EEVblog #807 - Mailbag

[EEVblog]

More Mailbag
Items from Lithuania & Israel!



SPOILERS:
JigMod Kickstarter: http://kck.st/1LwT4iA
A Breadboarding prototyping system
Lumintop Tool AAA Keychain LED Torch/Flashlight
http://amzn.to/1jr4Nbs
1992 Sony Video-8 Camcorder
Fluke 196 100MHz 1GS/s Scopemeter
And a security networking chip teardown

[Fungus]

What happened to the Fenix LD01?

Don't like the look of that key ring attachment. My bet: The rubber switch will be broken in less than a month.

Maybe you could attach the key ring using a zip tie or something.

[Barny]

A little hint:
Old cameras, tablets,.... don't like big SD-cards.
They work only with SD cards up to 2GB.

[German_EE]

OK, I'm missing something, what is so special about Shermer IL?

[Cliff Matthews]

Yup, Ontario was pronounced bang-on! (pop. 14 million, only California, Texas, NY and Florida are bigger). That kick-starter looked novel, he's from my area (what they call Canada's Tech-Triangle). I think I'll have to pay him a visit.. Thanks Dave, you must visit! Ontario's almost as awesome as EEVblog!

[AF6LJ]

Good Stuff Thanks Dave.
 

[SeanB]

No idea ( don't watch TV), so not a clue.

As to the rings on the BGA package, they are there as part of the package design, to provide a fixed edge when routing out the layers so they do not peel or delaminate, and then a nice alignment aid for the bonder vision to recognise the ends of the multiple layers when bonding.. The copper planes will be power and ground planes, there as the chip needs high current and having this power and ground plane next to each other with only a thin laminate means the low capacitance is very effective and is very low inductance. Might be only 100pF for the whole set of planes, but the inductance is essentially mostly there from the multiple bond wires feeding the chip. For security there would be another laminate over the whole lot, with a similar one as the lowest laminate layer ( or just one in from a routing layer), with a few traces meandering across and connected to ground and the power rail, and also feeding the standby voltage that keeps the on chip RAM used for program storage alive. One or two microvias will link them at random across the BGA ball area to internal layers, and then to the chip. The power wires will be designed so they will short out to each other when you try to probe, and the traces connect to the die to enable it. Some self destruct (  a lot of high power IO cells connected together in the chip periphery  that are normally tristated, and if tampering is detected they are turned on with the high and low side drives turned on so shorting the chip to cook it quickly). Same with the lid, though there you will need to have a connection made with silver loaded epoxy to the top mesh.

This chip does not have that, it is a regular ARM processor in a BGA package. No security, as the program resides in the external EEPROM, where it is trivial to read. It just is hot running, so they put the big passive cooler onto the package with a really good adhesive. Then there is 64M of DRAM right next to that for the Linux OS to run in.

[pascal_sweden]

Dave,

You need to use a small ring, and connect that small ring to your key ring.
Don't use the key ring directly.

The Maglite flashlights come with such a small ring if you look for an example

[crispy_tofu]

Good to see the JIGMOD has reached its goal! 

[free_electron]

the rings int he BGA are the power rings. they bond from the DIE directly to the rings. nothing special.

as for the scopemeter : you will find on the bottom of the board, dead center a toeasted sot23-6 power mosfet.
that fet is obsolete. it can be replaced by a n FDC666 provided you cut off one of the pins. the mosfet uses a non standard pinout.

[Rasz]

is there really a pcb material between the die and package metal plate in this BGA chip? that sounds terrible from thermal point of view

[AF6LJ]

is there really a pcb material between the die and package metal plate in this BGA chip? that sounds terrible from thermal point of view

Those chips are usually mounted upside down on the PCB that is the chip carrier, the backside of the chip faces the heatsink AMD use to build processors that way.

[Rasz]

is there really a pcb material between the die and package metal plate in this BGA chip? that sounds terrible from thermal point of view

Those chips are usually mounted upside down on the PCB that is the chip carrier, the backside of the chip faces the heatsink AMD use to build processors that way.

flip chip etc, yes I know
but in this particular one it looked like the chip Dave ripped open was like the third in the upper row kind:


and it looked like the die stayed  with most of the chip, then there was a cover of some laminate material ... then we get same llaminate material glued to the rest of the chip still attached to heatsink. So it appears metal window in chip package is completely useless
look at 34:60 in the video, you can clearly see pcb material between the die and metal plate, there even appear to be some thermal compound on the inside, WTF

[Xenix]

Shahriar from The Signal Path has made a taredown and repair video on the Fluke 196b...

Maybe it will help with the repair

[Stonent]

Yup, Ontario was pronounced bang-on! (pop. 14 million, only California, Texas, NY and Florida are bigger). That kick-starter looked novel, he's from my area (what they call Canada's Tech-Triangle). I think I'll have to pay him a visit.. Thanks Dave, you must visit! Ontario's almost as awesome as EEVblog!

And just for whatever reason, there's Ontario, CA (Canada) and Ontario, CA (California, USA)

[Stonent]

I recognized the package as being similar to what Intel used in the early 2000s for their chipsets like the i810 and VIA used for the VT8286A.

Here's a different view of a similarly packaged chip:

[max666]

is there really a pcb material between the die and package metal plate in this BGA chip? that sounds terrible from thermal point of view

Those chips are usually mounted upside down on the PCB that is the chip carrier, the backside of the chip faces the heatsink AMD use to build processors that way.

flip chip etc, yes I know
but in this particular one it looked like the chip Dave ripped open was like the third in the upper row kind:


and it looked like the die stayed  with most of the chip, then there was a cover of some laminate material ... then we get same llaminate material glued to the rest of the chip still attached to heatsink. So it appears metal window in chip package is completely useless
look at 34:60 in the video, you can clearly see pcb material between the die and metal plate, there even appear to be some thermal compound on the inside, WTF

No, I think you see it wrong. The die must be right against the metal window, under the white stuff. We don't see the die at all, we see only laminated material of the interposer. Dave separated the laminated fibre gals of the interposer, so we see laminated layers still stuck to the heatsink and a hole in laminated material of the interposer still on the board. I guess the white part in the centre is some material to grout the bond wires, but I have no idea how they bond those chips, I know nothing about that.

[AF6LJ]

OK, I'm missing something, what is so special about Shermer IL?

Director John Hughes set many of his movies in the fictitious suburb of Shermer.

http://thelister.blogspot.com.au/2010/06/ten-movies-featuring-fictional-town-of.html

I must be culturally deprived I don't even know who John Hughes is.

[leroy_is_brown]

I must be culturally deprived I don't even know who John Hughes is.

You might have seen his films though - "The Breakfast Club", "Sixteen Candles", "Ferris Bueller's Day Off", and "Home Alone" ring any bells?

[AF6LJ]

I must be culturally deprived I don't even know who John Hughes is.

You might have seen his films though - "The Breakfast Club", "Sixteen Candles", "Ferris Bueller's Day Off", and "Home Alone" ring any bells?

They all do but the only one I thought was any good was The Breakfast Club

[leroy_is_brown]

I must be culturally deprived I don't even know who John Hughes is.

You might have seen his films though - "The Breakfast Club", "Sixteen Candles", "Ferris Bueller's Day Off", and "Home Alone" ring any bells?

They all do but the only one I thought was any good was The Breakfast Club

Definitely my favourite as well.

[jonwil]

I must be culturally deprived I don't even know who John Hughes is.

John Hughes is a guy who owns a lot of car yards in Perth http://www.johnhughes.com.au/

[adcurtin]

SD cards that are 4GB are rare. Most 4GB cards are SDHC, which is a newer spec. SDHC is from around 2006 (I have a monitor from 2007 that still doesn't do sdhc). That camera said 2002 when powered on, so it is most likely too old to work with SDHC. A 2GB or less SD card should work fine.

[Fungus]

is there really a pcb material between the die and package metal plate in this BGA chip? that sounds terrible from thermal point of view

Maybe it doesn't generate much heat.

[Vgkid]

That chip breaking like that, sure was interesting.