《Hitachi Chemical Co Ltd : “Electrically Conductive Adhesive Composition, Connector and Solar Cell Module” in Patent Application Approval Process》：
By a News Reporter-Staff News Editor at Energy Weekly News — A patent application by the inventors Sukata, Shinichirou (Tsukuba-shi, JP); Hayashi, Hiroki (Tsukuba-shi, JP); Momozaki, Aya (Tsukuba-shi, JP), filed on January 11, 2012, was made available online on January 2, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.
This patent application is assigned to Hitachi Chemical Company, Ltd.
The following quote was obtained by the news editors from the background information supplied by the inventors: “As means for solving aggravated global warming or fossil energy depletion, attention is paid on a solar cell which is a power generating system using sunlight. A structure in which solar battery cells in which an electrode is formed on a monocrystalline or polycrystalline Si wafer, are connected in series or in parallel to each other via a wiring member, has been employed for the current main solar battery cells.
“For connection of the electrodes of the solar battery cell and the wiring member, it has been proposed to use an electrically conductive adhesive composition (for example, see Patent Literature 1). The electrically conductive adhesive composition of Patent Literature 1 is a composition obtained by mixing and dispersing of metal particles which are typified by silver particles in a thermosetting resin, and the electrical connection is mainly expressed by physical contact with these metal particles to the electrodes of the solar battery cells and the wiring member.”
In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors’ summary information for this patent application: “Technical Problem
“However, in a case of using the electrically conductive adhesive composition of Patent Literature 1 or the like for the connection of the electrodes of the solar battery cells and the wiring member, when exposed under an atmosphere of a high temperature and high humidity, a connection property tends to be degraded.
“Here, an object of the present invention is to provide an electrically conductive adhesive composition which has excellent conductivity, sufficiently suppresses decrease of the conductivity even after a high temperature and high humidity test (85.degree. C./85%), and impart an excellent connection property, in a case of being used for the connection of the electrodes of the solar battery cells and the wiring member.
“In addition, another object of the present invention is to provide a connected body and a solar cell module using the electrically conductive adhesive composition.
“Solution to Problem
“According to the present invention, there is provided an electrically conductive adhesive composition including: electrically conductive particles (A) containing metal having a melting point of equal to or lower than 220.degree. C. (hereinafter, also referred to as ‘electrically conductive particles (A)’); a thermosetting resin (B); a flux activator (C); and a curing catalyst (D), in which a reaction start temperature of the thermosetting resin (B) and the curing catalyst (D) is 130 to 200.degree. C. According to such an electrically conductive adhesive composition, by using the configuration described above, in a case of using the composition for the connection of electrodes of solar battery cells and wiring members, excellent conductivity is obtained, and decrease of the conductivity is sufficiently suppressed even after a high temperature and high humidity test (85.degree. C./85%).
“In addition, in the present specification, the ‘melting point’ refers to a value measured by Differential Scanning calorimetry (DSC), for example. Further, in the present specification, the ‘high temperature and high humidity test (85.degree. C./85%)’ refers to a test of exposing a subject under an atmosphere with a high temperature and high humidity of 85.degree. C. and 85% RH for 1500 hours, and ‘% RH’ represents relative humidity.
“It is preferable that the metal of the electrically conductive particles (A) contain at least one component selected from a group consisting of bismuth, indium, tin, and zinc. Accordingly, it is possible to decrease the melting point of the electrically conductive particles while maintaining excellent conductivity.
“It is preferable that the thermosetting resin (B) contain an epoxy resin, from a viewpoint of obtaining excellent connection stability.
“It is preferable that the flux activator (C) contain a compound having a hydroxy group and a carboxyl group.
“The electrically conductive adhesive composition may be suitably used for electrical connection of the electrodes of solar battery cells and a wiring member.
“In addition, according to the present invention, there is provided a connected body in which a plurality of solar battery cells are connected via a wiring member, in which electrodes of the solar battery cells and the wiring member are connected via the electrically conductive adhesive composition described above.
“Further, according to the present invention, there is provided a method for producing a solar cell module including: a step of applying the electrically conductive adhesive composition described above onto electrodes of solar battery cells; a step of disposing the electrodes onto which the electrically conductive adhesive composition is applied and a wiring member so as to face to each other; a step of laminating a sealing member and a light transmission member in this order onto a light-receiving surface of the solar battery cell; a step of laminating a sealing member and a protection member in this order onto a surface on an opposite side to the light-receiving surface of the solar battery cell; and a step of sealing the solar battery cells while electrically connecting and adhering the solar battery cells and the wiring members by heating the obtained laminated body.
“Furthermore, according to the present invention, there is provided a solar cell module in which electrodes of a plurality of solar battery cells and a wiring member are electrically connected to each other via the electrically conductive adhesive composition described above.
“Advantageous Effects of Invention
“According to the present invention, it is possible to provide an electrically conductive adhesive composition which has excellent conductivity and sufficiently suppresses decrease of the conductivity even after the high temperature and high humidity test (85.degree. C./85%), in a case of being used for the connection of the electrodes of the solar battery cells and the wiring member. In addition, by using the electrically conductive adhesive composition of the present invention, it is easier to collectively perform the connection of, and adhering of the solar battery cells and the wiring members and the sealing of the solar battery cells, and compared to a conventional producing step of a solar cell module, it is possible to realize low cost by shortening of steps and improvement of productivity.
BRIEF DESCRIPTION OF DRAWING
“FIG. 1 is a schematic view of a DSC chart to show a reaction start temperature of a thermosetting resin (B) and a curing catalyst (D).
“FIG. 2 is a schematic view showing main parts of a solar cell module according to the present invention.
“FIG. 3 is a view for illustrating one embodiment of a method for producing a solar cell module according to the present invention.
“FIG. 4 is a view showing pictures obtained by observing fusion states of metal in an electrically conductive adhesive composition between surface electrodes of a solar cell module and a wiring member using an X-ray inspection system.”
URL and more information on this patent application, see: Sukata, Shinichirou; Hayashi, Hiroki; Momozaki, Aya. Electrically Conductive Adhesive Composition, Connector and Solar Cell Module. Filed January 11, 2012 and posted January 2, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=6354&p=128&f=G&l=50&d=PG01&S1=20131226.PD.&OS=PD/20131226&RS=PD/20131226
Keywords for this news article include: Energy, Solar Cell, Hitachi Chemical Company Ltd..
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
《Hitachi Chemical Co Ltd : “Electrically Conductive Adhesive Composition, Connector and Solar Cell Module” in Patent Application Approval Process》：
By a News Reporter-Staff News Editor at Energy Weekly News — A patent application by the inventors Sukata, Shinichirou (Tsukuba-shi, JP); Hayashi, Hiroki (Tsukuba-shi, JP); Momozaki, Aya (Tsukuba-shi, JP), filed on January 11, 2012, was made available online on January 2, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.
This patent application is assigned to Hitachi Chemical Company, Ltd.
The following quote was obtained by the news editors from the background information supplied by the inventors: “As means for solving aggravated global warming or fossil energy depletion, attention is paid on a solar cell which is a power generating system using sunlight. A structure in which solar battery cells in which an electrode is formed on a monocrystalline or polycrystalline Si wafer, are connected in series or in parallel to each other via a wiring member, has been employed for the current main solar battery cells.
“For connection of the electrodes of the solar battery cell and the wiring member, it has been proposed to use an electrically conductive adhesive composition (for example, see Patent Literature 1). The electrically conductive adhesive composition of Patent Literature 1 is a composition obtained by mixing and dispersing of metal particles which are typified by silver particles in a thermosetting resin, and the electrical connection is mainly expressed by physical contact with these metal particles to the electrodes of the solar battery cells and the wiring member.”
In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors’ summary information for this patent application: “Technical Problem
“However, in a case of using the electrically conductive adhesive composition of Patent Literature 1 or the like for the connection of the electrodes of the solar battery cells and the wiring member, when exposed under an atmosphere of a high temperature and high humidity, a connection property tends to be degraded.
“Here, an object of the present invention is to provide an electrically conductive adhesive composition which has excellent conductivity, sufficiently suppresses decrease of the conductivity even after a high temperature and high humidity test (85.degree. C./85%), and impart an excellent connection property, in a case of being used for the connection of the electrodes of the solar battery cells and the wiring member.
“In addition, another object of the present invention is to provide a connected body and a solar cell module using the electrically conductive adhesive composition.
“Solution to Problem
“According to the present invention, there is provided an electrically conductive adhesive composition including: electrically conductive particles (A) containing metal having a melting point of equal to or lower than 220.degree. C. (hereinafter, also referred to as ‘electrically conductive particles (A)’); a thermosetting resin (B); a flux activator (C); and a curing catalyst (D), in which a reaction start temperature of the thermosetting resin (B) and the curing catalyst (D) is 130 to 200.degree. C. According to such an electrically conductive adhesive composition, by using the configuration described above, in a case of using the composition for the connection of electrodes of solar battery cells and wiring members, excellent conductivity is obtained, and decrease of the conductivity is sufficiently suppressed even after a high temperature and high humidity test (85.degree. C./85%).
“In addition, in the present specification, the ‘melting point’ refers to a value measured by Differential Scanning calorimetry (DSC), for example. Further, in the present specification, the ‘high temperature and high humidity test (85.degree. C./85%)’ refers to a test of exposing a subject under an atmosphere with a high temperature and high humidity of 85.degree. C. and 85% RH for 1500 hours, and ‘% RH’ represents relative humidity.
“It is preferable that the metal of the electrically conductive particles (A) contain at least one component selected from a group consisting of bismuth, indium, tin, and zinc. Accordingly, it is possible to decrease the melting point of the electrically conductive particles while maintaining excellent conductivity.
“It is preferable that the thermosetting resin (B) contain an epoxy resin, from a viewpoint of obtaining excellent connection stability.
“It is preferable that the flux activator (C) contain a compound having a hydroxy group and a carboxyl group.
“The electrically conductive adhesive composition may be suitably used for electrical connection of the electrodes of solar battery cells and a wiring member.
“In addition, according to the present invention, there is provided a connected body in which a plurality of solar battery cells are connected via a wiring member, in which electrodes of the solar battery cells and the wiring member are connected via the electrically conductive adhesive composition described above.
“Further, according to the present invention, there is provided a method for producing a solar cell module including: a step of applying the electrically conductive adhesive composition described above onto electrodes of solar battery cells; a step of disposing the electrodes onto which the electrically conductive adhesive composition is applied and a wiring member so as to face to each other; a step of laminating a sealing member and a light transmission member in this order onto a light-receiving surface of the solar battery cell; a step of laminating a sealing member and a protection member in this order onto a surface on an opposite side to the light-receiving surface of the solar battery cell; and a step of sealing the solar battery cells while electrically connecting and adhering the solar battery cells and the wiring members by heating the obtained laminated body.
“Furthermore, according to the present invention, there is provided a solar cell module in which electrodes of a plurality of solar battery cells and a wiring member are electrically connected to each other via the electrically conductive adhesive composition described above.
“Advantageous Effects of Invention
“According to the present invention, it is possible to provide an electrically conductive adhesive composition which has excellent conductivity and sufficiently suppresses decrease of the conductivity even after the high temperature and high humidity test (85.degree. C./85%), in a case of being used for the connection of the electrodes of the solar battery cells and the wiring member. In addition, by using the electrically conductive adhesive composition of the present invention, it is easier to collectively perform the connection of, and adhering of the solar battery cells and the wiring members and the sealing of the solar battery cells, and compared to a conventional producing step of a solar cell module, it is possible to realize low cost by shortening of steps and improvement of productivity.
BRIEF DESCRIPTION OF DRAWING
“FIG. 1 is a schematic view of a DSC chart to show a reaction start temperature of a thermosetting resin (B) and a curing catalyst (D).
“FIG. 2 is a schematic view showing main parts of a solar cell module according to the present invention.
“FIG. 3 is a view for illustrating one embodiment of a method for producing a solar cell module according to the present invention.
“FIG. 4 is a view showing pictures obtained by observing fusion states of metal in an electrically conductive adhesive composition between surface electrodes of a solar cell module and a wiring member using an X-ray inspection system.”
URL and more information on this patent application, see: Sukata, Shinichirou; Hayashi, Hiroki; Momozaki, Aya. Electrically Conductive Adhesive Composition, Connector and Solar Cell Module. Filed January 11, 2012 and posted January 2, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=6354&p=128&f=G&l=50&d=PG01&S1=20131226.PD.&OS=PD/20131226&RS=PD/20131226
Keywords for this news article include: Energy, Solar Cell, Hitachi Chemical Company Ltd..
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC