This article explains why you should conduct a patentability search and answers common questions about how to use the result of a patentability search based on my 20 years of experience as a patent attorney at a large law firm and as an associate general counsel of a public company. 

A patentability search will tell you if your idea is likely to be granted as an issued patent. Although the law doesn’t require you to conduct a patentability search (also known by a patent novelty analysis) before filing a petition, in my experience, having a search result before drafting the patent application is often the best first step in the patent process.

Regardless of whether you obtain a patentability search and opinion, an Examiner at The Patent Office will conduct a patent search of the invention in the U.S. application for a non-provisional patent to determine if a patent should be granted.  Why should you do a patentability check if the Patent Office will perform one? It is almost always recommended to have a patent search done in order to avoid having to prepare, file, and prosecute a patent application for an invention that is unlikely to be granted, or for which the patent’s business value may be limited by the prior art. You and your patent attorney can use the results of a search to help you draft a stronger application for your idea by focusing on the novel aspects.

A patentability search is used to identify whether or not your invention is new. Patents can only be granted for new inventions. Patents are not granted for new inventions if a prior patent application or patent discloses every detail of your invention. new). A search will give you information about the likelihood of you obtaining a patent for your invention.

Preparing a patent application after a patentability search is done can have several advantages, including:

  1. Increased likelihood of patent grant: A patentability search can identify any prior art that may prevent a patent from being granted. By identifying and addressing any potential issues before preparing the application, the chances of the patent being granted are increased.
  2. Reduced costs: By conducting a patentability search before preparing the application, the potential for wasted time and resources on an application that is unlikely to be granted is reduced.
  3. Increased specificity of claims: By identifying relevant prior art during the patentability search, the patent application can be drafted with more specific claims that are more likely to be granted.
  4. Improved quality of application: By understanding the state of the prior art, the patent application can be written in a way that is more likely to be understood and accepted by the patent office, leading to higher quality of the application.
  5. Increased competitiveness: By identifying potential competitors and their patents during the patentability search, the applicant can better position their application in the market.
  6. Better assessment of the market: A patentability search can help the applicant to understand the market for their invention and the competition, which can help them to make strategic decisions about how to protect and commercialize their invention.
  7. Better protection: By identifying potential issues early on and addressing them before filing the application, the patent holder can be sure that their invention is protected as much as possible.

If you find that your patentability search results indicate that your invention is unlikely to be granted a patent, because every detail of it has been disclosed in a prior patent application or patent patent, you can save money on filing, prosecuting, and preparing the application. A patentability search can be viewed as insurance against the possibility of not receiving a patent. This is after you have spent money on preparing, filing and prosecuting a patent request.

If some details of your invention are not found during the search, or they are not found in one prior art document (b) assuming that the unfound details provide a patentably distinct difference or improvement over prior art, then it will be worthwhile to pursue a patent on the details that were not discovered during the search. 

This is a business decision that you will need to make. Patent search helps you determine the extent of patent protection that you might be eligible for (e.g. What aspects of the invention are novel/non-obvious and protectable?   You can now determine if it is a good business decision to seek protection for your invention that might be protected by patents.

Should I hire a search specialist?

While you should do a sanity check using free on-line patent search engines, the European Patent Office has noted that: ” Free patent search tools are not necessarily more cost-effective than fee-based databases, once you factor in your manpower costs. Fee-based services offer added value in terms of speed, indexing, textual enhancement, formatting and display of results. You should also be aware of the limitations of free products.”

That said, even professional researchers can’t guarantee a patent search will be 100% accurate or foolproof. Due to restrictions in the database, there are greater chances of missing relevant patents when a free patent search is performed. Here is a small estimate of what costs could be incurred by relying on a single patent search. As of 2023, the cost of a paid search is USD 500 to 1500, while the cost of prosecuting and defending a patent application in the US is USD 5000 to 15000, depending on the law firm. Imagine the loss of money if the invention is not patentable.

Generally, yes. It does not mean that you will not be granted a patent if a similar product is not yet available on the market. While seeing a product being sold in the marketplace may be one way to determine whether an idea is prior art, the publication of an idea in patents or patent applications is another way to determine the prior art. Patent applications and patents filed at the Patent Office can disclose products that aren’t currently available on the market. There are many patents and patent applications. Even if your product has not yet been put on the market, it could be disclosed in a patent application at the Patent Office.

Patentability Search vs. Patent Clearance Research

A patentability search differs from a patent clearance or non-infringement search. Non-infringement searches and patent clearance searches are meant to determine if the commercialization or sale of your products/software services would violate any patents owned by another. A patentability search does not address whether your idea’s commercialization will infringe another patent.

Patentability Opinion After Search is Done

An attorney will review the result of the search and provide you with an opinion of Patentability.  In general, an example opinion will look like this:

Dear Inventor,

This letter is in response to your request for our analysis and opinion regarding Client’s intellectual property (IP) position. The analysis is based upon our study of various known prior art provided by Client and our understanding of the Client technology. 

I.  Summary of the Conclusions

It is our opinion that Client has a unique and defensible IP position and that the design, manufacture, use, or sale of the Client system can be protected through a combination of patents, trademarks, trade secrets and copyrights

While these opinions represent our careful analysis of all circumstances known to us at the present time and of the applicable patent laws, it is impossible for us to predict with certainty if and when any patent application will be granted or the outcome of actual litigation asserted by or against the Client system.  The reasons for these opinions are set forth in detail below.

II.  Facts and Assumptions Used In This Opinion

Our understanding of Client’s technology is based on information provided by Client and our analysis of that information.  Our opinion is based on the information and assumptions set forth in this opinion.  If any of this information or our assumptions are incorrect, the opinion expressed in this letter may have to be reconsidered.

III. Prior Art Techniques

USPN 6,167,948 (the ‘948 patent)

The ‘948 patent relates to a heat spreading apparatus with a first planar body for attachment to a heat generating surface which results in a hot region and a cool region on the first planar body. A second planar body connected to the first planar body is used to define a void between the first planar body and the second planar body. The void includes a planar capillary path and a non-capillary region. A fluid positioned within the void distributes heat by vaporizing the fluid from the planar capillary path in the hot region, condensing the fluid in the non-capillary region in the cool region, and moving from the non-capillary region to the planar capillary path in the hot region through capillarity.

FIG. 1 is a cross-sectional view of a heat spreader body 20 formed with a first planar body 22, in the form of a semiconductor package, and a second planar body 21, in the form of a lid. The semiconductor package 22 is a standard pin grid array package with a semiconductor void 24, which includes bond shelves 26. At the base of the semiconductor void 24 is a semiconductor 28. Bond wires (not shown) electrically couple the semiconductor 28 to the semiconductor package 22, which includes internal traces (not shown) with electrical connections to a set of package pins 30.

The lid 21 has a physical contour such that when it is attached to the semiconductor package 22 it defines a void with a non-capillary region 32. The non-capillary region 32 includes an adiabatic region 44 and a condenser 46. The void also includes a planar capillary fluid path 50, which includes an evaporator 51.

Heat produced by the semiconductor 28 migrates to the top of the semiconductor package 22. The generated heat is largely applied to the evaporator 51 of the heat spreader 20. Most of the heat is applied to the bottom surface 55 of the evaporator 51, some of the heat conducts through a heat transfer pillar 53 to heat the top surface 57 of the evaporator 51. Fluid within the evaporator 51 absorbs heat and vaporizes. The resultant vapor moves through the adiabatic region 44 where it does not loose or gain heat. It continues to move to the condenser region 46 where it cools and condenses on the interior walls of the device.

The condensed liquid is then drawn, through capillary fluid action, into the planar capillary fluid path 50. That is, the small dimensions of the device, discussed in detail below, result in liquid being drawn by capillary action from the non-capillary region 32, in particular the condenser 46, into the planar capillary fluid path 50. The planar capillary fluid path 50 leads back to the evaporator 51. Thus, the two-phase vaporization-condensation cycle repeats itself. This cycle results in heat produced by the semiconductor 28 being distributed over a relatively large area, instead of being localized near the semiconductor 28.

FIG. 2 illustrates a heat transfer pillar 53, which is formed on an evaporator surface 57 of an evaporator plateau 60. The evaporator plateau 60 rises from a non-capillary region surface 62. The planar capillary fluid path 50 is also formed above the non-capillary region surface 62. A fluid path bridge 63 links the planar capillary fluid path 50 with the evaporator plateau 60. Thus, the planar capillary fluid path 50 effectively includes the fluid path bridge 63 and the evaporator surface 57 of the evaporator plateau 60.

USPN 7,246,655 (the ‘655 patent) The ‘655 patent relates to a heat transfer device including a sealed container, a base layer, formed on the bottom face of the container, and a wick. The wick has a plurality of projections protruding upward from the base layer. A fluid is encapsulated in the container. The heat transfer device further includes a guide unit arranged on an inner face of the container, which guides the liquid to the wick.

FIG. 1 shows a heat transfer device with a thin container 1 having a rectangular cross-section. The container 1 is made of a metal having high heat conductivity such as copper, and has a sealed structure such that a bottom plate 2 and an upper plate 3, having large planar dimensions, are combined with side plates 4 having a short height. A porous structured wick 5 is placed in the center of an inner face of the bottom plate 2.

A structure of wick 5 is illustrated in FIG. 2 in an enlarged scale. The wick 5 is formed into a predetermined shape by consolidating particles 6. The particles 6 have excellent hydrophilicity with a fluid, and are composed of a material which does not react with the working fluid, e.g., a copper particle of several hundred micrometers (e.g., around 200 .mu.m) diameter. Those particles 6 are consolidated by sintering or the like, so as to form the wick 5.

The thickness of the wick 5 is not constant and the upper face thereof is rugged. Specifically, a substantially flat base layer 7 is formed by consolidating the above-mentioned particles 6 into one or more layers. A base layer 7 is attached to the inner face of the bottom plate 2 (i.e., an upper face in FIG. 1). At predetermined portions of the base layer 7, the particles 6 are heaped up and consolidated integrally with the base layer 7 by a sintering etc. Accordingly, the thickness of the wick 5 is thicker at those portions. The portions where the particles 6 are heaped up correspond to projections 8 of the wick. Those portions may be described as “stacks” or “cones”. The projections 8 may be shaped into an arbitrary shape like a cylinder, cone, or pyramid. In case of a conical shape, for example, the height of each projections may be around 1.8 mm, and an outer diameter of a base portion of each projections may be around 0.8 mm. Additionally, the projections 8 may be arranged at either regular or irregular intervals.

V.   Client’s Technology

Client’s technology is an improvement from non-conductive microporous coating using a non-thermally conducting glue to bind cavity-generating particles. While commercial surface enhancement techniques use cavities or grooves to increase active nucleation sites, the Client technology uses microporous surface structures for boiling enhancement. The coating can then be applied to an electronic component surface to remove heat from the electronic component.

The microporous surface is created using particles of various sizes comprising any metal which can be bonded by the soldering process including nickel, copper, aluminum, silver, iron, brass and various alloys in conjunction with a thermally conductive binder. The coating is applied while mixed with a solvent. In one embodiment, the solvent is vaporized after application to a surface prior to heating the surface sufficiently to melt the binder to bind the particles.

In one embodiment the thermally-conducting binder comprises solder paste that bonds the metal particles together in order to produce numerous microporous cavities on a target surface. The solvent may be chosen from the group comprising ethyl alcohol, isopropyl alcohol, acetone, methylethyl ketone (MEK), FC-72, FC-87, or similar highly evaporative solvent.

One recent innovation from Client is a very thin heat spreader that uses the binder technology. As shown below, the heat spreader has a base or first plate 10 that engages a top or second plate 20. The first plate 10 is adapted to be in thermal contact with a heat generating device such as a processor or graphics device, for example. 

In one embodiment, the first plate is a thin plate with a locally heated region that is thermally in contact with the heat generating device. The first plate can have a recessed portion, or can be completely flat. In combination, the first and second plates 10 and 20 form housing or chamber that stores a liquid. The liquid can be boiled when the first plate 10 is heated by the heat generating device, and the boiling action cools the heat generating device during its operation.

The second plate 20 has a plurality of structures 24 that project toward the first plate 10.  The structures 24 can be a series of barriers, ribs, or fins that can guide liquid flow motion within the chamber.  The liquid flow is enhanced by a bubble pumping action that will be discussed in more detail below.

To increase boiling heat transfer performance that is used also in the current heat spreaders, surface enhancement techniques have been investigated by researchers to augment nucleate boiling heat transfer coefficient and to extend the critical heat flux (CHF, or the highest heat flux that can be removed without exposing the surface to film boiling), and the techniques have been commercialized to maximize boiling heat transfer performance. Commercial surfaces for boiling enhancement include different types of cavities or grooves such as Furukawa’s ECR-40, Wieland’s GEWA, Union Carbide’s High-Flux, Hitachi’s Thermoexcel, and Wolverine’s Turbo-B. The surface enhancement techniques are to increase vapor/gas entrapment volume and thus to increase active nucleation site density.

Yet other Client technology allows cooling for portable devices regardless of orientation.  As shown below, a boiling cooler is shown as an enclosed vessel, comprising a base chamber 120 with a thermally conductive side mounted to a heat producing device 100 such as a processor. A Thermally-Conductive Microporous Coating (TCMC) 140 is applied to the surface of a thermally conductive column 130 within the base chamber 120 with which a heating electronic component 100 is coupled from outside the base chamber 120. The liquid coolant 150 partially fills the base chamber 120, at least partially covering the TCMC 140 surface area so that the heat flux conducted from the heating element/device 100 can induce the nucleate boiling of the liquid 150 at the microporous surface of TCMC 140. In this boiling cooler, the nucleate boiling heat transfer is significantly augmented by the TCMC 140 and becomes a dominant way to spread heat throughout the chamber. Conduction in this case becomes less important so that the whole body-shell of the cooling vessel, excepting the thermal conductive side 130, can be made of non-metal such as plastic material. Vapor coming out of the liquid boiling is held within the open space 160.

The above system is advantageous in that the system operates regardless of its orientation. The heat conducting surface is at least partially in contact with liquid in order for boiling to occur. The system ensures that the heat absorbing surface or coating contacts the coolant liquid to ensure an efficient transfer of heat from the heat source to the liquid and to the rest of the module. The system allows the system to run at top performance while minimizing the risk of failure due to overheating. The system provides a boiling cooler with a vessel in a simplified design using inexpensive non-metal material or low cost liquid coolant in combination with a boiling enhancement surface or coating.

For high temperature removal, Client can provide fins to supplement its coating in heat removal.  FIGS. 5-6 show another embodiment of a heat sink that includes a bottom housing or tub 320. Further, a plurality of sheets forming fins 330 are positioned above the tub or bottom housing 320. The bottom housing can receive a coolant existing in a first phase, in one case a liquid. The fins 330 are stacked above the bottom housing and have pipes 332 projecting there through to receive a second phase of the coolant. The space defined by the pipes 332 are sealed by a top housing or lid 350 positioned above the one or more fins 332 to define a pipe chamber 340. The boiling enhancement surface 326 is provided on an inner surface of the bottom housing 320. The boiling enhancement surface forms micro-cracks and provide more space to dissipate heat. In one embodiment, the boiling enhancement is providing using a boiling enhancement coating. Other non-coating surface enhancements such as scratches, machining, or sintering, can be used as a boiling enhancement surface to effect heat removal. In this embodiment, the heat sink uses discrete pipes 332 to be inserted through the holes, in the place of the cavities formed by the sheet metal stacks. The sheet metal stacks in this case may or may not have ‘lips’ that would otherwise form the cavity when joined in plurality.

VI. Uniqueness of Client’s Technology

Client’s technology is quite cost-effective when compared with the devices shown in the ‘948 patent and the ‘655 patent. Both of these patents rely on capillary forces and wick structures which are difficult to make and expensive. Compared to the prior art, Client’s coating technology is simpler and cheaper because Client’s systems do not need such wick structures and do not need to depend on any capillary forces. The Client coating is applied to a surface through a relatively low cost process that includes creating a uniform mixture of the cavity-generating particles, the thermally conductive binder, and the solvent using, for example, an ultrasonic bath.

The mixture is then applied to the surface using a method such as brushing, painting, spraying, vibrating, dipping the surface into the mixture, dripping, splatter, rotating the surface while dripping, or other methods known in the art. The treated surface is then heated to a temperature sufficient to vaporize the solvent. The surface is then further heated to a temperature sufficient to melt the solder paste such that it serves as a binder between the cavity generating particles. During this process, solder flux is used to expedite formation of micropores during the bonding process between the particles and later removed from the surface. Advantages to the mixture batch type application include that it is an inexpensive and easy process which does not require extremely high operating temperatures.

The surface is also relatively insensitive to coating thickness due to the high thermal conductivity of the binder. Therefore, larger size cavities can be constructed in the microporous structures for poorly wetting fluids (such as water) without causing serious degradation of boiling enhancement. For that reason, the new coating technique is efficient for various types of working liquids simply by changing the size of metal particle sizes since different surface tension of liquids requires different size range of porous cavities to optimize boiling heat transfer performance.

Client’s recent innovation provides a thin housing, chamber, container, or vessel having a liquid therein and one or more structures mounted in the chamber to induce a liquid flow pattern during a boiling of the liquid to distribute heat. The innovation replaces a conventional solid-block heat spreading unit with a low-profile chamber containing liquid. During operation, the device being cooled boils the liquid, and the liquid boiling is combined with a thin chamber or gap to create the bubble pumping action to induce a streamlined flow pattern that enhances the cooling effects. 

Additionally, the thin gap allows freedom of orientation with respect to gravity. The system uses nucleate boiling and condensation in a thin circular, square, or rectangular form for the heat spreading. The internal structures promote the streamlined flow pattern induced by nucleate boiling. The structures also provide mechanical strength that prevents bending of the plate and any assembly or parts built thereon. 

Further enhancement of heat spreader performance can be achieved by employing different surface treatments for boiling heat transfer. The total thickness of the hollow heat spreader can be as low as about 0.1 millimeter, providing weight reduction from conventional solid heat spreaders. The heat spreader cools the device through the boiling of the liquid and through the induced liquid flow pattern, and achieves cooling without requiring an external pump. The pumping power comes from the motion of bubbles due to buoyancy after they depart the boiling surface, which provides a strong liquid pumping power and heat spreading capability and thus provides excellent omni-directional performance that is relatively insensitive to direction and orientation of the heat spreader.

We are not aware of any prior art that shows Client’s coating technology to remove heat through boiling. The prior art typically uses wicks that remove heat through vaporization rather than through boiling. Further, when used in conjunction with low profile housing that generates a local bubble pumping action to induce a streamlined flow pattern that enhances the cooling effects.

VII. Conclusion

For all the foregoing reasons, we conclude that Client’s IP position is unique and defensible. Please note that by basing our conclusions on certain specific distinctions between the Client system and the prior art, we are not suggesting that other differences are insufficient to support the same conclusion.

Now over to you

In sum, a patentability search can strengthen a patent application by providing insight into the prior art and potential issues that may affect the patentability of the invention. This information can then be used to tailor the patent application to increase the chances of it being granted. Some ways a patentability search can strengthen a patent application include:

  1. Identifying prior art: A patentability search can reveal any prior art, such as existing patents, published papers, and other publicly available information, that may be relevant to the invention. This information can be used to tailor the patent application to distinguish the invention from the prior art.
  2. Tailoring claims: By identifying relevant prior art, the patent application can be drafted with more specific claims that are more likely to be granted. This can help to avoid claims that may be too broad or obvious and increase the chances of the patent being granted.
  3. Identifying potential issues: A patentability search can reveal any potential issues with the invention, such as prior art that may make the invention obvious or unpatentable. By identifying these issues early on, the applicant can address them in the patent application or adjust their strategy accordingly.
  4. Improving the quality of the application: By understanding the state of the prior art, the patent application can be written in a way that is more likely to be understood and accepted by the patent office, leading to a higher quality of the application.
  5. Increasing competitiveness: By identifying potential competitors and their patents during the patentability search, the applicant can better position their application in the market and understand the competition.
  6. Identifying new opportunities: A patentability search can also reveal new opportunities for the invention and help the applicant to understand the market for their invention, which can help them to make strategic decisions about how to protect and commercialize their invention.
  7. Enhancing the protection: By identifying potential issues early on and addressing them before filing the application, the patent holder can be sure that their invention is protected as much as possible.

Now that you see how the patentability search result is used, go and get yours done. This document can be helpful to your early stage investors as well, but be aware that the opinion is not meant to be shared with the public to protect the attorney client privilege.  Your attorney should be able to answer questions from institutional investors with more confidence with the analysis done on patentability.