Back contact solar cell, cell segment, photovoltaic module and string bonding method

A back-contact solar cell segment set, comprising:

• three solar cell segments obtained by dividing a solar cell along a dividing line between adjacent substrate segments, wherein the three solar cell segments correspond to the three substrate segments, and wherein the solar cell comprising:
• a substrate including three substrate segments, wherein the three substrate segments are adjacently arranged in a first direction;
• and
• an even number of positive main grids and negative main grids located on a backlight surface of each substrate segment, wherein the positive main grids and negative main grids extend in the first direction and are alternately arranged in a second direction,
• wherein an extension line of each positive main grid located on each substrate segment coincides with an extension line of one of the negative main grids located on an adjacent substrate segment, and an extension line of each negative main grid located on each substrate segment coincides with an extension line of one of the positive main grids located on the adjacent substrate segment;
• or wherein an extension line of each positive main grid located on each substrate segments coincides with an extension line of one of the positive main grids located on an adjacent substrate segment, an extension line of each negative main grid on the substrate segment coincides with an extension line of one of the negative main grids located on the adjacent substrate segment.

A photovoltaic module, comprising:

• a plurality of solar cell segments, wherein the plurality of solar cell segments are arranged at intervals in a third direction, and an extension line of each positive main grid located on each solar cell segment coincides with an extension line of one of the negative main grids located on adjacent solar cell segments, and an extension line of each negative main grid located on each solar cell segment coincides with an extension line of one of the positive main grids located on adjacent solar cell segments;
• and
• a plurality of welding strips extending in the third direction, wherein each welding strip connects one of the positive main grids with a corresponding negative main grid,
• wherein the plurality of solar cell segments comprises at least three solar cell segments obtained by dividing a solar cell along a dividing line between adjacent substrate segments, wherein the three solar cell segments correspond to the three substrate segments, and wherein the solar cell comprising:
• a substrate including three substrate segments, wherein the three substrate segments are adjacently arranged in a first direction;
• and
• an even number of positive main grids and negative main grids located on a backlight surface of each substrate segment, wherein the positive main grids and negative main grids extend in the first direction and are alternately arranged in a second direction,
• wherein an extension line of each positive main grid located on each substrate segment coincides with an extension line of one of the negative main grids located on an adjacent substrate segment, and an extension line of each negative main grid located on each substrate segment coincides with an extension line of one of the positive main grids located on the adjacent substrate segment;
• or wherein an extension line of each positive main grid located on each substrate segments coincides with an extension line of one of the positive main grids located on an adjacent substrate segment, an extension line of each negative main grid on the substrate segment coincides with an extension line of one of the negative main grids located on the adjacent substrate segment.