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I recently replaced the factory SSD in my Thinkpad X260. The factory SSD came with one side covered in conductive aluminum foil which is grounded to the chassis via the caddy-screw attachment. The replacement SSD has no foil.

The factory drive is covered along the three flat edges and on one broad side of the drive, leaving one broad side exposed. The covered side is closest to the outer plastic case while the uncovered side faces a plastic piece with a raised grid pattern.

Some questions:

  1. Does the SSD actually need to be protected inside the case like this?

  2. Would the copper conductive foil I use to shield my guitars be okay to use in this application?

  3. Would there be a benefit in covering both broad sides of the SSD with conductive foil?

  • the aluminum factory foil has adhesive only along the thin edges of the SSD and is unsealed on the edge nearest the connector, whereas the copper foil tape I have is 100% adhesive backed.
比尔盖子
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Russ Bain
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2 Answers2

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The main reason of the shield on the SSD is not protecting the SSD itself (although due to the principle of reciprocity, the computer and SSD are indeed also protected from the external interference), but to ensure that radiation from the computer conforms to electromagnetic compatibility regulations and does not generate harmful interference. You can say it's to protect the rest of the world from the computer and SSD. To protect the radio spectrum - a public resource shared by everyone - from mass-produced electronics, there are strict regulations on unintentional radiation from 30 MHz to 1 GHz and beyond. Before a new electronics gadget enters production, it's rigorously tested in a shielded anechoic chamber with a broadband antenna, the entire radio spectrum is scanned and checked to ensure that there are no spurious peaks.

Shielding is the primary method to comply with the regulations. Theoretically, the shield should completely enclosed the device by 360 degrees. But real devices have plugs, ports, slots, drive bays, and the shielding cannot be perfect. Sometimes these leaks have little effect, other times it can make the device to fail the regulatory compliance test - the effect is not obvious, and often can only be discovered by lab measurement. When a leak is found, additional shielding is strategically added to bridge the gap by the use of EMI foams, gasket, conductive tapes, metal enclosures, grounding screws, until the compliance test is passed.

Any aftermarket modification technically makes the computer uncertified as a whole. The end result may or may not comply with the regulations. However, since the purpose of these regulations is targeting mass-produced electronics, these kind of personal modifications are tolerated. Similarly, a self-built PC does not need to pass EMI/EMC compliance test for the same reason.

For personal use, a one-off modification like yours is usually a non-issue unless it's operating under unusual circumstances. Since the effect of shielding is often not obvious and counter-intuitive, even if one wants to restore its shielding, as an individual, one would not have access to a proper EMI test chamber to evaluate its effectiveness anyway. So as a personal user, the suggestion is just to "live with it" - it won't be less stable than any other self-built PC.

brhans
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比尔盖子
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  • The burden of EMC compliance falls on the manufacturer of the SSD in this case. They put it on market as a stand-alone product so they have to ensure that the SSD itself is compliant. The only responsibility of the consumer here is to be wary of fishy sites like Ebay or Aliexpress, which frequently sell non-conforming and illegal products. For example some SSD might be legal only in one particular country or region, not necessarily world-wide. – Lundin Apr 21 '23 at 08:09
  • @Lundin Individual components do need to pass EMI/EMC compliance tests individually, but it's a much lower bar. Meanwhile manufacturers of standalone computers have the additional obligation of passing compliance test using the whole system, and the use of certified components do not guarantee a pass. But we both agree that these regulations do not apply to end-users. – 比尔盖子 Apr 21 '23 at 10:17
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The manufacturer is not going to add shielding if it's not needed (but might possibly add it for cosmetic reasons). If the factory drive doesn't have it, then the factory drive doesn't need it. Adding shielding will have no effect unless you are in an extremely EMI-heavy environment like right next to a huge motor or welding equipment (in which case I'd be more worried about the rest of your laptop) and will definitely increase your chances of accidentally shorting something out. There might also be shielding inside the case that you are not seeing.

vir
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