Silicone heat resistant mats vs ESD safety - Page 1
Forum section: electronics / general

author: VSV_electron
author_rank: Regular Contributor
timestamp: March 26, 2023, 04:34:09 am
content: I've just spent some time reading through lots of similar threads on ESD mats. I now know (or at least I think I know) about the theory behind the construction of properly designed 2 or 3 layer ESD mats.However my question is on the typical Asian silicone heat resistant mats which are not ESD safe. They are found in different colors (but mostly blue) and sizes on various Internet market places.Isn't that some sort of contradiction to the ESD safety to use such a mat for soldering the ESD sensitive boards risking to damage them with the static charge?Is there a way to prevent these silicone mats from building up the static charge in them?One thing I'm not sure about is the terminology used for the ESD safe mats. The top layer is dissipating. Does 'dissipating' equal 'insulating' in this case? Something tells me that it is not and those are different physical qualities when they are applied to a material in question.Is the silicone heat resistant mat able to dissipate static charge? I know those pads are insulators. So perhaps the properly formulated question would be this: 'Can the insulator such as silicone mat dissipate static charge?'Suppose you charge the silicone mat with the static electricity by rubbing it with your acrylic sweater sleeves.Next you place an assembled board on the pad to solder/unsolder some components and... what? - Goodby the board? (Or in other words: 'Let's replace some more stuff on the board'?).Since many people buy those cheap silicone pads for repair job and general electronics projects, isn't that stupid taking into consideration the well known ability of those pads to damage the boards so easily with the static charge?

author: VSV_electron
author_rank: Regular Contributor
timestamp: March 26, 2023, 02:59:31 pm
content: Sadly there have be no replies so far on this "sensitive ESD" concern. :-)So I went ahead and decided to see if anyone has ever addressed this subject on YT with the emphasis on protecting the boards from the static discharge.Luckily I quickly found the Noel's video exactly on the subject (see his video at the bottom). You probably know Noel from the Retro Lab if you watch YT.Note: I wasn't in doubt regarding the ESD safety when posting this thread. I simply was surprised on the amount of YT videos advocating the ESD_NOT-safe silicone mats for electronic repairs and the lack of common sense (or maybe specific knowledge?) for avoiding them for that purpose.You can see for yourself how the ESD UN-safety is propagated on YT...https://www.youtube.com/results?search_query=silicone+soldering+matNoel's video:

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2023, 08:26:43 pm
content: Quote from: VSV_electron on March 26, 2023, 06:02:30 pmYou will have to accept that to many of us native English speakers, mixing up those two is a huge pet peeve. Even more so in electronics where a) silicon semiconductors are such a transformative technology, and b) we usebothof those things in the discipline, since we use silicon chipsandsilicone rubbers, lubricants, and adhesives.The “internet” claim that they’re often used interchangeability is true, but only in the sense that there are millions of examples of people using them in incontrovertibly incorrect ways. Frequent incorrect usage doesn’t mean it’s considered accepted or acceptable! (And this refers to both spelling and pronunciation, both of which get confused by the uneducated.)Anyway, I have a silicone baking mat, and I barely use it because of how much dust it attracts — I have to scrub it down with soap and water every time I want to use it for food, because it WILL attract all the dust from seemingly the entire apartment even just sitting in a drawer. So I have been quite skeptical of those silicone soldering mats. Maybe the manufacturers are smart and included a conductive additive (the way that ESD mats use carbon added to the rubber), but I don’t know whether they do or not. As such, I would be reluctant to use one for soldering. I just use a regular rubber ESD mat, with a large piece of blank FR4 as a soldering “placemat” to protect the mat from heat damage.

author: TimFox
author_rank: Super Contributor
timestamp: March 26, 2023, 09:58:27 pm
content: "dissipating": that layer must be conductive/resistive to dissipate charge."FR4" is the ubiquitous glass-epoxy laminate with a fire-resistant rating.From one of many quick results on Google:"FR4 is a class of printed circuit board base material made from a flame retardant epoxy resin and glass fabric composite. FR stands for flame retardant and meets the requirements of UL94V-0. FR4 has good adhesion to copper foil and has minimal water absorption, making it very suitable for standard applications."We native-speakers of English have hated the confusion of "silicone" and "silicon" since the time when "silicone" breast implants resulted in vulgar references to "silicone" semiconductors.Similarly, there is a clear distinction between "oxygen" and "oxide" in English and technical usage.

author: Gediminas
author_rank: Regular Contributor
timestamp: December 15, 2023, 08:44:05 pm
content: I made Video on this subject, in case someone is interested...

author: YouCanDoIt
author_rank: Regular Contributor
timestamp: March 11, 2024, 11:48:41 am
content: I want to thank you for this thread. I have purchased (at this point I would say by mistake) one of such silcon (or silicone? I have yet to understand the differences and if one of the twos is the one to be ESD safe) mats.QuoteI think that lot of people don't have the minimum idea on how is complex the ESD world. When they do an order for some items, they see accidentally such mats and wrist straps and given the cheap cost, given they know from very long time ESD protection is a concern that should be addressed, they just add them to the cart thinking they are done. When they receive the stuff, they attach the wrist strap to the mat and they think they are ready to go.I have done the same except with the following well in mind: "Ok, lets buy the most essential things and once received let investigate on what is missing in order to build a safe workstation".When I started the investigation (a week ago) I have discovered a very complex world where opinions are highly controversial. Most of the times I had to notice that what someone considers a good setup, for another one is completely bad.Until now I'm still very confused:OnAmazonand elsewhere there are full ESD safe workstation kits and they include such silicon mat. At this point, based on Noel's video and similar I have to believe that exist variants that are really ESD safe or they do false advertising. Noel talks aboutbluesilicon mat, but I see in the asian marketplaces the sameblackvariant. They are identical, so I suppose the only difference is the color. it's very confusing because in the customer review section people confirmed esd safety:Noel's video illustrated well the safety of ESD mat, but at the end of the video he also showed all the bad things. No heat resistance and unavoidable damages. He have not mentioned how much is difficult to work on a flat surface like that. The silicon mat solves all of these problems in addition to provide a very convenient organizer for all the stuff.Would be possible to combine both the mats and keep the same safety?I spent most of the time trying to sort outhow I could avoid the connection to the wall socket. Many people talks about thelethal dangerswhen playing with a socket that output electricity with no limit and unfortunately seems to be that thewall socket is the only safe way to ensure an ESD safe environment. People said that a good ESD wrist strap and Mat have a resistor to also lower any possible risk from a dead short. Well, I have checked mine and it is 1 Mega Ohms as should be (didn't checked the silicon mat for obvious reasons), however, whether this is true or not, I still feel scared to the thought that my life depends from a small chinese piece inside a cable. So, I'm thinking to add to my setup some sort ofmonitoring toolin order toprevent any kind of shock hazardwith the ability todetect and warn in case of an abnormal esd status. What you would recommend?How did you finally managed to build your environment? And have you been able to address the 3 concerns above?Thanks

author: YouCanDoIt
author_rank: Regular Contributor
timestamp: March 11, 2024, 12:45:48 pm
content: Quote from: Gediminas on December 15, 2023, 08:44:05 pmYour video really helped. So, even if good quality and temperature resistant it is still easy do damage. The version you show is rubber based, so I suppose it should provide a minimum of anti-slip effect to any board placed above. Problem is that where such ability is most needed is in the soldering phase (which requires some protection sheet to prevent damage). I can't imagine a paper stick able to keep a board firmly. A cotton towel may be better, but I'm afraid it is still not enough for high precision soldering where a small movement can cause issues. Had you chance to compare a silicon mat with the workarounds used in your mat?Noel's video illustrated at the end of video how easily the mat becomes damaged even with simple movement of the board. Same with your mat?I would first try to understand if it is really true about the non safety of such mats because I saw conflicting opinions (see point one of my list of concerns).

author: YouCanDoIt
author_rank: Regular Contributor
timestamp: March 11, 2024, 01:03:21 pm
content: Quote from: tooki on March 26, 2023, 08:26:43 pmI have not seen any report about such problems with dust and the ones I saws are advertised as anti-dust. So, may be you're right, they're now using some additive to prevent that. I can't find anyone who uses a blank FR4 as a soldering “placemat”. The one I saw in pictures seems to be very slippery and I can't imagine how could be possible to use them for soldering (even worse for high precision soldering), but my eyes could fool me.

author: tooki
author_rank: Super Contributor
timestamp: March 12, 2024, 08:37:24 pm
content: Quote from: YouCanDoIt on March 11, 2024, 11:48:41 amSiliconis the element (14 on the periodic table) from which semiconductors, abrasives (silicon dioxide, aka carborundum; also used as an additive in salt to prevent clumping) and silicones are made. (In many languages, the equivalent word is something like “silicium”, e.g. German “Silizium”.)Silicone, also called polysiloxane, is an oil or polymer based on silicon. Normally encountered as oil, gel, and rubber. (In languages that call the element “silicium”, the word for silicone is similar to English, e.g. German “Silikon”.)People frequently confuse the two terms, and additionally some people distinguish between them in writing, but pronounce them the same!Basically, unless you’re talking about semiconductors or abrasives, you likely mean “silicone”. Rubber? Silicone. Breasts? Silicone. Lubricant? Silicone. Sealant? Silicone.

author: eutectique
author_rank: Frequent Contributor
timestamp: March 13, 2024, 03:35:59 am
content: Silicone Valley and Silicon Valley are two distinct areas.

author: tooki
author_rank: Super Contributor
timestamp: March 13, 2024, 09:16:33 pm
content: Quote from: eutectique on March 13, 2024, 03:35:59 amIndeed!!

author: YouCanDoIt
author_rank: Regular Contributor
timestamp: March 14, 2024, 02:18:58 pm
content: Thanks for the responses! If I have understood well, whether they are silicon or silicone, it doesn't make difference. They're both not ESD safe. I still can't explain the meaning of the posted photo. At this point I have to believe that it is just false advertising or tests performed in the wrong way.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2024, 08:58:24 am
content: Quote from: YouCanDoIt on March 11, 2024, 01:03:21 pmFR-4 boards are no less slippery than an ESD mat in practice — the fact that most PCBs are quite lightweight means that they slide easily on practically any surface. So if you need something to not move around at all, you will need to secure it no matter what, whether by using “helping hands” or taping it down with Kapton tape or blue-tack or something. On the other hand, for microscope work, including soldering, I prefer the smooth surface of the FR-4, because if I need to slide the board a tiny amount, on the FR-4 it will just go easily, whereas on the textured surface of the ESD mat, it can slide unevenly, or snag. (Also, the mats don’t always lay 100% flat. The FR-4 is absolutely flat.) Every place I’ve worked, the electronics people use FR-4 and/or phenolic boards and/or veroboard to solder on when needed.Soft surfaces like cotton or a paper towel can occasionally be useful, but not for precision work, because stuff wiggles way too much on them.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2024, 09:12:48 am
content: Quote from: YouCanDoIt on March 14, 2024, 02:18:58 pmI don’t think you have understood, then. There is no such thing as a silicon mat.Quote from: YouCanDoIt on March 14, 2024, 02:18:58 pmWho knows. Maybe some manufacturers actually do make properly ESD-safe silicone. Unfortunately there’s no way to know from just their photos, since those are so often faked. You’d have to buy one and test it.Quote from: YouCanDoIt on March 11, 2024, 11:48:41 am2. An ESD mat has a few jobs: to provide an ESD-safe work surface (even if the table surface itself is not ESD-safe); to protect the table surface; and to protect your workpieces (since it is slightly soft). And in the case of a metal table surface, it has one other hugely important task: to provide a fundamentally insulating surface to work on, so that your PCBs don’t short out when you power them up directly on the bench. Notably absent from the list: “looking pretty”.3. They sell ESD plugs to go into your wall socket to connect the ground only. But you can also build one yourself by buying a plug (the kind sold for making your own power cables or for repairs) and simply connecting only a ground wire. You need to have the 1Mohm resistor somewhere, but wrist straps normally contain it anyway. The mats already have substantial resistance, so they don’t really need a series resistor. I have my mat connected to the enclosure of a power supply, which in turn is grounded.