The first-line solar panel manufacturers have upgraded the previous 156 166 sizes solar panel production line to 182 and 210 sizes. This upgrade has a direct impact on the rapid increase of solar panel power, of which the increase of output current is the most obvious.

The current of the latest solar panel has increased by 40% – 80% compared with the current of conventional solar panels in the past, as a result, most photovoltaic junction boxes designed in the past can not be suitable for the latest solar panels.

In this case, various photovoltaic junction box factories, solar panel factories, and diode factories have accelerated technology research and development and launched “high current photovoltaic junction box”.

Generally speaking, there are several technical schemes for PV junction boxes to realize high current transmission and bypass hot spot protection:

1. The bypass diode current in the traditional junction box is upgraded, such as replacing a larger overcurrent chip. However, subject to the structural design of the junction box, diode packaging standards, and technical requirements, the current general current is upgraded to 20a, and it is difficult to continue to rise after 25A. However, the 30A current junction box can be used for 210 solar panels, which can not be fully met.

2. The traditional diode bypass circuit is designed as “modular”. The diode chip, plastic encapsulated body, and conductive terminal connected to current carrying transmission are “module integrated welding plastic encapsulated molding”, which can effectively shorten the heat dissipation distance of the chip and increase the heat dissipation efficiency.

At the same time, double chips can be connected in parallel to increase the overcurrent capacity. The technology and products have been tried in some first-line large factories, and the current can reach 25a and 30A.

3. Although the “module integrated welding and plastic packaging” technology looks good, the process requires a large amount of new investment in “module diode” packaging and testing equipment in the industrial chain.

At the same time, because the overall dimensions of “module diode” required by each solar panel factory are different, diode companies need to meet the requirements of different customers, so they have to invest in multiple sets of production equipment, molds, etc., with a large investment in production expansion and long production cycle.