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newbie toons

newbie toons

2011-08-02 by shoestring

Hello HPCBers,


I've this special project that requires some innovation to be practical 
on my budget.

The gallium nitride transistor is new, invented by a grad student in 
2006, and used by the military.  The cost of packages that exploit the 
ultra-fast dV/dt (4 volts per nanosecond) is upwards of $200 each.  I've 
seen as high as seven-hundred dollars for a GaN in a high-current package.

Good news... the raw die, with solder-bumps for reflow-soldering, is 
available for around $5 each (five bucks).

However, standard circuit board surface mounts will not celebrate the 
GaN transistor's chiefest qualities --speed.  My personal project (as a 
retired programmer), a resonant refrigerator, depends on short, high 
power pulses beyond what a MOSFET can do... enter the GaN transistor.

I've a design that is innovative, I reckon.  It involves producing the 
0.025 millimeter circuit-board landing pads for reflow soldering by 
stacking copper foil of the same thickness, with the insulation path 
between pads filled with epoxy.  The completed lamination is sawn into 
small strips and polished, and the laminations on the edge become the 
landing pads for the GaNs.

I've 3D perspective illustrations if anyone is interested.  What I'm 
hoping to find is an EE perspective of the necessary things, like solder 
masking the tiny buss, and things I'm unfamiliar with.  I am proceeding 
slowly, shoestring budget in force.

Testing is also needed, and I'm learning the details of RF as I go... 
all advise is special.


Thanks,
AZdon

Re: [Homebrew_PCBs] newbie toons

2011-08-02 by Stuart Schaffert

I understand the mounting concept you have described, but I don't know how to implement it, yet.  I do have a question though.  The die for the transistor is normally mounted in a package and then the package is mounted on a heatsink.  How do you plan to dissipate the heat in this application?  You will also need to cover the die with something, most likely a safe epoxy compound, to protect it from damage and contamination.

Stuart
Show quoted textHide quoted text
  ----- Original Message ----- 
  From: shoestring 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Tuesday, August 02, 2011 10:35 AM
  Subject: [Homebrew_PCBs] newbie toons


    
  Hello HPCBers,

  I've this special project that requires some innovation to be practical 
  on my budget.

  The gallium nitride transistor is new, invented by a grad student in 
  2006, and used by the military. The cost of packages that exploit the 
  ultra-fast dV/dt (4 volts per nanosecond) is upwards of $200 each. I've 
  seen as high as seven-hundred dollars for a GaN in a high-current package.

  Good news... the raw die, with solder-bumps for reflow-soldering, is 
  available for around $5 each (five bucks).

  However, standard circuit board surface mounts will not celebrate the 
  GaN transistor's chiefest qualities --speed. My personal project (as a 
  retired programmer), a resonant refrigerator, depends on short, high 
  power pulses beyond what a MOSFET can do... enter the GaN transistor.

  I've a design that is innovative, I reckon. It involves producing the 
  0.025 millimeter circuit-board landing pads for reflow soldering by 
  stacking copper foil of the same thickness, with the insulation path 
  between pads filled with epoxy. The completed lamination is sawn into 
  small strips and polished, and the laminations on the edge become the 
  landing pads for the GaNs.

  I've 3D perspective illustrations if anyone is interested. What I'm 
  hoping to find is an EE perspective of the necessary things, like solder 
  masking the tiny buss, and things I'm unfamiliar with. I am proceeding 
  slowly, shoestring budget in force.

  Testing is also needed, and I'm learning the details of RF as I go... 
  all advise is special.

  Thanks,
  AZdon



  

[Non-text portions of this message have been removed]

RE: [Homebrew_PCBs] newbie toons

2011-08-02 by Boman33

It sounds like an interesting project.

The 3D drawing would be helpful so would be some links to the manufacturer.

What is so special about the current package that makes it so expensive.

Any references on the refrigeration process?

So many questions..

Good Luck,

Bertho

===============================
Show quoted textHide quoted text
From: shoestring   Sent: Tuesday, August 02, 2011 13:36
Hello HPCBers,

I've this special project that requires some innovation to be practical 
on my budget.

The gallium nitride transistor is new, invented by a grad student in 
2006, and used by the military. The cost of packages that exploit the 
ultra-fast dV/dt (4 volts per nanosecond) is upwards of $200 each. I've 
seen as high as seven-hundred dollars for a GaN in a high-current package.

Good news... the raw die, with solder-bumps for reflow-soldering, is 
available for around $5 each (five bucks).

However, standard circuit board surface mounts will not celebrate the 
GaN transistor's chiefest qualities --speed. My personal project (as a 
retired programmer), a resonant refrigerator, depends on short, high 
power pulses beyond what a MOSFET can do... enter the GaN transistor.

I've a design that is innovative, I reckon. It involves producing the 
0.025 millimeter circuit-board landing pads for reflow soldering by 
stacking copper foil of the same thickness, with the insulation path 
between pads filled with epoxy. The completed lamination is sawn into 
small strips and polished, and the laminations on the edge become the 
landing pads for the GaNs.

I've 3D perspective illustrations if anyone is interested. What I'm 
hoping to find is an EE perspective of the necessary things, like solder 
masking the tiny buss, and things I'm unfamiliar with. I am proceeding 
slowly, shoestring budget in force.

Testing is also needed, and I'm learning the details of RF as I go... 
all advise is special.

Thanks,
AZdon



[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] newbie toons

2011-08-02 by Stefan Trethan

I think resonant refrigeration is cool. Sounds to me like one of the
real innovations that may lead to actual useful products.

That stacking idea could actually work, having seen PCBs cut and
polished that is exactly what you get. You'd have to use suitably thin
prepregs or something between the copper to get the wanted pitch. But
how would you contact the "far side" of the conductor stack? Would you
just fan it out in some way?

Are you sure the die comes with solder bumps and not bond pads like
silicon chips? I know nothing about GaN.

ST
Show quoted textHide quoted text
On Tue, Aug 2, 2011 at 7:35 PM, shoestring <don@...> wrote:
> Hello HPCBers,
>
>
> I've this special project that requires some innovation to be practical
> on my budget.
>
> The gallium nitride transistor is new, invented by a grad student in
> 2006, and used by the military.  The cost of packages that exploit the
> ultra-fast dV/dt (4 volts per nanosecond) is upwards of $200 each.  I've
> seen as high as seven-hundred dollars for a GaN in a high-current package.
>
> Good news... the raw die, with solder-bumps for reflow-soldering, is
> available for around $5 each (five bucks).
>
> However, standard circuit board surface mounts will not celebrate the
> GaN transistor's chiefest qualities --speed.  My personal project (as a
> retired programmer), a resonant refrigerator, depends on short, high
> power pulses beyond what a MOSFET can do... enter the GaN transistor.
>
> I've a design that is innovative, I reckon.  It involves producing the
> 0.025 millimeter circuit-board landing pads for reflow soldering by
> stacking copper foil of the same thickness, with the insulation path
> between pads filled with epoxy.  The completed lamination is sawn into
> small strips and polished, and the laminations on the edge become the
> landing pads for the GaNs.
>
> I've 3D perspective illustrations if anyone is interested.  What I'm
> hoping to find is an EE perspective of the necessary things, like solder
> masking the tiny buss, and things I'm unfamiliar with.  I am proceeding
> slowly, shoestring budget in force.
>
> Testing is also needed, and I'm learning the details of RF as I go...
> all advise is special.
>
>
> Thanks,
> AZdon
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

Re: [Homebrew_PCBs] newbie toons

2011-08-02 by Stefan Trethan

Wait a minute, how would you solder this?
If the pitch goes below a certain minimum it ough to be tricky to
solder without bridges?

ST
Show quoted textHide quoted text
On Tue, Aug 2, 2011 at 9:08 PM, Stefan Trethan <stefan_trethan@...> wrote:
> I think resonant refrigeration is cool. Sounds to me like one of the
> real innovations that may lead to actual useful products.
>
> That stacking idea could actually work, having seen PCBs cut and
> polished that is exactly what you get. You'd have to use suitably thin
> prepregs or something between the copper to get the wanted pitch. But
> how would you contact the "far side" of the conductor stack? Would you
> just fan it out in some way?
>
> Are you sure the die comes with solder bumps and not bond pads like
> silicon chips? I know nothing about GaN.
>
> ST
>
>
>
>
>
> On Tue, Aug 2, 2011 at 7:35 PM, shoestring <don@...> wrote:
>> Hello HPCBers,
>>
>>
>> I've this special project that requires some innovation to be practical
>> on my budget.
>>
>> The gallium nitride transistor is new, invented by a grad student in
>> 2006, and used by the military.  The cost of packages that exploit the
>> ultra-fast dV/dt (4 volts per nanosecond) is upwards of $200 each.  I've
>> seen as high as seven-hundred dollars for a GaN in a high-current package.
>>
>> Good news... the raw die, with solder-bumps for reflow-soldering, is
>> available for around $5 each (five bucks).
>>
>> However, standard circuit board surface mounts will not celebrate the
>> GaN transistor's chiefest qualities --speed.  My personal project (as a
>> retired programmer), a resonant refrigerator, depends on short, high
>> power pulses beyond what a MOSFET can do... enter the GaN transistor.
>>
>> I've a design that is innovative, I reckon.  It involves producing the
>> 0.025 millimeter circuit-board landing pads for reflow soldering by
>> stacking copper foil of the same thickness, with the insulation path
>> between pads filled with epoxy.  The completed lamination is sawn into
>> small strips and polished, and the laminations on the edge become the
>> landing pads for the GaNs.
>>
>> I've 3D perspective illustrations if anyone is interested.  What I'm
>> hoping to find is an EE perspective of the necessary things, like solder
>> masking the tiny buss, and things I'm unfamiliar with.  I am proceeding
>> slowly, shoestring budget in force.
>>
>> Testing is also needed, and I'm learning the details of RF as I go...
>> all advise is special.
>>
>>
>> Thanks,
>> AZdon
>>
>>
>>
>>
>> ------------------------------------
>>
>> Be sure to visit the group home and check for new Links, Files, and Photos:
>> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>>
>>
>>
>>
>

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