European Head Office Avery Dennison Lammenschansweg 140, P.O. Box 28, 2300 AA Leiden, The Netherlands T. +31 71 579 4100, F. +31 71 579 4180 2012 Avery Dennison Corporation. All rights reserved. Fasson and all other Fasson brands, product names, codes and service programmes are trademarks of the Avery Dennison Corporation. All other brand and product names are trademarks of their respective owners. Produced in April 2012. Excellent fit between product performance and application Next generation polyimide labels for Printed Circuit Boards
Labels on Printed Circuit Boards Excellent fit between product performance and application Printed Circuit Boards (PCBs) are used to hold and connect electronic components. They exist inside every electronic device. PCBs are assembled in an automated process where they are exposed to extreme heat and chemicals. In this assembly process, the traceability of the PCB is vital. Avery Dennison s specially designed polyimide label constructions ideally suit the application of PCB tracking during manufacturing. Our labels maintain their physical integrity and due to the excellent heat-resistant topcoats ensure that the tag remains legible upon exposure to extreme temperatures and chemicals. Finding a perfect match between performance and purpose is crucial for minimizing costs. Avery Dennison offers a complete product range that allows you to make the perfect choice of label material fitting the application requirements. These identification and tracking labels are integral parts of PCBs, which are in turn used in computers, telecommunications equipment, consumer electronic goods, industrial equip ment, medical instruments, automotive sys tems, military systems and aerospace engineering. Fit-for-purpose PCB labels are engineered to withstand heat and aggressive chemicals The Avery Dennison portfolio of polyimide labelstocks delivers value and flexibility throughout the PCB supply chain. Our new cost competitive Transfer Polyimide I Matt White TC11 thrives under the very high temperatures of today s lead-free soldering (as high as +260 C, continuously for 5 minutes). After soldering and PCB cleaning with common aggressive cleaning agents, these printed labels remain clearly readable. Our well-established Polyimide I&II Matt White grades ideally suit the most demanding PCB labeling applications where the label is exposed to extreme peak temperatures of up to +280 C and is to experience superior resistance to highly corrosive solvents. In addition, these grades also allow for the high resolution, fine feature size print. The maximum temperature range specified for many PCB soldering processes is between +240 C and +260 C. At the same time, peak temperatures of up to 280 C are not uncommon. The process temperature choice is end-product and end-application specific. Our fit-for-purpose polyimide portfolio fully addresses the range of requirements in PCB labeling. Facestocks Avery Dennison polyimide facestocks and topcoats are engineered components, matched to deliver high performance in demanding applications. All polyimide label materials are optimized for thermal transfer printing. Transfer Polyimide I Matt White TC11 is based on a 25μm polyimide with a thick matt white topcoat. The total caliper of the facestock is 45µm. This material can be printed with a variety of thermal transfer ribbons and features high solvent resistance. To achieve a good print performance an increased temperature setting of the thermal transfer printer might be required. Polyimide I Matt White - is based on a 25μm polyimide with a premium thick matt white topcoat. The total caliper of the facestock is 43µm. This material is optimized for thermal transfer printing of high density barcodes with superior chemical and scratch resistance. Polyimide II Matt White - is based on a 50μm polyimide with a premium thick matt white topcoat. With the high caliper of this facestock (68µm) automatic dispensing of labels is improved. This material is optimized for thermal transfer printing of high density barcodes with superior chemical and scratch resistance. Gloss top-coated versions of these products are also available on request. 2 3
Adhesive S8088 adhesive is a solvent acrylic adhesive specially formulated to withstand extremely high temperatures, corrosive solvents and high UV radiation. Service These products are stocked in Europe and are slit to order with a minimum order quantity of 45 m 2. See table for more details on service options. UL recognition (UL969) Transfer Polyimide I Matt White TC11 S8088 and the Polyimide I and II Matt White S8088 are UL recognized. The UL file number is MH27538. Avery Dennison Polyimide product portfolio Product code Excellent Good Product Face material Performance Service, slit to order UL Facestock Adhesive Liner Thickness of base film Thickness of face incl. topcoat Peak service temp/time AO291 Transfer Polyimide I Matt White TC11 S8088 BG50Wh 25μm 45μm 260 C/5mins AI300 Polyimide I Matt White S8088 50#SCK 25μm 43μm 280 C/5mins AH415 Polyimide II Matt White S8088 50#SCK 50μm 68μm 280 C/5mins Chemical resistance Thermal Transfer Printability Slit Roll Slit Roll Master Roll, any slit width 100mm 1000mm x 600mm x 600mm x UL recognized For more information about polyimide labeling solutions please contact your Avery Dennison Representative. 4 5
Facts about the PCB manufacturing process What is a printed circuit board? The base board is made by laminating together sheets of a non-conductive material (typically fibreglass) and sheets of copper. Holes are then drilled through the board and made conductive. During the assembly process components are applied on top of the board and soldered in place. Why are labels used? Electronic equipment manufacturers benefit from automated assembly, processing, test and packaging systems which include automatic identification. A bar code label is normally adhered to a printed circuit board before the assembly process to enable automatic identification and traceability. What are the conditions labels are used in? The label must withstand the high temperatures during the soldering process and the harsh chemicals used during the cleaning process. There are two main processes for soldering: wave and reflow. Wave Solder In the wave solder process components are fixed to the board using the drilled holes, and are fixed in place with molten metal solder. Labels adhered to the bottom surface of the board in the wave solder process experience temperatures up to 280 C. Labels adhered to the top surface of the board may experience considerably different temperatures. This will depend on the material used, the thickness of the PCB and whether or not they are placed near drilled holes. Components Through the board ( thru hole ) PC Board Wave of molten solder 1. Wave solder process - board is exposed to molten metal solder at up to 280 C. Reflow Process Components are placed on the PCB with a solder paste. The solder is then melted in a reflow oven. Typically the preheating takes 150 to 180 seconds at 150 C, followed by the re-flow for 60 seconds with a peak oven temperature of 220 C. In the reflow process labels adhered to the board may experience temperatures up to 220 C. The top side of the board gets hotter than the bottom side. HEAT SOURCE: Hot Air, IR, Vapor The Cleaning Process After soldering the boards are washed at elevated temperatures to clean away the remainder of the solder flux and to prepare the board to further coating and bonding processes. The cleaning processes vary greatly and use a combination of water, harsh solvents, pressurised spray and ultrasound to remove the residues. Our printed product confirmed to be suitable after having been tested by cleaning agents of a European market leader. Soldier paste Circuits 2. Reflow process - board is exposed to temperatures up to 220 C to melt the solder paste in place. 6 7
What products are used for labelling? Polyimide is an orangey-brown translucent polymer film which has a very high heat resistance. Polyimide is normally used at either 1mil (25 μm) or 2mil (50 μm) for label material. In order to improve the contrast of barcodes a thick heat and chemical resistant topcoat is applied onto the polyimide. The topcoat can be matt or glossy and is usually white. Matt topcoats are often preferred because of their good printability and low reflection during the bar code scanning. The topcoat is very thick and is typically 15-20 μm on top of the base film. Finally the polyimide is coated with a special high temperature and chemical resistant adhesive. Polyetherimide and other alternative lower cost polymer products used for PCB labeling work at elevated temperatures, but they have limited use in new higher temperature processes. For labels applied after the soldering process, polyester or tamper evident labels are commonly used. Tamper evident labels help administer warrantees by assuring the serial number cannot be transferred to another board. How are the labels printed? Most labels are printed by thermal transfer. It is essential to choose a chemical and heat resistant ribbon to ensure the print is still readable at the end of the assembly process. The chemical resistance of the print is improved by exposure to heat during the soldering process before the cleaning stage. Fasson datasheets contain ribbon recommendations and performance results with popular PCB cleaning agents. How are the labels applied? Labels are applied onto printed circuits boards either automatically or manually. Care should be taken to select the correct dispenser setting for the thinner polyimide products. 8 9