US 5,958,556 AGranted

Vibration damped and stiffened circuit articles

AssigneeMinnesota Mining and Manufacturing Company

InventorJeffrey W. McCutcheon

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Abstract

The present invention provides circuit articles which are damped and stiffened relative to resonant vibrations and shock. At least one vibration damping and stiffening member comprising a constraining member comprising a base having at least one projection and a layer(s) of vibration damping material is attached to the circuit article. These member(s) act to stiffen the circuit article and also add significant damping to the circuit article while potentially taking up only a relatively small circuit article surface area.

Claims35

Dependent claims

A damped and stiffened circuit article comprising:

(a) a circuit article having at least one substantially flat surface;
(b) a vibration damping and stiffening member(s) attached to at least one substantially flat surface of the circuit article, wherein each vibration damping and stiffening member independently comprises:
(I) a constraining member, wherein the constraining member comprises:
(i) a base, wherein the base has an upper surface, a lower surface, and at least one side;
and
(ii) at least one projection attached to and extending away from the base in a manner such that at least one of the following is true:
(A) at least one projection is attached to and extends away from an upper surface of the base, (B) at least one projection is attached to and extends away from a lower surface of the base, (C) at least one projection is attached to and extends away from an upper surface of the base and at least one projection is attached to and extends away from a lower surface of the base;
wherein the height of at least one projection is at least about 10% of the average thickness of the base;
wherein the average thickness of the base of at least one vibration damping and stiffening member falls within the range of about 0.0254 to about 7.62 mm:
wherein the width of the base of at least one vibration damping and stiffening member falls within the range of about 1.27 to about 76.2 mm;
and wherein the height of at least one projection of at least one vibration damping and stiffening member ranges from about 0.0254 to about 76.2 mm;
(II) a vibration damping material layer(s) comprising a viscoelastic material(s) wherein the vibration damping material layer(s) have a loss factor of at least about 0.01 and a Young's modulus of at least about 3.times.10.sup.3 Pascals at 25 degrees C., wherein the vibration damping material layer(s) is bonded to at least a portion of the lower surface of the base;
(III) optionally an intermediate connecting member attached to the vibration damping material layer(s) on a side opposite the constraining member, wherein the intermediate connecting member has a Young's modulus greater than the Young's modulus of the vibration damping material layer(s);
wherein the constraining member has a Young's modulus greater than the Young's modulus of the vibration damping material layer(s);
wherein the vibration damping and stiffening member(s) is attached to at least one substantially flat surface of the circuit article in a manner such that the circuit article is stiffened and vibrationally damped;
and
wherein about 0.005 to about 20 percent of the total area of the circuit article has vibration damping and stiffening member(s) attached thereto such that the damping of the circuit article is improved by at least about 10% in at least one vibrational mode compared to a same circuit article subjected to a same static or dynamic input without any vibration damping and stiffening members attached.

14 more elements

Dependencies are inferred from the claim text.

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Abstract

A damped and stiffened circuit article comprising:

(a) a circuit article having at least one substantially flat surface;
(b) a vibration damping and stiffening member(s) attached to at least one substantially flat surface of the circuit article, wherein each vibration damping and stiffening member independently comprises:
(I) a constraining member, wherein the constraining member comprises:
(i) a base, wherein the base has an upper surface, a lower surface, and at least one side;
and
(ii) at least one projection attached to and extending away from the base in a manner such that at least one of the following is true:
(A) at least one projection is attached to and extends away from an upper surface of the base, (B) at least one projection is attached to and extends away from a lower surface of the base, (C) at least one projection is attached to and extends away from an upper surface of the base and at least one projection is attached to and extends away from a lower surface of the base;
wherein the height of at least one projection is at least about 10% of the average thickness of the base;
wherein the average thickness of the base of at least one vibration damping and stiffening member falls within the range of about 0.0254 to about 7.62 mm:
wherein the width of the base of at least one vibration damping and stiffening member falls within the range of about 1.27 to about 76.2 mm;
and wherein the height of at least one projection of at least one vibration damping and stiffening member ranges from about 0.0254 to about 76.2 mm;
(II) a vibration damping material layer(s) comprising a viscoelastic material(s) wherein the vibration damping material layer(s) have a loss factor of at least about 0.01 and a Young's modulus of at least about 3.times.10.sup.3 Pascals at 25 degrees C., wherein the vibration damping material layer(s) is bonded to at least a portion of the lower surface of the base;
(III) optionally an intermediate connecting member attached to the vibration damping material layer(s) on a side opposite the constraining member, wherein the intermediate connecting member has a Young's modulus greater than the Young's modulus of the vibration damping material layer(s);
wherein the constraining member has a Young's modulus greater than the Young's modulus of the vibration damping material layer(s);
wherein the vibration damping and stiffening member(s) is attached to at least one substantially flat surface of the circuit article in a manner such that the circuit article is stiffened and vibrationally damped;
and
wherein about 0.005 to about 20 percent of the total area of the circuit article has vibration damping and stiffening member(s) attached thereto such that the damping of the circuit article is improved by at least about 10% in at least one vibrational mode compared to a same circuit article subjected to a same static or dynamic input without any vibration damping and stiffening members attached.

14 more elements