Analog Angle Article

Reliable components, but flimsy systems

Sometimes by choice, sometimes by necessity, I take electronic products apart to either just see how they are made, or to do try to fix them. (My investigatory goals are far less ambitious than our “Under the Hood” Teardown pieces, honchoed by David Carey of our Portelligent group, I assure you.)

My general impression is that our industry is making great parts but lousy products, measured by their medium-to-long term reliability. The short, immediate word that comes to my mind is “flimsy”. [Note that I am not discussing software and firmware problems here, that's a whole other story; I am just looking at hardware performance.]

Yes, ICs are amazingly reliable, and so are most of their support components. But I see too many products with hairline cracks in their PC boards (especially if it's a keyboard); with crud under the membrane pushbuttons; and with internal boards and assemblies that are no longer properly fastened to the case or enclosure.

I also see lots of intermittent connectors and connections. There's just too little metal-metal surface area for consistent contact, and too little body-retention or strain-relief material. The result is that the dc contact is inconsistent, as is RF situation.

I recently had some problems with an SMA connector on an 802.11 antenna “extension” cable. When I looked at the connector, I could see that there is very little spare surface area to accommodate any mechanical mismatch due to unavoidable flexing, strain, or motion. I am sure there is a high-reliability version of the connector pair, but you won't find that on a consumer product. And the connectors used for cable TV (commonly called Type F) range from barely decent to downright abysmal.

Who's to blame here? Sure, it would be easy to blame the vendors, but that's only part of the story. It's us, the consumers, who demand and expect smaller, lighter products, almost regardless of effect on quality and reliability.

Certainly, while ICs can be scaled down with no loss of reliability (if done right), and more functional integration onto an IC can lead to improved reliability due to reduction of board interconnects, the total product-design situation is not so clear cut. And while lighter, smaller assemblies are less affected by vibration and impact due to their reduced mass and higher natural resonances, those parameters are only part of the design story.

The reality is that the pieces of a product have to connect to each other electronically and mechanically. Lighter, smaller subassemblies and connectors make it harder to do that right, with the results that we are all seeing: products that simply don't stand up to normal use. They also negate the benefits that we have obtained through the very hard work of IC designers, production, packaging, and QA/QC engineers.♦

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