Horizontal Etching Equipment
SCHMID horizontal wet processing systems are based on a uniform modular concept, enabling individual plant configurations with fully integrated lines from wafer loading to cell testing, sorting and packing. A smooth-action conveying system suitable for all standard wafer sizes guarantees damage free transport of the sensitive wafers through all the different process, rinsing and drying zones.
In the process zones the wafers are flooded in an immersion bath. The frequency-controlled pumps reduce the turbulence. Together with the bath circulation design a very uniform processing of the wafers over the whole working width is achieved.
Hazardous fumes by the HF and HF/HNO3 process are efficiently removed out of the totally sealed process and service area by a unique module and exhaust design. The intelligent safety system is linked with the facility management: in emergency cases all mediums flow automatically in enclosed tanks. Electronic control of sliding panels and locking is assured.
Rinsing is performed after every chemical process step to minimize drag-in and drag-out of chemicals. The multiple cascade technology employed decreases the consumption of DI water. In the final drying operation, side channel blowers in the Dry Jet dryer perform the function of compressors, lowering the noise level and cutting the operating costs. The efficiency of the Dry Jet is enhanced by the long operating zone being the basis for uniform and stain-free dried wafers.
- Gentle wafer handling without transport damage
- Transport system designed for the handling of different wafer sizes in one line
- Reduced drag-in/out of chemicals
- Shorter and more constant process guarantees a high reproduction accuracy
- Process control through automatic dosing and bath monitoring
- Continuous circulation of chemistry
- Stain-free drying with dry jets
- Extendable process line
Modules in PP and PVDF, clean room design, Alkaline Texturing in SS
125 mm, 156 mm and 210 mm, wafer thickness ≥120 µm
Immersion bath with frequency-controlled pumps to reduce turbulences on the surface or wetting by chemistry from top side
Multiple cascades, rinsing with spray nozzles, standby control of water feed and flow monitoring
Quick-release filters (cartridges of 5 − 80 µm)
5 track or 10 track transport system for 156 x 156mm (other sizes available)
Dry Jets supplied by high-performance blowers with HEPA filtration
500 − 4400 cells/h (156 x 156 mm) 5 track
up to 7600 cells/h (156 x 156 mm) 10 track
By PLC and web-based visualization system
The APCVD - Atmospheric Pressure Chemical Vapor Deposition System - is a state of the art, well proven and economical device. It is an effective platform for a variety of coating layers used in Photovoltaics. The tool can deposit exceptional films to create an emitter layer, or passivate a surface, along with many others applications as well. Examples of these films are: SiO2, TiO2, PSG (Phosphorus doped glass), or BSG (Boron doped glass). The APCVD enables advanced cell concepts like Bifacial, PERT and IBC.
A single tool can have multiple injector heads and deposit different films with each injector. The tool transports wafers on ceramic rollers with low stress to the wafers in a low contaminate environment. This system has a very high throughput, low maintenance, extremely low usage of gases, high deposition rate, superior uniformity and low running costs. Another version of this system is available with more injector heads and metal mesh belt for specimen transport.
Typical Film Applications
Effective Cap Layer or Diffusion Barrier
Easily Controllable Phosphorous Dopant Source for N-type Cells
Boron Dopant Source (Alternative to BBr3)
Reflective or Anti-Reflective Layer
- Roller transport conveyor system enables industry best Cost of Ownership
- Multiple injector heads in series maximize process throughput, uniformity, and flexibility while minimizing cost
- Maintenance conscious design allows interior access with the push of a button
- Automatic process exhaust and precursor mass flow control guarantee consistent film results
- Three tiers of graded, power saving insulation further reduce energy bills
- Stable, unsurpassed temperature uniformity control supports excellent process results
- Userfriendly HMI
Dimensions (depending on configuration)
(L x W x H) 2500 x 2000 x 2400 mm
156 x 156 mm
Throughput (depending on process)
2000 - 4000 wafers per hour
Multi Busbar Connector
SCHMID’s Multi Busbar Connector uses round copper wires instead of flat ribbons to interconnect solar cells to strings. While maintaining the proven reliability of a soldered connection, the concept enables much shorter and narrower grid fingers. Reduced silver consumption for the cell production and lower series resistance result in higher module power output at lower production cost.
In a unique and innovative process, individual cells are connected to strings using round copper wires. The wires with a core diameter of 360 µm and a 15 µm SnPbAg coating are covered with flux inside the machine. The front-to-back soldering of the wires to the cells is performed on a preheated chuck. The wires are held by special parallel grippers. A motion axis system together with a high precision imaging system ensures exact cell placement with an accuracy of 0.05 mm. Thus, a precise overlap of the small wires and the metallization pattern of the cells is guaranteed, even with minimal solder pad sizes. The subsequent soldering to strings is done contact-free by infrared light.
- New cutting edge stringing process, ideal for the latest generations of high efficiency solar cells and premium module products with high aesthetic requirements
- Less silver consumption on the front side of the cells compared to standard technology
- Less shading, lower series resistance and improved light harvest, up to 5W more module power output
- Compatible with standard mono and poly crystalline screen printed cells
- Easy to integrate into existing module production lines
- No new materials introduced in module fabrication process, therefore no reliability risks
156 mm x 156 mm
160 – 250 μm
Up to 1200 cells/h
Number of busbars: