Polyimide labels for Printed Circuit Boards

Transcription

1 Polyimide labels for Printed Circuit Boards The right match for any PCB labelling application

2 Labels on Printed Circuit Boards Matching product performance with application needs Printed Circuit Boards (PCBs) are used to hold and connect electronic components and are found inside every electronic device. They are assembled in an automated process, where they are exposed to extreme heat and chemicals. During assembly, traceability of the PCB is vital and this requires the use of identification and tracking labels. Avery Dennison s polyimide label constructions are specially designed to ensure reliable PCB tracking during manufacturing. They maintain their physical integrity, and excellent heat-resistant topcoats ensure that tags remain legible when exposed to extreme temperatures and chemicals. Finding a good match between label performance and application is crucial for minimizing costs, and Avery Dennison offers a complete product range that allows you to make the right choice for specific requirements. Identification and tracking labels are integral parts of the PCBs used in computers, telecommunications equipment, consumer electronic goods, industrial equipment, medical instruments, automotive systems, military systems and aerospace engineering. PCB labels are engineered to withstand heat and aggressive chemicals The Avery Dennison portfolio of polyimide labelling materials delivers value and flexibility throughout the PCB supply chain. > > Our new economy Polyimide products with the topcoats TC13 and TC14 perform exceptionally well at the very high temperatures used in today s lead-free soldering (up to +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 suit the most demanding PCB labelling applications where labels are exposed to extreme peak temperatures of up to +280 C. These grades offer superior resistance to highly corrosive solvents, and also allow for high resolution, fine feature print. Maximum temperatures specified for many PCB soldering processes are between +240 C and +260 C, and peak temperatures of up to 280 C are not uncommon. Process temperatures are end-product and end-application specific, and the Avery Dennison polyimide portfolio fully addresses the entire range of PCB labelling requirements. /en/home/solutions/durable-goods

3 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, and printed labels offer good resistance against the harsh chemicals used in the production and cleaning of PCBs. > > Polyimide I GL WH TC13 - based on a 25μm polyimide with a thick glossy topcoat. The total caliper of the facestock is 40μm. This material can be printed with a variety of thermal transfer ribbons and features good chemical resistance. To achieve a good print performance, an increased temperature setting for the thermal transfer printer may be required. > > Polyimide I WH TC14 - based on a 25μm polyimide with a thick semi-matt white topcoat. The total caliper of the facestock is 46μm. This material can be printed with a variety of thermal transfer ribbons and features good chemical resistance. To achieve a good print performance, an increased temperature setting for the thermal transfer printer may be required. > > Polyimide II WH TC14 - based on a 50μm polyimide with a thick semi-matt white topcoat. The total caliper of the facestock is 71μm. This material can be printed with a variety of thermal transfer ribbons and features good chemical resistance. To achieve a good print performance an increased temperature setting of the thermal transfer printer may be required. The following materials are optimized for thermal transfer printing of high density barcodes with superior chemical and scratch resistance. > > Polyimide I Matt White - based on a 25μm polyimide with a premium thick matt white topcoat. The total caliper of the facestock is 43μm. > > Polyimide II Matt White - 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. Adhesive 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 available with small minimum order quantities. See table for more details on service options. UL recognition (UL969) All standard products in the Polyimide range are UL recognized. The UL file number is MH27538.

4 Avery Dennison Polyimide product portfolio Product code BC668 BB810 BC133 AI300 AH415 Facestock Polyimide I GL WH TC13 Polyimide I WH TC14 Polyimide II WH TC14 Polyimide I Matt White Polyimide II Matt White Caliper PI film 25 µm 25 µm 50 µm 25 µm 50 µm Total caliper facestock 40 µm 46 µm 71 µm 43 µm 68 µm Appearance glossy semi-matt semi-matt matt matt Adhesive Liner BG50wh BG50wh BG50wh 50#SCK 50#SCK Peak service temp/ time 260 C, 5 min 260 C, 5 min 260 C, 5 min 280 C, 5 min 280 C, 5 min Chemical resistance TT printability Automatic dispensing - - yes - yes Ready Width 100 mm x 500 lm 150 mm x 500 lm 250 mm x 500 lm 500 mm x 500 lm 100 mm x 500 lm 150 mm x 500 lm 250 mm x 500 lm 500 mm x 500 lm 100 mm x 500 lm 150 mm x 500 lm 250 mm x 500 lm 500 mm x 500 lm 150 mm x 420 lm 150 mm x 420 lm 300 mm x 420 lm Master Roll, any slit width 100mm 1000 mm, roll length: > 100 lm 1000 mm, roll length: > 100 lm 1000 mm, roll length: > 100 lm 600 mm x 450 lm 600 mm x 450 lm UL recognized Excellent Good - not recommended For more information about polyimide labelling solutions please contact your Avery Dennison Representative.

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 attached to a printed circuit board before the assembly process to enable automatic identification and traceability. What conditions must labels withstand? Labels must cope with 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 Process Components 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 on to the bottom surface of the board in the wave solder process experience temperatures up to 280 C. Labels on to the top surface of the board may experience considerably different temperatures. Depending on the material used, the thickness of the PCB and whether or not they are placed near drilled holes. Reflow Process Through the board ( Thru hole ) PC Board Components are placed on the PCB with a solder paste. The solder is then melted in a reflow oven. Typically 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 attached to the board may experience temperatures up to 220 C. The top side of the board gets hotter than the bottom side. Molten solder 1. Wave solder process - board is exposed to molten metal solder at up to 280 C. 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 for 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 products have been confirmed as suitable after testing with the cleaning agents of a European market leader. Molten Solder Circuits 2. Reflow process - board is exposed to temperatures up to 220 C to melt the solder paste in place.

6 What products are used for labelling? Polyimide is an orangey-brown translucent polymer film with a very high heat resistance. Polyimide is normally used at either 1mil (25 μm) or 2mil (50 μm) for labelling 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 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 have also been used for PCB labelling work at elevated temperatures, but they are of 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 to administer warranties by ensuring that 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. 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. The chemical resistance of the print is improved by exposure to heat during the soldering process before the cleaning stage. Avery Dennison datasheets contain ribbon recommendations and performance results with popular PCB cleaning agents. DISCLAIMER - All Avery Dennison statements, technical information and recommendations are based on tests believed to be reliable but do not constitute a guarantee or warranty. All Avery Dennison products are sold with the understanding that purchaser has independently determined the suitability of such products for its purposes. All Avery Dennison s products are sold subject to Avery Dennison s general terms and conditions of sale, see Avery Dennison Corporation. All rights reserved. Avery Dennison and all other Avery Dennison brands, this publication, its content, product names and codes are owned by Avery Dennison Corporation. All other brands and product names are trademarks of their respective owners. This publication must not be used, copied or reproduced in whole or in part for any purposes other than marketing by Avery Dennison _16415EN Asia Pacific 32/F., Skyline Tower 39 Wang Kwong Road Kowloon Bay, Kowloon, Hong Kong Europe Willem Einthovenstraat BH Oegstgeest The Netherlands South America Rodovia Vinhedo- Viracopos, KM 77 CEP Vinhedo - SP, Brazil North America 8080 Norton Parkway Mentor, OH