Thursday, February 17, 2011

BPAI says "in thermal contact" doesn't apply to reference material simply because "all materials are thermally conductive to some degree"

Takeaway: The application on appeal was directed to semiconductor manufacturing techniques involving plasma. The Examiner asserted that the claim limitation "a stem, the stem being in thermal contact with the gas distribution portion" read on the reference structure because "rudimentary thermodynamics requires all tangible materials .. to be 'in thermal contact' via ... conduction, convection [or] radiation." The BPAI found that the Examiner didn't show that a person of ordinary skill in the art of plasma processing would have understood "thermal conduction" to have this idealized meaning. The BPAI reversed the anticipation rejection on this and other grounds.

Ex parte Srivastava
Appeal 2009013335, Appl No. 10/755,617, Tech. Center 1700
November 22, 2010

The claim at issue read:
1. A baffle plate assembly for distributing gas flows into an adjacent process chamber containing a semiconductor wafer to be processed, comprising:
     a single generally circular planar gas distribution portion having a plurality of apertures therein;
     a flange surrounding the gas distribution portion; and
     an apertureless impingement device centrally attached to the gas distribution portion,
     wherein the device includes
          a generally circular cap and a stem,
          the stem being in thermal contact with the gas distribution portion.

The Examiner rejected the claim as being anticipated by Kinnard.  On appeal, the Applicant argued a three claim limitations, and distinguished the "thermal contact" limitation as follows:

Further, though the sapphire impingement plate 62 in [Kinnard] does "prevent the radially inward portion of the wafer 22 from overheating", it is essentially floating from a thermal perspective, and hence gets heated up by the hot plasma impinging on it, thereby serving as a site for recombination of active species. In contrast, Applicant's claims include, inter alia, a generally circular cap and a stem, the stem being in thermal contact with the gas distribution portion, which serves to minimize and/or prevent species recombination since thermal contact with the gas distribution portion serves to cool the generally circular cap and stem.

In the Answer, the Examiner further explained his reasoning as follows:

To this end, the Examiner emphasizes that rudimentary thermodynamics requires all tangible materials (solid, liquid, and gas) to be "in thermal contact" via any one of the three modes of heat transfer: conduction, convection, and radiation. Thus, not only are Applicant's claimed elements "in thermal contact", but also are Kinnard's equivalents, as well as all other apparatus made by man.

The BPAI reversed the anticipation rejection, finding that the Examiner erred on all three disputed limitations. In particular, the Examiner's interpretation of "thermal contact" as covering all materials was "not well taken" by the Board:

We also note that the Examiner has not come forward with any evidence that Kinnard standoffs 54 are thermally conductive. The Examiner’s argument, based on “rudimentary thermodynamics,” that all tangible materials are in “thermal contact” via some mode of heat transfer with everything else is not well taken. The Examiner has failed to come forward with credible evidence that persons having ordinary skill in the art would have understood the “thermal contact” limitation in such an idealized fashion that it would have no meaning in the plasma-processing laboratory or workplace. Glass or ceramic rods, for example, when heated at one end, will eventually get hot, but they are very poor heat conductors, and hence very poor “thermal contacts” compared to metal rods. While it might be possible to show it that a person having ordinary skill in the art would have recognized that Kinnard used metal rods as standoffs (or, in an obviousness rejection, that it would have been obvious to do so), the Examiner has failed to make such arguments.

My two cents: Though the Board did not explain its analysis in these terms, I think the issue is best framed as claim construction rather than what the reference did or did not teach.

I don't work with semiconductors, and I don't know if the reference disclosed the thermal contact limitation. But this looks to me like a case of overreaching by the Examiner: the Examiner's overly broad interpretation doomed the rejection at the Board, even if the reference would anticipate the limitation under a more reasonable interpretation.


  1. This is just another example of the idiotic lengths examiners will go to reject claims.

    It's the same as the case Karen posted awhile ago where the examiner interpreted a rigid element of the prior art as reading on a claimed flexible element on the "reasoning" that "hur, everything's got some degree of flexibility, hur, ain't I so clever, hur."

    Jeez Louise when are examiners going to stop this nonsense?

    Apparently never.

    And so the backlog grows.

    Karen, you are correct in that the panel should have construed the claimed limitation that " the stem being in thermal contact with the gas distribution portion" consistent with the spec and with the interpretation one of ordinary skill would have reached, and then determined whether the applied reference(s) actually met the feature.

  2. While I might disagree with having made a 102 rejection in this instance (I probably do) I note that this is but the tip of the new "thermal" revolution. Attorneys are drafting cases dealing with inventions in thermal engineering with loosey goosey terms like "thermal contact" that they make up off the tops of their heads and have modeled on things like "electrical contact". One of ordinary skill has no interpretation of this word as they certainly do not ever use it in the context which it is used here. It is, as the board points out, but refuses to believe, meaningless.

    Indeed, the examiner here did the best he could in a situation taxing on even the most skilled of examiners who are not familiar with the use of 112 2nd. Really all that needed to be recited was "contact" as opposed to "thermal contact" because that is, practically speaking, exactly what the attorney meant by it. Fact is, all the examiner needed to do was to make a 112 2nd Miyazaki rejection and get straight for the record what the applicant meant by "thermal contact". As soon as the applicant did not respond (because it has no definition other than "contact" or "contact where thermal energy aka "heat" can flow directly from one object to another, aka "contact" in this context") and instead changed the words he used then we're all in the clear. Or maybe he'd just admit to one of the above interpretations and we could all go about our lives.

    In fact, note that a Miyazaki rejection might have saved the applicant the time and expense of an appeal as the issue would be nipped in the bud and would likely end up with the examiner realizing his 102 would not hold up for the amended claim or for the interpretation the applicant was arguing reasonably for.


    Oh look I happened to google it just to make sure I was right. See, the thing is, the term is pretty much just being abused in the patent arena to stir up confusion and to try to get claims which are more broad than an examiner might regard them to be.

    The upcoming problem in patent law that is only going to get worse and worse as time goes by is the loose way we police the way people draft claims.

    Fact is, we need to clamp down on nonsense like this with legislation as it is literally just going to get worse and worse as the years go by if nothing is done. Applicant simply does not need the freedom to use nonsense to distinguishlol his claims.