MC9S08AW failures

[kosthala]

Hello,

We are using the MC9S08AW32 model for our products (for the last 4 years) and recently we have faced some failures on field. After examination of the faulty boards, we have found out that the VDD and VSS pins were short circuited internally.

We also inspected the chips direct from the tray (taking all the antistatic precautions) and we found that the VDD and VSS pins were already short circuited on a few chips.

We also have a few problems with the A/D module and the FLL module (not locking up).

Do you have faced similar problems with the specific family?

Thanks in advance.

[polosoft]

Hi, same problem here in Argentina, almost 2% of PCB manufactured (bottom layer wave soldered, reflow on top, AW on top layer) had AW60 shorted VDD and VSS (without ever applied power), and almost 1% of chips will die eventually on field (I remember one that shorted with less than 9 ohms between VDD and VSS).

We didn't have problem with A/D or FLL (only problem is a oscillator very sensitive to moisture running with 32KHZ crystal, but that's normal I  think).

We are considering not using AW for new products

PD: Sorry for my english

[kosthala]

Hi,

We are also thinking to change the microcontroller family. We are going to use the AC family.

By the way, the mask number of the AW family we use is 5M75B. Can you check the mask of your faulty chips? Maybe it is an errata of the specific mask.

Thanks. 

[ok2ucx]

Dears,

if you ever experience such failure (like short-circuit on a freshly unpacked device), you should always raise CQI (customer quality incident) report to Freescale via your sales representative. The investigation will be done and the root cause of this issue will be identified.

All devices being sold are normally fully tested, so I'm little worried how the tested chip could be short-circuit.

Pavel

[kosthala]

Hello,

About two years ago, we send a faulty device to the Freescale, via our sales representative. The device was taken direct from the tray (taking ALL the antistatic precautions). The answer, after the Freescale investigation, was that the reason for the failure was ESD.

However the problem still exists until today. 

[J2MEJediMaster]

I understand your concern and possibly your frustration. However, the only way to have the matter looked into is for you submit some parts to us so that we can test them and determine what is going on.

---Tom

Message Edited by J2MEJediMaster on 2010-02-12 11:03 AM