Which hotplate to do imperial 0201, 0402 and 0603 - Page 1
Forum section: electronics / general

author: Wilson__
author_rank: Frequent Contributor
timestamp: September 26, 2024, 01:23:29 am
content: Which hot plate can doimperial 0603, 0402 (and even 0201)prototyping? Two or four layers, 0.6 or 0.8mm board thickness. Normal pcb material.Is the photo unit ok? 100 by 100mm, 550 watts, 39 USD at Amazon. No auto temperature profile. May manually set a few temperature points during the heating up period and roughtly following the temperature profile.It looks not too difficult on youtube videos. Slow and carefully hand place smd to, says, 80% correct position.Is 7X to 45X zoom stereo optical (not camera) microscope good for imperial 0201 RC?Does smaller smd size demand better solder paste, flux and hot plate? Is 63% tin, 37% lead solder easier for prototyping?Many thanks

author: Siwastaja
author_rank: Super Contributor
timestamp: September 26, 2024, 10:18:47 am
content: Get a bigger one if you can, you'll soon have a larger PCB to work on.I'm assuming you are going to use that for preheating and combine it with hot air from above, or manual soldering with soldering iron. For that kind of purpose the product is probably OK.Those Chinese ebay/aliexpress/amazon specials often have safety issues, so don't be too surprised if it electrocutes you to death or catches fire. My HYLKKO brand hot air station had 50 ohms of resistance in protective earth binding by having crimped one small and oxidized strand of copper in the ring lug. Which was quite a feat, I would expect to see >1Mohm or <1ohm, nothing in between.

author: SMTech
author_rank: Frequent Contributor
timestamp: September 26, 2024, 11:57:48 am
content: Magnification or not, 0201 will be a challenge to work with. I'm sure some smartarse will come on here and say they fit 800+ an hour with nothing but tweezers, but for mortals 0201 is pretty small and therefore has suitably small pads, tiny paste deposits and all the fun that is handling something that small and it not deciding the only place it wants to be is stuck to anything but the PCB..There's really little reason to go 0201&smaller unless you have pretty severe space constraints (which would present their own challenges) or taking extreme steps to obey the "place as close to X as possible" written in a datasheet. Anything below 0603 IMHO is where it really starts to ramp up the requisite skill and proper equipment really comes into its own.

author: Whales
author_rank: Super Contributor
timestamp: September 26, 2024, 12:10:22 pm
content: I prefer the smaller hotplate for rework. A small (100mm) hotplate can often fit underneath a PCB whilst avoiding the legs of TH parts. I generally design my boards to have no TH parts in the middle because of this.FWIW I don't go below 0603. I prefer 0805 and only go smaller when I have to. I have no problems hand-dosing solder for these sizes, but 0.5mm pin pitch parts are a pain and make me wish for stencils.

author: Wilson__
author_rank: Frequent Contributor
timestamp: September 26, 2024, 12:35:32 pm
content: Quote from: Siwastaja on September 26, 2024, 10:18:47 amMany thanks. For the first prototype, it will be a blank virgin pcb. I want to use it for soldering without hot air nor soldering iron. Youtube video shows, apply solder paste, carefully hand pick chip slower, heat up whole pcb on hot plate and done.yes, it can be used as preheat (web says 100 celcius) when I need to re-work and replace some chip.yes, those issue are known. At low price point, some are manufactured to different standard (which is properly stated in doc and people should respect that fact and know what they buy at that price point). At higher price point, somewill say they meet specific UL standard for US market (some are 110 volts only, some universal voltage).EDIT: if one is a business employer, one need to buy safety approved equipments at workplace to meet health and safety laws and employee insurrance and ... (thousand words follow)

author: Kean
author_rank: Unknown
timestamp: September 26, 2024, 12:59:55 pm
content: Yes, you can do full reflow of a PCB on these hotplates.They are a bit problematic in terms of temperature control, so are fine for prototyping but not really suitable for production.For example some models will not show when they overshoot the set point temperature, and mine can easily go 10C over and takes quite some time to settle due to thermal mass.In terms of component size, the hotplate doesn't really matter. What matters is paste application and component placement. Both start to get quite tricky at 0201 size.Lead based paste is still available from some places, and is certainly easier for reflow and rework on prototypes. I don't bother any more, and just use good quality lead free for everything to avoid mixing.

author: Wilson__
author_rank: Frequent Contributor
timestamp: September 26, 2024, 01:13:25 pm
content: Quote from: Kean on September 26, 2024, 12:59:55 pmWhat is higher quality (suitable for smaller smd chip) solder paste for soldering first prototype on virgin pcb (and may be also flux for replace RC)?Does paste has different solder ball size and need to use specific type for smaller SMD?

author: SMTech
author_rank: Frequent Contributor
timestamp: September 26, 2024, 01:42:58 pm
content: Solder ball size is denoted by the notation T3 / T4 / T5 and you can Google the ranges each of those denote. As a rule of thumb an aperture needs to be at least 5 balls across to be reasonably sure it will get through a stencil without jamming. This increases to 8 for a round aperture to get enough solder solder on the pad. This is for a stencil however, not the device. If you are dispensing you need to apply a similar rule using the ID of the needle as well as choosing a paste intended for dispensing, if possible. Stencils are far and away the easiest/best way to apply solder however, preferably framed.

author: Kean
author_rank: Unknown
timestamp: September 26, 2024, 01:54:27 pm
content: Yeah I use T4 paste for 0603 and 0402 designs. I like Loctite GC10, or at a pinch the Chipquick pastes. I will likely try Aim SAC305 M8 next.Basically avoid any solder paste sold on ebay/Amazon/Aliexpress. Chipquick can be bought from Digikey/Mouser/etc.I've only hand soldered 0201 parts, as I'm not (yet) silly enough to design anything with them. I have just used them for repairing damaged tracks, or painful design mods.

author: Wilson__
author_rank: Frequent Contributor
timestamp: September 26, 2024, 04:35:42 pm
content: Quote from: Kean on September 26, 2024, 01:54:27 pmIn old leaded age, flux was resin and wash by Isopropyl alcohol.Now leadfree age, some document say water soluable flux, some say they can be left un-washed. For prototype of quantity one, may be I want to wash it. Seem un-washed sticky to finger and osciloscope probing?For quantity of one prototype and usetin/lead 63/37% solder paste, for 0603 or 0402 imperial,what washing fluid to use?I need to place five of these chip. grid is 0.05mm in photo. lead width 0.2mm and spacing between pin 1 and 2 is 0.2mm.Is that doable for one prototype with that hot plate, good mouser/digikey solder/flux and good microscope for me, un-trained operator? May be if not good, desolder, clean and re-do, multiple times?

author: Kean
author_rank: Unknown
timestamp: September 26, 2024, 08:09:36 pm
content: The requirement for washing is about the type of flux, rather than whether the solder is lead free.You should read up on the different types of flux. There are lots of types for all the different process requirements out there.Here is an article that covers a lot of the details:https://www.pillarhouse.co.uk/technology/flux-choosing-the-correct-flux-type-technical-articleFor water soluble flux, you generally must wash the board within a short time frame after reflow to avoid problems.For no clean flux, you generally don't need to wash the board at all unless you have high impedance circuits or other requirements around cleanliness.There shouldn't be sticky flux left behind after reflow unless the flux wasn't properly activated and burnt off. That mostly happens with hand soldering or rework, in which case you'll need to clean.I don't use water soluble flux, so I mostly use isopropanol for spot cleaning. For full PCB cleaning, I use Electrolube SWAS in an ultrasonic cleaner (as long as all parts can handle immersion and ultrasonics), then rinse with deionised water.With regard to that small transistor, the main problem I suspect you will have is properly applying paste, and I'd recommend strongly to use a stencil. Prototype stencils are cheap these days.When placing the parts you want to avoid lateral movement that will spread the paste around. Try to place the component directly in alignment from above with as little sideways adjustment as possible.Before attempting soldering small parts, you really should get some basic experience with solder paste and reflow. If you don't have any PCBs at hand, you can easily find practice or hobby PCBs available to experiment with