ,  131 , the moving electrode  151  is formed on the moving body  150 . 
     A lens mounting portion  117  on which the convergence lens  111   a  is mounted is formed on the top surface of the fixed body  130 , and a light through hole  118  for passing light is formed at the center of the lens mounting portion  117 . 
     A suspension  135  is connected to the upper fixed body  130  so as to support the optical pickup head. A side of the suspension  135  is fixed to a fixed structure (not shown), and the other side thereof is electrically connected to an external power pad  136  by a solder ball joint method. 
     The fixed body  130  includes the lower fixed body  120 ; the upper fixed body  130 ; a lower fixed body electrode pad  137  for supplying power to the moving body  140 ; an upper fixed body electrode pad  138 ; and a moving body electrode pad  139 . 
     The lower fixed body electrode pad  137  and the upper fixed body electrode pad  138  are electrically connected to the external power connecting pad  136 , as depicted in  FIG. 5 , there is the solder ball joint method for connecting the lower fixed body electrode pad  137  and the upper fixed body electrode pad  138  to the external power connecting pad  136  by using solder ball (B), as depicted in  FIG. 6 , there is a joint method for connecting them by using wire (W). 
     In order to support the moving body  150  elastically, an elastic-supporting portion  155  is formed between the upper and lower fixed bodies  130 ,  120 . 
     As depicted in  FIG. 7 , the elastic-supporting portion  155  can be constructed to have a width (W), as depicted in  FIG. 8 , it can be constructed to have a thickness (t), as depicted in  FIG. 9 , it can be constructed so as to be curved several times. 
     In the optical pickup head of the optical recording reproducing apparatus, when power is on and the optical disk  10  is rotated, the slider  110  is ascended above the surface of the optical disk  10  by the air bearing surface  111 . Herein, the magnetic coil  113  magnetizes the surface of the optical disk  10 . Light from an optical system (not shown) is irradiated and reflected onto the surface of the optical disk  10  through the convergence lens  11   a,  and accordingly information recorded on the optical disk  10  is read. 
     In the meantime, in the optical pickup head of the optical recording reproducing apparatus, when focal length error occurs between the convergence lens  111   a  and the optical disk  10  because of vibration of an optical disk driving unit (not shown), flatness of the surface of the optical disk and assembly error, etc. of each construction part, static electricity is generated by supplying power to the fixed bodies  130 ,  120  and the moving body  150  through the upper and lower power pads  138 ,  137 ,  139 , herein, by operating the moving body  150  with the static electricity, the focal length error is compensated. 
     Hereinafter, the focal length error compensation will be described with reference to accompanying  FIGS. 10 and 11 . 
       FIG. 10  illustrates focal length error compensation of the optical pickup head of the optical recording reproducing apparatus in accordance with the present invention. 
     As depicted in  FIG. 10 , when focal length between the optical disk  10  and the convergence lens  111   a  is too short, by applying power to the lower fixed body  120 , the upper fixed body  13  and the moving body  150  in order to generate static electricity between the upper fixed electrode  131  and the moving electrode  151  greater static electricity between the lower fixed electrode  121  and the moving electrode  151 , the whole moving body  150  is ascended at the same height, and accordingly focal length error is compensated. 
       FIG. 11  illustrates focal length error compensation of the optical pickup head of the optical recording reproducing apparatus in accordance with the present invention. 
     As depicted in  FIG. 11 , when an optical axis of the optical recording reproducing apparatus  10  is slant at Θ°, by applying power to the lower and upper fixed bodies  120 ,  130  and the moving body  150  in order to generate static electricity between the lower fixed electrode  121  and the moving electrode  151  greater (or smaller) than static electricity between the upper fixed electrode  131  and the moving electrode  151 , the both sides of the moving body  150  have a different ascending height, and accordingly focal length error is compensated. 
     Hereinafter, a fabrication method of an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention will be described with reference to accompanying drawings. 
       FIG. 12  is a flow chart illustrating a fabrication method of an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention. 
     As depicted in  FIG. 12 , the fabrication method of the optical pickup head of the optical recording reproducing apparatus in accordance with the present invention includes steps of preparing a mother material on which a silicon layer is laminated on both sides of the insulating layer as shown at step S 10 ; forming a lower body having a lower fixed electrode at a side of the mother body by using a certain semiconductor device fabricating processes, forming an upper body having an upper fixed electrode at the other side and forming a moving body installed between the upper and lower fixed electrodes so as to be movable and have a moving electrode alternately arranged between the upper and lower fixed electrodes as shown at step S 11 ; joining the body obtained through the preparing step S 10  to a slider as shown at step S 12 ; and combining a convergence lens with the body as shown at step S 13 . Hereinafter, a lubricant-coated optical pickup head of an optical recording reproducing apparatus in accordance with the present invention will be described with reference to accompanying  FIGS. 13˜15 . 
       FIGS. 13˜15  illustrate a lubricant-coated optical pickup head of an optical recording reproducing apparatus in accordance with the present invention; 
       FIG. 13  is an exploded-perspective view illustrating an optical pickup head;  FIG. 14A  illustrates an example of an elastic-supporting portion; 
       FIG. 14B  is a longitudinal-sectional view illustrating a lubricant-coated optical pick up head an optical recording reproducing apparatus in accordance with the present invention; and  FIG. 15  illustrates a lubricant-coated surface of a slider. 
     As depicted in  FIGS. 13˜15 , the lubricant-coated optical pickup head  200  of the optical recording reproducing apparatus includes a slider  210  installed so as to be slidable along the surface of the optical disk  10 , having a convergence lens  211   a  for focusing light at a side and having a lubricant-coated air bearing surface  211 ; a lower fixed body  220  arranged at the top of the slider  210  and having a lubricant-coated lower fixed electrode  221  on the inner circumference at regular intervals; an insulating layer  240  interposed between the lower fixed body  220  and the upper fixed body  230 ; a moving body  250  inserted into the inner circumference of the lower and upper fixed bodies  220 ,  230  so as to be movable in the optical axis direction and having a lubricant-coated moving electrode  251  at the outer circumference so as to be alternately arranged between the lower and upper fixed electrodes  221 ,  231 ; and plural electrode pads  237 ,  238 ,  239  for supplying power to the lower, upper and moving bodies  220 ,  230 ,  250  in order to drive the moving body  250 . 
     The lower, upper and moving electrodes  221 ,  231 ,  251  are arranged as a comb-pattern. 
     The lubricant-coated air bearing  211  is formed at the bottom of the slider  210  corresponded to the optical disk  10 . 
     An elastic-supporting portion  255  is formed between the upper and lower fixed bodies  230 ,  220  to support the moving body  250  elastically. 
     As shown in following Chemical Formula 1, the lubricant can be obtained by mixing DDMS (dichlorodimethylsilane) with a solvent of toluene or isooctane, etc. to have concentration within the range of 1˜10 mMOL, herein, it is the most preferable to have concentration of 1 mMOL. 
     [Chemical Formula]
 
(CH 3 )CL 2 SL
 
     As depicted in  FIG. 15 , in a chemical structure of DDMS (D) single-layered on the air bearing surface  211  of the slider  210 , the air bearing surface  211  made of transparent glass substance is hydrophilic, and accordingly DDMS(D) can be easily single layer-coated. 
     Head group (D 1 ) of DDMS (D) is immobilized on the air bearing surface  211  through a covalent bond, methyl group (D 2 ) chemically combined with the head group (D 1 ) is hydrophobic and has characteristics not combined with other substances. Because of the DDMS (D)&#39;s characteristics, a single layer having a thickness of several A is formed on the air bearing surface  211  of the slider  210 , and accordingly the formed single layer reduces friction with the optical disk. 
     In addition, not shown in drawings, unlike the air bearing surface, in order to coat the DDMS onto the fixed electrode and the moving electrode made of silicon, plural OH groups are formed on the surface of the fixed and moving electrodes by using hydrogen peroxide so as to have hydrophile property, afterward, the DDMS (D) is coated onto he fixed and moving electrodes. 
     Afterward, with reference to accompanying  FIGS. 16˜20 , a method for coating lubricant on an optical pickup head of an optical recording reproducing apparatus in accordance with the present invention will be described with reference to accompanying  FIGS. 16˜20 . 
       FIG. 16  is a flow chart illustrating an example of a coating process of a lubricant-coated optical pickup head in accordance with the present invention. 
     As depicted in  FIG. 16 , the method includes steps of coating lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head into lubricant; and dipping the optical pickup head into the toluene solvent in order to eliminate the rest of lubricant not coated onto the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider. 
       FIG. 17  illustrates a lubricant coating apparatus; and  FIG. 18  is a flow chart illustrating another example of a coating process of a lubricant-coated optical pickup head in accordance with the present invention. 
     First, as depicted in  FIG. 17 , the lubricant coating apparatus  300  includes an oxidizing agent storing tank  310  for containing an oxidizing agent; a lubricant storing tank  320  for storing lubricant; a solvent storing tank  330  for storing a solvent; and a lubricant coating container  340  respectively connected to the oxidizing storing tank  310 , the lubricant storing tank  320  and the solvent storing tank  330 . 
     An oxidizing agent storing tank adjusting valve  311  is connected to the oxidizing agent storing tank  310 , a lubricant storing tank adjusting value  321  is connected to the lubricant storing tank  320 , a solvent storing tank adjusting value  331  is connected to the solvent storing tank  330 , and a discharge value  341  is installed at the lubricant coating container  340 . 
     As depicted in  FIGS. 17 and 18 , another example of the coating method of the lubricant-coated optical pickup head includes steps of installing an optical pickup head in a flow channel of a coating instrument in which lubricant flows and coating the lubricant onto the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider of the optical pickup head by opening the lubricant storing tank adjusting valve  321  as shown at step S 30 ; and eliminating the rest lubricant not coated onto the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider of the optical pickup head by making the toluene solvent flow by shutting the lubricant storing tank adjusting valve  321  and opening the solvent storing tank adjusting valve  331  as shown at step S 31 . 
       FIG. 19  is a flow chart illustrating yet another example of a coating process of a lubricant-coated optical pickup head in accordance with the present invention. 
     As depicted in  FIG. 19 , yet another example of the coating process of the lubricant-coated optical pickup head in accordance with the present invention includes steps of forming a silicon dioxide film on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head into hydrogen peroxide as shown at step S 40 ; dipping the optical pickup head into the toluene solvent in order to eliminate the rest hydrogen peroxide on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider as shown at step S 41 ; coating lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by dipping the optical pickup head into the lubricant as shown at step S 42 ; and dipping the optical pickup head into a solvent in order to eliminate the rest lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider as shown at step S 43 . 
       FIG. 20  is a flow chart illustrating still another example of a coating process of a lubricant-coated optical pickup head in accordance with the present invention. 
     As depicted in  FIG. 20 , still another example of the coating process of the lubricant-coated optical pickup head in accordance with the present invention includes steps of forming a hydrogen peroxide film on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider by arranging an optical pickup head in a flow channel in which hydrogen peroxide flows as shown at step S 50 ; making a toluene solvent flow into the flow channel in order to eliminate the rest hydrogen peroxide not coated on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider as shown at step S 51 ; making lubricant flow into the flow channel in order to coat the lubricant onto the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider as shown at step S 52 ; and making the toluene solvent flow into the flow channel in order to eliminate the rest lubricant on the upper and lower fixed electrodes, the moving electrode and the air bearing surface of the slider as shown at step S 53 . 
     As described-above, by coating single-layered lubricant of several A on the surface of the slider, it is possible to prevent the surface of the optical disk from being damaged by the slider, by reducing frictional force between the slider and the optical disk, damage on the optical disk can be reduced, and accordingly life-span of the head of the optical recording reproducing apparatus can be increased. 
     In addition, due to moisture in the air, a fixed electrode and a moving electrode fabricated by the MEMS technique may be adhered to each other in performing of minute operation, by coating lubricant on the fixed and moving electrodes, adhesion can be prevented, and accordingly minute operation can be performed smoothly. 
     Because methyl group adhered to the DDMS has hydrophile property, by absorbing moisture of the fixed and moving electrodes, adhesion thereof can be prevented. 
     Because the DDMS single layer is stable at a high temperature, it can perform lubricant operation smoothly even at 300˜400° C. 
     As described-above, in the present invention, by coating lubricant on the surface of the slider, lubricant operation can be performed without damaging characteristics of the head, scratch phenomenon can be prevented by reducing a frictional force, and accordingly life-span of the head and the recording medium can be increased. 
     And, the adhesion problem of the moving and fixed electrodes fabricated by the MEMS technique can be solved. 
     And, because the DDMS single layer is stable at a high temperature, lubricant operation can be performed smoothly after passing a package process in which a temperature rises at 300˜400° C.