tag:blogger.com,1999:blog-175004091875960054.post4709678844314319552..comments2024-02-28T04:16:24.345-08:00Comments on Silicon Exposed: BGA process notesAndrew Zonenberghttp://www.blogger.com/profile/16821509563933020441noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-175004091875960054.post-62764629158603597122021-06-20T03:04:50.442-07:002021-06-20T03:04:50.442-07:00amazing article on how you have describes the enti...amazing article on how you have describes the entire process in a simple way<br /><br /><a href="https://toasterovenshub.com/" rel="nofollow">best affordable toaster ovens for kitchen .. </a>toasterovenshubhttps://www.blogger.com/profile/03915389012100783888noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-30111194932137831202020-04-25T13:46:06.341-07:002020-04-25T13:46:06.341-07:00Thanks For sharing an amazing article on toaster o...Thanks For sharing an amazing article on toaster ovens you have described it in <a href="http://besttoasterovens2020.com/" rel="nofollow">detail</a>Online Gaming Forumhttps://www.blogger.com/profile/14351237453148941608noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-35541329969345877582012-08-18T05:41:26.120-07:002012-08-18T05:41:26.120-07:00I find that the power and NC balls are usually eno...I find that the power and NC balls are usually enough to deal with this. I forget exactly how many balls I'm using in this design but it's most of them... http://i.imgur.com/bTHyx.pngAndrew Zonenberghttps://www.blogger.com/profile/16821509563933020441noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-72602071767838891642012-08-17T23:16:00.747-07:002012-08-17T23:16:00.747-07:00With a 1-mm grid and 6/6 rules, the maximum via di...With a 1-mm grid and 6/6 rules, the maximum via diameter would be 540um (21.4 mils). This only matters for the fourth row where you have to squeeze traces past another row of vias to escape on the bottom layer. Sacrificing an occasional via from the third row might mitigate this?<br />haunmahttps://www.blogger.com/profile/17824319190609806134noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-38027165280672819032012-08-17T18:08:56.096-07:002012-08-17T18:08:56.096-07:00I think I've pushed the via ring even smaller ...I think I've pushed the via ring even smaller in really tight spots (580um or so sound right?)<br /><br />I've done some pretty extensive characterization of Laen's process and I've found that drill registration is dead on and you can almost always get away with significantly smaller rings than the official minimums. Standard disclaimer applies, this is a "use at your own risk" process tweak and isn't guaranteed to work (or have good yields in high volume).<br /><br />That being said, I've made something like a dozen boards including five FTG256s and have not had one fail yet. If you push the rules only where necessary, you should be fine.<br /><br />The fab is capable of much better resolution than his advertised rules, and if you pay extra ($75 flat fee for the entire panel, IIRC) you can get 5/5 rules and smaller rings guaranteed. So basically your options are to cheap out and take the risk, or pay a little extra for peace of mind.Andrew Zonenberghttps://www.blogger.com/profile/16821509563933020441noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-48167366222219309182012-08-17T16:33:12.259-07:002012-08-17T16:33:12.259-07:00Thanks. So that matches Laen's specified mini...Thanks. So that matches Laen's specified minimum drill, but the "annular ring" ends up being ~ 5.5 mils (140 um). The minimum is supposedly 7 mils, unless the "minimum drill" is actually the unplated hole, in which case the plated hole is a couple mils narrower and the annular ring ends up where it should be.<br /><br />One more question: For escaping the BGA's third and fourth rows in, if you use one via per ball in "dog-bone" fashion (vias centered between four pads), then you end up with a grid of 610-um vias on 1000-um centers. With your min trace/space width, the gaps aren't wide enough to route a trace between the vias. So how does the fourth row get out?<br />haunmahttps://www.blogger.com/profile/17824319190609806134noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-62876426437465462272012-08-17T12:30:26.719-07:002012-08-17T12:30:26.719-07:00I don't remember what the rules on the website...I don't remember what the rules on the website are but this is what I've been using:<br /><br />Min trace width: 152 μm<br />Min space: 152 μm<br />Min drill: 330 μm<br />Min via diameter: 610 μm<br /><br />Pad-to-mask clearance: 50 μm<br /><br />The BGA pads are 400 μm diameter on 1000μm centers.Andrew Zonenberghttps://www.blogger.com/profile/16821509563933020441noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-13896556749323408752012-08-17T12:26:10.224-07:002012-08-17T12:26:10.224-07:00Hey Andrew,
This is great. I've been looking...Hey Andrew,<br /><br />This is great. I've been looking for examples of 1mm BGA with the OSH Park boards. Could you share your pad/via rules for the FTG256? I haven't been able to figure out how the dogbone vias would fit given the stated 13mil/7mil minimums for drill and annular ring. That would seem to dictate a minimum via diameter of 27 mils, way too big.<br /><br />haunmahttps://www.blogger.com/profile/17824319190609806134noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-38006488837712778772012-07-07T11:30:57.296-07:002012-07-07T11:30:57.296-07:00On two layers or four? 0.8mm (CSG324 etc) and 0.5m...On two layers or four? 0.8mm (CSG324 etc) and 0.5mm (CSG196 etc) lead pitch are not really possible on those rules but 1mm (FTG256) is very doable. FGG484 is 1mm too but needs six layers to break out completely.<br /><br />Here's a sneak preview of a spartan6 FTG256 board I made on the oshpark 4-layer process:<br /><br />http://i.imgur.com/dzC2X.jpg<br /><br />http://colossus.cs.rpi.edu/~azonenberg/downloads/s6sbc-datasheet.pdfAndrew Zonenberghttps://www.blogger.com/profile/16821509563933020441noreply@blogger.comtag:blogger.com,1999:blog-175004091875960054.post-33369904512870021352012-07-07T00:59:46.349-07:002012-07-07T00:59:46.349-07:00Awesome work! I'm also interested in hobbyist-...Awesome work! I'm also interested in hobbyist-accessible assembly of boards using the BGA Spartan-6 parts and am keen to see if you're able to escape a useful number of signals from one using Dorkbot/OSH Park's fab tolerances.<br /><br />I had a bit of a play around with the footprint once and wasn't convinced that it would be possible! I can't remember exactly which package I tried to target though.Anonymoushttps://www.blogger.com/profile/16011363726949920188noreply@blogger.com