What are the quality control of each process of photovoltaic modules?

06 Jun , 2022

I. Quality control points of preparation group


The main materials prepared by the preparation group are: cell, backsheet, EVA, tin coated tape, glass, aluminum frame, etc. .


Cell appearance: the cell cannot have hidden cracks, lobes, broken pieces (chipped edges and missing corners) . Single cell cannot have obvious color unevenness, and the cell color of the same module should be consistent. Electrical performance: the electrical performance of each component with the first required power to the same level, and then in accordance with the working current of the cell (IWORK) graded to match, unified power components in the cell working current should be in the same level. If there is a shortage of cells of the same grade, a higher grade of power and current should be selected to make up the cells.


Laser scribing: The scribed cells not only meet the drawing requirements in size, but also the scribed cells are observed under the optical microscope, and the depth of the cut is required to be within 1/2-2/3 of the cell thickness, and the cells are free from chipping cracks, and the cut surface is visually flat and bright.


TPT / EVA: In cutting TPT / EVA must be cut in accordance with the dimensions specified in the bill of materials, in the case of special materials, the need to make changes in size must notify the technology, process, in addition to each process must be communicated between. At the same time every two hours must be cut material size measurement, and make a record.


Tin-coated tape: Tin-coated tape should be cut first according to the size specified in the bill of materials, in fact, in the process of cutting to measure the size from time to time, the soaking time and baking time of the tin-coated tape to the standard specified in the process work instructions.


Glass: glass is pulled from the warehouse to the workshop between the use of the first to confirm the size of the glass, in the process of production a drag also to carry out random measurements of size.


2.Quality control point of the press tape


First is the temperature of the soldering iron head, heating table temperature calibration, so that must work within the process temperature range. Welding surface: the welding surface is flat and bright, no solder slag, spoil, high point burr, flux whitening (soldering iron head must be changed every 5 work such as once and do a good job of recording). Soldering effect: there can be no false solder, desoldering, off-line .


Welding misalignment: frontal tin coated tape end to the edge of the cell distance of 3mm (± 0.5mm) offset the main grid line < 0.5mm cell appearance inspection: can not have hidden cracks, lobes, broken pieces (chipped edge missing corners) .


3. String with quality control points


First is the temperature of the soldering iron head, heating table temperature calibration, so that must work in the process temperature range. Welding surface: the welding surface is flat and bright, no solder slag, spoil.


Welding effect: check the front and back side of the cell can not have false welding, desoldering, off-line .  Tin coated belt can not have high points, burrs exist.


Welding misalignment: adjacent to the front of the two cells coated tin tape offset ≦ 1mm, the reverse side of the coated tin tape offset the main grid line distance <1/2 main grid line, the distance between the two adjacent cells is 2 (± 0.5mm)


Cell appearance inspection: there can be no hidden cracks, lobes, broken pieces (chipped edges and missing corners).


4. Layout quality control points


The distance between the head of the battery string and the edge of the glass, the distance between the tail and the edge of the glass on both sides of the battery string to the edge of the glass must meet the requirements of the drawing design, the welding of the sink band meets the requirements of the drawing, the bending of the lead wire must have a certain angle, and the lead wire must not have the phenomenon of deformation. High-temperature adhesive paper must be fixed according to the design of the drawings to paste, not a single less.


When laying the insulated TPT and TPT, the lead bend must be the alignment point. 


Check in the board does not allow debris (solder slag, hair, tpt wire) cell without hidden cracks, lobes, broken pieces (chipped edges and corners) phenomenon.


5.Lamination quality control points


The laminator parameters must be set in accordance with the requirements of the process documentation, laminator temperature spot check and the actual temperature in ± 2 for qualified, in the replacement of materials (EVA) when the corresponding process parameters must be done to adjust.


After each lamination of high-temperature cloth, silicone sheet on the residual EVA adhesive must be cleaned up in a timely manner.


Daily temperature spot check and cross-linking experiment must be done, and also to check the standard to see if it is within the normal range. Component EL test and appearance inspection according to each “crystalline silicon solar module inspection specification” inspection standards.


6. Assembly quality control points


Assembly quality control points are mainly manifested in the following: after the frame assembly machine has finished assembling the frame, we should pay attention to the B side of the frame from time to time to see if there is any scratching, and the gap between the long frame and the short frame after the assembly should not exceed 0.5mm, and we should measure the diagonal size of the assembly after the frame is assembled regularly and keep records.


7. Test quality control points


Test under standard test environment: STC condition: 1000w/m2, AM1.5, temperature 25℃±2 ℃.


The calibration procedure shall be operated in strict accordance with the operation instruction, and the component labeling shall meet the design requirements with clear handwriting and clean printing.


8. Packaging quality control points


Packaging control points are mainly manifested in: the lack of glue on the back of the components must be very sensitive to the phenomenon, the front scraping and cleaning must be done without spoils attached to the glass above.


Carton appearance should be clean, no obvious scratches. Model number, quantity, and manufacturer information are clearly visible.


The outer box should have fragile or no-pressure label, the label is firmly pasted, neat and beautiful. After packing, the spacing between the packing strip and the edge of the box is symmetrical and beautiful.