JLCPCB 6 layer, plugged and plated via in pad, with ENIG, FOR $20!!!!!! - Page 1
Forum section: electronics / general

author: AnasMalas
author_rank: Regular Contributor
timestamp: November 04, 2022, 09:18:40 am
content: They do so for 6 layers, and apparently it is going to be cheaper for 4 layers.Here's their article for it, although I have not found a way in the quote portal to select whether or not I want vias to be filled. Do they just fill all of themhttps://jlcpcb.com/help/newsdetail/019666d056614efca51a965283c90751/86e689fe1363412d9ae61002e3de27f6Edit: Yeah so they casually dropped that the 6 layer board is now $20. Holy sh*t

author: asmi
author_rank: Super Contributor
timestamp: November 04, 2022, 06:13:10 pm
content: That's good. I wish they would start offering more high-speed-friendly 6 layer stackup as existing one only allows for top and bottom layers to be used for high-speed signals due to thick dielectric between layers 2-3 and 4-5.

author: sokoloff
author_rank: Super Contributor
timestamp: November 04, 2022, 07:21:48 pm
content: I wonder why the subject line for this thread is blank. (Makes it difficult to click to open it.)When adding a comment, there is a subject line defined. Very strange.

author: AnasMalas
author_rank: Regular Contributor
timestamp: November 05, 2022, 10:13:36 am
content: Quote from: asmi on November 04, 2022, 06:13:10 pmI agree. I hadnt looked at thier 6 layer options before. But when I posted this and went to have a look I was very confused... It's like 3 2-layer boards stuck together... You can do sig/gnd/sig+pwr/gnd/gnd/sig or sig/pwr/gnd/sig/gnd/sig but only if signals on layer 1 stay on that layer. Oh wellQuote from: sokoloff on November 04, 2022, 07:21:48 pmVery weird! I see it just fine

author: aeg
author_rank: Regular Contributor
timestamp: November 06, 2022, 10:32:09 am
content: Quote from: sokoloff on November 04, 2022, 07:21:48 pmYour ad blocker is removing the link because the URL contains the string "offers".

author: Kasper
author_rank: Frequent Contributor
timestamp: November 11, 2022, 04:22:17 pm
content: Quote from: AnasMalas on November 05, 2022, 10:13:36 amWhy do you say signals must stay on layer 1? Are you familiar with layer change caps?Doesn't look like JLC does blind vias but thin outer dielectric is useful for that. So you can get a feasible aspect ratio on blind micro-vias.

author: AnasMalas
author_rank: Regular Contributor
timestamp: November 12, 2022, 06:49:21 am
content: Quote from: Kasper on November 11, 2022, 04:22:17 pmYes. I dont think they are not good enough for return current for multiple reasons including via inductance, capacitance resonance (a 10 ns rise time can be found on a cheapo MCU. That's 100 MHz, way past your average 0.1 uF mlcc's 2-10 MHz resonance).The only good way for return current to go from pwr to gnd layers is if they are REALLY close together. In a 10 layer board that has a [s g s s g p s s g s] stackup, you can go from 4 to 7 and vise versa without a stitching via just as you can do so with layers 1 and 3. You can go from layer 1 to 4 with a stitching via, and then move the trace to layer 7 later on, but you cannot go from layer 1 to 7.Meanwhile a [s g p s] 4 layer stackup is one of the worst stackups you can use, unless on that stackup signals never leave their layers. A [s g p s] 4 layer stackup would work well enough for transitioning layers, but no one in their right mind would do that.The stackup I suggested and said to never move a signal from layer 1 was sig/pwr/gnd/sig/gnd/sig, which with their "best" stackup for this would look like [s p g s g s]. They also offer it like this [s p g s g s].Imo the best 6 layer stackup is [s g s p g s], which they dont offer.

author: DavidAlfa
author_rank: Super Contributor
timestamp: November 12, 2022, 06:53:34 am
content: Yeah but 50x50mm

author: AnasMalas
author_rank: Regular Contributor
timestamp: November 12, 2022, 06:58:41 am
content: Quote from: DavidAlfa on November 12, 2022, 06:53:34 amTouché, but you get 5 of them. For between $60 and $70 you can get upto 120x120mm50x50mm could be good enough for a little adapter card, for example for putting a high pincount chip with most of that it needs on a 2 layer power supply board or whatever

author: Kasper
author_rank: Frequent Contributor
timestamp: November 12, 2022, 07:12:55 am
content: Thank you for explaining.

author: Ian.M
author_rank: Super Contributor
timestamp: November 12, 2022, 09:08:14 am
content: Quote from: aeg on November 06, 2022, 10:32:09 amIf using uBlock Origin, disabling cosmetic filtering on eevblog.com resolves the vanishing post title issue.