2773results about "Screen printers" patented technology

The invention relates to the technical field of silk-screen printing, in particular to a printing material allowance detection mechanism and method and a silk-screen printing device. The printing material allowance detection mechanism comprises a screen printing plate, a scraper assembly and an image acquisition device, the screen printing plate is arranged on a rack of the silk-screen printing device, a mesh area and a non-mesh area surrounding the outer side of the mesh area are arranged on the screen printing plate, meshes are formed in the mesh area, and the screen printing plate is used for bearing printing materials; the scraper assembly is in sliding connection with the rack, the scraper assembly is configured to be capable of horizontally moving above the screen printing plate, the scraper assembly comprises two scrapers which are arranged in parallel in a spaced mode, and the two scrapers are configured to be capable of alternately ascending and descending so as to abut against the screen printing plate; the image acquisition device is connected to the scraper assembly or is arranged on the rack; the image acquisition device is used for acquiring an image of a mesh area between the two scrapers; the detection result of the mechanism is not influenced by bubbles generated by printing materials, whether the screen printing plate is lack of materials or not can be accurately detected, and the phenomenon of misjudgment is avoided.

The utility model discloses a solar cell constant tension printing screen, which comprises a screen frame, a metal wire mesh and a printing plate wire slot, the metal wire mesh is tensioned on the screen frame through a tensioning wire mesh, the printing plate wire slot is arranged on the metal wire mesh, the tensioning wire mesh bypasses the arc-shaped edge of the screen frame and is bonded on the outer frame wall of the screen frame, and the printing plate wire slot is arranged on the metal wire mesh. A tension sensor is arranged between the arc-shaped edge of the screen frame and the tensioning wire screen; and a silk screen tension pressure stabilizing strip is also propped against the tensioning silk screen and is movably supported on the screen frame through a thrust spring. The silk screen tension pressure stabilizing strip abuts against the inner side face of the tension silk screen and can support the tension silk screen. The tension sensor is a thin film pressure sensor, and the installation angle alpha of the tension sensor is 45 degrees. The tension sensors are installed on the arc frame edge of the screen frame, and at least one tension sensor is installed on the arc frame edge of each side edge of the screen frame. The screen printing plate can automatically adjust the tension of the silk screen so as to ensure the stability of the tension of the silk screen.

The invention discloses a full-opening solar cell printing plate, and belongs to the technical field of solar cell printing. The full-opening solar cell printing plate comprises a frame, an annular auxiliary material piece and a graphical steel plate, the graphical steel plate is arranged on the annular auxiliary material piece, an avoiding area is larger than a graphical area of the graphical steel plate, the graphical steel plate comprises a buffer metal layer and a first metal layer, the graphical area of the buffer metal layer is provided with a plurality of first grid line holes, and the first grid line holes are communicated with the annular auxiliary material piece. A plurality of second grid line holes are formed in the pattern area of the first metal layer, at least one buffer metal layer is arranged on the pasting and printing face of the first metal layer, the first grid line holes are communicated with the corresponding second grid line holes, and the hardness of the buffer metal layer is smaller than that of the silicon wafer. According to the method, the surface of the steel plate can be matched with the uneven surface of the silicon wafer in the printing process, consumption of printing silver paste is saved, stable batch production is facilitated, and the electrical performance of a battery piece is improved.

The invention provides top frame equipment applied to an etching process and a silk screen processing process, and relates to the technical field of silk screen processing. The invention discloses top frame equipment applied to an etching process. The top frame equipment comprises a rack, a mounting groove body, a jacking assembly, a moving mechanism, a gluing nozzle and a rolling assembly, the mounting groove body is connected with the rack and is used for mounting the stretching auxiliary screen printing plate; the jacking assembly is connected with the rack and used for installing a target screen frame, and the jacking assembly drives the target screen frame to abut against the screen cloth; the gluing nozzle is connected with the moving mechanism, and the moving mechanism drives the gluing nozzle to move, so that the gluing nozzle coats glue to the screen cloth along the outline of the target screen frame; the rolling assembly comprises a supporting shell and a compaction roller, the supporting shell is connected with the moving end of the moving mechanism, the compaction roller is rotationally connected with the supporting shell, and the moving mechanism drives the compaction roller to move, so that the compaction roller rolls glue on the screen cloth along the outline of the target screen frame. The screen cloth and the target screen frame can be bonded more compactly through glue.

A laser alignment tool is a device that facilitates the efficient and accurate alignment of a product for different manufacturing processes such as Direct-to-Film, screen printing, embroidery, etc. The device includes a tool base, at least one laser module, a controller, and a portable power source. The tool base corresponds to the portion of the device that supports the operation of the at least one laser module. The tool base also facilitates the attachment of the device to a surface adjacent to the product that needs to be aligned. The at least one laser module emits one or more light beams on the adjacent surface that can be used to align the desired product. The controller enables the user to selective control the operation of the at least one laser module. The portable power source provides the electrical power necessary for the operation of the at least one laser module.

The utility model provides a cleaning device which is used for cleaning a screen printing plate, the cleaning device comprises a rack, a driving part and a wiping part, the screen printing plate to be cleaned is placed on the rack, the driving part is arranged on the rack, the wiping part is connected to a movable part of the driving part, the driving part is configured to drive the wiping part to move, and the wiping part is arranged on the rack. And the wiping piece is enabled to abut against the plate surface of the screen and then slide along the plate surface of the screen so as to wipe pollutants on the screen. According to the cleaning device provided by the invention, the screen printing plate can be automatically cleaned, so that the cleaning efficiency of the screen printing plate is improved.

The utility model discloses a screen printing machine glue scraping mechanism which comprises an installation plate, a first side supporting plate, a second side supporting plate, a rotating plate, scraping plates, a limiting block, a limiting clamping plate, an air cylinder and a clamping piece. The rotating plate can be driven by a motor to rotate, and therefore the scraping plates on the upper end face and the lower end face of the rotating plate can be continuously switched; according to the invention, a single scraper is prevented from being heated and softened after being continuously contacted and rubbed with a silk screen, the influence on the printing quality after the printing pressure is reduced is avoided, the heat dissipation of the scraper is also facilitated in the rotating process of the scraper, the limiting block is a square limiting block with the periphery in smooth transition, the limiting clamping plate is a clamping plate with a U-shaped section, and the limiting block is clamped on the limiting clamping plate; by arranging the limiting block and the limiting clamping plate, the motor can drive the rotating plate to rotate by 90 degrees at a time, so that the scraping plates on the upper end face and the lower end face of the rotating plate are conveniently positioned, converted and adjusted, the clamping piece is driven by the air cylinder to descend to clamp the scraping plates, and the stability of the scraping plates and the reliability of the device can be improved when the device does reciprocating glue scraping motion.

The invention relates to the technical field of printing screens, in particular to a screen and a manufacturing method thereof, a solar cell and a production method thereof, and a photovoltaic module. The screen printing plate comprises a film body, graphical grid line printing holes are formed in the film body, the grid line printing holes comprise grid line main body printing holes and lap joint printing holes which are communicated, and the grid line main body printing holes are configured to be consistent with an auxiliary grid printing area or a main grid printing area in graph. The lap joint printing hole is configured to be consistent with the pattern of the lap joint printing area; in the thickness direction of the film body, one end of each grid line main body printing hole is exposed out of the first surface, and the other end of each grid line main body printing hole is positioned in the film body; the lap joint printing hole penetrates through the film body, and the two ends of the lap joint printing hole are exposed out of the first face and the second face respectively. When the screen printing plate is used for printing, not only can the slurry cost be reduced, but also higher printing quality can be achieved.

Improvements in the technical field of solar panel (2) manufacturing are provided. To this effect, a process for manufacturing solar panels (2) is disclosed in which rows (4) of solar elements (3) are bonded together by an electrically conductive adhesive, with the electrically conductive adhesive being applied to the solar elements (3) during a transfer movement of the rows (4) of solar elements (3).

The invention discloses a glass printing device based on a UV imprinting technology, relates to the field of glass printing, and solves the problem that an existing glass printing device is difficult to take out a glass plate finished product large in size and thin. The glass printing device comprises a device base and a driving table installed at the top of the device base, and an air exhaust air bellow is installed on the inner side of the driving table; a containing table is installed at the top of the air exhaust air box, a plurality of air suction holes are formed in the top of the containing table, a UV stamping machine is installed at the top of the device base, and a film covering roller set is installed on the outer side of the UV stamping machine. The plate lifting mechanism is used for lifting the processed glass plate upwards, the plate lifting mechanism is mounted on the inner side of the placing table, and the plate lifting mechanism comprises four top plates arranged at the top of the placing table; by means of the plate lifting mechanism, the top plate lifts the machined glass plate, the long and thin glass plate can be machined conveniently, and therefore the effects of stable coining and convenient material taking are achieved.

The invention relates to the technical field of circuit board processing, in particular to a manufacturing process of a high-performance inner-layer ultra-thick copper circuit board which comprises a bearing table, a back plate and the like. A back plate is arranged on the bearing table. Printing ink is stored through the storage box, the situation that printing ink is not evenly printed due to printing ink diffusion is avoided, and the printing ink printing effect of equipment is improved; through the structure that the middle of the flow dividing rod is high and the two sides of the flow dividing rod are low, ink is slowly collected into the storage box along the flow dividing rod in cooperation with flowability of the ink, the problem that the ink utilization rate is low is solved, and meanwhile the situation that the ink is accumulated and hardened for a long time is avoided. The circuit board is ejected upwards through the ejector rod, then a worker can hold the lower side of the circuit board with hands to take out the circuit board, and the circuit board is prevented from being damaged while the worker conducts discharging conveniently. And the circuit board is accurately placed on the upper side of the fixing frame through cooperation of a guide plate and a limiting block, so that feeding by workers is more convenient.

The invention provides a vertical screen printing machine CCD automatic alignment device, and relates to the field of circuit board production, the vertical screen printing machine CCD automatic alignment device comprises a mounting plate seat, two conveying double guide rails are arranged on the two mounting plate seats, a first vertical feeding frame and a second vertical feeding frame are arranged on the two conveying double guide rails respectively, a PCB body is arranged on the first vertical feeding frame, and the PCB body is arranged on the second vertical feeding frame. And a CCD (Charge Coupled Device) camera mechanism is arranged on one mounting plate seat. The CCD camera mechanism is arranged, the problem of alignment of the vertical printing machine is solved, a target hole is automatically found after the position of a PCB area calibration hole is photographed through four cameras or two cameras at opposite angles, front and back symmetrical screen frames are controlled through algorithm software to automatically adjust the position to be aligned with a screen graph, high-precision printing is achieved, and the printing efficiency is improved. And meanwhile, when the CCD camera mechanism runs and is used, the adjusting hand wheel can be quickly locked through the hand wheel locking module after being used, the situation that the adjusting position deviates is avoided, and the printing precision is further improved.

Device (10) for producing three-dimensional screen-printed workpieces, in particular a 3D screen-printing system, with a printing screen (12) and with a squeegee device (14) for flooding the printing screen (12) with a printing compound and / or for pressing printing compound through the printing screen (12), wherein the squeegee device (14) has at least one squeegee tool (16), an adjusting device (28) for adjusting the inclination of the squeegee tool (16), and a squeegee bearing (34) which allows an inclination adjustment of the squeegee tool (16) by means of the adjusting device (28) about an inclination axis (N), wherein the squeegee bearing (34) has at least one spring bearing (36, 38).

The utility model discloses an HTCC ceramic chip hole-filling printing machine printing platform which comprises a rack table, a horizontal transverse sliding rail is horizontally and transversely arranged on the rack table, an installation base is arranged on the horizontal transverse sliding rail in a sliding mode, and a drag chain used for driving the installation base to slide on the horizontal transverse sliding rail is arranged on the rack table. A printing platform is arranged on the mounting base, a mounting block is arranged on one side of the mounting base, a rotating breathable paper feeding shaft and a rotating breathable paper receiving shaft are horizontally and longitudinally arranged on the mounting block, and breathable paper is wound on the breathable paper feeding shaft and the breathable paper receiving shaft. The breathable paper is led out of the breathable paper feeding shaft, passes through the printing platform and then is wound on the breathable paper receiving shaft, a negative pressure hole is formed in the printing platform, and the breathable paper on the printing platform is adsorbed to the printing platform through negative pressure in the negative pressure hole. The printing platform of the HTCC ceramic chip hole filling printing machine is used for small hole filling printing of HTCC ceramic chips.

The invention provides a vertical silk-screen up-and-down bidirectional screen shifting device, and relates to the field of circuit board production, the vertical silk-screen up-and-down bidirectional screen shifting device comprises mounting frames, the two mounting frames are each provided with a screen shifting mechanism, screen mechanisms are arranged in the two mounting frames, and a same PCB body is arranged between the two screen mechanisms; fixed plate frames are fixedly connected to the outer walls of the two sides of the two mounting frames, and displacement processing modules are arranged on the four fixed plate frames; the displacement mechanism for moving the screen printing plate comprises four fixing frame pieces. According to the PCB printing screen shifting device, the effect of shifting of the PCB printing screen is achieved, the position between the PCB and the screen shifts between the previous printing and the current printing, printing ink left in the previous printing is staggered from the position of a hole in the printed PCB, and therefore the amount of the printing ink left on the screen is always only the amount left in the previous printing, and the printing efficiency is improved. And the ink is prevented from blocking holes.

The invention relates to the field of photovoltaic technology, in particular to a solar cell, a photovoltaic module and a printing screen. The solar cell comprises a substrate, the substrate is provided with a fine grid, a first connecting point and a second connecting point, the first connecting point comprises a first connecting part, the second connecting point comprises a second connecting part, the width of the first connecting part is L1, the width of the second connecting part is L2 in the second direction y, and L1 and L2 meet the condition that L1 / L2 is larger than or equal to 1.02 and smaller than or equal to 1.5. In the process of assembling the solar cell and the solder strip to form the photovoltaic module, the contact area between the first connection point and the solder strip is increased by arranging the first connection part with a larger size along the second direction y, so that the connection strength between the first connection point and the solder strip is improved; therefore, the first connection point can be preferentially arranged in the high-risk area on the substrate, so that the possibility of relative displacement or mutual separation of the first connection point and the second connection point in the high-risk area is reduced, and the stability and the reliability of the solar cell and the photovoltaic module in the working process are improved.

The utility model relates to the technical field of SMT (Surface Mount Technology), in particular to a quick release device for an SMT red glue printing screen. Comprising a frame, a supporting plate and a printing screen plate, an inserting groove is formed in the frame, the supporting plate is installed on the frame through the inserting groove, and the printing screen plate is detachably installed on the supporting plate; a push-out assembly is arranged in the frame, and the supporting plate is pushed out of the inserting groove through the push-out assembly so that the printing screen can be replaced conveniently. The device has the effect of improving the mounting or dismounting and replacing efficiency of the printing screen plate, and has the characteristics of simple structure and convenience in operation.

The invention relates to the technical field of screen printing plates, in particular to a printing screen printing plate, a manufacturing method, a solar cell and a photovoltaic module. The printing screen comprises a screen body and a reinforcing part. A printing groove extending in the first direction is formed in the screen printing plate body and penetrates through the thickness direction of the screen printing plate body. The reinforcing part is arranged at the position, provided with the printing groove, of the screen printing plate body, the reinforcing part is arranged corresponding to the part of the printing groove, at least part of the reinforcing part is hollowed out, and the hollowed-out position of the reinforcing part is communicated with the printing groove. The printing screen has the advantages of high printing quality and high structural strength, can print continuous current collection grid lines, facilitates current collection of the current collection grid lines, and can meet the process and test requirements of electrifying a solar cell.

The utility model relates to the field of steel drum printing, and discloses an automatic steel drum printing system which comprises a conveying frame, an opening searching positioning assembly, a printing assembly and an overturning assembly, a lifting workbench is arranged in the conveying frame, the conveying frame is provided with a mounting frame, and the printing assembly is arranged at one end of the mounting frame. The printing assembly comprises a guide rail, a printing frame, a first driving piece and two sets of printing pieces, the guide rail is arranged at one end of the mounting frame, the printing frame is arranged in the mounting frame, the printing frame is provided with a first printing area and a second printing area, the two sets of printing pieces are arranged at one end of the guide rail, and each printing piece comprises a sliding block, a second driving piece, a connecting block, an air cylinder and a scraping plate; the second driving piece is arranged between the sliding block and the guide rail, the connecting block is arranged at one end of the sliding block, the air cylinder is arranged at one end of the connecting block, and the scraper is arranged at the output end of the air cylinder. The copywriting of the first printing area and the copywriting of the second printing area are printed on the same axial direction of the steel drum through the two sets of printing pieces, the printing procedures of the steel drum are reduced, and the printing efficiency of the steel drum is improved.

The invention relates to the technical field of printing, in particular to a full-automatic printing device. A full-automatic printing device comprises an annular rack, a material plate frame which moves circularly and is used for supporting a printing plate is arranged on the rack, a scraping part which is arranged in a mirror image mode is arranged in the middle of the rack, and a drying part which is used for heating and drying is arranged on the outer side of the scraping part. The full-automatic printing device adopts an annular rack as a main body structure, a circularly moving material plate frame is arranged on the rack to bear a printing plate, scraping parts are symmetrically mounted in the middle of the rack, and a drying part is integrated on the outer side of the rack and used for heating and drying; the scraping part is composed of a vertical frame fixed to the middle of the rack, supporting arms capable of swinging up and down are hinged to the two sides of the vertical frame, a pressing plate and a scraping plate which can be adjusted front and back and up and down are assembled on the supporting arms, and accurate scraping and pressure control over a printing plate are achieved through positioning and pressing of the pressing plate and synchronous lifting and translation actions of the scraping plate. And in cooperation with continuous circulating movement of the material plate frame and instant drying of the drying part, an integrated printing operation process is formed.

The invention belongs to the technical field of electrode printing, and discloses a full-opening steel plate and printing equipment. The full-opening steel plate comprises a steel plate body, a full-opening pattern used for printing fine grids and connecting lines at a time is formed on the steel plate body, the full-opening pattern comprises a plurality of main lines extending in the first direction and a plurality of connecting parts arranged on the main lines in the second direction, and the main lines are arranged in a continuous opening mode and used for printing and forming the fine grids. And the connecting parts are used for synchronously printing to form connecting lines during printing so as to bridge the adjacent fine grids in the second direction. The steel plate body at least comprises a first metal layer and a second metal layer. The first metal layer forms an outline of a full-opening pattern. The second metal layer is stacked on the first metal layer and is provided with an ink penetrating pattern corresponding to the full-opening pattern, and the ink penetrating pattern is at least arranged in a discontinuous opening mode in the area corresponding to the connecting part. The thin grid and the main grid / connecting line can be printed at a time, the problems of alignment errors and silver paste waste are avoided, and the production efficiency is high.

The invention discloses an easy-to-adjust efficient lettering operation table capable of being accurately positioned and finely adjusted, which comprises a bottom plate, a two-dimensional moving platform, a tool fixing plate and a silk screen fixing table, the two-dimensional moving platform is arranged on the bottom plate and is provided with a displacement adjusting device for adjusting movement in the X-axis direction and the Y-axis direction of the plane of the bottom plate; the tool fixing plate is arranged on the two-dimensional moving platform, a detachable universal tool is arranged on the tool fixing plate, and a detachable special tool core is arranged in the universal tool; the silk screen fixing table is fixed to the bottom plate through a height fixing rod, a height adjusting device of the silk screen fixing table is arranged on the height fixing rod, and a printing silk screen is arranged on the silk screen fixing table. The operation table has the advantages of high-precision positioning and quick switching, and is high in universality, and the lettering efficiency is remarkably improved. The daily printing quantity of a single device reaches more than 3000 pieces, compared with a traditional screen printing table, the efficiency is remarkably improved, and a large amount of working time cost can be saved.

The utility model discloses a silica gel button screen printing mould, which comprises a mould plate and a cover plate, the upper surface of the mould plate is provided with a groove capable of placing a workpiece, the cover plate is supported on the upper surface of the mould plate and shields the groove, the cover plate is provided with a positioning through hole, and the rear part of the cover plate is hinged with the mould plate so that the cover plate can be turned backwards to be opened. The rear side edge of the cover plate is provided with a pressing part, and the rear side edge of the pressing part is located behind the rotating axis of the cover plate. Due to the adoption of the design, when a user needs to open the cover plate, the cover plate can be directly opened by knocking the upper surface of the edge of the rear side of the pressing part by adopting a tool and certain force, and convenience and rapidness are achieved.

The screen printing machine comprises a feeding mechanism, a printing machine table and a discharging mechanism which are arranged in sequence, and the feeding mechanism is used for conveying battery pieces to be printed to a feeding position; the printing machine table comprises a machine frame, a transferring mechanism and at least two printing parts, each printing part comprises a mounting machine frame, a printing table and a printing mechanism, the mounting machine frames extend in the second horizontal direction, and the printing tables can move to the material receiving station, the printing station and the discharging station in the second horizontal direction to be mounted on the mounting machine frames; the printing mechanism is used for printing the battery pieces on the printing table on the printing station; the transfer mechanism is used for picking up the battery pieces at the feeding position, conveying the picked battery pieces to the positions above the material receiving stations of all the printing parts in the first horizontal direction and then releasing the battery pieces to the printing tables located on the material receiving stations. According to the screen printing machine, the overall length of the machine table is greatly shortened, and equipment can be conveniently placed in a workshop.

The utility model relates to the technical field of solder paste printing, and particularly discloses a steel mesh cleaning device which comprises a driving platform, a glue scraping plate installed on the driving platform and used for scraping sundries on a silk screen steel mesh, and a glue removing assembly used for removing the sundries on the glue scraping plate. The steel mesh cleaning equipment provided by the utility model can effectively solve the problem of higher production cost caused by higher consumable consumption speed of the existing cleaning equipment.

Disclosed in the present disclosure is a printing screen, comprising a screen body and a surface treatment layer. The screen body comprises a printing side, a bottom side and several penetratingly-arranged grid lines, the printing side and the bottom side being arranged opposite each other. The surface treatment layer is arranged on the printing side and / or the bottom side or in the grid lines, the surface treatment layer comprising micro-nano structures or coating structures. The surface treatment layer is provided on the printing side and / or bottom side of the screen body, so that the resistance of a squeegee on the printing side during printing can be controlled, thereby controlling the amount of ink, improving the uniformity and ink discharge performance; the surface energy of the bottom side can be changed, improving the quality of the printing screen; the scratch resistance of the bottom side can be improved; and the hardness of a lower surface can be changed, improving the performance of the screen body.

An exchanging unit for use in a printing device including a printing section to execute a printing process of printing a viscous fluid on a processing target object using a screen mask, and includes a receiving section configured to receive an accommodation rack having multiple shelf sections each configured to accommodate a frame that is capable of supporting an exchangeable member for use in the printing device, a lifting and lowering section configure to lift and lower the accommodation rack between an exchange position where to exchange the exchangeable member and a liftable position situated further downwards than the exchange position, and a moving section configured to move the accommodation rack between the liftable position where the accommodation rack can be lifted up by the lifting and lowering section and an accommodation position where the accommodation rack enters an interior of a housing of the printing device.

The invention is suitable for the technical field of solar cells, and provides a solar cell, which comprises a silicon substrate, pad points and a main grid, at least one end of the main grid is connected with the pad point, and the thickness of the main grid close to the connection position of the main grid and the pad point is larger than the thickness of at least one main grid away from the pad point. The thickness of the main grid at the connection position with the pad point is larger than that of at least one grid line far away from the pad position, so that the resistance at the connection position of the main grid and the pad point is reduced, and the photoelectric conversion efficiency of the solar cell is further improved.

The invention provides a printing screen capable of improving the ink penetration effect. The screen printing plate comprises a screen frame and screen cloth arranged in the screen frame, the screen cloth comprises a graphic area and a peripheral area annularly arranged outside the graphic area, the graphic area comprises a metal support, the two ends of the metal support are connected with the peripheral area, and the thickness of the metal support is smaller than that of the peripheral area.

The invention relates to the technical field of solar cells, in particular to a solar cell, an electrode structure of the solar cell, a printing screen assembly and a photovoltaic assembly. The electrode structure comprises a confluence substructure and a plurality of collector grid lines. Each confluence substructure comprises two interconnecting grid lines arranged at an interval and a lap-joint grid line connected between the two interconnecting grid lines, the interval arrangement direction of the two interconnecting grid lines is a first direction, and the extension direction of the interconnecting grid lines is a second direction. The plurality of current collection grid lines are arranged at intervals along a first direction, the current collection grid lines extend along the first direction, and two adjacent current collection grid lines in the first direction form a pair. In at least one pair, the ends, close to each other, of the two current collection grid lines intersect with the two interconnected grid lines in the same confluence substructure. The electrode structure can be used for printing the collector grid lines with narrower line width, and the collector grid lines can be intersected with the interconnected grid lines even if printing deviation occurs in the second direction, so that the conversion efficiency of the solar cell is improved.