Pressure indicator films for high temperature applications
AssigneeInternational Business Machines Corporation
InventorsScott B. King, Brandon M. Kobilka, Joseph Kuczynski, Jason T. Wertz
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Abstract
In an example, a pressure indicator film includes a first polymeric film material and a second polymeric film material that satisfy a threshold thermal degradation temperature. The pressure indicator film includes microcapsules on a surface of the first polymeric film material and a developer material on a surface of the second polymeric film material. The microcapsules are formed from a polymeric shell material that satisfies the threshold thermal degradation temperature. The microcapsules encapsulate a payload that includes a pH indicator and a solvent having a boiling point that is greater than the threshold thermal degradation temperature.
Claims17
A pressure indicator film comprising:
- a first polymeric film material that satisfies a threshold thermal degradation temperature that corresponds to a temperature associated with a printed circuit board (PCB) lamination operation;
- a second polymeric film material that satisfies the threshold thermal degradation temperature;
- microcapsules on a surface of the first polymeric film material;
- and
- a developer material on a surface of the second polymeric film,
- wherein the microcapsules are formed from a polymeric shell material that satisfies the threshold thermal degradation temperature, the polymeric shell material including a polyimide material, and
- wherein the microcapsules encapsulate a payload that includes a pH indicator and a solvent having a boiling point that is greater than the threshold thermal degradation temperature.
A process of forming a pressure indicator film, the process comprising:
- applying microcapsules to a surface of a first polymeric film material, wherein the first polymeric film material satisfies a threshold thermal degradation temperature that is not less than 100° C., wherein the microcapsules are formed from a polymeric shell material that satisfies the threshold thermal degradation temperature and wherein the microcapsules encapsulate a payload that includes a developer material and a solvent having a boiling point that is greater than the threshold thermal degradation temperature;
- applying a powder to a surface of a second polymeric film material, wherein the second polymeric film material satisfies the threshold thermal degradation temperature and wherein the powder includes a pH indicator material;
- and
- joining the first polymeric film material to the second polymeric film material to form a pressure indicator film.
A process of forming a pressure indicator film, the process comprising:
- performing an electrospraying operation to form a first set of microcapsules, the first set of microcapsules having a polyamic acid (PAA) shell material encapsulating a payload that includes a pH indicator and a solvent;
- forming a second set of microcapsules having a polyimide shell material by heating the first set of microcapsules to imidize the PAA shell material;
- applying the second set of microcapsules to a surface of a first polyimide film;
- applying a developer material to a surface of a second polyimide film;
- and
- joining the first polyimide film to the second polyimide film to form a pressure indicator film.
Dependencies are inferred from the claim text.