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Feb 24, 2016 | I have a customer who is rather inexperienced, and asking us for a solution for them. They have a circuit board that's roughly two inches long by 1/2" wide or so, with component placements on one end of the board. The other end has a trace that I suspect is an antenna for RFID or some other type of application. They'd like to protect the component placements with a transparent material (as there are indicator LEDs contained in this section), akin to potting....though, they'd prefer to not use a pot. They're thinking of something along the lines of a thicker material that I could dip the board into to cover the components. We've reviewed the inability of standard conformal coating to accomplish this. We've also suggested using a case enclosure, but, they also want to prevent end users from reworking the components. Anyone have any thoughts as to a type of translucent material that is viscous
Jul 24, 2015 | Is anyone conformal coating flex circuits? have done it in the past, used silicon as it will flex,, however its not the most robust material! tends to peel/flake off.
Nov 10, 2013 | package Inductor falling apart from the circuit." What do you mean by "falling apart?" Tell us more about the situation [ie, material, processes, etc] First, require use of the IPC-7351B Standard as the sole basis for laying-out pads on circuit boards. Second, if someone wants to use a pad design that either: * Wasn't covered in IPC-7351B ... OR * Was for a component that was in the standard but not compliant with the standard ... The proposed
Nov 10, 2013 | Conformal coating to avoid oil leak from circuit board Assuming your conformal coating material was selected with the intent of living a life in contact with oil, why doesn't your coating meet the IPC-A-610D requirement of that there be no voiding, no breaks in the surface, no loss of adhesion, etc? Further, without much background information about the current situation, if the leakers are: * Soldered: Why don't your boards meet the IPC-A-610D requirement that through hole components have at least 75% hole fill? * Press fit: What does your conformal coating material supplier say about getting better coverage?
Nov 5, 2013 | bandgap was previously thought to be a necessary condition for population inversion in lasers, where most of a material's electrons are boosted from their ground state (valence band) across the circuit board bandgap to their exited state (conduction band) after which they decay back to the ground state ) -- but also other materials circuit board -- exhibit numerous excitations in the terahertz range," said Gierz. "Aside from fundamental research, terahertz light sources have numerous other applications." Graphene could make the illusive terahertz laser possible circuit board, according to a recent report from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg. Sources of terahertz radiation, such as that used by those security scanners that look underneath your clothing
Feb 6, 2013 | . ] * Richard R. Lathrop Jr., 104 Wilson Circle, Exton, PA 19341 H(610) 594-8229 rlathrop2atverizon.net * Richard Lathrop, Technical Service Manager, SMT Materials, Heraeus Circuit Materials Division, may be contacted at (610) 825-6050, ext. 265; e-mail: rlathropat4cmd.com. * smtnet .com/library/index.cfm?fuseaction=view_article&article_id=1872/ * Joachim Wiese, W.C Heraeus GmbH, Circuit Materials Division, Heraeusstrasse 12-14, D-63450 Hanau, Germany; +49-6181-35-4937, F+49-6181-35-3091, joachim.wieseatheraeus.com * eLPe design, Inh. Brigitte Bucke, Cranachstr. 52 - 12157 Berlin, USt.-IdNr. DE262923716; +49 (0) 30 / 856 864-0 F: +49 (0 I doubt anyone will send you the gerbers for the Benchmarker board. Here are my notes on the board: BENCHMARKER II TEST BOARD * Heraeus Materials Technology LLC [Benchmarker II test board that streamlined material testing for rapid customer support, product development and problem solving
Nov 15, 2012 | more complex, minor issues can cause big problems. For many circuit board manufacturers, material compatibility can be an issue that causes intermittent failures. “Making sure that your manufacturing materials and manufacturing processes are compatible with each other is a critical consideration in the development and characterization of a manufacturing process,” said Doug Pauls, one of the leaders in the 5-32b SIR and Electrochemical Migration Task Group that developed IPC-9202, Material and Process Characterization/Qualification Test Protocol for Assessing Electrochemical Performance. Testing for material compatibility has been touched on in some standards, primarily J-STD-001. Previous versions of J-STD-001 had an appendix that provided one possible approach, but many people found it lacking when it came time to translate the lab-based tests to actual products. “There have been material
May 30, 2012 | Richard Lathrop, technical service manager, SMT materials, Heraeus Circuit Materials Division, may be contacted at (610) 825-6050, ext. 265; e-mail: email@example.com.
May 16, 2012 | Here's some notes from a Bob Willis presentation Assembly of Flexible Circuits with Lead-Free Solder Alloy [Bob Willis leadfreesoldering.com] * Flexible Circuit Construction ** Base Material - 0.05mm Copper 18/18 um ESPANEX from Holders Technologies ** Liquid Solder Mask -MPR80 Amber - Nippon Assemby of flexible printed circuits Steel ** Solder Finishes – *** Immersion Nickel/Gold - Aurotech, from Atotech *** Immersion Tin - Stannatech from Atotech *** Immersion Silver - Sterling from MacDermid *** OSP - Glicoat SMD P2 from Shikoku * Assembly Pallet for Flexible Circuit ** Thermal relief areas on the base of pallet to improve
Mar 16, 2012 | in the edge to ensure the new piece will fit properly. The groove width should be approximately one-third the circuit board thickness. The groove depth should be approximately 0.762 mm (0.030 in.) deep. Now, cut a piece of replacement board material that is the same thickness and type as the piece removed We'd repair a drop board like this. Here's what our old friend Jeff Ferry said is a published article ... When boards lose their edge: when the corner of a circuit board breaks or is damaged, the problem cannot be ignored by Jeff Ferry One of the most easily, and most frequently, damaged areas of a circuit board is the edge or corner. Corner damage often occurs when employees mishandle or drop the board. Since circuit boards are generally rectangular, corners are particularly vulnerable to damage. Corners may feature crucial board elements (mounting holes) or be connected to the housing
Nov 1, 2011 | of the top experts to create an up-to-the-minute, comprehensive resource covering every aspect of flexible circuit technology. This edition is expanded, adding timely and crucial information to existing chapters on Materials, Design, Implementation, Manufacturing and Assembly. Technical information Flexible Circuits Technology 4e Download snip Dear Reader, Five years of ground-breaking innovation at blazing speeds in the realm of flex circuits has culminated in the publication of Flexible Circuit Technology, 4th Edition. Joseph Fjelstad, a world-renowned expert in the field and a 40-year veteran of the industry, has gathered some
Mar 24, 2011 | Circuit Card Assembly Molding You're correct. There's no point in conformal coating a board that you intend to pot. We're aware of no IPC [or IPCish] standards or guidelines for potting or encapsulation. We'd guess that materials and / or equipment suppliers would be the best place to start.
Oct 7, 2010 | Craig & Rem - I would also recomend switching to ENig - OSP would be my sencond choise ENig will give you the flatness your looking for plus the best shelf life. Enig is about 5% more than Hot Air. Enig also does not cause as much stress on the circuit board during its application as does Hot Air - With Lead free material - less stress is always better. Regards, Boardhouse
Oct 1, 2010 | circuits in our process and we place all flex in a "dry room" for at least 48 hours before using. This room is a controlled humidy area where the rH < 25%. The lower the rH, the less time needed to pull all the moisture out of the material. Flex Circuit Assembly Process (Sitiffeners) You don't necessarily have to bake the flex circuits, but you do have to worry about moisture. Polyimide is very hydroscopic, and depending on the flex construction, any moisture in the product can lead to delamination. Adhesive based flex circuits are very sensitive to this. We run only flex
Oct 1, 2010 | is to ensure that the baking process that is incorporated for processing the flex circuits is extended a bit to allow the rigid material to be baked completely dry. Cheers, ..rob Flex Circuit Assembly Process (Sitiffeners)
Jun 16, 2010 | I would be concerned with either material at that temp. i would re-post your question on one of the engineering forums below. http://www.eng-tips.com/ http://www.electronic-circuits-diagrams.com/forum/ Regards, Boardhouse
Jan 29, 2010 | The SMT MFG Process for Flex circuits is relatively the same as traditional SMT process, the key is your PCB supplier. The good flex circuit shops will supply the circuits in a rigid carrier or if Rigid/Flex the supplier will create a support structure made from the rigid material to support
Sep 14, 2009 | Glycols, polyglycols, polyglycol surfactants, polyethers, and glycerine are used in water-soluble flux formulations because they provide excellent wetting of the board surface and dissolve the more active materials used in these formulations. [Printed Circuits Handbook, 43.4.1 Vehicle, CF Coombs
Sep 3, 2009 | > I'd be more concerned with the pcb itself then I > would be with standard SMT components. Are you > using a PCB with a high Tg? (170 degrees C or > greater) The circuit board material is NP-170B (Nan Ya Plastics Corporation). It has a Tg of 170C
Jan 7, 2009 | Hi! Just joined the circuit. Hot Bar soldering is very reliable provided the Flexible Printed Circuit (FPC) and Rigid PCB design support this technique. Some of the critical aspects that need to be considered include Stencil apperture design for solder paste application, PCB/FPC footprint design , Thermal transfer characteristics though the FPC material (eg.polyimide), Alignment accuracy (FPC to PCB), Thermode geometry, Thermal Profile, Thermode Pressure and Process cycle time. It is recommended to have a jig for alignment of PCB with FPC contacts.
Sep 30, 2008 | Residues from different no-clean fluxes produce different levels of variation in RF circuits. Some no-clean fluxes work fine. Following this, a no-clean flux can produce different levels of variation in RF circuits depending on the process setup. Often the data sheets for solder paste with no -clean flux aimed at RF applications say, "This material has been utilized on various assemblies with RF designs without cleaning; however, the compatibility of flux residues on RF assemblies is strongly dependent upon circuitry design." The tech sheet from your AIM NC254 No-clean solder paste gives
Sep 16, 2008 | "....over 3500 apertures in a circuit that is about 1 x 1.5 inches..." 8O Yeah, Larry would definitely be the go-to on this one. :P I would think reducing stencil thickness would be your best bet to avoid that ratio problem, but how durable is a .004" stencil with more air than material in it?
Jul 21, 2008 | The industry mantra for the past decade or so has been minimizing material costs and inventory turns. Buyers in the EMS are given directives to buy as cheap as possible to meet these directives. Consequently, they cheap out on the most important part of the Printed Circuit Board Assembly
May 7, 2008 | Causes of Delamination ["Quality Assessment of Printed Circuit Boards" Lund, Preben; Bishop Graphics 1985 0137450354] The reason for delamination is epoxy starvation in the glass cloth layers or an incomplete curing of the base material. It has been reported that some manufacturers of laminates have reduced the lamination press cycle a little in order to increase production. In multilayer boards, visible delamination may be due to poor lamination of layers or insufficient bonding of prepregs to the inner layer copper circuits. Here, the PCB manufacturer is in a way also the "manufacturer " of the base material. Delamination may develop, however, in a board after assembly and soldering. There are several possible reasons for this: * Asymmetrical buildup of multilayer boards. * Faulty soldering techniques, such as skipping the baking which removes retained moisture from the board. (A 1 to 2
Mar 9, 2008 | . * Pre-printed labels applied before soldering is polyimide facestock with polyimide over-laminate. * Labels applied after soldering is polyester facestock or tamper evident facestock with matching thermal transfer ribbon. Printed circuit board label material selection should be done carefully so thermal, chemical and optical scanning requirements are matched to the specific application needs. That way, intended automation objectives can be realistically met. [Meeting Tough Requirements for Printed Circuit Boards, P Henkel, Founder, Electronic Imaging Materials, Keene, NH] Q2. The board requires Q1. What kind of labels/ink/sharpe can be used under conformal coating without disolving etc...? A1. While we're not familiar with the conformal coat you have selected, this might help. Label selection: The following chemically durable materials are recommended. ("In-plant" printed labels can
Feb 18, 2008 | In theory, no clean flux residues are electrically benign...period. Here's a good test. Subject the board to some moisture/humidity, and have your circuit designer ohm-out any areas that may be affected by conductive material. Option B: Have a lab, like Trace Labs, verify ionic cleanliness.
Jan 9, 2008 | I solder LEDs everyday from 0402 sizes on up. I work for an optical company so every product I make has LEDs. Some products have hundreds of LEDs per circuit. The problem is that clear materials are not filled materials and thus don't have the advantages of those material used in standard
Jun 25, 2007 | Once the HumiSeal conformal coating has been applied to the printed circuit board it is usually best to allow the material to reach a touch-dry stage, before heating the board to accelerate the cure schedule. This avoids potential problems such as bubbles and other defects being introduced
Feb 15, 2007 | Jim, In a previous life, we built some flex circuits for a customer. The configuration was a flex cable, with a circuit at one end of it. We had fixtures made out of the same material that we had selective wave solder fixtures made from. Cut an indention in the material in the shape of the flex SMT on Flexible circuits circuit, and included a clip to hold the circuit securely in place. I didn't work on it personally, but it seemed to work through screening, pick/place, and reflow (conveyorized line). cheers ..rob
Oct 2, 2006 | Printed Circuit Boards All of us wave solder FR4 all day-long, not to say we have never had problems doing it. The selection of the laminate material should depend on the burnin application. We'd be concerned about a FR4 burnin board that saw GT 150*C for extended periods. Polyimide||up to 240*C G-Tech||up to 180*C BT Material||up to 170*C FR4||up to 150*C
Feb 28, 2006 | standard developed by the Institute for Interconnecting and Packaging Electronic Circuits [IPC]. As an element of the Company�s quality policy, we inspect printed circuit boards as this document requires. This is to eliminate misunderstandings between the Company and its suppliers, facilitating or blisters, the actual condition is an internal phenomenon and is detectable from the exterior. Internally Observable||3||Require microsectioning in order to assess acceptability requirements. 2 EXTERNALLY OBSERVABLE CHARACTERISTICS 2.1 Board Edges 2.2 Base Material Surface 2.3 Base Material Subsurface 2 .4 Solderability Protection 2.5 Holes � Plated � Through - General 2.6 Holes Unsupported 2.7 Printed Contacts 2.8 Marking 2.9 Solder Resist (Solder Mask) 2.10 Dimensional Characteristics 3 INTERNALLY OBSERVABLE CHARACTERISTICS 3.1 Dielectric Material 3.2 Conductive Patterns - General 3.3 Plated
Feb 26, 2006 | Start with: * Clark "Handbook of Printed Circuit Manufacturing * Coombs "Printed Circuits Handbook * Jawitz "Printed Circuits Board Materials Handbook
Feb 24, 2006 | Hi Ken, There may be different composites of Durastone, but there are certainly mixes out there that are. http://www.ascenteceng.com/resources/materials.html We used durastone as a carrier for flex circuits as well. Cheers, Rob.
Jan 18, 2006 | We manufacture solder and dont charge, so agree with the others and change elsewhere just make sure you are changing to better material if unsure stick with what you have and pay for it under duress. Cheers Greg York BLT Circuit Services Ltd England
Oct 20, 2005 | during the soldering process on larger BGAs the corners can bend up or down due the large copper heatsink on top expanding quicker than the material the bga is made out of, in the worst cases this can lead to to the balls lifting out of the paste and giving open circuits (either at the corners
May 26, 2005 | CircuitCam offers great support, a superb product and CheckPoint can handle the Bill of Material comparison tasking you asked about. Friendly staff, good training and I do not receive endorsements $$$$. Just a good product. Circuit cam related software
Apr 25, 2005 | You indicate that PBBs and PBDEs are included in FR4 materials!! Does this include PCB (Printed Circuit Boards)??
Sep 28, 2004 | We're aware of no such standard. Check with ink suppliers [eg, Conductive Compounds, Coats Circuit Products, Creative Materials, etc] to confirm.
Sep 25, 2004 | IPC-HDBK-830, Guidelines for Design, Selection and Application of Conformal Coatings says: A conformal coating may have several functions depending on the type of application. The most common are: * Inhibit current leakage and short circuit due to humidity and contamination from service to conformal coat your board for a particular reason. You have selected a conformal coating material with properties that are different from other materials, most likely. You specific materials [eg, solder mask, nc flux residue, etc] that interact with the coating. You have developed a specific production
Apr 12, 2004 | Printed circuit boards materials Can you share some information on the hazardous materials and cleaning details for your manufacturing processes, please ? These are the questions I need to ask you: 1. Do you use brominated fire retardant in PWB material? If not, what other type of materials do you use instead? 2. Do you use
May 24, 2003 | We have an electronic circuit with a miniature stepper motor, quartz crystal, Electrolytic capacitor,chip resistors and few smt LEDs. The PCB material is CEM1 with SMOBC and HALS finish. This circuit is assembled in a plastic casing and goes in to a car as a dash board instrument. Now it has to pass a water ingress test. The spec for the water ingress test is that 2 drops of water per sec is made to fall on the instrument (plastic casing) and the instrument has to run for atlaest one hour. Our circuit has failed within 15 minutes since there are gaps in the plastic casing. Water has entered the electronic circuit and shorting has taken place. Provinding gaskets to pass this tests need redesign of plastic casing which is time consuming and costly. We are now looking at some sealants that would totally seal the water entry on to the circuits. Kindly suggest suitable sealants for this harsh
May 2, 2003 | Flex Circuits reflowing Hi Chris, I had worked for a flex circuit house for 10 years. You should be able to follow your solder paste guidelines for times and temps. You may want to consider pre-baking the flex if it is made with Kapton. Kapton is Hygroscopic and will delaminate in the oven if it has absorbed too much moisture from the air. We used to bake at 100 degrees F for a min of 4 hours. This eliminated the delamination issue. The only other concerns would be the insulating material used. Kapton should be fine, Mylar and Polyester have been used as cover coat insulation. These materials have a significantly
Apr 23, 2003 | Flex circuit pallets What's the actual brand name of the material? I could give you our experiences with most brand types both from a manufacturing and customer standpoint. Thanks, Chad Haima Pentagon EMS
Mar 7, 2003 | Pretty much everything under the sun. For example if Company A wanted to hire Company B to build printed circuit cards designed by Company A; What type of T & C might Company B seek in their contract/agreement with Company A? The following things come to mind: 1) Schedule, 2) Who purchases material?, 3) What happens if there is an Engineering Change--who pays for labor, material, and obsolescence?, 4) What is the price?, 5) Payment terms after each delivery, 6) Warranty, 7) NRE/Minimum Buys, ... Ya know...stuff like that. Any idea on stuff I missed above? Thanks, Greg
Feb 13, 2003 | Heraeus Inc. Circuit Materials Div, 24 union hill rd. West Conshohocken, PA 19428 (610) 825-6050
Dec 13, 2002 | I have heard of people using tiny lead-shot filled bags to hold down thru-hole components on circuit boards while running through a wave solder machine on selective solder pallets. How successful has this been? What kind of material is being used for the bags? Has anyone used an alternative material to lead shot..ie stainless steel shot? Going to make up some bags for those lil buggers that you can't get to with a clamping style hold-down.
Nov 28, 2002 | I got here before the experts did.
Underwriters Laboratory Incorporated is an organization located in the United States and is purely concerned with product safety performance. UL operates laboratories for the investigation of materials, products, equipment, etc. and sets standards which are aimed at reducing hazards affecting life and property.
In the case of printed circuit boards, the UL standards are:
* U.L. 94 - Flammability rating
* U.L. 796 - Performance Standards for Printed Circuit Boards
The UL 94 standard covers the operating temperature and flammability rating of the board . Most of OEM require UL approved boards and their fabricators apply a registered UL mark to every circuit to show that the board performs to this standard.
One take on the answer to your question is here:
Nov 15, 2002 | of development, then HASL or one of the lower contact resistance materials are a better match for your temporary debug needs. More - -
OSP is a bummer from an automated many points test strategy if you have to go through repeated tests after heat is applied to the OSP as well as go through cycles of testing is prohibitive on a circuit by circuit basis to create a manufactuing process. Bummer.
YiE, MA/NY DDave
Nov 15, 2002 | of development, then HASL or one of the lower contact resistance materials are a better match for your temporary debug needs. More - - OSP is a bummer from an automated many points test strategy if you have to go through repeated tests after heat is applied to the OSP as well as go through cycles of testing is prohibitive on a circuit by circuit basis to create a manufactuing process. Bummer. YiE, MA/NY DDave
May 6, 2002 | Our company specializes in quick turn Printed Circuit Boards; prototype and short run quantities. A customer has inquired about using Kevlar as the substrate. Can anyone give us the name of a supplier of Kevlar? Is the production process compatible with the FR4 material we most frequently process
Apr 29, 2002 | Flux residue effects on circuit performance? You can try using the brand-solvent "Genesolv 2004" in conjunction with a degreaser machine(source for own machine type?). this all helps to clean off the NC flux. we used it all integrated together, to clean a satellite modular card. reason we had to use NC flux, is coz the base PCB materials
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