How solar panels are made
The plastic film in a solar panel goes into the laminator milky and comes out clear, glued for good to cells and glass.
- stations
- 11
- things upstream
- 59
- raw sources
- 21
- steps from the ground
- 8
The short version
Solar panels start from finished cells, sorted by output under simulated sunlight. Machines solder them into strings with copper ribbon and stack them between glass and a plastic back sheet, with film called EVA on both sides. Heat and vacuum turn the milky film clear and glue the sandwich together. An aluminum frame, a junction box and a flash test finish the job.
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Sort the cells
Each finished cell goes through a sorter, which tests it under simulated sunlight and groups it by electrical performance.
Goes in -
Wash the front glass
A glass washer rinses and dries the sheet that will face the sun. A station then cuts EVA film, a clear encapsulating plastic, and lays it on top.
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Solder cells into strings
A stringer machine solders thin copper ribbons over the busbars of each cell and links them in rows. Silicon cracks easily, so the soldering is tuned to keep heat and mechanical stress down.
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Bus the strings together
A layup station places the strings on the film. Bus ribbons are soldered across them to finish the circuit and bring out the output leads. Inspectors look it over and measure its dark current behavior.
Goes in -
Stack the back layers
More EVA and a protective back sheet are cut to length and placed over the circuit. Some designs use a second layer of glass at the rear. Automatic placement holds position to within a tenth of a millimeter.
±0.1 mm
Goes in -
Laminate under heat
In a chamber with vacuum and pressure control, the stack is heated until the milky EVA cross-links into a clear plastic that bonds cells, glass and back sheet for good.
around 140 °C
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Trim the edges
Excess film and back sheet are cut away around the edge of the cured laminate.
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Add the junction box
A junction box goes on the rear with bypass diodes, which route current around broken or shaded cells, and the output cables.
Goes in -
Press on the frame
At a frame press, an edge gasket or a bead of silicone goes on and an aluminum frame closes around the laminate. It adds stiffness and makes the module easier to install.
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Flash test the output
A sun simulator, or flasher, fires a light at the module and records its electrical performance. Electroluminescence imaging looks for flaws in the cells.
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Check isolation and grade
A high-voltage test measures the insulation between circuit and frame, and the frame's ground connection is checked. After a final visual check, modules are rated by output and packaged.
Worth repeating
- Within ten years the silicon used per watt-peak declined from 16 grams to 6 grams.
- In that time the thickness of a silicon wafer fell from 300 micrometers to about 160 to 190.
- Solid-state PV systems often last anywhere from 10 to 30 years.
Back to the ground
Follow every input upstream and solar panel starts as these 21 raw sources.
Everything it is made of See it on the map
Open the whole family tree
Where it goes next
Solar panel feeds 1 line directly.
Keep walking
Sources
Cite this page: "How solar panels are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/solar-panel