CN101708668B - Scraper for screen printer - Google Patents

Abstract

The invention discloses a scraper for a screen printer. The flat bottom contact surface of a scraper body on one side in contact with a screen is improved into a curved surface which recesses towards inside of the body. When the scraper is used for scraping, the scraper generates a certain pressure applied on the screen, so the screen generates the same reaction force applied to the scraper simultaneously. As the contact surface of the scraper is an inwards recessed curved surface, the scraper body also suffers an own resilience force. The reaction force at two ends of the scraper body is greater than that in the middle part of the scraper body, and the own resilience force applied at the two ends of the scraper body is smaller than that in the middle part of the scraper body, so that the scraper body is uniformly stressed integrally. Therefore, the contact surface of the scraper is deformed, and the contact surface of the scraper is changed from an inwards recessed curved surface to a flat surface, so that the contact part of the screen and the contact surface of the body is basically kept horizontal, and finally screen-printed Al-back surface field has uniform thickness.

Description

A kind of scraper that is used on the screen process press

Technical field

The present invention relates to a kind of serigraphy instrument, especially relate to a kind of scraper that is used on the screen process press.

Background technology

The electrode wires in the front of silicon solar cell (grid line) is in order to compile the free electron that silicon solar cell produces, and the aluminium back of the body field at the back side of silicon solar cell is used to form the P+ at the back side.The electrode wires in the front of silicon solar cell and the aluminium at back side back of the body field forms silver grating line and aluminium back of the body field through super-dry and sintering then normally through electrocondution slurries such as screen printer print silver and aluminium.At present; Screen process press (Fig. 1 and Fig. 2 only provide part-structure) as depicted in figs. 1 and 2 commonly used; It comprises printing seats 1, places printing seats 1 below and is used to place the silica-based bar 2 of silicon chip 9, is connected with silica-based bar 2 and is used to transmit the conveyer belt 3 of silicon chip 9 and is arranged at the printed panel 4 between silica-based bar 2 and the printing seats 1; Printed panel 4 is fixedly connected with printing seats 1; The bottom surface of printed panel 4 does not contact with the surface of silicon chip 9 on being placed in silica-based bar 2 mutually; Its spacing is 20nm-10um; Printed panel 4 mainly is made up of framework 41 that adopts aluminum to process and the web plates 42 that are arranged in the framework 41, and web plate 42 adopts the rubber-like plastic sheetings to process, and on the web plate 42 and corresponding section, silicon chip 9 position that is placed on the silica-based bar 2 is provided with mesh 43; Be connected with the slurry system of scraping on the printing seats 1; Scrape scraper working track 51, the scraper crane 52 that is connected with scraper working track 51, the doctor blade holder 53 that is connected with the bottom of scraper crane 52 that the slurry system comprises the both sides upper end that is arranged at printing seats 1, be arranged at scraper 54 on the doctor blade holder 53 and reach the advance and retreat scraping delivery motor (not shown) that is connected with scraper crane 52 and is used to drive scraper 54 starts, scraper crane 52 can move on scraper working track 51, and the position of scraper 54 is corresponding with the position of silicon chip 9 on being placed in silica-based bar 2; Scraper 54 is rectangular-shaped; Its schematic cross-section is as shown in Figure 3, and the scraper 54 general rubber-like engineering plastics that adopt are made, and the side that scraper 54 is used for contacting with web plate 42 is the plane.Utilizing this screen process press to print electrode or aluminium back of the body field, is the groundwork process that example is introduced this screen process press at this with printing aluminium back of the body field, at first on web plate 42, adds aluminum slurry 6 (roughly being placed on the centre position of web plate 42); Conveyer belt 3 work are sent into a silicon chip 9 on the silica-based bar 2, and adjusting scraper crane 52 drops to the appropriate location makes the bottom surface of scraper 54 contact with the end face of an end of web plate 42, and 54 pairs of web plates of scraper 42 produce certain pressure; Utilize advance and retreat scraping delivery motor that scraper 54 is advanced, forward is scraped aluminum slurry 6, and aluminum slurry 6 is penetrated on the silicon chip 9 through mesh 43; When scraper 54 arrives the other end of web plate 42; Through regulating scraper crane 52, through advance and retreat scraping delivery motor scraper 54 is oppositely advanced again again, oppositely scrape aluminum slurry 6 to the appropriate location; Unnecessary aluminum slurry 6 is laid on the web plate 42 again; So that scrape slurry next time, conveyer belt 3 will be printed with the silicon chip of aluminium back of the body field and see off, will descend a slice silicon chip 9 to send into substrate holder simultaneously.After the scraper of above-mentioned screen process press used for a long time, the related work personnel found to print an aluminium back of the body became uneven that obtains, and promptly aluminium back of the body field is thinner along the mid portion of scraping the slurry direction, and both sides are then thicker, thereby had a strong impact on the quality of silicon solar cell.

Summary of the invention

It is even that technical problem to be solved by this invention provides a kind of thickness of the electrode that obtains of printing or the aluminium back of the body that can make, and simple in structure be used for the scraper on the screen process press.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of scraper that is used on the screen process press; Comprise body; The side that described body is used for contacting with web plate is a contact-making surface; Described contact-making surface is a curved surface to described body interior depression, and the bottom of the cross section of described body be the curve that caves in to described body interior, the longitudinal section of described body be shaped as rectangle.

The relation of the radius of curvature of described curve and the width of described body is: $R^2-{(R-H)}^2={\left(\frac{L}{2}\right)}^2,$ Wherein, R representes the radius of curvature of curve, and L representes the width of body, and H representes that the width with body is the action of the string of chord length, and the relation of the width of action H and body does $L=\sqrt{1620008H-4H^2}.$

The material that described body adopts is the rubber-like engineering plastics.

Compared with prior art; The flat contact-making surface that the invention has the advantages that a side that is used for contacting with web plate through the body with scraper is improved to the curved surface to the inner recess of body, and the bottom of the cross section of body is the curve to body interior depression, the longitudinal section of body be shaped as rectangle; When using this scraper to scrape slurry; Scraper can produce certain pressure to web plate, so web plate also can be given the identical reaction force of scraper simultaneously, simultaneously because the contact-making surface of this scraper is an inner sunken face; Therefore the body of scraper also receives the screen resilience of itself simultaneously; The reaction force that the reaction force that the two ends of the body of scraper receive receives greater than the intermediate portion, the two ends of the body of scraper receive the screen resilience that self screen resilience receives less than the intermediate portion, make that like this body of scraper is whole stressed more even; Therefore make the contact-making surface generation deformation of scraper; Its contact-making surface is by the inner sunken face complanation, and the part that makes web plate contact with the contact-making surface of body like this keeps horizontal plane basically, and the thickness that the final aluminium that makes printing obtain is carried on the back the field is comparatively even.The width of the body of scraper is depended in the bottom of the cross section of body to the size of the radius of curvature of the curve of body interior depression; Because the silicon solar cell of producing is not of uniform size; The width of employed like this scraper is also different; When then designing the contact-making surface of scraper, need to confirm the degree of contact-making surface indent, can the relation table of the width of the radius of curvature of the curve that caves in to body interior and body be shown according to the width of the body of scraper: $R^2-{(R-H)}^2={\left(\frac{L}{2}\right)}^2,$ Wherein, R representes the radius of curvature of curve, and L representes that the width of body is a chord length, and H representes that the width with body is the action of the string of chord length, and the relation of the width of action H and body does $L=\sqrt{1620008H-4H^2},$ The width of the body of scraper commonly used is 1800mm, and action can be designed to 2mm.

Description of drawings

Fig. 1 is the partial structurtes sketch map one of existing screen process press;

Fig. 2 is the partial structurtes sketch map two of existing screen process press;

Fig. 3 is the schematic cross-section of existing scraper;

Fig. 4 a is the cutaway view of existing screen process press before printing;

Fig. 4 b is the cutaway view of existing screen process press when printing;

Fig. 4 c utilizes existing screen process press to scrape the silicon chip that is printed with aluminium back of the body field that obtains behind the slurry;

Fig. 5 a is the cross sectional representation of scraper of the present invention;

Fig. 5 b is the longitudinal section sketch map of scraper of the present invention;

Fig. 6 a utilizes scraper of the present invention to scrape before the slurry and the position view of web plate, silicon chip and aluminum slurry;

Fig. 6 b is when utilizing scraper of the present invention to scrape slurry and the position view of web plate, silicon chip and aluminum slurry;

Fig. 6 c utilizes scraper of the present invention to scrape the silicon chip that is printed with aluminium back of the body field that obtains behind the slurry.

The specific embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

The present invention at first causes printing the electrode that obtains or the aluminium back of the body and analyzes along the even problem of became uneven of scraping the slurry direction using existing screen process press to carry out serigraphy, the cross-sectional schematic before Fig. 4 a has provided existing screen process press and prints, and Fig. 4 b has provided the cross-sectional schematic in the existing screen printer print process; Fig. 4 c has provided the side sketch map of the silicon chip with aluminium back of the body that utilizes that existing screen printer print obtains; The scraper of existing screen process press is in practical work process, because web plate 42 all has elasticity with scraper 54, like this when scraper 54 presses down; Scraper 54 receives the reaction force of web plate 42 to it; Scraper 54 is uneven at the reaction force that A point, C point and B point receive, since nearer from the aluminium chassis 41 of printed panel 4 on the web plate 42 with A point and the corresponding location point of C point, thereby the reaction force that scraper 54 is produced is bigger; Opposite because far away from the aluminium chassis 41 of printed panel 4 on the web plate 42 with the corresponding location point of B point; Thereby the reaction force that scraper 54 is produced is less, and at this moment in fact deformation has taken place scraper 54, and its bottom surface no longer is plane and be outer gibbosity; The aluminium back of the body 7 became uneven that so directly cause printing to obtain; Be that aluminium back of the body field 7 is thinner along the mid portion of scraping the slurry direction, both sides are then thicker, thereby had a strong impact on the quality of silicon solar cell.

The present invention is through above-mentioned analysis; Proposed a kind of scraper that is used on the screen process press, shown in Fig. 5 a and Fig. 5 b, it comprises the body of being processed by the rubber-like engineering plastics 8; The side that body 8 is used for contacting with the web plate (not shown) is a contact-making surface 81; Contact-making surface 81 is a curved surface to body 8 inner recess, and the bottom of the cross section of body 8 is the curve to body 8 inner recess, shown in Fig. 5 a; The longitudinal section of body 8 be shaped as rectangle, shown in Fig. 5 b.

At this; The width of the body 8 of scraper is depended in the bottom of the cross section of body 8 to the size of the radius of curvature of the curve of body 8 inner recess; Because the silicon solar cell of producing is not of uniform size, the width of employed like this scraper is also different, when then designing the contact-making surface of scraper; Need to confirm the degree of contact-making surface indent, can the relation table of the width of the radius of curvature of curve and body 8 be shown according to analysis according to the width of the body 8 of scraper: $R^2-{(R-H)}^2={\left(\frac{L}{2}\right)}^2,$ Wherein, R representes the radius of curvature of curve, and L representes the width of body 8, and H representes that the width with body 8 is the action of the string of chord length, and the relation of the width of action H and body 8 does $L=\sqrt{1620008H-4H^2},$ The width L of the body 8 of the normal scraper that uses is 1800mm, is that the action H of the string of chord length is 2mm with the width L of this body 8 then.

Fig. 6 a has provided and has used this scraper to scrape before the slurry and the position view of web plate 42, silicon chip 9 and aluminum slurry 6; Fig. 6 b has provided when this scraper is scraped slurry and the position view of web plate 42, silicon chip 9 and aluminum slurry 6; Fig. 6 c is printed with the side sketch map that aluminium is carried on the back the silicon chip of field 7 after having provided and having used this scraper to scrape slurry; The screen process press that uses this scraper is in practical work process; When the body 8 of scraper pressed down, the body 8 of scraper can produce certain pressure to web plate 42, and this moment, web plate 42 also can produce identical reaction force to scraper; Simultaneously because the contact-making surface 81 of this scraper is an inner sunken face; Therefore the body 81 of scraper also receives the screen resilience of scraper itself simultaneously, and the body 8 of scraper all is uneven at reaction force and the screen resilience that D point, F point and E point receive, and the reaction force that D point and F point place receive is relatively large; The screen resilience that D point and F point receive is then less relatively; The reaction force that E point place receives is less relatively, and the screen resilience that the E point receives is then relatively large, and the superposed force of the screen resilience that receives respectively of the two ends of the superposed force of the screen resilience that receives of the mid portion of body 8 and the reaction force that receives web plate 42 and body 8 and the reaction force that receives web plate 42 is suitable basically like this; Therefore make the contact-making surface 81 of scraper its body 8 when scraping slurry that deformation has taken place; Its contact-making surface 81 no longer is that original inner sunken face has formed planar base surface, makes web plate 42 keep horizontal plane basically with the part that the contact-making surface 81 of body 8 contacts like this, and the thickness that the final aluminium that makes printing obtain is carried on the back field 7 is comparatively even.

Claims (2)

1. scraper that is used on the screen process press; Comprise body; The side that described body is used for contacting with web plate is a contact-making surface; It is characterized in that described contact-making surface is a curved surface to described body interior depression; The bottom of the cross section of described body is the curve to described body interior depression; The longitudinal section of described body be shaped as rectangle; The relation of the radius of curvature of described curve and the width of described body is:

wherein, R representes the radius of curvature of curve, and L representes the width of body; H representes that the width with body is the action of the string of chord length, and the relation of the width of action H and body is

2. a kind of scraper that is used on the screen process press according to claim 1 is characterized in that the material that described body adopts is the rubber-like engineering plastics.

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