Grow Project : Sun_burns Every Summer !

guod

Well-Known Member
no need for diodes, simple bridge is enough. the recom can go easily down to 10V
 

stardustsailor

Well-Known Member
.....They ask way much ,for a tiny pad stencil ...
Right thickness is 120 um (Osram Suggested ) .(thickness of solder paste=thickness of stencil foil/sheet..)
solder fackin paste trouble.JPG...


Yeah ,right ....
I'm doing my best ,ya know ...

How to apply 100-150 um solder paste in the pad ?


Hmmmmmm.......

.....
 

stardustsailor

Well-Known Member
Stencil stupid idea #1 :

Take the base of fried Oslon.(Unsolder it first from pcb and remove as much solder as possible ...)
Heat it at 200-300 °C ....
Place it over thin plactic foil ..( i.e Mylar ..) ...

metal pads will burn their way ,through thin plastic(100-150 um ) foil ....
Leaving the so bewished stencil ....
(Underneath better have a total flat metal surface to absorb heat instantly ,so to avoid " over melting " the edges of stencil ....


Shit ..Do I have to decrease weed consumption ?
 

stardustsailor

Well-Known Member
Hey ....

Wait a min ...
I have a hand held cutting laser ...
It can cut any plastic foil ......

No...

Cut a stencil of that size,manually by hand ?
I'm too old for that .....
My eyes lack the ... image resolution,contrast and magnification needed ,for such a job ...
And my hands most of times are trembling rather much ..... ..Peeing 'n ' jerking ,feeling the same ....;-P

Anyway ...
 

stardustsailor

Well-Known Member
Just kiddin with light now ...

P3026218.jpgP3026220.JPGP3026221.JPG...

(I've made some pretty interesting tools...like the " Viole(n)t light scalpel " shown here ....
Used to be-in it's previous silicon-based life form - a mere ,worthless Blue-ray recorder ....
Now it lives it's legend ..
My little light saber ,there ...)
 

picolada

Well-Known Member
Just kiddin with light now ...

View attachment 2548615View attachment 2548616View attachment 2548617...

(I've made some pretty interesting tools...like the " Viole(n)t light scalpel " shown here ....
Used to be-in it's previous silicon-based life form - a mere ,worthless Blue-ray recorder ....
Now it lives it's legend ..
My little light saber ,there ...)
nice SDS!
when i saw your pictures i remembered a video which i watched for making a laser with a ligter..:lol:
http://www.youtube.com/watch?v=5erjj6aS5Ws&feature=player_embedded#!
 

stardustsailor

Well-Known Member
....I can't bridge the damn led ....
Here ,I admit it .....

Way tiny contacts ....
I've to think someting else ....

Tried to unsolder the base ,by touching the solder gun tipless onto the led base .....
Not only didn't unsolder ...
When I removed (burning hot blue-purple ) solder gun from led base and immediately placed my finger ,
so to "feel " where I "stand " ....
Dam' it ...
I must have done a great job .......
....
Led base was cold as ice ....
With more than 3 min ,in close touch with the solder gun .....
Heat gets "sucked up " immediately ...
....
Cool ....

But how one gets to rework a mc pcb placed on a 2 kg heatsink ,huh ?
How ?
 

stardustsailor

Well-Known Member
Sometimes the solution is just there , in front of our eyes .....
P3026223.JPGP3026224.JPG.........

Back on the game .....With one red less ...
(Reds are taking their revenge on me ..... )
P3026225.JPGP3026226.JPGP3026227.JPG.........

[video=youtube;U6tV11acSRk]http://www.youtube.com/watch?v=U6tV11acSRk[/video]
 

stardustsailor

Well-Known Member
Take a peek of making of the "bucks' pcb " of ..second box ......


From etching process......
P3026228.JPG...

To solder paste applying for soldering (hot-plate ) the ' 1206 package ' smd resistor at Vref ....
P3026229.JPG.....


Hot-plating done ....
P3026231.JPG....

Sprayed with protective transparent-bluish lacquer .....(Teslanol T7 )
P3026234.JPG...

Ready for drilling holes .....

[video=youtube;FDYIdBZUl2Y]http://www.youtube.com/watch?v=FDYIdBZUl2Y[/video]
 

Chronikool

Well-Known Member
She lives again! :)

Bit of a New Zealand flavour in the mix.....loving it....although they should have stuck with their D'n'B.... :)
 

stardustsailor

Well-Known Member
Well ....Mostly out of curiosity ....
Took an ordinary plastic card ( credit sized .. ) ..
Laser cut it ,manually by hand ,in less than 3 min ...
Not much "care " taken for the stencil to be good ...
(Just for the fun of it ... )

Applied stencil to a mcpcb ...
And with finger ,pressed solder paste....

Card ( the wanna-be stencil ....) removed ....

P3036235.JPGP3036237.JPG....

Not so bad .....Ok,it's crooked,uneven ,pathetic ...
But not bad at all,regarding the way that was done and the time consumed ....

I bet I can make way better stencil than that ....

Even better with a special tiny drill ...
On a transparent plastic foil ....

( So I can see ,where exactly I'm placing the stencil ....)

Can do it from metal (S.steel ) sheet and chemically etch away ,the stencil pattern ...
(HCl + H2O2 )
But with this metal stencil ,I won't be able to see ,where I'm placing it ,precisely ...
(Although stencil pattern would be almost perfect ...Thermal transferring the laser toner again .... )

So ...Transparent foil 100-150 um ,is what I need .....
And a steady hand .....
 

salmone

Well-Known Member
...maybe...http://bonybrown.blogspot.gr/2013/01/home-made-solder-paste-stencil.html

Preliminary Recommended Stencil Aperture

Solder Stencil

The application of solder paste has a significant influence on the solder quality of the component.
Since it is the cause of around 60 – 70 % of all failures which arise during the SMT assembly process,
this generally represents the most critical process in the entire process chain.
In the industry commonly laser cut stencils, usually made from stainless steel (CrNi) or electroformed stencils (Ni) are used.
Aperture sidewalls are typically trapezoidal (5°) to ensure a uniform release of the paste
and reduce solder smearing or so called edge tears.
In order to achieve a high quality soldering, the solder paste must be applied in the exact position,
geometry and precise volume is required.
The volume of the printed solder paste is determined by the stencil aperture (Opening of the stencil) and the stencil thickness.
The solder - joint thickness (Standoff Height) for OSLON LED should be typically between 50 µm to 75 µm,
which is directly influenced from the amount of solder printed on the center thermal pad (Heat slug) area.
Stencil thickness used in industry SMT assembly process varies from 100 µm to 150 µm (0,004 in to 0,006 in) range,
with typical 120 µm for OSLON LED.
However the actual used stencil thickness depends on the other SMD components on the PCB....

http://www.i-led.co.uk/PDFs/OSLON-SSL-soldering.pdf

https://www.youtube.com/watch?v=JWUJtmgh55M

https://www.youtube.com/watch?v=W-FXD6zQ60g

https://www.youtube.com/watch?v=vj8c83QzANw

http://www.instructables.com/id/Making-stencils-for-solder-paste-at-home/?ALLSTEPS

http://rayshobby.net/?p=1246

...Thanks...
 
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