Disclosure of Invention
The invention aims to provide silicon wafer cleaning equipment.
In order to solve the above technical problem, the present invention provides a silicon wafer cleaning apparatus, comprising: the flower basket comprises a cleaning tank and a flower basket main body capable of sinking into the cleaning tank; the flower basket main body comprises two end plates arranged in parallel, and three toothed bars fixedly connected with the two end plates respectively, wherein the three toothed bars are arranged into an L shape, and a plurality of clamping teeth are uniformly distributed on the toothed bars; three support rods which are respectively in one-to-one correspondence with the three toothed bars are further arranged between the two end plates, the three support rods are arranged into an L shape which is opposite to the three toothed bars, sliding grooves which extend obliquely downwards are respectively formed in the positions, located on the support rods, of the end plates, the end parts of the sliding grooves are fixedly connected with expanding springs which are in contact connection with the support rods, and the two ends of each support rod respectively penetrate through the two end plates; the silicon chip can be inserted between two adjacent clamping teeth and is respectively contacted with the three supporting rods; the inner side walls of the two short edges of the cleaning tank are respectively provided with a push block, the tank bottom of the cleaning tank is provided with a slide rail parallel to the short edge of the tank bottom, the push block is provided with a stepped push surface, and the push surface can be simultaneously contacted with the three support rods; the end plate can be inserted into the cleaning pool and can slide along the slide rail; after the end plate is pushed, the push block can push the supporting rod to slide along the sliding groove and compress the opening spring so that the silicon wafer slides out from between the two clamping teeth to be in contact with the supporting rod; after the end plate is loosened, the spreading spring rebounds and pushes the silicon wafer to be inserted back between the two clamping teeth through the supporting rod.
Furthermore, two pushing motors are arranged on the bottom of the cleaning pool in a mirror image mode; after the end plate is inserted into the cleaning pool, the pushing motor can push the end plate to drive the supporting rod to be in contact with the pushing surface; after the pushing motor loosens the end plate, the expanding spring rebounds.
Furthermore, two long-edge inner side walls of the cleaning pool are obliquely provided with a plurality of spray heads, each spray head forms a spray area, the spray area is higher than the top surface of the end plate when the end plate slides in the cleaning pool, and the spray heads can wash the side walls of the silicon wafers.
Furthermore, an installation plate is rotatably connected between the two end plates and is linked with the support rod; a plurality of water falling holes are uniformly formed in the mounting plate, and the water falling holes correspond to the silicon wafers inserted between the two clamping teeth one by one; a plurality of scrapers which are distributed at equal intervals are arranged at the bottom of the mounting plate, the width of each scraper is equal to the distance between two adjacent silicon wafers, the scrapers are connected with the mounting plate through restoring springs, and the top wall of each scraper is provided with a water collecting tank; the supporting rod can be linked with the mounting plate to rotate to be vertical to the silicon wafer when sliding, the spraying area is higher than the height of the mounting plate when in the state, and flushing water sprayed by the spray head can be collected in the water collecting tank; the washing water can press the scraper to be attached to two adjacent silicon chips to slide and wash the silicon chips; and after flushing water in the water collecting tank is discharged, the scraping plate rebounds and is attached to the surfaces of the two adjacent silicon chips to scrape water stains.
Furthermore, the top of the scraper is provided with two scraping strips in a mirror image manner, and the bottom of the scraper is provided with two brush heads in a mirror image manner; when the scraper plate descends, the brush head can be attached to the surface of the silicon wafer and brush stains on the surface of the silicon wafer; when the scraper plate ascends, the scraper strip can be attached to the surface of the silicon wafer and can scrape water stains on the surface of the silicon wafer.
Furthermore, the bottom of the water collecting tank is provided with an overflow hole penetrating through the scraping plate, the overflow holes are obliquely arranged, and the oblique directions of two adjacent overflow holes are opposite; the cleaning water in the water collecting tank can wash the silicon wafers on two sides after passing through the overflow holes, and the brush head brushes away stains on the surfaces of the silicon wafers; after the cleaning water in the water collecting tank flows through the overflow holes, the scraping strips can be attached to the silicon wafer to rebound and scrape water stains on the surface of the silicon wafer.
Furthermore, two drain grooves arranged in a mirror image mode are formed in the top wall of the scraping plate, and the drain grooves are located between the scraping strips and the water collecting grooves; wherein water scraped by the scraper bar is guided into the water-repellent tank and discharged from both sides of the scraper.
Furthermore, opposite side walls of the two end plates are respectively and correspondingly provided with a rotating shaft, the rotating shafts are positioned above the supporting rods at the tops, the rotating shafts can be inserted and rotated with a linkage piece, and the linkage pieces extend to two sides of the supporting rods at the tops; the opposite side walls of the two end plates are respectively and correspondingly provided with a first limiting block, and the first limiting blocks are as high as the rotating shaft; the opposite side walls of the two end plates are respectively and correspondingly provided with a second limiting block, the second limiting blocks are positioned obliquely above the rotating shaft, and the rotating shaft is positioned between the first limiting block and the second limiting blocks; the mounting plate is fixedly connected with the linkage piece, and after the linkage piece is inserted into the rotating shaft, the mounting plate can lean against the second limiting block; when the supporting rod compresses the spreading spring, the mounting plate can be driven by the linkage sheet to turn over to be in contact with the first limiting block; when the opening spring rebounds, the supporting rod can push the linkage sheet to drive the mounting plate to overturn to lean against the second limiting block.
Furthermore, the linkage piece comprises a fan-shaped insertion piece and baffle plates fixed at two ends of the insertion piece, the arc center angle of the insertion piece is larger than 180 degrees, the insertion piece is matched with the rotating shaft, and the two baffle plates extend to two sides of the supporting rod at the top; the mounting plate is fixedly connected with the insertion sheet, and the support rod can push the right baffle to drive the mounting plate to fall onto the first limiting block; the bracing piece can promote left baffle drive the mounting panel rotates to leaning on the second stopper.
The silicon wafer cleaning equipment has the beneficial effects that after the end plate is inserted into the cleaning pool, the end plate is pushed towards the push block to enable the end plate to slide along the slide rail at the bottom of the cleaning pool, the three support rods are synchronously pushed by the push block, further, the support rods slide downwards along the slide grooves to be separated from the silicon wafers and compress the opening springs, the support rods slide obliquely downwards to enable the silicon wafers to slide down and to be contacted with the support rods again in the cleaning process, at the moment, the clamping positions of the clamping teeth on the silicon wafers can be exposed for cleaning, so that the cleaning effect of the whole silicon wafers is improved, after the cleaning is finished, the push block loosens the support rods, the support rods push the silicon wafers to be inserted back between the two clamping teeth under the effect of the resilience force of the opening springs, and the silicon wafers are.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.
Referring to fig. 1 and 2, fig. 1 is a perspective view of a preferred embodiment of a silicon wafer cleaning apparatus according to the present invention; FIG. 2 is an enlarged view of a portion A of FIG. 1; as shown in fig. 1 to 9, when cleaning a silicon wafer 2, a basket body 1 is generally used to insert the silicon wafer 2 to fix the silicon wafer 2, specifically, the basket body 1 includes two parallel end plates 11, and three rack bars 12 and three support bars 13 disposed between the two end plates 11, the three rack bars 12 and the three support bars 13 are respectively arranged in an "L" shape, two "L" are oppositely disposed, specifically, two rack bars 12 are vertically arranged, another rack bar 12 is horizontally arranged below, two support bars 13 are vertically arranged, another support bar 13 is horizontally extended below, the rack bars 12 and the support bars 13 are in one-to-one correspondence, a plurality of clamping teeth 121 are uniformly distributed on the rack bars 12, the clamping teeth 121 on the vertically arranged two rack bars 12 are horizontally extended, the clamping teeth 121 on the horizontally arranged rack bars 12 are vertically extended, that is, that the clamping teeth 121 are all toward the direction in which the silicon wafer 2 is inserted, the silicon wafer 2 can be inserted between the two clamping teeth 121 and clamped by the two clamping teeth 121, meanwhile, the side wall of the silicon wafer 2 leans against the support rods 13 which are vertically arranged, the bottom wall of the silicon wafer 2 is supported on the support rods 13 which are horizontally arranged, and therefore, the installation of the silicon wafer 2 is completed, but when the silicon wafer 2 is cleaned in such a way, the position where the silicon wafer 2 is contacted with the clamping teeth 121 is difficult to clean, and in order to solve the problems, the following improvements need to be made on the structure:
the end plates 11 are provided with sliding grooves 111 at the positions of the support rods 13, the sliding grooves 111 extend in the direction away from the toothed bars 12 and incline downwards, the support rods 13 extend out of the two end plates 11, a distraction spring 14 is arranged in the sliding groove 111 to push the support rod 13, so that the support rod 13 is positioned at the high position of the sliding groove 111, the support rod 13 can slide along the sliding groove 111 under the pushing of an external force and compress the distraction spring 14, after the external force is removed, the expanding spring 14 rebounds to push the support rod 13 back to the high position of the sliding groove 111, before cleaning, after each silicon wafer 2 is inserted between two clamping teeth 121 in sequence, the support rod 13 is manually broken to compress the expanding spring 14, the supporting rods 13 are driven to synchronously flap the silicon wafers 2 when the expanding springs 14 rebound, so that the silicon wafers 2 are arranged orderly, and the loose silicon wafers 2 can be stored orderly so as to be convenient for the disassembly of the silicon wafers 2.
Referring to fig. 3 and 5, fig. 3 is a schematic structural view of a preferred embodiment of the support rod of the present invention at a high position; FIG. 4 is a schematic structural view of a preferred embodiment of the present invention with the support pole in a lowered position; FIG. 5 is a partial enlarged view of portion B of FIG. 1; as shown in fig. 1 to 5, in order to push the supporting rod 13 during cleaning, the silicon wafer cleaning apparatus further includes:
the washing tank 3 is provided with a washing tank,
the cleaning tank 3 is a cuboid, a cleaning tank is arranged from top to bottom, the cleaning tank 3 is used for cleaning the silicon wafers 2, the length of the cleaning tank is equal to that of the supporting rod 13, when the flower basket main body 1 is placed in the cleaning tank 3, the supporting rod 13 slides downwards along the inner wall of the cleaning tank 3, at the moment, the supporting rod 13 can play a guiding role, the downward sliding linearity of the flower basket main body 1 is ensured, and the silicon wafers 2 are prevented from falling off; the inner side walls of two short sides of the cleaning pool 3 are respectively provided with a push block 31, one side wall of the push block 31 is close to the inner side wall of a long side of the cleaning pool 3, the other side wall of the push block 31 is provided with a push surface 311, specifically, the push block 31 is of a structure that the width of the upper part is larger than that of the lower part, namely, the push surface 311 is in a step shape, the push surface 311 can synchronously contact with three support rods 13, after the basket body 1 is inserted into the cleaning pool 3, one transverse side of the push surface 311 and the transversely arranged support rods 13 are positioned on the same horizontal plane, the push block 31 pushes the end plate 11 to enable the end plate 11 to slide along a slide rail 32 at the bottom of the cleaning pool 3, the push surface 311 has a limiting effect on the transversely arranged support rods 13, so that the three support rods 13 are synchronously pushed by the push block 31, and then the support rods 13 slide downwards along the slide groove 111 to be separated, make silicon chip 2 can the landing and contact with bracing piece 13 again in the cleaning process, the chucking position that is pressed from both sides tight tooth 121 before this moment on silicon chip 2 can expose, wash, thereby whole silicon chip 2's cleaning performance has been improved, after the washing is accomplished, bracing piece 13 is loosened to ejector pad 31, bracing piece 13 pushes silicon chip 2 under the resilience force effect of strutting spring 14 and inserts back to two and press from both sides between the tight tooth 121, and guarantee through the resilience force that each silicon chip 2 arranges neatly.
In this embodiment, the clamping position of the clamping teeth 121 on the silicon wafer 2 can be exposed before, i.e. the clamping teeth 121 are clamped by replacing the place where the silicon wafer has been washed, in such a way that the whole silicon wafer 2 can be cleaned, and the structure of the clamping teeth 121 is such that the cross-sectional area gradually decreases away from the rack bar 12, even if the silicon wafer 2 tilts up when the silicon wafer 2 falls on the support bar 13 at the lower part of the sliding groove 111, the two sides of the silicon wafer 2 are still between the two clamping teeth 121 and do not go over the clamping teeth 121.
It should be noted that the length of the slide rail 32 is greater than the length of the end plate 11, and in the process that the end plate 11 slides along the slide rail 32, if the end plate 11 is separated from the slide rail 32, the end plate 11 may tilt to incline the silicon wafer 2 toward the rack bar 12, so that the effect of completely cleaning the silicon wafer 2 cannot be achieved, therefore, a dovetail groove 321 needs to be formed in the slide rail 32, and meanwhile, a slider 112 adapted to the dovetail groove 321 is arranged at the bottom of the end plate 11, and the slider 112 cannot be separated from the slide rail 32 when sliding through the design of the dovetail groove 321, so that the sliding linearity of the end plate 11 is ensured, and when the support bar 13 slides to the lower position of the slide groove 111, the silicon wafer 2 can be ensured to incline toward one side of.
After the basket body 1 is inserted into the cleaning tank 3, in order to push the end plate 11, the following scheme can be adopted:
two pushing motors 33 are arranged on the bottom of the cleaning pool 3 in a mirror image mode, the pushing motors 33 correspond to the pushing blocks 31 one by one, the distance between the two pushing motors 33 is equal to the distance between the two end plates 11, so that the two end plates 11 can move synchronously, meanwhile, the pushing motors 33 can be arranged outside the cleaning pool 3, and the situation that the pushing motors 33 are wet and damaged is avoided; wherein the end plate 11 inserts wash pond 3 to with the slide rail 32 laminating back, specifically, push motor 33 can promote end plate 11 slides to ejector pad 31 direction along slide rail 32, end plate 11 slide drive three bracing piece 13 simultaneously with push away the face 311 contact, continue to promote end plate 11 and make bracing piece 13 compress along sliding tray 111 and strut spring 14 for silicon chip 2 can expand so that clean push motor 33 loosens behind the end plate 11, strut spring 14 kick-backs and drives bracing piece 13 and promote silicon chip 2 and resume the normal position.
In order to effect the cleaning of the silicon wafer 2,
the inner side walls of the two long sides of the cleaning pool 3 are uniformly provided with a plurality of spray heads 34, specifically, the spray heads 34 are transversely and uniformly arranged and uniformly distributed, the spray heads 34 on the two sides are in one-to-one correspondence to ensure that the cleaning water for washing the two sides of the silicon wafer 2 is uniform, the cleaning effect of the silicon wafer 2 is ensured, each spray head 34 forms a spray area, and the spray area is higher than the height for mounting the silicon wafer 2, so that the cleaning water is sprayed on the silicon wafer 2 from the oblique upper side, namely the spray area is higher than the top surface of the end plate 11 when the end plate 11 slides in the cleaning pool 3, the completeness for washing the silicon wafer 2 is ensured, and the cleaning effect of the silicon wafer 2 is.
Referring to fig. 6 and 7, fig. 6 is a partially enlarged view of portion C of fig. 1; FIG. 7 is a cross-sectional view of the preferred embodiment of the squeegee of the invention at section D in FIG. 6; as shown in fig. 1 to 7, in order to further improve the cleaning effect of the silicon wafers 2, when the silicon wafers 2 are cleaned, a horizontally arranged scraper 4 is installed above each two adjacent silicon wafers 2, the width of the scraper 4 is equal to the distance between the two adjacent silicon wafers 2, and the silicon wafers 2 are brushed by sliding the scraper 4 downwards to improve the cleaning effect of the silicon wafers 2, specifically,
for the downward sliding of the scraper 4, a water collecting tank 41 can be arranged at the top of the scraper 4, the height of a spraying area is higher than the rising and falling height of the scraper 4, so that the spray head 34 can spray water into the water collecting tank 41, the mass of the whole scraper 4 is increased after water is continuously filled in the water collecting tank 41, the scraper 4 can slide downwards under the action of gravity, meanwhile, a brush head 42 can be arranged at the bottom of the scraper 4, the brush head 42 is bidirectional, two sides of the brush head 42 are attached to two sides of the scraper 4, and the brush head 42 brushes stains on the surface of the silicon wafer 2 while following the descending of the scraper 4, so that the cleaning effect of the silicon wafer 2 is improved;
furthermore, two scraping strips 43 can be installed on two sides of the upper end surface of the scraper 4 in a mirror image manner, the two scraping strips 43 are respectively attached to the surfaces of the silicon wafers 2 on two sides, the width of the scraping strips 43 is gradually reduced from the scraper 4 to the direction far away from the scraper 4, so that the installation stability of the scraping strips 43 can be ensured, the situation that the scraping strips 43 are turned over and deformed is avoided, meanwhile, a hydrophobic groove 44 with two mirror images is formed in the upper end surface of the scraper 4, the hydrophobic groove 44 is positioned between the water collecting groove 41 and the scraping strips 43, the wider end of the scraping strip 43 is close to the hydrophobic groove 44, the hydrophobic groove 44 penetrates through the scraper 4 in the length direction, in the ascending process of the scraper 4, the scraping strips 43 can scrape the water on the surfaces of the silicon wafers 2, further, the convenience for drying after the silicon wafers 2 are cleaned is improved, the drying time is shortened, the cleaning efficiency of the silicon wafers 2 is improved, and meanwhile, the, the water is discharged from two sides, through the design of the water drainage groove 44, the situation that the scraped water flows back into the water collection groove 41 to increase the weight of the scraper 4 to influence the ascending of the scraper 4 is avoided, and meanwhile, in order to avoid the scraped water from being retained in the water drainage groove 44, the water drainage groove 44 is designed to be of a structure with a high middle part and two low sides, so that the water in the water drainage groove 44 can be discharged from two sides;
in order to lift the scraper 4, two ends of the upper surface of the scraper 4 can be respectively provided with a restoring spring 45, when the water collecting tank 41 on the scraper 4 is filled with water and is heavy and slides downwards, the restoring spring 45 is stretched, and when cleaning water in the water collecting tank 41 is emptied, the restoring spring 45 rebounds and drives the scraper 4 to lift;
in order to drain the washing water in the water collecting tank 41, a spillway hole 46 vertically penetrating the scraping plate 4 is opened at the bottom of the water collecting tank 41, the spillway hole 46 is obliquely arranged, the inclination directions of two adjacent spillway holes 46 are opposite, namely, the adjacent two overflow holes 46 are arranged in a staggered way, when the scraper 4 descends, the cleaning water in the water collecting tank 41 can pass through each overflow hole 46 to wash the silicon wafers 2 on the two sides, the silicon wafer 2 is washed in a close range to improve the cleaning effect of the silicon wafer 2, the water accumulation speed of the water collection tank 41 should be higher than the water flowing speed of the overflow holes 46, after the spray head 34 stops spraying water, the washing water in the water collecting tank 41 is slowly discharged from the overflow hole 46, when the whole weight of the scraper 4 is smaller than the elastic force of the recovery spring 45, the recovery spring 45 can rebound to drive the scraper 4 to ascend, and the design of the water drainage groove 44 can avoid the situation that cleaning water flows back into the water collection groove 41 and wets the silicon wafer 2 through the overflow hole 46 for the second time in the ascending process of the scraper 4;
referring to fig. 8 and 9, fig. 8 is a schematic structural view of a preferred embodiment of the open state of the mounting plate according to the present invention; FIG. 9 is a schematic structural view of a preferred embodiment of the mounting plate of the present invention in a covering state; as shown in fig. 1 to 9, in order to install each scraper 4, a mounting plate 5 can be rotatably connected between two end plates 11, meanwhile, a water falling hole 51 is formed on the mounting plate 5, the water falling holes 51 are distributed at equal intervals, the positions of the water falling holes 51 correspond to the silicon wafers 2 one by one, two restoring springs 45 on one scraper 4 are fixed at two ends of the water falling hole 51, when the mounting plate 5 rotates to be horizontal, each scraper 4 can also be horizontal to slide downwards, a first limiting block 113 is arranged at the same height of the rotating position of the mounting plate 5 on the end plate 11, when the mounting plate 5 rotates to abut against the first limiting block 113, the mounting plate 5 is horizontal to provide a rising and falling point of the scraper 4, through the arrangement of the rotatable mounting plate 5, when the silicon wafers 2 need to be cleaned, the mounting plate 5 is covered above the silicon wafers 2 to facilitate the cleaning of the silicon wafers 2, when the silicon wafers 2 need to be loaded and unloaded, the mounting plate 5 can be rotated and opened, so that convenience is brought to the mounting and dismounting of the silicon wafers 2.
Preferably, the mounting plate 5 is mounted when the silicon wafer 2 needs to be cleaned, and the mounting plate 5 is removed when the silicon wafer 2 needs to be disassembled and assembled, so that the cleaning and the assembling and the disassembling of the silicon wafer 2 can be facilitated better, the scheme can be adopted, wherein the end plate 11 is provided with a rotating shaft 114 which is as high as the first limiting block 113, the rotating shaft 114 is positioned above the supporting rod 13 at the top, the rotating shaft 114 is matched with a linkage piece 6, the thickness of the linkage piece 6 is smaller than the distance between the silicon wafer 2 at the outermost side and the end plate 11, and therefore the linkage piece 6 cannot be interfered by the silicon wafer 2 in the rotating process; linkage piece 6 is "C" shape, linkage piece 6 has an opening so that be inserted by pivot 114, and simultaneously, linkage piece 6 can revolve pivot 114 and rotate, install this linkage piece 6 in the both sides of mounting panel 5, when needs installation mounting panel 5, as long as insert pivot 114 with linkage piece 6 just, when need not use mounting panel 5, can extract linkage piece 6 from pivot 114 and just can pull down mounting panel 5, and time saving and labor saving facilitates for the washing and the dismouting of silicon chip 2.
It should be noted that although the cleaning and dismounting of the silicon wafer 2 can be facilitated, the switching of the covering or opening state of the mounting plate 5 to the silicon wafer 2 still depends on manual operation, while the cleaning of the silicon wafer 2 generally uses a strong corrosive solution, and the threat to the life of workers is undoubtedly increased by excessive manual intervention, in order to solve the above problems, the following scheme can be adopted to realize the automatic switching state of the mounting plate 5:
a second stop block 115 is fixed at the upper right of the rotating shaft 114, the second stop block 115 is located at the upper right of the rotating shaft 114, so that the rotating shaft 114 is located between the first stop block 113 and the second stop block 115, the second limiting block 115 provides the mounting plate 5 with a leaning function in an opened state, the linkage sheet 6 comprises a fan-shaped plug sheet 61 and baffle plates 62 fixed at two ends of the plug sheet 61, the mounting plate 5 is fixedly connected with the insertion sheet 61, the arc center angle of the insertion sheet 61 is larger than 180 degrees, the plug-in sheet 61 is matched with the rotating shaft 114, the design that the arc center angle is more than 180 degrees ensures that the rotating shaft 114 is inserted into the plug-in sheet 61, so as to realize the rotation between the rotating shaft 114 and the inserting piece 61 without falling off, the arc center angle is preferably 320 degrees, therefore, the opening range of the plug sheet 61 is small when the plug sheet 61 is sleeved in the rotating shaft 114, and the situation that the plug sheet 61 is broken due to overlarge opening range of the plug sheet 61 when the plug sheet 61 is plugged for multiple times is avoided; the two baffles 62 extend to two sides of the supporting rod 13 at the top; after the end plate 11 is placed in the cleaning tank 3, the insertion sheet 61 is inserted into the rotating shaft 114 to complete the installation of the mounting plate 5, the baffle plate 62 abuts against the second limiting block 115, the pushing motor 33 pushes the end plate 11 to enable the supporting rod 13 at the top to be pushed by the pushing block 31, the supporting rod 13 slides along the sliding groove 111 and pushes the baffle plate 62 at the right side to enable the insertion sheet 61 to rotate around the rotating shaft 114, so that the mounting plate 5 rotates to be supported on the first limiting block 113 from the second limiting block 115 to achieve the installation of the end plate 11, and meanwhile, the mounting plate 5 covers the silicon wafer 2; after silicon chip 2 washs the completion, push motor 33 loosens end plate 11, make bracing piece 13 slide to the eminence along sliding tray 111 under the rebound effect of strutting spring 14, bracing piece 13 promotes left baffle 62 simultaneously and makes plug-in strip 61 revolve axle 114 and rotate, thereby mounting panel 5 rotates to leaning on second stopper 115 from first stopper 113, mounting panel 5 opens when taking out end plate 11 in order to realize, and then mounting panel 5 automatic lid closes the automation and opens, reduce artificial participation, provide the guarantee for workman's life safety.
In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.