Mark,
You showed me three examples of 20 mil traces. There is no components with 10 or 8 mil pads and all these traces look to be the same size as the pads so again .020" is the minimum reasonable size for thermal transfer, which is the width of the smallest pads. I have included a photo of what I am talking about. This is a snapshot of ExpressPCB with three of the smallest components and the smallest pads. The pads line up nicely with 20 mil traces. Do you disagree? can you prove to me where your 10 mil traces are again. And no those also are not 8 mil traces. Again the smallest pad is 24 mil. so your traces should be much smaller than the smallest pad.
The good news is the photo transfer method just using the sun and the same laser output with Pulsars foil can achieve 6 mils without a problem which again is an industry standard as the minimum for PC boards.
Your mistake is thinking that I'm using 0.05" lead spacing IC's. Your image shows spacing relative to a 0.05" lead pitch IC. The IC's on my boards are 0.5mm. If I used 20mil traces then there would be no space between the traces at all. 0.5mm is about 19mil length. The 8mil trace image is using an IC with 0.4mm lead spacing, that's less than 16mils from centre lead to centre lead.
I've been doing this for quite a while now. Try to assume I know the basics like the difference between 10 and 20 mil.
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Mark Higgins
Angelgroove said:This is important because I do not believe any manufacturer using the thermal transfer method can put down anything less than a .020" trace repeatable and reliably. This is an issue here and it should be resolved one way or another. Especially in relation to Pulsar's product line.
This is important because I do not believe any manufacturer using the thermal transfer method can put down anything less than a .020" trace repeatable and reliably. This is an issue here and it should be resolved one way or another. Especially in relation to Pulsar's product line.
So, let me get this straight. Out of the two alternatives; you not doing the Toner Transfer process properly, or me and others in this thread lying, you chose to believe that we are probably lying without doing any research on your own to verify either story. You must have a lot of friends.
1. Because you gave it one try and cannot do less than 20mil does not mean others can't. For once, do something that I suggest and go to the Homebrew ML that I linked earlier. Pulsar advertises all over their site less than 10mil and shows plenty of images. IF YOU CAN'T GET LESS THAN 20mil YOU ARE DOING IT WRONG. Talk to the Pulsar support guy, who is very helpful, about fixing your process. It's obvious that you don't have a lot of experience here, why can you not take advice? If you want more examples of people being able to do Toner Transfer with finer pitch, they have a search site called google. "toner transfer pcb" will give you loads of examples.
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I for one with any internet form, with out the references, the dates, the paper than cannot be found or anything like that is merely an opinion and not fact filled.
What I am doing here is reasonably trying to replicate what other have done and simply report it. That is the scientific process. Take it with a dose of salt if you like it is merely my opinion and if there is a fact it then is true. I show everything based on facts like the outside board dimensions so that anyone can verify the leads. I also do not dispute the process merely am saying what are the problems. I am not about to spend money on new equipment that may or may not fix any problem. I have spent too many years of chasing down problems and it usually ends up as a giant rat hole with no end in sight. If I cannot do it with my high end equipment, I am not about to trade it in for specialized equipment simply to prove a point. I am quite happy with 20 mil traces. If I need smaller, it will then be a photo resist method.
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What I also hear is hurt ego. Well simply do the scientific process to your proofs. If you do not, it is merely an opinion, and expect to be questioned. If that is all this website is about, Puslar better take the front row here and show their work and how they did it. Because after all it looks to me Pulsar is making a lot of money here, and its is no wonder why some do not trust the process.
You think this is what has happened because of all of the evidence to suggest this? For someone that likes proof and facts you jump to conclusions so easily it's frightening.I think what has happened is you have spent a lot of time and money getting all of this just right. I am not interested in doing that and merely want to do simple boards that I can reasonably put one together. That is it in a nutshell. If that means 20 mil traces then so be it.
He was told that a while ago and like all advice in here he ignored it.Guys,
As you know there's lots of threads here that show it works and lots of methods (all about the same really). Maybe AngelGoove should go search/read the forums here before preaching to the MANY that are doing it, some for a long time.
For QFN I use a hot air rework station. I really like working with QFN now as it's pretty easy. I put down a bit of paste, tiny bit on the thermal and a bit around the pads, drop it on and hit it with some hot air and it sits right down in place. Parts will align themselves to a degree, with tension when in reflow.
Cheap shot. Call Frank if have questions. Or shoot him some email and he will post here. At any rate it would be the right thing to stop badmouthing stuff you know so little about.Anglegroove said:I hear nothing as to this ad-hock toner system...
What the what? Where do you get this stuff from? I can do 8mils without difficulty, I've done 6mils on a test board and I can likely do better than that. I'm getting pitting with the new etching method I'm using. The hydrochloric acid/pyroxide. Even then, I'm not getting this wavyness you are talking about. Ferric Chloride gives me clean nice lines, no pitting. I really like the acid etchant, but I'm only using it now for test stuff that I don't care about. The copper looks rashed for me, but I don't use that green Pulsar sealant stuff, either.What conclusion can I draw from here thus far?
1. The thermal toner style will work down to 10 mils and maybe down to 8. The traces will be pitted and nothing outside of loading them up with solder will fix that. I used to do that in High School when we had poor quality .062" traces. For hobby purposes this should work just fine. Anything over 20 mil will be tolerable.
Because I use a hot air workstation on a QFN chip you've concluded that all small outline chips need "special equipment". I wouldn't do QFN's anymore with a regular iron, but I have in the past. Otherwise 0.5mm leaded packages I always use the iron. Search on Youtube for SMT soldering and there are videos that show different methods for iron soldering small pitch chips.2. You need special equipment to achieve the super small VSOP devices. I primarily stay away from them because that to me is the purview of professionals. We do not need to get so small, we need microscopes to do that kind of work.
You ramble a lot and make a lot of conclusions that are contrary to the facts that are presented. It's very strange.3. I still feel that photo resist is the way to go if you do desire the VSOP devices only because you should not get the pitting and your line accuracy (we haven't even gotten into the waviness of the lines) increases because photo positive developed can hold a 2µm accuracy. I hear nothing as to this ad-hock toner system in expected accuracy. At 1200 DPI and mechanically transferring all of that in an system that creates too many unknowns (consistency between lamination passes for instance).
Sort of reminds me of talking to Crashsite. Do you suppose ?DirtyLube said:You ramble a lot and make a lot of conclusions that are contrary to the facts that are presented. It's very strange.
I would like to see you use a soldering iron on a 10 mil trace. Maybe you make a U-tube video for the only person on the planet that can solder with a soldering iron on 10 mil traces. This is a tall tale.
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