Choose a stringer

Three Tabber-Stringers — Match One to Your Cell and Your Rated Line

You arrive with a cell spec and a throughput target, not a model number. This page lines all three stringers up on the handful of dimensions that decide between them, so you leave pointed at one machine's page instead of reading three.

BC route
SML-S60
≥4800
pcs/h half cell

The dense, high-busbar, thin-cell BC machine.

See the machine
TOPCon / PERC
SML-S40
≥3400 / ≥3200
pcs/h · two rated gears

Rated as two gears by busbar count.

See the machine
Entry tier
SML-S15
1100
pcs/h half cell

For a first line or a single added string.

See the machine

None of the three is the "top" one — each is the specialist for a route and a rate, and the wrong-sized machine is a wrong pick even when it is the fastest. Read the column whose route and rate match yours, then open that page.

Three tabber-stringers of the SolarModule Line range on a module assembly floor
One stringing station · three cells, three rates

Locate yourself

Answer Three Questions, and the Machine Picks Itself

You do not need to read three spec sheets to choose. Three questions settle it, in order — each narrows the field before the next, so by the third you are usually down to a single machine.

Most buyers are down to one machine after the second question; the third only matters if your design is dense. If any answer is "not sure", that is exactly what the drawing is for — send it and we answer the three for you →

Side by side

The Three Stringers, Row by Row

All three stringers cover the very same busbar span — 3BB–20BB — so that row can't tell them apart, and neither can most of the others. What separates them is two columns: route, the cell each was built to solder, and throughput, the rate each holds. Read down the column matching your route, then across those two rows — where the table agrees is the family's common floor, and where it splits is where your decision sits.

There is no row here where all three are identical — a row that never differs cannot help you choose, and those belong on the single-machine pages instead.

DimensionSML-S60SML-S40SML-S15
Route / cellBC, 166–210 mm, half / one-thirdPERC / TOPCon, 166–210 mm half cellTOPCon / PERC, 166–210 mm, half / one-third
Throughput≥4800 pcs/h half cell≥3400 (3–12BB) / ≥3200 (13–20BB) pcs/h1100 pcs/h half cell
Busbars / thickness3BB–20BB, 25BB-ready · 110–200 μm3BB–20BB (25BB-ready) · 110–200 μm3BB–20BB · 120–200 μm
Placement accuracy≤±0.05 mm · ≤±0.04°≤±0.1 mm · ≤±0.04°≤±0.1 mm · ≤±0.04°
Cell pitchnegative −1 to −0.5 mm · positive 1–5 mmpositive 1–5 mm onlypositive 1–5 mm only
Peel force≥0.5 N (0.6 mm ribbon)front ≥0.5 N · rear ≥1 N (0.4 mm)≥0.5 N (0.7 mm ribbon)
Power30 kW avg / 45 kW peak40 kW avg / 60 kW peak15 kW avg / 20 kW peak
Footprint / weight8050×2800×2500 mm / 7000 kg7850×1600×2500 mm / 4500 kg6900×1800×2300 mm / 3000 kg

Really only two rows earn their place. Cell pitch fences the S60 off from the other two, and throughput fans all three apart. Placement, peel force, power and footprint fall in behind — they rarely overturn what pitch and rate have settled.

A table has done its job the moment one row lets you say: that's the machine I don't need.

Where the family sits

One Station, Three Cells

Before you weigh the differences, place what they share. All three occupy the same single station in the module line — stringing — between the scriber upstream and the layup machine downstream.

1Scribeupstream 2StringS60 · S40 · S15 all sit here 3Layupdownstream

Whichever you pick sits in the same slot, reads a scribed cell on the in-feed and hands a finished string to layup on the out-feed. So the choice among the three is never about where the machine sits or what it does — it is about which cell it solders and how fast it holds the rate.

The dividing line

The One Line That Splits the S60 From the Other Two

Of every row in the table, one is a hard capability boundary rather than a matter of degree: cell pitch. It is the row most worth understanding before you choose, because getting it wrong is not a shortfall you can tune around later.

Here is the situation it catches. On the table the S60, S40 and S15 look close enough that rate and budget seem to decide it. But if your module design packs cells edge to edge — a dense, negative-pitch layout where one cell slightly overlaps the next rather than sitting a gap away — then rate and budget do not decide anything, because only one of the three can lay that geometry.

That machine is the SML-S60. Its pitch range runs negative, −1 to −0.5 mm, and positive, 1 to 5 mm — it can place cells with an overlap or with a gap. The SML-S40 and SML-S15 run positive pitch only, 1 to 5 mm: they place cells with a gap between them and cannot close to a negative overlap. This is not one machine being a weaker version of another — it is two different placement geometries, each built for one of them.

How to tell which you need takes one look at your own layout. If the cell-to-cell spacing on your module drawing is a positive gap, any of the three can run it and the route-and-rate questions decide. If your design calls for cells overlapping — negative spacing — the choice collapses to the S60 before rate or budget enter the conversation.

The one mismatch no tweak recovers

Pick a positive-pitch machine for a negative-pitch module and the line will not produce the module you designed. There is no setting to change — it is a different machine, after the crate has shipped.

BC cells laid at negative pitch, overlapping edge to edge, on the SML-S60
Negative pitch — S60 only cells overlap Positive pitch — all three gap between

Not settled on the drawing board yet? The pitch decides more than any other single number here.

The common floor

What All Three Share

Some numbers are the same on all three machines, and those are exactly the ones not to decide on — a figure that does not differ cannot tell two machines apart. See them together once, so your attention goes to the rows that do differ.

≥95%
Rated utilization — identical on all three
3BB–20BB
Busbar range every one of the three covers
Infrared
The welding method shared across the range

Read these as the family's common floor, not a tie-breaker. Where the three genuinely diverge — pitch, rate, placement class, peel-force scheme, power and footprint — is where a choice actually lives, and every one of those rows is on the table above.

Changing format later

Changing Format Later Is a Tooling Change

Buyers worry that adding busbars later means buying a different machine. Across this range it usually doesn't — the number that actually matters for selection isn't today's count.

The 25BB jump is where the three split

All three stringers already carry 3BB–20BB, so stepping the busbar count anywhere inside that band is a guide-tooling swap, not a new stringer — the frame, transport and robot stay put on every one. The one place it stops being free is the jump to 25BB: the SML-S60 and SML-S40 ship 25BB-ready and have the headroom, while the SML-S15 does not — reach past 20BB and the S15 is out. So what matters for selection isn't today's count; it's whether your roadmap ever crosses 20BB.

See the compatibility and changeover page

The cost of a wrong pick

What a Wrong Pick Actually Costs

Two mismatches account for almost every stringer chosen badly — both cheap to avoid on paper and expensive to discover on the floor. Neither is a machine underperforming; each is a machine asked to do something it was never built to do.

Positive-pitch machine under a dense module

Sign for the S40 or S15 on rate and budget, then hand it a negative-pitch BC layout, and the line does not run slow — it cannot lay the module at all. The cells are designed to overlap; a positive-pitch stringer can only leave a gap. The module you drew never comes off the line, and the fix is a different machine after the crate has already shipped.

Entry machine under a high-rate contract

Size the line on the S15's 1100 cells an hour because it is the lightest and cheapest, then sign a supply contract written against a few thousand cells an hour, and the shortfall lands on your delivery dates, not the datasheet. The machine meets its own rated number — it simply was never the tier the contract assumed.

Both mismatches are settled by the same two rows of the table — pitch and throughput — read against your real design and your real contract before the order, not after.

Open a page

Open the Machine's Page

With the table down to one machine, these three cards open onto each one's full page. The number each card leads with is the one that actually places a stringer in its class — throughput — because that is what your rated line is signed to hold: ≥4800 on the S60, ≥3400 / ≥3200 on the S40, 1100 on the S15.

SML-S60 BC high-speed stringer

SML-S60 — BC High-Speed Stringer

≥4800 pcs/hBC · negative-pitch capable

The BC specialist, for dense high-busbar thin-cell modules.

Open the SML-S60 page
SML-S40 multi-busbar stringer

SML-S40 — Multi-Busbar Stringer

≥3400 / ≥3200 pcs/hTOPCon / PERC · two gears

Rated as two gears by busbar count, positive pitch.

Open the SML-S40 page
SML-S15 entry stringer

SML-S15 — Entry Stringer

1100 pcs/hEntry tier · TOPCon / PERC

For a first line or a single added string.

Open the SML-S15 page

Not a stringer?

Not a Stringer? Its Neighbors on the Line

Stringing sits in the middle of the stretch we build, so it has a neighbor on each side and both are ours to hand you. Scribing feeds it from before; layup takes its strings after. If a stringer isn't what you're placing, one of those two is — here is each, one line apiece.

Laser scribing station, upstream of the stringer

Laser scribing — the station just before

The cells a stringer solders reach it already cut and separated at the scriber; that family has its own selection page.

See the laser scribers
SML-A6 robotic layup station, downstream of the stringer

Robotic layup — the station just after

Finished strings pass to a layup machine, or the stringer runs standalone; the docking height is spelled out on the SML-A6 page.

See the SML-A6 layup

Shared site baseline

The Site Baseline They All Share

The three stringers differ in power and air drops — those rows are on the table above — but they sit on the same site baseline, the same whichever one you land on.

Shared requirementAll three stringers
Floor load≥600 kg/m²
Compressed air0.6–0.8 MPa
Environment5–40 °C; humidity 5–70%, non-condensing
See line utilities and layout for the per-machine footprint, power and air drops
Footprint, wide → narrow S60 S40 S15

Which acceptance you sign

Choosing the Stringer Picks Your Pull-Force Test

The three stringers do not share one acceptance test — the weld-strength line reads differently on each, and that difference only shows with all three side by side.

One choice sets the weld-strength criterion

The SML-S60 is signed off at ≥0.5 N with one sub-floor point allowed per busbar; the SML-S40 holds two floors on a single weld, front ≥0.5 N and back ≥1 N; the SML-S15 ties its ≥0.5 N to a 0.7 mm ribbon grade. Picking the machine is picking which of these three your line is accepted against — something no single-machine page can put in one view.

See how acceptance is run

Still between two?

Still Between Two? Send the Drawing

If the three questions leave you between two machines, the drawing settles it faster than any more reading. Three steps, and the answer comes back sized to your line.

1

Send the cell drawing

Route, size, thickness and busbar count — the four things that place you on the table.

2

Tell us the rate and the layout

The throughput the line must hold, and whether your module packs cells dense or leaves a gap.

3

We name it and size it

One of the three, with a configuration proposal for your format, back within 24 hours.

Reply within 24 hours
Depth view down a running tabber-stringing line

Get pointed to one

Get Pointed to the Right One

One drawing in, one machine and one proposal back — the low-commitment way to turn a shortlist of three into a decision.

We point you to one of the three and size it within 24 hours · email.