"Low-ESR Aluminum Electrolytic Failures Linked to Taiwanese Raw Material
Problems

  On September 13, 2002, it was reported to Passive Component Industry
Magazine by contacts in Japan that an unusually high rate of failures of
low-ESR aluminum electrolytic capacitors produced in Taiwan by Lelon
Electronics, Luxon Electronics, and other aluminum capacitor manufacturers
had been traced to a problem with an aqueous electrolyte that had been used
throughout the Taiwanese electrolytic capacitor industry.
  Reportedly, the problem developed after a materials scientist working for
Rubycon Corporation in Japan left the company and began working for Luminous
Town Electric in China. The scientist then developed a copy of Rubycon P-50
type water-based electrolyte, used in low-ESR aluminum electrolytic
capacitors developed by Luminous and equivalent to the Rubycon ZA and ZL
series. Subsequently, the scientist's staff members defected with the
formula, and began to sell and electrolyte at a low price to many of the
major aluminum electrolytic houses in Taiwan, including Luxon Electronics,
Lelon Electronics, and other aluminum capacitor manufacturers. (IBM has
stated that five companies were affected, while other sources in Taiwan
suggest that as many as 11 companies were affected.)
   Unfortunately, the staff members who defected from Luminous Town Electric
with the formula copied only the partial formula, and the subsequent
electrolyte produced was unstable when packaged in a finished aluminum
capacitor. The instability of the electrolyte in the low-ESR aluminum
electrolytic capacitors using this water-based electrolyte leads to the
build-up of excess hydrogen inside the aluminum can, which results in either
a rupture of the can itself or destruction of the rubber end-seal. Either
failure is potentially catastrophic due to the leaking electrolyte.
According to top material scientists in the aluminum capacitor industry, if
the correct amount of additives is not mixed into a water-based electrolyte,
electrolysis will occur, releasing a high amount of hydrogen gas in the can
and resulting in catastrophic failure.
Subsequent lifetime tests on low-ESR aluminum electrolytic capacitors
produced in Taiwan by Japanese aluminum capacitor hours revealed the
occurrence of catastrophic failure of the Taiwanese aluminum electrolytic
capacitors after 2000 hours of operation on parts rated for 4000 hours of
operation. Intel has stated that the aluminum capacitors with the poor
electrolyte may fail after only 250 hours of operation.
Industry sources have further revealed that many top companies in the
computer motherboard and telecom infrastructure businesses have been
scrambling to obtain low-ESR parts from aluminum electrolytic capacitor
suppliers who did not have plants in Taiwan. Subsequent reports suggest that
Rubycon Corporation, Nichicon, and Nippon Industries (NIC Components) have
been inundated with orders for low-ESR aluminum capacitors, as more
customers shy away from Taiwanese-produced parts. Rubycon, Nichicon, and
Nippon Industries ( NIC Components) do not have plants in Taiwan, and thus
were not exposed to the bad electrolyte in their low-ESR aluminum
capacitors. Further intelligence has revealed that lead times for low-ESR
aluminum capacitors are now increasing, and price increases are imminent as
Japanese suppliers prepare to fill the void left by this unfortunate
incident.
Many industry insiders note that some major Japanese aluminum capacitor
houses also have offshore production plants in Taiwan, including Nippon
Chemi-Con (Hsien Plant) and Matsushita (Nantou Hsien Plant). However, our
research has concluded that many of these companies obtain their
electrolytes directly from Japan and were probably not affected by the
tainted supply. Other Taiwanese suppliers, such as Jamicon (Kamei),
apparently were not affected because they obtain their electrolytes from
Japan. Teapo has stated that it also gets its electrolytes from Japan, and
was not affected or disqualified.
Some industry insiders further speculate that many of the original equipment
manufacturers in the computer industry may not be aware of the problem
because visibility into component supply chains is limited due to the
increased usage of contract electronic manufacturers in Taiwan. Other
industry sources have commented that the movement of contract electronic
manufacturers to Asia, coupled with a tendency to source low-cost components
locally, opens up the potential for additional component problems in the
future.

Effects on The Market
Total Taiwanese production of aluminum electrolytic capacitors is
approximately 22.5 billion pieces or 30% of the global aluminum electrolytic
capacitor unit shipments. Thus, the failure of these Taiwanese aluminum
electrolytic capacitors could have a major impact on the prime industries
that consume these products, namely computer motherboards and high-speed
modems; although, depending on the number of parts sold and range of buyers,
the problem may affect the power supply, monitor, and game console
industries. It is important to emphasize, however, that the products that
have been affected are only the low-ESR type aluminum capacitors, which
account for less than 20% of Taiwan's aluminum electrolytic capacitor
production volume.

Potential Long-Term Effects
The effects of the bad electrolyte on the aluminum electrolytic capacitor
supply chain are not known at this time. Two factors play an important role
in determining the effects:


How long have these electrolytes been in the field;


Has the problem been contained to Taiwan, or have the electrolytes found
their way to other nations?
As the industry becomes aware of the problem, it may experience a shift in
the supply chain for aluminum capacitors. This could result in an increase
of lead times and prices for low-ESR aluminum capacitors.

Publisher's Note: Information about this story was obtained from multiple
sources, many of which wish to remain anonymous due to the ramifications to
the entire supply chain for aluminum electrolytic capacitors. However, the
story has been confirmed by a variety of sources, including manufacturers of
aluminum capacitors, as well as consumers of aluminum electrolytic
capacitors in the computer industry. It is our intention to report this
information so that companies subscribing to Passive Component Industry
Magazine are aware of this situation and take steps to determine their
exposure levels to this emerging problem.
At press time, IBM Corporation also confirmed the reports regarding failures
of Taiwanese aluminum capacitors, stating that five Taiwan-based companies
are involved, not just three. IBM further stated that it is not planning a
recall. The problem is limited to desktop computers only - no laptops are
affected. IBM further stated that the problem is universal, affecting most
brand name computer manufacturers in North America and Japan. IBM has
recorded some failures in the field, but plan on handling them under product
warrantee. IBM would not speculate on the effect this may have on the
aluminum electrolytic capacitor supply chain, but conceded that the effect
may be substantial. Intel also confirmed the story, but suggested the
problem might be more widespread and may have affected other aluminum
product lines, not just the low-ESR parts. Dell Computer also confirmed the
story, but would not comment further because of existing secrecy agreements.

Further intelligence revealed that Kamei/Jamicon sources its electrolytes
from Sanyo in Japan, and likely was not affected by the faulty electrolyte
supply. Teapo has stated that it obtains its electrolytes from Japan and was
not affected. They also stated that the situation is isolated to a few
suppliers in Taiwan, and is not characteristic of its product line or the
Taiwanese aluminum capacitor market in general. Teapo suspects it is an
attempt by Japanese aluminum capacitor suppliers to gain market share, and
that the unfortunate incident involving a few companies will unfairly
categorize the entire aluminum capacitor industry in Taiwan"


-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Brian Ellis
Sent: Wednesday, October 13, 2004 3:25 AM
To: [log in to unmask]
Subject: Re: [TN] Aluminum electrolytic Cap's


Hey, wait a minute, Joyce. I haven't seen a WET elco for at least 50
years. All elcos today, to the best of my knowledge, are dry and neither
need nor have venting. A wet elco literally has liquid in them and, if
you shake them, you can hear/feel it slopping around. Wet elcos had the
advantage they were self-healing. I think the last manufacturer was
possibly Philips in the 1940s.

Dry elcos are not really dry, but have a moist absorbent material
between the electrodes, but they are not self-healing, therefore do not
generate gas. The dielectric is a pre-anodised layer on the anode,
before the capacitor is wound, so there is no electrolysis within the
case and no gas generation. The moist layer is actually there just as a
contact from the cathode to the thin dielectric.

And if what you say were true, there would be two problems:
a) you could not have hermetic components
b) if the component were vented, the small amount of moisture in the
absorbent layer would be lost by evaporation and the elco would become
pF, instead of uF!

Brian

Joyce Koo wrote:

> Disagree on the the coating... although the coating may be softer
initially,
> the acrylic coating can be hardened during the life of the product, may be
> interfere the venting mechanism.  Agree with your customer, it should not
be
> coated (see attached).
>
> my 1.6 cents.
>                             jk
>
> "In the operation of a wet electrolytic capacitor a certain amount of gas
is
> generated from the electrolysis of the electrolyte and unless means is
> provided for the purpose quite high pressures may be built up inside the
> container. For this reason it has been found necessary to provide the
covers
> with some form of vent. In practically all instances this vent takes the
> form of a thin sheet of gum rubber which is perforated by a very small
hole.
> The thickness of the rubber and the size of the perforation determine the
> pressures at which venting action will occur. In practice it is desirable
to
> obtain venting action at the lowest pressure which will prevent actual
> leakage or escape of electrolyte through the perforation. "
>
>
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]On Behalf Of Brian Ellis
> Sent: Monday, October 11, 2004 2:32 AM
> To: [log in to unmask]
> Subject: Re: [TN] Aluminum electrolytic Cap's
>
>
> I see no reason why hermetically sealed elcos cannot be conformally
> coated. If an elco generates pressure, it is because it is already in a
> fault condition and should therefore be changed, anyway.
>
> Brian
>
> Lum Wee Mei wrote:
>
>>Hello,
>>
>>Since we are on electrolytic cap, how about conformal coating (acrylic) on
>
> them?
>
>>We have been coating them since day one as no one has instructed that
>>electroltic cap cannot be coated.
>>
>>Recently, there have been opinion that we cannot coat them as there will
>
> be no
>
>>gap for the pressure to escape - similar to the below issue?
>>
>>What are your opinions?
>>
>>Regards,
>>Wee Mei
>>
>>
>>Quoting Brian Ellis <[log in to unmask]>:
>>
>>
>>
>>>It depends on what cleaning medium you are using. If you are using a
>>>halogenated solvent and just a microgram penetrates inside the casing,
>>>you will see customers complaining of failures after 6 months to 2
>>>years. This is well-known and was publicised by Sprague in the 1960s.
>>>This company recommended using only hermetically sealed elcos if
>>>cleaning in halogenated solvents. They also tested aqueous cleaning and
>>>determined zero effect by aqueous cleaning, including with saponifiers
>>>which could cause superficial corrosion of the outer case. However,
>>>IMHO, it always makes sense with aqueous cleaning to have each stage
>>>slightly warmer (say 5 deg C) than the previous one, so that you always
>>>have positive pressure inside the cans while they are wet, to prevent
>>>the ingress of contaminated water.
>>>
>>>Brian
>>>
>>>Scott Lefebvre wrote:
>>>
>>>
>>>
>>>>We have a problem with the plastic disk coming off after being process
>>>
>>>through our In-Line PCB washer.  What concerns if any should I have.
>>>
>>>
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or
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