stencil cleaning

"stencil cleaning" search results in the Electronics Forums



9777 result s found for "stencil cleaning" in the Electronics Forums

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solder paste printing

Mar 29, 2019 | of Printed Circuit Boards (PCBs) using Surface Mount Technology (SMT), solder paste is deposited on the bond pads of the PCBs using stencil/screen printing technique. The last few years have seen the development and introduction of new printing mechanism to meet the miniaturisation challenge of electronic an opening as the printing head passes over the stencil apertures. The flow profile of the solder paste inside such a chamber plays a key role in determining the volume of solder paste deposited onto the PCB pads. In this paper we investigate the paste flow inside such a chamber and its influence

When to implement high speed pick and place machines?

Feb 4, 2014 | for, there problem was more the way the machine was being used. I estimated (roughly) that it could turn out about 4 times the volume by just running 4 boards on a panel instead of one because the girl who had to hand stencil, had basically to run in a circle from stencil machine to putting the plate

HMP hand soldering.

Sep 18, 2012 | , use your best judgement for the the best tip)Your tip should remain tinned till use(there should never be a time when you whip your tip with a wet sponge)when ready to use;use the hakko wire sponge to clean your tip(no stabbing motions to clean, this will damage your tip, just a wipe across the wire

Ionic - MIL-P-28809A vs IPC TM650 (2.3.25C)

Nov 19, 2008 | ="http://listserv.ipc.org/scripts/wa.exe?A2=ind0510&L=technet&D=1&T=0&P=93119" target="_blank">http://listserv.ipc.org/scripts/wa.exe?A2=ind0510&L=technet&D=1&T=0&P=93119 You seem to be using your own corporate cleanliness standard of 0.8 ugNaCl/cm2 for assemblies rather than the 1.56 standard value. Coming from a cleaning equipment manufacturer, I like it when a customer has an internal standard because usually it means they have a good handle on the cleaning required for their assemblies and it makes everything else much easier. I am assuming that your value is based on the measurement you achieve in your Omegameter. The values

Printed Circuit wash system

Jul 1, 2008 | Vapor degreasing systems * Thermal Equipment [Baron-Blakeslee]; Torrance, CA; thermalequipment.com * Exselect Engineering; Concord, ON CAN; exselect.com * Branson Ultrasonics; Danbury, CT; bransoncleaning.com * Greco Brothers; Providence, RI; grecobrothers.com Aqueous cleaning systems * Aqueous Technologies; 4059 Skyron Dr, Doylestown, PA 18901; 215-40-0650 F215-340-1737 emcgti.com * Unit Design; 580 W Lambert Rd., Suite F, Brea, CA 92821; 888-604-5500 714-672-9944 F714-672-9988 unitdesign.com Steve Pence Ultrasonic cleaner * Blackstone-NEY Ultrasonics, Division of Cleaning Technologies Group, LLC

MyData Missing Placements

Jul 10, 2007 | to get plugged up. We periodically take the tool out and look at the tip under a vision microscope. We have taken a fine tip exacto knife and cleaned out the blocked hole. This can lead to expanding the tip hole too big which gives problems also. Mydata makes replacement tips for each tool. I it has placed a part when it actually has not, this now becomes a yield issue that you want to fix. 5) A suggestion for testing any changes to settings or tip cleanings, etc. Take a pcb and put double sided tape on it. Then put it in the machine and load the board like normal. This alows you

Reflow Profile Design

Jun 15, 2007 | of product we ran and then thermocoupled that board, so we should have an accurate simulation of a real product running. Everything is RoHS. The failure was a clean snap of the BGA part off the PCB, with all the solder on the BGA itself with the pad on the PCB clean (gold) without any solder on it to move into a new factory on Monday that's got the space for the shiny new 10 zone oven with active cooling. However when I saw the way the BGA's were breaking off in customer returned product, I realized this was not the cause, as we should not be getting the clean break like this if the solder had

Swatch Group Granted Lead Exemption?????

Apr 24, 2007 | for the simple reason that no alternatives to the 6 substances are either proven reliable, work as well as the product it replaces, or are proven better for the environment. The bottom line is CFC elimination has encouraged new technology such as No-Clean/No-Residue soldering eliminating cleaning and post

Use lead-free alloy wire during rework for Leaded Process

Nov 1, 2006 | drop requirement. Karl Seelig, Vice President of Technology AIM In his 25 years of industry experience, Mr. Seelig has authored over 30 published articles on topics including lead-free assembly, no-clean technology, and process optimization. Karl holds numerous patents, including four for lead -free solder alloys, and was a key developer of no-clean technology. kseelig@aimsolder.com

Necessity of ROSE in commercial quality processes

Feb 27, 2006 | Thanks Mike, you are correct. According to Flux designation we could have some residual of ions on PCB/PBA. My experience was mainly by using Omegameter SMD-600 (automatic and dynamic ROSE)on samples to detect TIC (Total Ionic Contamination) after PBA wash off process. PBA soldered by Clean water with a risk to clog the filters(Mix Bed). Our NC assembly Process (SMT and Wave) does not include TIC test after assembly. In our processes, TIC test is a must as an SPC step, only for PBA soldered by Clean Process (WS Paste and WS flux). To MASRI I do not have experience on PBA for TV products

IONIC CLEANLINESS SPEC FOR BARE PWBs

May 9, 2004 | ; solderability problems) while the rest of the > board is clean. As a manufacturer of ionic > contamination testers, I recommend that our > customers NOT breathe a sigh of relief if the > cleanliness result is a few points under the > maximum allowed. Use a high test result as a > flag and conduct additional testing such as ion > chromatography (CSL Labs or American > Competitiveness Institute conduct such tests). > If an ionic contamination tester indicates a low > level of contamination (less than 2 �g/in of > NaCl) then odds are good that your board is > clean . > > Personally, I would not accept an > incoming board that measures more than 0.5 �g/in > of NaCl. It is perfectly acceptable to expect > incoming boards to be very clean. > > Mike 800) > 218-8128 Hello Gents, I learaned a lot by reading your treads. I would ask

SMT EQUIPMENT FOR LOW VOLUME HIGH MIX

May 9, 2003 | can continue to work towards minimizing attrition but first get the job done efficiently. 3. When a job is almost done, have a programmer standing by the machine, a person to change the stencil screen, a feeder audit person if needed and a person to load raw boards. 4. The current job running stops specializes in this specific area I also suggest you goto our website. Check out Bliss University at http://www.blissindustries.com it explains in more detail how to use feeder, reel, and stencil carts to make this entire process easy

BGA Rework

Apr 10, 2003 | Thanks for your replies guys, there's some good info there. Dave, answers to your questions: The stencil was initially a big problem as with the Egineering Model's (EM's) and Engineering Qualifing model (EQM's) we kept getting short circuits due to too much paste. To fix this we reduced the pad size (these are all teardrop shape pads). We then found that the reliabily of the print went right down because the stencil was right on the limits of what could be done. We introducted a critical inspection of the solder paste print at at least times ten mag. This was unfortunatly ignored in build

SIR starting point...?

Oct 21, 2002 | of electronics has made the focus on contamination and its link to product reliability more important than ever. Dozens of pastes, fluxes, and cleaning materials, as well as continued miniaturization of packaging and designs further complicate matters. This report hopes to achieve several goals: 1 correlation between common, industry-accepted rose/modified rose (omegameter/ionograph type) testing and long term product reliability. 4. Determine the effect PWB plating finish (HASL, Immersion Silver and Cu OSP) has on both bare PWB contamination as well as soldered assembly in a no clean and water soluble

imm. silver

Aug 30, 2002 | Risk of Removing Protective Coating When Cleaning Misprinted Boards||10||2||2||2||10||10||10 Highly Solderable = 10; Least Solderable = 1 Solderability at Wave Solder (no prior reflows)||10||6||6||6||7||8||9 Highly Solderable = 10; Least Solderable = 1 Solderability at Wave Solder (after 2-3 reflows ) and using a no-clean flux||10||1||2||5||7||8||9 Easily Wire Bonded = 10; Can't Wire Bond To = 1 Ability of Surface to be Wire Bonded||1||1||1||1||1||10||9

Indium No-clean and Inert Reflow oven (N2)

Aug 1, 2002 | Indium No-clean and Inert Reflow oven (N2) ... Product: Solder Paste and SMT Assembly No-Clean Category: Process Submitted: 07/31/2002 10:23 AM Last Updated: 08/01/2002 07:19 AM Status: Solved Discussion Thread Response (Jake Lutke) 08/01/2002 07:19 AM Nitrogen is not recommended for use with NC-SMQ92J. The paste was designed

Bad Buisness

Apr 18, 2002 | it should, and stencil inspection doesn't work and auto cleaner doesn't work either, has never worked since it has been installed, never worked for three years. Tech: excuse me, are you having a problem with your screen printer ? Eng: YES, what you can't hear me all of a sudden ? I tell you this bad machine is broken, has always been broken not like the old machine I used to work on. The paste is not going down the way it should,and stencil inspection doesn't work and auto cleaner doesn't work either, has never worked since it has been installed, never worked for three years. Tech: uh, sir ? Eng: YES ?? Tech

BCC Technology --- Placement, Rework, Reflow

Apr 4, 2002 | Hi, hope this helps : 1) BCC (bump chip carrier) production for us, was with a 5mils Stencil. The outer perimeter smallish pads are not much of a problems. For the central large pad, we split the paste print (corresponds to the Stencil apperture opening) into four smaller sized quadrants

adhesive on pads

Apr 1, 2002 | will react under bias to create the electromigration condition. ACTIVE IONIC MATERIAL. Proper cleaning of the laminate surface during the fabrication processes, adequate flux activation during all thermal excursions, and subsequent cleaning (as required by flux vehicle used) in the assembly process

AMP Mictor

Oct 1, 2001 | used a slitting tool that AMP developed, and it seemed to work fine for us. We would: * Slit the boards. * Deposit paste on the connector through hole barrels and SMT pads on the secondary of the board. * Place secondary side SMT components and reflow. * Clean and inspect secondary side SMT. * Deposit pins [now resting on a �crown� of solder from bottom side SMT assembly]. * Place primary side SMT components and reflow. * Clean and inspect primary side SMT. Get Amp Application Specification 114-11004 covering the use of Mictors. I looked for it on the AMP site, but got very confused. Your sales �back-plane� style. * Leister tool to hit and �clean-up� connector bridges. [We struggled in try to understand bridging with too little solder. We think it went back to: A �too many things wrong about the situation to get good flow� situation. And solder, being ornery by its very nature, would vasty

Solder flow thru via on pad

Sep 25, 2001 | want to start. * Starved solder connections: Increase the amount of paste printed to accommodate the loss of material used to fill the via and make the bumps on the other side. [Ummm, this sounds dicey. Enlarging the stencil aperture could cause bridging between PGA balls. Increasing the stencil

PIHR Inspection Criteria

May 17, 2001 | Paste Deposit Satisfactory Solder paste deposit is complete and conforms to the same size as the stencil aperture dimensions and may be printed onto the surface of the solder mask and over the through hole Acceptable Solder paste deposit conforms to the aperture in the stencil design there is some evidence of minor paste displacement Unacceptable The solder paste deposit is incomplete and does not conform to the designed aperture in the stencil. There is evidence of paste smudging on the surface of the board. Pin-In-Hole/Intrusive Reflow Inspection Standards Component Pin

Solder paste layout

May 10, 2001 | I am unaware of any industry standard for specifying apertures for SM stencils. I am aware of IPC-7525, Stencil Design Guidelines. You can obtain it from IPC [http://www.ipc.org]. Further, it seems like there is an article on stencil

Dbl-Sided Reflow Question

Jun 2, 2000 | Hey CK, we�re all sodder googoo�s ... wanna be gurus Why donchu tell �em not to put sodder in your vias? Er, makit so the sodder won�t flow out of the bottom of the vias and cause dem stalactites? OK OK, here�s wacha do, modify the second side stencil to add holes that correspond to the via stalagmites (nee stalactites) that way the stencil will lay flat and you�ll get good gasketing. Cool huh? Yeh yeh yeh, that�ll add more paste to the vias and make the board even more unreliable than it was before with a smaller amount of sodder in the via, but at least you�ll get a good print!!! Anywho

Converting to 'No-Clean' process

Apr 17, 2000 | Re: Converting to 'No-Clean' process / manufacture electronic assemblies shall be selected such that their combinations produce products acceptable to this standard. Objective evidence of this compatibility shall be maintained and available for review. When major elements of the proven processes are changed, (e.g. flux, solder paste, cleaning or metalization." 3 CHOICE OF THE FLUX. J-STD-001C, 4.2 reads: "Flux shall be in accordance with J-STD-004. For Class 3: a) Flux shall conform to flux activity levels L0 or L1 of flux materials rosin (RO), resin (RE), or organic (OR), except organic flux activity level L1 shall not be used for no-clean

Top Side BGA Reflowing @ Wave Solder

Oct 11, 1999 | to control your process. | | JohnW | Hi CK, Above recommendation from both Dave F and John W are correctly. But may I ask your process again before your found the problem solder bridging under BGA at Wave soldering. - Reflow Soldering with Clean process or no clean process? - If no clean process

Soldering to Gold

Sep 18, 1999 | , but I�m not buying ... | | | | Intermetallics. I�m not buying "cleaning + conformal coating MAY provide sufficient mechanical support to prevent them 'orrible intermetallics." First, the intermetallics were formed "long" before the connection was cleaned or coated. They are formed during . In no way did I wish to suggest that the intermetallics would miraculously disappear by cleaning and coating, which I infer is what you inferred. If you like, this speculation is rather like the proven method of using NON-conductive underfill adhesives for ensuring the electrical connection of BGAs levels in my monthly solder pot analysis. While that�s probably true, but: | | | | � What about marginal soldering situations that occur before changing-out the solder pot? Because, (1) I�m not sure of the safety margin of gold concentration that�s acceptable before I should clean the pot (versus when

Soldering to Gold

Sep 18, 1999 | ... | | Intermetallics. I�m not buying "cleaning + conformal coating MAY provide sufficient mechanical support to prevent them 'orrible intermetallics." First, the intermetallics were formed "long" before the connection was cleaned or coated. They are formed during the soldering process and continue to form as long would miraculously disappear by cleaning and coating, which I infer is what you inferred. If you like, this speculation is rather like the proven method of using NON-conductive underfill adhesives for ensuring the electrical connection of BGAs, in that the resins provide the mechanical support . While that�s probably true, but: | | � What about marginal soldering situations that occur before changing-out the solder pot? Because, (1) I�m not sure of the safety margin of gold concentration that�s acceptable before I should clean the pot (versus when I must clean the pot), (2) things that happen

Cylindrical diodes Missing during SMT process.

Aug 25, 1999 | | | | | | | Hello everyone, | | | | | | We found many cylindrical diodes missing during SMT process. Could someone tell us how to prevent this problem? Is it effective to change the shape of stencil apture or reduce fan speed in reflow oven? Thanks in advance. | | | | | | | | | | | | Gyver . So, check that the parts are definitely in place before the boards go through reflow. If they are, make sure that pad sizes are big enough, and you are putting down enough paste (0.006" thick stencil will be fine). Another problem we have encountered in the past is contamination of the components end

Cylindrical diodes Missing during SMT process.

Aug 24, 1999 | | | | | | Hello everyone, | | | | | We found many cylindrical diodes missing during SMT process. Could someone tell us how to prevent this problem? Is it effective to change the shape of stencil apture or reduce fan speed in reflow oven? Thanks in advance. | | | | | | | | | | Gyver . So, check that the parts are definitely in place before the boards go through reflow. If they are, make sure that pad sizes are big enough, and you are putting down enough paste (0.006" thick stencil will be fine). Another problem we have encountered in the past is contamination of the components end

Re: Air-Vac stuff

Aug 20, 1999 | are molten, the component is lifted from the board. | | � Cleaning the Holes: | After component removal, an air cleaning hood is lowered against the board surface. Low pressure air is applied to the lead pattern, forcing the molten solder from all holes. | | � Resoldering: | Replacement component

Re: Air-Vac stuff

Aug 20, 1999 | the board. | | | | � Cleaning the Holes: | | After component removal, an air cleaning hood is lowered against the board surface. Low pressure air is applied to the lead pattern, forcing the molten solder from all holes. | | | | � Resoldering: | | Replacement component is inserted and fluxed. Then molten

solder mask between qfp pads

Aug 20, 1999 | | | | | | | One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate contact with the pad and allowing solder paste to squeeze under the stencil and encouraging solder bridging. Another school of thought seems to be that the solder mask prevents bridging between pads. Anyone have experience/preference in solder mask or lack of solder mask between pads? | | | | | | | | | | | | Gerry | | | | | | | | | | | I have

Re: Air-Vac stuff

Aug 19, 1999 | are molten, the component is lifted from the board. | | � Cleaning the Holes: | After component removal, an air cleaning hood is lowered against the board surface. Low pressure air is applied to the lead pattern, forcing the molten solder from all holes. | | � Resoldering: | Replacement component

Micropax Connector Repair (Through Hole Version)

Aug 17, 1999 | little mini-wave. Ok so far as the connector comes out fairly easy. The trick is getting a new one back in. Does anyone know, or care, what I mean? | | | | | | | | | | | | The biggest problems after removal is cleaning out the holes of residual solder. Solder sucking or blowing doesn't get it. I came up to get closer to the eutectic melting point. Then, I'll insert the soldering iron tip in the top and see what happens. Still, I wonder, there must be a better way to get the holes cleaned out, and no - mechanical drilling wont' get it even close. | | | | | | | | | | | | Once the holes are clean, back long as the tip I/D on the solder sucker matches that on the PTH on the PCB and the tip is really clean you should get enough heat transmission to melt and remove the remaining solder without removing all the pads as well. | | | | | | | | | | I have had some success using this method in a similar

Micropax Connector Repair (Through Hole Version)

Aug 17, 1999 | little mini-wave. Ok so far as the connector comes out fairly easy. The trick is getting a new one back in. Does anyone know, or care, what I mean? | | | | | | | | | | | | The biggest problems after removal is cleaning out the holes of residual solder. Solder sucking or blowing doesn't get it. I came up to get closer to the eutectic melting point. Then, I'll insert the soldering iron tip in the top and see what happens. Still, I wonder, there must be a better way to get the holes cleaned out, and no - mechanical drilling wont' get it even close. | | | | | | | | | | | | Once the holes are clean, back long as the tip I/D on the solder sucker matches that on the PTH on the PCB and the tip is really clean you should get enough heat transmission to melt and remove the remaining solder without removing all the pads as well. | | | | | | | | | | I have had some success using this method in a similar

Micropax Connector Repair (Through Hole Version)

Aug 17, 1999 | -wave. Ok so far as the connector comes out fairly easy. The trick is getting a new one back in. Does anyone know, or care, what I mean? | | | | | | | | | | The biggest problems after removal is cleaning out the holes of residual solder. Solder sucking or blowing doesn't get it. I came up with an idea, yet to the eutectic melting point. Then, I'll insert the soldering iron tip in the top and see what happens. Still, I wonder, there must be a better way to get the holes cleaned out, and no - mechanical drilling wont' get it even close. | | | | | | | | | | Once the holes are clean, back to the mini-wave and insert sucker matches that on the PTH on the PCB and the tip is really clean you should get enough heat transmission to melt and remove the remaining solder without removing all the pads as well. | | | | | | | | I have had some success using this method in a similar situation. The vacuum desoldering tool I

Micropax Connector Repair (Through Hole Version)

Aug 17, 1999 | as the connector comes out fairly easy. The trick is getting a new one back in. Does anyone know, or care, what I mean? | | | | | | | | The biggest problems after removal is cleaning out the holes of residual solder. Solder sucking or blowing doesn't get it. I came up with an idea, yet unsuccessful as well . Then, I'll insert the soldering iron tip in the top and see what happens. Still, I wonder, there must be a better way to get the holes cleaned out, and no - mechanical drilling wont' get it even close. | | | | | | | | Once the holes are clean, back to the mini-wave and insert the connector is really clean you should get enough heat transmission to melt and remove the remaining solder without removing all the pads as well. | | | | | | I have had some success using this method in a similar situation. The vacuum desoldering tool I used was a Hakko model 470 but any other with a good vacuum

Micropax Connector Repair (Through Hole Version)

Aug 13, 1999 | . The trick is getting a new one back in. Does anyone know, or care, what I mean? | | The biggest problems after removal is cleaning out the holes of residual solder. Solder sucking or blowing doesn't get it. I came up with an idea, yet unsuccessful as well, that uses a thermal "drill" to melt through . Still, I wonder, there must be a better way to get the holes cleaned out, and no - mechanical drilling wont' get it even close. | | Once the holes are clean, back to the mini-wave and insert the connector into the board using an alignment fixture so the pins won't bind and bend (they do this very

DENDRITES

Aug 9, 1999 | with residual chemistries from even the plating processes and wash them into the board weave - the infamous CAF influences reported by Prof. Laura Turbini at Georgia Tech. | | You are apparently running no-clean. So you probably have a higher pre-heat on your soldering? Are you also wave soldering fluxing are this side of the pond....unless you are too? | | Hope this helps, Regards Graham N | Hi! IMHO, Graham and others have offered sound advice but should like to add my tuppence worth. I don't like the idea of conformal coating over any old "no-clean" residues and, most especially, with a silicone-based one . My advice is therefore: Check whether you really need to conformally coat (i.e. what would be the failure rate of your product in practical service with and without and would either be acceptable?) If you do really need to and you wish to achieve a better reliability, then consider a cleaning process

Oven Temperature for Solder Reflow

Aug 7, 1999 | component's and how big they are, how clean is your oven ? flux build up over time is a killer and will seriously effect your profile, the best time to profile if you can is right after the oven is cleanned, then do it again right before it's due to be cleanned then you'll get a max / min tolerance window

Metal baskets for cleaning of PCBA's

Apr 21, 1999 | Re: Metal baskets for cleaning of PCBA's (The Cheap way) | HELP | I need any information on how to purchase "Metal baskets" | (dimensions 3" height x 18" width and length) for our HUGE cleaning machine for our PCBA's. Pleas eif anybody could give me sales info, or company information it would be greatly appreciated. Thank you. | | SLVCAL@aol.com | 1

About the current issues of surface mount devices

Apr 13, 1999 | require peculiar storage racks. | 4 Some semi-automated printers with vision systems allow printing without the stencil being aligned to the board. | 5 Some ovens do not allow the lower zones to be adjusted separately from the upper zones. | | The best place to find the capabilities of machines is from

Intrusive soldering

Mar 25, 1999 | | Rob, | | We are also using intrusive reflow to simultaneously process SMT and Thru-hole components. Our arrangement goes as follows: | | - Screen print solder paste to the single sided PCB using 0.008" laser cut stencil. | - Apply adhesive dots to selected components. | - Place SMT

Intrusive soldering

Mar 23, 1999 | Rob, We are also using intrusive reflow to simultaneously process SMT and Thru-hole components. Our arrangement goes as follows: - Screen print solder paste to the single sided PCB using 0.008" laser cut stencil. - Apply adhesive dots to selected components. - Place SMT components (1206, 0805

DEK fine pitch autoflex pin breakage

Mar 19, 1999 | Folks, I think we are getting closer to being very happy with DEK stencil printers of the 265 GSX variety. However, problems continue arising concering fine pitch autoflex tooling pin breakage. We are told by the British engineering establishment, they are seeing very little breakage but ours

Adhesion loss on passives over wave

Mar 19, 1999 | preceding yours, I have another no-clean paste enroute that will allow me to conduct comparison experiments, and further validate (or not) the no-clean paste interaction theory. I doubt very much that handling is at the root here, although arguably all the torsion the boards go through prior to wave may

Fuji GSP-II For Sale

Mar 8, 1999 | would be surprised. It is spotless and has lived its entire life in a cleanroom. Options include AC, dial indicator for squeegee pressue adjusting, stencil separation and teaching box, lots of spacers, all manuals. | | We also have an MCS16F Controller we would throw in for one total low, low price

Re: BGA repair/rework

Mar 6, 1999 | I'm having a fun time between BGA rework/repair using an SRT 1000 and SPC efforts (much easier) using DEK stencil printing processes and BTU reflow with 6 Fuji lines in between. Concerning the BGA stuff, I'm getting about 60% success using this rework capability as being able to remove, place

Defluxing Advanced Packages

Used SMT Equipment