WCA January 2014

63 / 72

61
Wire & Cable ASIA – January/February 2014
They are available at and
include:
• SEMI PV18-0811: Guide for Specifying a
Photovoltaic Connector Ribbon
• SEMI PV19-0811: Guide for Testing Photo-
voltaic Connector Ribbon Characteristics
Finished PV ribbon products are packed on
spools/reels or discs/pancakes. The most
common spools used for PV ribbon in Europe
are DIN K125, K160, K200 and K250 and in
Asia also P4 and P10.
Critical quality
parameters for PV ribbon
All of the above PV ribbon specifications are
important in their own way. Type of copper
and its purity determines material conductivity
and the maximum level of softness achievable
for the ribbon. Solder composition, its coat thickness and
coating composition influence the quality of solder joint
and panel durability.
High elongation of PV ribbon is important to prevent failure
of solder joints between the bus bar and interconnect
ribbon, which may occur due to stretching/tension due to
temperature oscillations during the panel operation.
Continuous daily, sometimes extreme temperature
fluctuations during the lifetime of the solar panel, put
solder joints to the test for the duration of the panel
lifespan, which is on average 25 years.
The two parameters that have been critical for most PV
ribbon manufacturers are camber and yield strength. Many
PV ribbon manufacturers find it difficult to achieve high
level of ribbon softness whilst ensuring its straightness.
Achieving sufficient softness and low camber could
mean the difference between winning and losing a supply
contract.
STEP 1:
STEP 2:
STEP 3:
STEP 4:
Payoff
Payoff
Payoff
Payoff
Takeup
Takeup
Takeup
Takeup
Rolling
Rolling
Annealing
Pickling Rinsing Fluxing Hot Dip
PlasmaPREPLATE Hot Dip
Traditional Process of Hot Dip Tinning
PlasmaPREPLATE in Hot Dip Tinning Process
❍
❍ Figure 4: Production steps in the traditional and PlasmaPREPLATE tinning
process for PV ribbon production
Traditional Tinning PlasmaPREPLATE
Process type Multi-line tinning process
with wet chemical surface preparation
Single line high-speed tinning,
Dry surface treatment without fluxing
Production speed 5-60m/min , subject to ribbon softness 150m/min – super soft ribbon
No of lines/output 4-25, subject to quality, ribbon softness 1 – super soft high-quality ribbon
Annealing type furnace/resistive/induction (off-line) Plasma (inline with tinning)
Surface preparation
for tinning
Acid, rinsing, fluxing prior to tinning
Expensive and harmful to operator
Dry, chemical-free plasma treatment
Low cost and operator friendly
Production cost High – labour, chemicals, energy Low
Production continuity More frequent changeover – 50kg spools Less changing over – 500kg spools
Scrap rate High – wet processes difficult to control
operator experience and skills are key
Low
Inline PLC-based quality control
Solder wastage High – flux contamination in tin bath Low – flux-free production
Production control
Limited PLC with manual assistance –
complex multi-line production/line-to-line
reference
Fully PLC controlled production – inline
PLC quality control and alarm system
Capital investment Low High
Production line footprint Large Compact
❍
❍ Table 1: Typical production parameters for traditional PlasmaPREPLATE tinning in PV ribbon production