Solar Panel Layup and Bussing Machine: 10W to 600W Modules, TOPCon BC PERC HJT

Quick answer: A layup and bussing machine does two jobs that are normally two separate stations: it lays solar cell strings onto the module glass and solders the bus ribbons that collect their current. Ooitech builds one family of them, the SAW series, in six models that between them cover 10 W to 600 W modules. SAW-100A handles small formats up to 800 × 450 mm, SAW-300A and SAW-400A cover mainstream module sizes, and SAW-500A, SAW-500L and SAW-600A take long and large-format modules up to 2500 × 1250 mm. Rated cycle is ≤ 15 s per group of two strings, breakage is ≤ 3‰, soldering is high-frequency electromagnetic, and every model runs inline with a stringer or standalone from trays.

SAW series layup and bussing machine, built and branded by Ooitech.

Inline operation: strings arrive from the stringer, finished string layers leave on the glass conveyor.

What the machine does

The machine takes finished cell strings and turns them into a bussed string layer on module glass. Everything between those two points happens in a single pass:

• Tray loading. Four tray stations hold the strings. A servo-driven loading arm with vacuum cups lifts two strings at a time.

• String positioning. Fibre-optic sensors and mechanical stops locate each string against the module layout, two strings simultaneously.

• Bus ribbon handling. Ribbon is drawn from coils, straightened, cut to the length set on the touch screen, and carried to the belt in a mechanical guide groove.

• Layup. The positioned strings are placed onto the cut ribbons in the module layout.

• Bussing. High-frequency electromagnetic heads solder both ends of each string under closed-loop temperature control.

• Terminal lead soldering. A second ribbon mechanism cuts and places the junction-box lead ribbon and solders two leads at a time at fixed spacing.

• Unloading. A servo-driven arm lifts the finished string layer and places it on the glass station of the line.

Space and interfaces are reserved for an automatic loading port and for automatic terminal-lead and insulation-sheet stations, so the line can be automated further without replacing the machine.

Layup heads positioning cell strings; the bus-ribbon welding heads run behind them on the same gantry.

Why layup and bussing in one machine

On a line built from separate stations, strings are laid up on the glass at one machine, then the glass is transferred to a second machine that solders the bus ribbons, then transferred back. Each transfer is a handling step on unsoldered strings, and every handling step is a chance to crack a cell or shift a string out of position.

Combining the two operations removes those transfers. The strings are positioned once, soldered while they are still held by the same fixturing that placed them, and released directly onto the glass. In practice this shows up as three things: breakage stays at the machine's rated ≤ 3‰ because there are fewer clamp-and-release cycles, the string layout is more repeatable because it is never re-registered at a second machine, and the operator has one station to load and one set of parameters to set instead of two.

The footprint is smaller as well. One machine of 5780 to 8560 mm in length, depending on model, replaces two stations plus the conveyor between them.

Two operating modes: inline or standalone

Inline. The machine sits directly behind a tabber-stringer. Strings arrive on the line conveyor, are picked from the loading box, and the finished string layer goes straight onto glass. This is the configuration to choose when the stringer runs at or above the layup machine's rated cycle, because it removes manual tray loading from the operator's job entirely.

Standalone. Strings are brought to the machine in trays and loaded manually, with four tray stations acting as a buffer. A module line that has no room for a continuous inline layout, or one that runs a stringer on a different takt, can still use the same machine this way. Ooitech's own specification recommends inline where the line layout allows it, since tray loading is what limits capacity in standalone mode.

Cell technology compatibility

All six models are specified around the same cell handling envelope, so the same machine type serves a line that builds more than one product:

• Cell thickness 0.13–0.25 mm, which covers current TOPCon and HJT production as well as thinner wafers.

• TOPCon, PERC and HJT strings in multi-busbar layouts; the ribbon specification and welding program are set per product on the touch screen.

• BC strings, including the isolation-paper handling that BC cell strings require: the four tray stations can be configured as a 2+2 arrangement with a paper-removal position.

• String width 83–210 mm on five models and 166–210 mm on SAW-600A, so half-cell and full-cell strings of both the 182 mm and 210 mm families can be run on the same width envelope.

Module size range: 10 W to 600 W

The series is split by module format rather than by cell type, because the module length is what determines the machine's travel, ribbon length and frame size. SAW-100A takes modules up to 800 × 450 mm, which is the glass-glass and portable end of the market at roughly 10 W to 100 W. SAW-300A to SAW-500A step up through 1580 × 850, 1600 × 1150 and 1950 × 1150 mm, covering mainstream 60-cell and 72-cell formats. SAW-500L and SAW-600A reach 2500 mm in length, which is where large-format single-glass and bifacial modules sit.

That span matters because it lets one machine series serve a product programme that includes both small consumer modules and full-size panels, instead of needing separate tooling and separate operator training for each.

Model range and specifications

Six models, split into two format groups. Small and mid-format first:

Large format:

Two notes on reading the tables. Machine dimensions exclude the alarm light tower and any extension frames. SAW-600A is built in sections rather than as one frame, which is why its footprint is quoted as length by width with no single overall height.

Choosing between the models

Model selection comes down to the largest module you intend to build, and whether you need vision positioning:

• SAW-100A — portable, glass-glass and small consumer modules up to 800 × 450 mm; the only model with a 200 mm minimum string length and 6 kW supply.

• SAW-300A — modules up to 1580 × 850 mm; the narrowest large-format frame, for lines that never build a full-size panel.

• SAW-400A — modules up to 1600 × 1150 mm; the general-purpose choice for 60-cell and 72-cell formats.

• SAW-500A — modules up to 1950 × 1150 mm; covers 182 mm half-cell modules at full length.

• SAW-500L — modules up to 2500 × 1150 mm; long modules on a standard 1150 mm width, with five welding heads.

• SAW-600A — modules up to 2500 × 1250 mm including 210 mm strings; the only model with CCD vision positioning and a 16 s cycle.

If one machine has to cover a mixed product programme, size it on the largest module and accept the lower throughput on small formats. If the small-format volume is large enough to justify a second machine, SAW-100A is considerably cheaper to run on 10 W to 100 W work than running those modules through a 2500 mm machine.

These values are common to all six models unless the model table above says otherwise.

Technical Parameters

Core components

The machine uses a mix of domestic and imported components, selected for serviceability rather than for brand name:

Consumables and maintenance

Three items carry a defined replacement interval, which keeps planned maintenance simple:

Weekly checks that matter more than the consumable schedule: ribbon path alignment at the guide groove, vacuum level at the loading and unloading arms, and the light curtain test. A ribbon that has drifted in the groove shows up as a solder offset before it shows up as a scrap module.

Strings in place on the bus ribbons, immediately before the welding heads pass over both ends.

Watch the machine run

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The clip shows the machine laying up cell strings and soldering the bus ribbons in a single pass, with the loading arm feeding two strings at a time.

The finished string layer on module glass, ready for the next station in the line.

What to specify when buying

Most of the specification errors that surface at commissioning come from module data that was not stated at order. Have these ready before comparing models:

• Largest and smallest module format you intend to run, length by width, including any frame overhang. The largest format sets the model; the smallest decides whether a single machine is economical.

• Cell type and thickness, and whether BC strings with isolation paper are part of the programme, which determines the tray station configuration.

• String layout: number of strings per module, string length and width, and the spacing of the busbar positions.

• Ribbon specification, including whether the junction-box lead ribbon differs from the string bus ribbon.

• Inline or standalone, and if inline, the dock height and takt of the upstream stringer.

• Utilities: three-phase five-wire supply at 6, 8 or 10 kW depending on model, plus 0.6–0.8 MPa dried air at 300 L/min.

• Acceptance criteria: breakage rate, solder pull strength and the visual standard for solder fillet and ribbon position, agreed before the FAT.

Warranty and service

The standard Ooitech terms for this machine are 12 months from successful installation, or 16 months from the bill of lading date, whichever comes first. During that period maintenance labour and the spare parts needed for maintenance are supplied free of charge; consumables, and the courier cost of spare parts, are not included. If the customer's engineers cannot resolve a fault, Ooitech sends engineers to the plant, with the round-trip tickets, local transport, hotel and food paid by the buyer.

Warranty does not cover damage from misuse, modification by anyone other than Ooitech's authorised technicians, or operation outside the manual. After the warranty period, online service and technical guidance continue free of charge, spare parts are supplied at preferential prices, and on-site work is quoted at Ooitech's standard rates. Software upgrades are free for the life of the machine, on every model in the series.

FAQ

What does a layup and bussing machine do?

It lays finished cell strings onto module glass in the module layout and solders the bus ribbons that collect current from those strings, including the junction-box lead ribbons. On this machine both operations happen in one pass, without transferring the glass to a second station.

How many models are there, and which one do I need?

Six. SAW-100A for modules up to 800 × 450 mm; SAW-300A, SAW-400A and SAW-500A for mainstream formats up to 1950 × 1150 mm; SAW-500L and SAW-600A for large formats up to 2500 mm long. Size the machine on the largest module you will build, and add CCD vision, which only SAW-600A has, if you run 210 mm strings at the top of the range.

What throughput can I expect?

At the rated 15 s cycle the machine completes 240 groups per hour, and each group is two strings, so 480 strings per hour. A six-string module needs three groups, which is about 80 modules per hour at rated cycle before availability and product changeovers. Real output is typically 80 to 90 per cent of that figure, and the stringer upstream has to keep up with it.

Can it run BC cells and 210 mm half-cut strings?

Yes. BC strings are supported, with the four tray stations configurable as a 2+2 arrangement that includes an isolation-paper removal position. String width runs to 210 mm across the series, and SAW-600A takes 166–210 mm strings in modules up to 2500 × 1250 mm.

Does it have to be inline with a stringer?

No. All six models run standalone from trays, which is the usual choice where the line layout has no room for a continuous flow. Inline is recommended where the layout allows it, because manual tray loading is the step that limits capacity in standalone mode.

What maintenance does it need?

Nozzles every 30 days, PTFE belts and the AFC30 air filter element every 90 days, plus weekly checks of ribbon path alignment, vacuum level and the light curtain. Software updates are free and are supplied by Ooitech for the life of the machine.

Further reading

• SAW-100A layup and bussing machine — the small-format model in detail, for modules up to 800 × 450 mm.

• Why bussing causes cell cracks — what overlap soldering does to a cell, and where the cracks originate.

• How a tabber and stringer works — the station immediately upstream of this machine.

• DH200-Y automatic bussing machine — the standalone bussing option where layup is already handled elsewhere.

• Solar panel laminator machine — the next station in the line, and how to choose and run one.

About Ooitech

Ooitech (Wuhan Ooi Photoelectric Technology Co., Ltd) has more than 15 years of experience in renewable energy and industrial laser application, and supplies turnkey PV module manufacturing plants from 5 MW to 1.2 GW for M2 to M12 (156–210 mm) cell formats. The company builds tabber-stringers, layup and bussing machines, laminators, framing machines, EL and IV testers and complete conveyor lines, and has exported to Poland, Hungary, Korea, Mexico, India, Egypt, Algeria, Saudi Arabia, Syria and Kazakhstan.

The SAW series is designed, built and supported by Ooitech, with software developed in-house and free upgrades for the life of the machine. Static and moving parts share a common spare-parts list across the series, so a plant that runs more than one model carries one set of consumables.

For a model recommendation against your module list, or for a quotation on a complete line, send the module data through the quote form and we will size the machine against it.