[SI-LIST] : references on leadframe and package pin materials and signal degradation

Jan Vercammen ([email protected])
Fri, 16 Jul 1999 11:44:51 +0200

----------
X-Sun-Data-Type: text
X-Sun-Data-Description: text
X-Sun-Data-Name: text
X-Sun-Charset: us-ascii
X-Sun-Content-Lines: 65

Mike,

I better give you my references on leadframes and signal pin degradation myself. Three
articles which personally recommend are:

"Time domain interconnect model generation of Alloy-42 lead frames"
Osario, R., Electrical performance of Electronic Pack., 1994, IEEE 3rd Topical Meeting on
pages 83-85, ISBN 0-7803-2411-0

"Electrical Characterization and modeling of simultaneous switching noise for leadframe pacakages"
Miura, M, et al., Electronic components and technology Conference, 1995. Proceedings., 45th
pages 857-864, ISBN 0-7803-2736-5

"Signal degradation throughmodule pins in VLSI packaging"
Huang, IBM Journal of Research & development, vol 31-4, page 489+ (1987)

It is possible that there is stiil missing one article, if so, I will put it on the si-list.

I have also started with some preliminary analysis of the inductance-resistive behaviour
of package leads using a two-diminsional simulator (based on Weeks, cfr IBM journal of R&D).

i have include two attachements, both are pdf files (2x 4kbyte) which you can read and print with
acrobat reader. The first file is the pul (per unit length) inductance of SMD leads of various
materials, the second file is the pul resistance.

I have modeled 5 pins (or better part of the leadframe), in the plots the data is labeled:
- pack_cu.dax: a Copper leadframe SMD pin (standard size)
- pack_al42.dax: an alloy-42 leadframe SMD pin (standard size)
- cu_snpb.dax: a solder dipped Copper leadframe SMD pin (standard size)
- al42_snpb.dax: a solder dipped alloy-42 leadframe SMD pin (standard size)
-bondw_au.dax: a standard gold bond wire

The x is either l, for inductance (H/m), or t, for the resistance (ohm/m).

The inductance data (first file) shows that the wirebond inductance is somewhat higher
than the pin inductance. Once the skin effect starts to work the internal inductance
diminishes and the total inductance decreases asymptotic to its high freq. value.
The y-scale is in Henry/m, so do not forget to scale to aproximate the pul inductance for
finite length wirebonds and leadframe pins.

The resistance data (second file) shows the effects of the pure materials and the solder
coating. Notice that the high frequency resistance can be as 10 to 50 times as large
as the DC resistance.
The lower graph is for a copper leadframe, the solder dipped (coated) copper leadframe is
follows the copper leadframe closely, however at about 100MHz they split because the
RF current starts to concentrates itself in the solder coating. This graph and the solder
dipped alloy-42 coincide for high frequencies. Note that alloy-42 isn't a good conductor.

I have not taking into account the permeability data from the first article, becuase this
would change the alloy-42 results completely. I have adjusted my simulator for frequency
dependent magnetic materials, however I have no time to work out any results for now.

These data and the literature indicates that package pin degradation is a concern (or
a fortunate coincidence??).

Hope this helps,

Jan vercammen

----------
X-Sun-Data-Type: default
X-Sun-Data-Description: default
X-Sun-Data-Name: packl.pdf
X-Sun-Encoding-Info: uuencode
X-Sun-Content-Lines: 77

begin 600 packl.pdf
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7/@IS=&%R='AR968*,CDU-0HE)45/1@HY

end
----------
X-Sun-Data-Type: default
X-Sun-Data-Description: default
X-Sun-Data-Name: packr.pdf
X-Sun-Encoding-Info: uuencode
X-Sun-Content-Lines: 81

begin 600 packr.pdf
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M,)K#HFL#REK6(% .&P-R!0YB- M#T0G_1!5] (E;X2L+&@.2MX,5(E&+BQ$
MG2IG@O@@FO$'+P8<QC6._J#<7GZO'.1&I_+RH1KN>="<GZUB>E%<&]9PL+GM
M%=>X" EI](B%8D#!:*RQY"G1AY( _D32=)6B'%& DD'6/!DH_I#TE(N$P!F#
M> S\(I2 D\HB2LB)1Q0D7)V3\FY 0IC/%&,(,Y7$/@O+*+[J8-RVC6#5I$NH
MWPB>9"4A<=) V)F]XND>@R@K!@#:/I4B8 T4.=&&I6)I0XD.0^:\.T/3;A_
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D8S,W839D,&%A/ET*/CX*<W1A<G1X<F5F"C,Q-#@*)25%3T8*

end

**** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****