The lamination laying process is the process of connecting the solar cell strings with the back side in series and passing the inspection, laying them with the panel glass, the cut EVA, and the back plate according to a certain level, and welding the bus belt and the lead electrode according to the requirements of the design process. . When laying in layers, ensure the relative position of the battery string and glass and other materials, and adjust the distance between the batteries.
1. Laminated table
The laminated laying table is used for the operation platform of the photovoltaic module laminated process and the inspection platform for the basic electrical performance of the laminated photovoltaic module.
(1) The aluminum alloy profile frame and aluminum plastic adopt flat plate setting.
(2) The height of the humanized table top is adjustable (0-40mm), so that every operator is in the best working condition.
(3) One-key operation can complete photocurrent and voltage detection under uniform illumination, alarm for unqualified trends, and discover various quality hazards in time before lamination.
(4) Welding station, scissors, interconnection bar, bus bar and other tools are placed in a special tool box.
(5) The surface of the tempered glass and the surface of the battery glass adopt non-scratch contact technology.
(6) Using 12 300W iodine tungsten lamps and 5 30W fluorescent lamps, the measuring range of the ammeter is 0-100A, the measuring range of the voltmeter is 0-100V, and the accuracy is 1%.
2. cutting table
The cutting table is a device that can cut EVA film and TPT backplane film according to process requirements. It can be divided into three types: manual, semi-automatic and fully automatic.
3. Inspection before stacking
(1) Place the cleaned glass on the laminated laying table (with the wrinkle side facing up). The four corners of the glass are aligned with the positioning angles on the laying table. Clean the glass with a clean dust-free clot.
(2) Spread a cut EVA film on the glass (the glossy surface of the EVA faces the glass wool surface, and the EVA is not allowed to be picked up by bare hands), aligned with the glass, and the length and width edges of the EVA are about 5mm larger than the glass.
(3) Place the welded battery strings on the laid EVA film in sequence, turn on the work lights of the laying table, and start the inspection.
(4) Check if there are any cracks in the battery (if there are cracks, the cracks will transmit light). After the cracks are found in the inspection, mark the rework and return to the string welding for repair.
(5) Check whether the battery slices have false welding (lift the battery slices one by one, if there is false welding, the welding ribbon will fall off). After the inspection finds that there is a false welding, make a rework mark and return to the string welding for repair.
(6) Check whether there is any deviation in the arrangement of the battery slices. When the offset size is greater than 0.5mm, return the battery string to series welding for repair.
(7) Check whether there are debris (welding beads, ribbons, hair, etc.) on the battery, regardless of the size, as long as it is easy to identify with the naked eye, remove it.
(8) Check whether the positive and negative leads of the battery string are too short, defective or soldered incorrectly. If so, return the battery string to the string for repair.
(9) Check whether the positive and negative poles of the battery (the lead wire on the front is the negative pole, and the lead wire on the reverse is the positive pole) are arranged correctly, and they are not welded together with the same polarity. The arrangement of the cells is a “positive and negative positive and negative positive and negative” arrangement . When making low-power components, check whether the cell array pattern in each battery string is consistent with the design drawing. If it is inconsistent, return the battery string to string welding for repair.
4. Operation of laminated laying
(L) With the anti-reflection film of the battery sheet facing down, use a steel ruler to adjust the distance between the front and rear, left and right of the battery string according to the design requirements, and fix the distance between the string and the string with high temperature tape.
(2) Fix each bus bar with high temperature tape, keep the distance between the bus bars at 2-3mm, and weld the bus bar and the serial welding tape of each battery string; when welding the bus bar, use the tweezers to hold the edge of the solder joint and lightly Lift gently to prevent the EVA from melting and affecting the quality of the laminate . Use an electric soldering iron to solder the solder joints with your right hand (the time for soldering a single solder joint is controlled at ls). After the tin melts, remove the soldering iron first. After cooling for 1 second, remove the tweezers to check whether the soldering is firm. Finally, cut off the excess ribbon .
(3) Take a long strip of EVA film and clip it between the long and short bus bars, with the edge flush with the battery; take the TPT insulation strip to separate the long lead wires from the short lead wires (depending on the situation) .
(4) Solder the positive and negative lead-out bus bars on the part where the component is ready to lead out; the lead spacing is 45~50mm, and the length is 50~60mm. The distance between the wire outlet and the edge of the proximal glass depends on the size of the junction box and aluminum alloy frame. It depends on the height. Put a high-temperature cloth before soldering the lead wires, and trim all excess tinned soldering tape after soldering; tear off 4 pieces of 20mm long tape to fix two long straight bus bars .
(5) Put the second layer of EVA film on the spliced battery pack (smooth side up), and place the EVA so that the left, right, up and down edges are evenly spaced.
(6) According to the design requirements, make a small slit at the position where the EVA film leads out.
(7) At the lead-out position, lead the positive and negative leads of the module to the EVA through the slit.
(8) Lay the TPT back sheet film on the EVA, with the white matte side facing down and the shiny side facing up. When placing the TPT back sheet film, the left and right positions are evenly spaced from the edge.
(9) According to the design requirements, cut a small slit at the position of the lead on the TPT backplane film, and lead the positive and negative leads of the module on the TPT backplane .
(10) Use scotch tape to press the positive and negative leads, and then use scotch tape to fix the TPVT to the glass. Stick two scotch tapes on the long side and one scotch tape on the wide side to prevent the TPT backplane from shifting.
(11) After laying, connect the positive and negative test leads of the laying platform to the positive and negative poles of the component lead wires; turn on the test light source switch to check whether the electrical performance of the component is qualified; judge whether the component is in good condition based on the voltage and current test data.
5. Laminate laying process specification
(1) EVA film cutting size: length and width should be 20mm more than the glass size respectively.
(2) TPT backplane cutting size: length and width should be 10mm more than the glass size respectively.
(3) EVA film cutting size error; ±2mm.
(4) Cutting size error of TPT backplane: ±1mm.
(5) Laminated welding temperature: 350℃-370℃.
(6) The minimum distance between the battery string and the battery string: (2±0.5) mm.
6. Visual inspection after stacking
(1) Check whether the polarity of the photovoltaic module is reversed.
(2) Check whether there is any sundries on the surface of the module, whether it is missing corners or cracks, whether the distance between the module strings is neatly arranged, and whether the size from the edge of the glass is consistent.
(3) Check whether the components EVA and TPT completely cover the glass and exceed the edge of the glass by more than 5mm.
(4) The TPT surface should be free of wrinkles and scratches, and the surface should be clean and clean.
7. Matters needing attention in the process of laminated laying
(1) The electric soldering iron is in a high temperature state during use. Be careful not to hurt yourself and others. When not in use, place it on the soldering iron stand. Do not place it randomly, so as not to cause fire and burn items. The electric soldering iron should be cut off when it is not used for a long time.
(2) The workbench must be cleaned to prevent debris from falling into the components.
(3) The welding method of the bus bar should be correct, so as not to affect the power of the components and the flatness and appearance of the bus bar.
(4) The cells in the same assembly should have no color difference.
(5) The position of the positive and negative lead wires of the components should be correct and meet the design requirements.
(6) Wear finger cots during the tape application process, and wear gloves during the rest of the process.
(7) When moving components for inspection, please handle with care.
(8) EVA from different manufacturers cannot be mixed.