through vias

"through vias" search results in the Electronics Forums



38 results found for "through vias" in the Electronics Forums

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Printing off contact

Feb 9, 2007 | Printing off contact Not an expert on PCB manufacture, but it looks like mask from other side of PCB flowed through vias before this side was masked. Is it possible previous vendor masked this side first, or used film-type mask which would not flow through?

PCB Blistering / Delamination

Jul 18, 2006 | PCB Blistering / Delamination What are the root failures of PCB Blistering / Delamination? Could layers short together through vias or thru-holes?

what's the difference between a thru vias and a blind via?

Jul 30, 2004 | what's the difference between a thru vias and a blind via? Consider a 6 layer board. The Through via gets drilled from top layer to bottom layer. All 6 layers has the hole drilled in it. A blind via is a via that does not got through the entire 6 layers. It would go from layer 1 to layer 2

Plated through via's in pads.

Jul 22, 2003 | Plated through via's in pads. Plated through via's in pads. Have the PCB fabricator use a conductive paste to fill the vias and then finish by plateing over the via. Make sure it's coplanar to the side they're on, usually secondary side for discretes. PT

Plated through via's in pads.

Feb 11, 2003 | Plated through via's in pads. Plated through via's in pads. Use a PCB fab house that is capable of "Conductive Via Filling" is the way to do it right. A conductive epoxy is used to fill the drilled via PRIOR to final plating. After final plating, the surface of the "Filled Via" will appear to be the same as the other BGA pads

Plated through via's in pads.

Feb 11, 2003 | Plated through via's in pads. Plated through via's in pads. I believe I've seen some board houses advertise the ability to plate vias completely shut, so that they can be placed within the outlines of a pad without causing the problems you noted. I've seen this scheme used on very densely populated digital boards to conserve

Plated through via's in pads.

Feb 10, 2003 | Plated through via's in pads. Plated through via's in pads. Hi You are probably right. The only thing I will tell you is that one time as thee DFM engineer working between many electronic designers, component manufacturers and CEMs (contract electronic manufacturers) the component manufacturer would not budge and say

Plated through via's in pads.

Feb 10, 2003 | Plated through via's in pads. Plated through via's in pads. Thanks for all the info guys. Dont think that the problem is a thermal one and I believe the guys designing the board just need to design them out. I have directed the customers we get the boards from to read this posted question so that they could see some

Plated through via's in pads.

Feb 10, 2003 | Plated through via's in pads. Plated through via's in pads. Specify a .1 mm diameter FHS with tolerance of +.3 -.1 using a .15 mm stencil.

Plated through via's in pads.

Feb 10, 2003 | Plated through via's in pads. Plated through via's in pads. BPan, I would like to discuss a possible solution to this that involves some of the suggestions found here but, with a twist that our process offers. This would be better discussed one on one somewhere other than this forum so if you still need suggestions please

Plated through via's in pads.

Feb 6, 2003 | Plated through via's in pads. Plated through via's in pads. Hi "some customers/designers want to have via holes to be present in the PCB pad, due to some belief that it helps in heat dissipation. " As I think about this I don't know exactly why they would be concerned. I can imagine in some exotic products with really hot

Plated through via's in pads.

Feb 6, 2003 | Plated through via's in pads. Plated through via's in pads. Actually, the most common reason I have seen vias in pads is for grounds in RF applications where the frequencies are high enough that you need a ground RIGHT THERE!... not .1" away. Vias and traces have RF properties of capacitance and inductance, so running a short

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. Iman On your situation: As an earlier poster stated, your options are limited to opening you stencil aperture to compensate for the paste lost to the via. On your designer's belief that "it helps in heat dissipation": Could be true, but: * Hole will fill with solder

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. If by the Powers Ta Be (customer/designer), you can't change the PCB design, negotiate for the PCB fab house, to block the via holes with their (green?) solder mask some customers/designers want to have via holes to be present in the PCB pad, due to some belief

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. Investigate "Solid Solder Deposition"

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. You're correct that a thicker solder deposit will make bridging on fine pitch devices a bigger risk. Another alternative could be to slightly over-print the pads (onto the soldermask) ala pin-in-paste process. Basically adding enough solder to fill the via during

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. First off, get them designed out. I had this problem once and filled them with SMD adhesive and cured prior to printing. We were careful to be sure the solder lands were clean of any adhesive prior to curing. It worked out very well and we did this process until

Plated through via's in pads.

Feb 5, 2003 | Plated through via's in pads. Plated through via's in pads. Hello Everyone, Is anyone out there building smt boards that have plated through vias directly located through the pads. We are seeing some of these designs and the soldering is very poor because the solder is flowing through the via. We think that we will have to use

Solder Balls in Vias

Jun 4, 2002 | Solder Balls in Vias If you have solder balls in vias on the "component side" it probably is your wave solder process. Most waves have an option that is designed to make sure your surface mount parts solder - but if turned up too high, can actually push solder up through via holes. Without

changing from no-clean to clean

May 21, 2002 | to the secondary side and is allowed to flow to the primary side through via. * Don�t underestimate the cost of running NC. [Search the fine SMTnet Archives for previous commented about this.] On your idea of soldering only the 0.8mm BGA with NC and using WS on the rest of the board: If you solder with the NC

Support Fixtures or Systems

Jul 30, 2001 | is being printed. Misplaced vacuum ports can actually pull solder through vias, watch for this when designing fixtures. Skewed or missing components may be traced back to the tooling on reflow. An example would be a cell phone riding on a pallet. There must be proper clearances and support built

Via-in-pad

Jan 17, 2000 | Michael

HELP!! via sizes, location

Oct 6, 1999 | ? | | | Frank, | I think I understand you correctly, that you have solder wicking up through via holes....and you dont want this. If that is the case then have them coated in solder resist on your next purchase and apply temporary resist (spot mask/masking dots)prior to process. | As far as solder bath level

HELP!! via sizes, location

Oct 5, 1999 | I think I understand you correctly, that you have solder wicking up through via holes....and you dont want this. If that is the case then have them coated in solder resist on your next purchase and apply temporary resist (spot mask/masking dots)prior to process. As far as solder bath level

pcb design for bga grounding.

Aug 13, 1999 | or as anyone overcome this problem any

pcb design for bga grounding.

Aug 12, 1999 | or as anyone overcome this problem any other

pcb design for bga grounding.

Aug 12, 1999 | or as anyone overcome this problem any other way ?

Spray flux through vias!!

Sep 29, 1998 | Re: Spray flux through vias!! Re: Spray flux through vias!! Thank you Steve for your input it was very usefull. I think I skipped a few pertinant details on my initial message though, the component which we found the flux contamination on was on the top side of the board, I was curious if the flux could come up through the via

Spray flux through vias!!

Sep 28, 1998 | Re: Spray flux through vias!! Re: Spray flux through vias!! | I have had some field failures returned recently, the boards had flux contamination under the components in a sensitive area, Nothing really visible until the component was removed, and the board had no evidence of rework of any type. Is it possible for flux

Spray flux through vias!!

Sep 28, 1998 | Spray flux through vias!! Spray flux through vias!! I have had some field failures returned recently, the boards had flux contamination under the components in a sensitive area, Nothing really visible until the component was removed, and the board had no evidence of rework of any type. Is it possible for flux to come

Providing Thermal Relief On Vias

Jun 4, 1998 | (if than't not an oxymoron) design a through via with thermal relief on a board that has: | | | 1 Mixed technology and will be wave soldered after reflow | | | 2 Fine pitch QFPs on the top side | | | 3 Through vias connected to leads on fine pitch QFPs | | | Dave F | | | | Hi Dave, | | Hopefully I

Providing Thermal Relief On Vias

Jun 4, 1998 | sensitive circuit board designer (if than't not an oxymoron) design a through via with thermal relief on a board that has: | | | 1 Mixed technology and will be wave soldered after reflow | | | 2 Fine pitch QFPs on the top side | | | 3 Through vias connected to leads on fine pitch QFPs | | | Dave F

Providing Thermal Relief On Vias

Jun 4, 1998 | 't not an oxymoron) design a through via with thermal relief on a board that has: | | 1 Mixed technology and will be wave soldered after reflow | | 2 Fine pitch QFPs on the top side | | 3 Through vias connected to leads on fine pitch QFPs | | Dave F | | Hi Dave, | Hopefully I won't sound to arrogant here

Providing Thermal Relief On Vias

Jun 3, 1998 | board designer (if than't not an oxymoron) design a through via with thermal relief on a board that has: | | 1 Mixed technology and will be wave soldered after reflow | | 2 Fine pitch QFPs on the top side | | 3 Through vias connected to leads on fine pitch QFPs | | Dave F | Dave, | How about putting

Providing Thermal Relief On Vias

Jun 3, 1998 | 't not an oxymoron) design a through via with thermal relief on a board that has: | 1 Mixed technology and will be wave soldered after reflow | 2 Fine pitch QFPs on the top side | 3 Through vias connected to leads on fine pitch QFPs | Dave F Hi Dave, Hopefully I won't sound to arrogant here but these "

Providing Thermal Relief On Vias

Jun 3, 1998 | 't not an oxymoron) design a through via with thermal relief on a board that has: | 1 Mixed technology and will be wave soldered after reflow | 2 Fine pitch QFPs on the top side | 3 Through vias connected to leads on fine pitch QFPs | Dave F Dave, How about putting a heat sink in the board? Got a layer

Providing Thermal Relief On Vias

Jun 3, 1998 | 't not an oxymoron) design a through via with thermal relief on a board that has: | 1 Mixed technology and will be wave soldered after reflow | 2 Fine pitch QFPs on the top side | 3 Through vias connected to leads on fine pitch QFPs | Dave F Christ Dave, You've arisen and are resurrected. Oxymoron is an apt term

Providing Thermal Relief On Vias

Jun 3, 1998 | 't not an oxymoron) design a through via with thermal relief on a board that has: 1 Mixed technology and will be wave soldered after reflow 2 Fine pitch QFPs on the top side 3 Through vias connected to leads on fine pitch QFPs Dave F

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