Issue link: https://iconnect007.uberflip.com/i/1038326
38 PCB007 MAGAZINE I OCTOBER 2018 per lines, two surface treatment lines, and a direct metallization line. GreenSource also uses a variety of different Atotech wet chem- istry processes, such as our high-throw elec- troless copper (Printoganth T1), blind micro- via filling process (Inpulse 2HF), electrolyte for through-hole, BMV and conformal plating (Inpulse 2THF), electrolyte for conformal or flash plating (Inpulse 2HT), as well as laser di- rect drilling pretreatment (BondFilm LDD SR), higher copper loading bonding enhancement (BondFilm HC), and our ENIG process (Auro- tech DC). Matties: How do you comply with Green- Source's need for system-to-software integra- tion? Schmidt: Our solution comes with a fully inte- grated communication interface that translates Atotech hardware and process data and secure- ly exchanges this data via multiple platforms, such as SEMI (Semiconductor Equipment and Materials Organization) Equipment Commu- nications Standard (SECS), generic equipment model (GEM), or open platform communica- tions (OPC) to the host manufacturing execu- tion system (MES) software in real time. This enables factory integration of multiple toolsets for optimized productivity and yield improve- ments. We meet the customer requirements and run the equip- ment at low chemistry, water, and energy consumptions. At the same time, we can assure mini- mum waste (e.g., wastewater or dragout chemistry), which—in the case of GreenSource—was exactly what Alex wanted. Matties: What was new in the equipment that has never been done before? Schmidt: GreenSource had a special request to install a new rinsing system to allow the high flow of a rinsing solution, which would then be used sev- eral times. Instead of fresh water for the rins- ing system, we operate with recycled water. For this prerequisite, we installed new devices to the system to avoid particles due to algae gen- eration in the rinses. Algae generation is an is- sue when using re-circulating water. One has to understand that when panels leave a chemical process tank, there will be chemical dragout on the panel. There are at least three rea- sons why this needs to be removed: to stop the chemical reaction, prepare the panel for the next process step (panel must be clean), and avoid contamination of the proceeding process step. The roller configuration used in our lines and the mechanical design in the outlet area of each module allows us to reduce the solu- tion level above the panel to a minimum with the result that less chemistry will be dragged out. We use anti-dragout and dam rollers to minimize dragout. However, chemistry will al- ways remain in the drilled holes, on the sur- face along the outer edges, and as a very thin liquid film on the surface of the panel. In gen- eral, process chemistries are highly sensitive to contaminations. Hence, dilution factors must be very high to achieve long bath life and pro- cess reliability as required by the industry to- day. In the case of an electroless copper pro- cess for advanced high-density interconnect (HDI) products, the dilution factor must be Figure 2: Atotech's side-by-side electroless lines installed at GreenSource Fabrication.