I still say you should determine this yourself by practical trials, if
this is really an issue. We don't even know which alloy you are using
nor the thermal sinking of your ICs or the boards on which they are mounted.
Brian
Madhusudhan Kulkarni wrote:
> We are planning to do BGA IC packaging,How many pins to be provided for
> 1 Amp current and what should be solder ball size?
>
> Regards
> Madhusudhan Kulkarni
>
>
>
> ----- Original Message ----- From: "Brian Ellis" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, January 29, 2007 5:55 PM
> Subject: Re: [LF] BGA Solder ball
>
>
>> Is this, in any way, relevant? AFAIK, BGAs are essentially used for
>> connecting large pin-outs to (usually) digital devices running at low
>> power. After all, they are arrays, implying a plurality of connections.
>>
>> However, it should be relatively easy to determine the equation of the
>> form and size of the wetting sessile drop after reflow and thus, with
>> integral calculus and the resistivity of the alloy used, calculate the
>> resistance and thus the IR drop. The power dissipated will be IČR and
>> from that and the thermal characteristics, along with the maximum
>> permissible temperature, determine the max current,
>>
>> More easily, because of the heat conduction above and below the ball,
>> I would guess that we are talking in the order of, at least, an
>> ampere. If you are really worried about this, in view of the number of
>> variables, I would say that an empirical approach would be best: rack
>> up the current through a ball until it reaches an undesirable
>> temperature.
>>
>> Brian
>>
>> Madhusudhan Kulkarni wrote:
>>> What is the current rating of BGA solder ball, how to caluclate?
>>>
>>> Regards
>>> Madhusudhan Kulkarni
>>>
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