https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 I think the frequency should settle down to 1/(10*Tpd) but it doesn't. We might do some pcb footprint tests for the tiny EPC fets, and I thought a board with a lot of ring oscillators would be a good way to test for good soldering. The EPC data sheet recommends a tiny solder-mask-defined pad arrangement that the board houses don't do well. I want to try some big klunky pads with conventional mask clearances. -- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
GaN fet ring oscillator
Started by ●June 14, 2021
Reply by ●June 14, 20212021-06-14
Am 14.06.21 um 17:27 schrieb jlarkin@highlandsniptechnology.com:> > https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 > > I think the frequency should settle down to 1/(10*Tpd) but it doesn't. > > We might do some pcb footprint tests for the tiny EPC fets, and I > thought a board with a lot of ring oscillators would be a good way to > test for good soldering. > > The EPC data sheet recommends a tiny solder-mask-defined pad > arrangement that the board houses don't do well. I want to try some > big klunky pads with conventional mask clearances.JLCPCB had absolutely no problem with the datasheet pads. All it did was to trigger a request for confirmation that solder mask ON parts of the pad was intended. Gerhard
Reply by ●June 14, 20212021-06-14
On Mon, 14 Jun 2021 18:01:41 +0200, Gerhard Hoffmann <dk4xp@arcor.de> wrote:>Am 14.06.21 um 17:27 schrieb jlarkin@highlandsniptechnology.com: >> >> https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 >> >> I think the frequency should settle down to 1/(10*Tpd) but it doesn't. >> >> We might do some pcb footprint tests for the tiny EPC fets, and I >> thought a board with a lot of ring oscillators would be a good way to >> test for good soldering. >> >> The EPC data sheet recommends a tiny solder-mask-defined pad >> arrangement that the board houses don't do well. I want to try some >> big klunky pads with conventional mask clearances. > >JLCPCB had absolutely no problem with the datasheet pads. >All it did was to trigger a request for confirmation >that solder mask ON parts of the pad was intended. > >GerhardPCBWAY did this: https://www.dropbox.com/s/v6isv7k1t3fre0w/PCBWAY_Mask.jpg?raw=1 Q1 is horrible. And a US board house recently complained about the solder mask resolution requirement. I like the idea of bigger conventional pads; the thermals will be better too. -- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
Reply by ●June 14, 20212021-06-14
On Monday, June 14, 2021 at 9:57:50 AM UTC-7, jla...@highlandsniptechnology.com wrote:> https://www.dropbox.com/s/v6isv7k1t3fre0w/PCBWAY_Mask.jpg?raw=1 > > Q1 is horrible.Try WellPCB. US board houses are good at getting the most out of 20-year-old processes and equipment, and at whining about competition from China, but not at much else. -- john, KE5FX
Reply by ●June 14, 20212021-06-14
On Mon, 14 Jun 2021 09:57:36 -0700, jlarkin@highlandsniptechnology.com wrote:>On Mon, 14 Jun 2021 18:01:41 +0200, Gerhard Hoffmann <dk4xp@arcor.de> >wrote: > >>Am 14.06.21 um 17:27 schrieb jlarkin@highlandsniptechnology.com: >>> >>> https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 >>> >>> I think the frequency should settle down to 1/(10*Tpd) but it doesn't. >>> >>> We might do some pcb footprint tests for the tiny EPC fets, and I >>> thought a board with a lot of ring oscillators would be a good way to >>> test for good soldering. >>> >>> The EPC data sheet recommends a tiny solder-mask-defined pad >>> arrangement that the board houses don't do well. I want to try some >>> big klunky pads with conventional mask clearances. >> >>JLCPCB had absolutely no problem with the datasheet pads. >>All it did was to trigger a request for confirmation >>that solder mask ON parts of the pad was intended. >> >>Gerhard > >PCBWAY did this: > >https://www.dropbox.com/s/v6isv7k1t3fre0w/PCBWAY_Mask.jpg?raw=1 > >Q1 is horrible. > >And a US board house recently complained about the solder mask >resolution requirement. I like the idea of bigger conventional pads; >the thermals will be better too.My proto boards just arrived. This is pretty ugly: https://www.dropbox.com/s/pyeibpqfmd9oxl8/Z498_GaN.jpg?raw=1
Reply by ●June 14, 20212021-06-14
John Miles, KE5FX wrote:> On Monday, June 14, 2021 at 9:57:50 AM UTC-7, jla...@highlandsniptechnology.com wrote: >> https://www.dropbox.com/s/v6isv7k1t3fre0w/PCBWAY_Mask.jpg?raw=1 >> >> Q1 is horrible. > > Try WellPCB. > > US board houses are good at getting the most out of 20-year-old > processes and equipment, and at whining about competition from China, > but not at much else. > > -- john, KE5FX >Nah, Pentalogix and Screaming Circuits are both tops. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●June 14, 20212021-06-14
John Larkin wrote:> On Mon, 14 Jun 2021 09:57:36 -0700, jlarkin@highlandsniptechnology.com > wrote: > >> On Mon, 14 Jun 2021 18:01:41 +0200, Gerhard Hoffmann <dk4xp@arcor.de> >> wrote: >> >>> Am 14.06.21 um 17:27 schrieb jlarkin@highlandsniptechnology.com: >>>> >>>> https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 >>>> >>>> I think the frequency should settle down to 1/(10*Tpd) but it doesn't. >>>> >>>> We might do some pcb footprint tests for the tiny EPC fets, and I >>>> thought a board with a lot of ring oscillators would be a good way to >>>> test for good soldering. >>>> >>>> The EPC data sheet recommends a tiny solder-mask-defined pad >>>> arrangement that the board houses don't do well. I want to try some >>>> big klunky pads with conventional mask clearances. >>> >>> JLCPCB had absolutely no problem with the datasheet pads. >>> All it did was to trigger a request for confirmation >>> that solder mask ON parts of the pad was intended. >>> >>> Gerhard >> >> PCBWAY did this: >> >> https://www.dropbox.com/s/v6isv7k1t3fre0w/PCBWAY_Mask.jpg?raw=1 >> >> Q1 is horrible. >> >> And a US board house recently complained about the solder mask >> resolution requirement. I like the idea of bigger conventional pads; >> the thermals will be better too. > > My proto boards just arrived. > > > This is pretty ugly: > > https://www.dropbox.com/s/pyeibpqfmd9oxl8/Z498_GaN.jpg?raw=1 > >Blech. Who perpetrated that one? Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
