Back to results
US 11,240,918 B2Granted
Method for flip-chip bonding using anisotropic adhesive polymer
AssigneeResearch & Business Foundation Sungkyunkwan University
InventorsTae Il Kim, Ju Seung Lee
Life of this patent
Estimating the term…
Abstract
The present invention discloses flip-chip bonding method using an anisotropic adhesive polymer. The method includes applying an adhesive polymer solution containing metal particles dispersed therein onto a circuit substrate to form an adhesive polymer layer such that the adhesive polymer layer covers the metal particles; drying the adhesive polymer layer; and positioning an electronic element to be electrically connected to the circuit substrate on the dried adhesive polymer layer and causing dewetting of the polymer from the metal particles.
Claims9
A structure for flip-chip bonding, comprising:
- a circuit substrate;
- an anisotropic adhesive polymer layer disposed on the circuit substrate, the anisotropic adhesive polymer layer having an interface location;
- and
- a metal particle entirely covered by the anisotropic adhesive polymer layer to thereby form an air-adhesive-metal location at the interface location with a thickness of the anisotropic adhesive polymer layer covering the metal particle between the metal particle and air,
- wherein, at the interface location, the anisotropic adhesive polymer layer has an effective interfacial potential in a metastable state, such that the anisotropic adhesive polymer layer is spinodally dewetted from the metal particle upon reduction of the thickness of the anisotropic polymer layer covering the metal particle,
- wherein the anisotropic adhesive polymer layer is coated to have a thickness of 100 nm to 500 nm, and a diameter of the metal particle is 50 nm to 300 nm,
- wherein a function of the effective interfacial potential is expressed as a following Equation 1:
- Φ
-
- (
- h
- )
- =
- c
- h
- 8
- +
- Φ
- vd
-
- (
- h
- )
- =
- c
- h
- 8
- -
- A
- 12
-
- πh
- 2
- <
- Equation
-
-
- 1
- >
- wherein in the Equation 1, h represents the thickness of the anisotropic adhesive polymer layer covering the metal particle, c represents a short-range interaction strength between the anisotropic adhesive polymer layer and the metal particle, A represents an effective Hamaker constant of the metal particle, Φvd (h) denotes a function of van der Waals force based on the thickness h,
- wherein c in the Equation 1 is obtained from a following Equation 2:
- Φ
-
- (
- h
- *
- )
- =
- c
- h
- *
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- *
- 2
- =
- σ
-
- [
- 1
- -
- (
- 1
- +
- tan
- 2
-
- θ
- )
- -
- 1
- 2
- ]
- <
-
- Equation
-
-
- 2
-
- >
- wherein in the Equation 2, θ represents a contact angle between the metal particle and the anisotropic adhesive polymer layer, σ represents a surface tension of the anisotropic adhesive polymer layer, and h* denotes an equilibrium film thickness of the anisotropic adhesive polymer layer as a thickness that is formed by a spinodal dewetting,
- wherein, in the metastable state, a value of the function of the effective interfacial potential changes from a negative value to a positive value as a value of h increases and, then, a slope of the function of the effective interfacial potential is changed to a negative value, and
- wherein a minimum thickness of the adhesive polymer layer at the interface location is defined as the thickness h at which the slope of the function of the effective interfacial potential changes from positive to negative.
89 more elements
A structure for flip-chip bonding, comprising:
- a circuit substrate;
- a relief electrode partially formed on the circuit substrate;
- and
- an anisotropic adhesive polymer layer disposed on the circuit substrate and entirely covering the relief electrode with a thickness of the anisotropic adhesive polymer layer,
- wherein, in the locality of the relief electrode, the anisotropic adhesive polymer layer has an effective interfacial potential in a metastable state, such that the anisotropic adhesive polymer layer is spinodally dewetted from the relief electrode upon reduction the thickness of the anisotropic polymer layer covering the relief electrode,
- wherein the anisotropic adhesive polymer layer is coated to have a thickness of 100 nm to 500 nm, and a relief height of the relief electrode is 50 nm to 300 nm,
- wherein a function of the effective interfacial potential is expressed as a following Equation 1:
- Φ
-
- (
- h
- )
- =
- c
- h
- 8
- +
- Φ
- vd
-
- (
- h
- )
- =
- c
- h
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- 2
- <
-
- Equation
-
-
- 1
-
- >
- wherein in the Equation 1, h represents the thickness of the p anisotropic adhesive polymer layer covering the relief electrode, c represents a short-range interaction strength between the anisotropic adhesive polymer layer and the relief electrode, A represents an effective Hamaker constant of the relief electrode, Φvd (h) denotes a function of van der Waals force based on the thickness h,
- wherein c in the Equation 1 is obtained from a following Equation 2:
- Φ
-
- (
- h
- *
- )
- =
- c
- h
- *
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- *
- 2
- =
- σ
-
- [
- 1
- -
- (
- 1
- +
- tan
- 2
-
- θ
- )
- -
- 1
- 2
- ]
- <
-
- Equation
-
-
- 2
-
- >
- wherein in the Equation 2, θ represents a contact angle between the relief electrode and the anisotropic adhesive polymer layer, σ represents a surface tension of the anisotropic adhesive polymer layer, and h* denotes an equilibrium film thickness of the anisotropic adhesive polymer layer as a thickness that is formed by the spinodal dewetting,
- wherein, in the metastable state, a value of the function of the effective interfacial potential changes from a negative value to a positive value as a value of h increases and, then, a slope of the function of the effective interfacial potential is changed to a negative value, and
- wherein a minimum thickness of the anisotropic adhesive polymer layer at the interface location is defined as the thickness h at which the slope of the function of the effective interfacial potential changes from positive to negative.
95 more elements
A structure for flip-chip bonding, comprising:
- a circuit substrate having a surface;
- an anisotropic adhesive polymer layer disposed on the surface of the circuit substrate, the anisotropic adhesive polymer layer having a first interface location and a second interface location;
- and
- a metal conductor disposed on the surface of the circuit substrate and separated from air by a first thickness of the anisotropic adhesive polymer layer to thereby form an air-adhesive-metal location at the first interface location,
- wherein the surface of the circuit substrate is separated from air by a second thickness of the anisotropic adhesive polymer layer to thereby form an air-adhesive-substrate location at the second interface location,
- wherein, at the first interface location, the anisotropic adhesive polymer layer has an effective interfacial potential in a metastable state, such that the anisotropic adhesive polymer layer has a property to be dewetted from the metal conductor in response to a stimulus effective to reduce the first thickness of the anisotropic polymer layer covering the metal conductor and the second thickness of the anisotropic polymer layer covering the substrate, and
- wherein, at the second interface location, the anisotropic adhesive polymer layer has an effective interfacial potential in a metastable state or in a stable state, such that the anisotropic adhesive polymer layer has a property to remain spread on the surface of the circuit substrate in response to a stimulus effective to reduce the first thickness of the anisotropic polymer layer covering the metal conductor and the second thickness of the anisotropic polymer layer covering the substrate,
- wherein the anisotropic adhesive polymer layer is coated to have a thickness of 100 nm to 500 nm, and a thickness of the metal conductor is 50 nm to 300 nm,
- wherein a function of the effective interfacial potential is expressed as a following Equation 1:
- Φ
-
- (
- h
- )
- =
- c
- h
- 8
- +
- Φ
- vd
-
- (
- h
- )
- =
- c
- h
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- 2
- <
-
- Equation
-
-
- 1
-
- >
- wherein in the Equation 1, h represents the thickness of the anisotropic adhesive polymer layer covering the metal conductor, c represents a short-range interaction strength between the anisotropic adhesive polymer layer and the metal conductor, A represents an effective Hamaker constant of the metal conductor, Φvd (h) denotes a function of van der Waals force based on the thickness h,
- wherein c in the Equation 1 is obtained from a following Equation 2:
- Φ
-
- (
- h
- *
- )
- =
- c
- h
- *
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- *
- 2
- =
- σ
-
- [
- 1
- -
- (
- 1
- +
- tan
- 2
-
- θ
- )
- -
- 1
- 2
- ]
- <
-
- Equation
-
-
- 2
-
- >
- wherein in the Equation 2, θ represents a contact angle between the metal conductor and the anisotropic adhesive polymer layer, σ represents a surface tension of the anisotropic adhesive polymer layer, and h* denotes an equilibrium film thickness of the anisotropic adhesive polymer layer as a thickness that is formed by the spinodal dewetting,
- wherein, in the metastable state, a value of the function of the effective interfacial potential changes from a negative value to a positive value as a value of h increases and, then, a slope of the function of the effective interfacial potential is changed to a negative value, and
- wherein a minimum thickness of the adhesive polymer layer at the interface location is defined as the thickness h at which the slope of the function of the effective interfacial potential changes from positive to negative.
97 more elements
A flip-chip structure, comprising:
- a circuit substrate having an adhesion region and an exposure region;
- an electronic element adhered to the circuit substrate in the adhesion region of the circuit substrate by an anisotropic adhesive polymer layer, at least a portion of the anisotropic adhesive polymer layer being in a metastable state;
- and
- a metal conductor disposed between the circuit substrate and the electronic element, the exposure region of the circuit substrate conforming to a shape of the metal conductor, the shape corresponding to a dewetting of the metastable state of the anisotropic adhesive polymer layer,
- wherein a surface of the metal conductor and a surface of the circuit substrate are exposed to air in the exposure region, and
- wherein the metal conductor directly contacts the electronic element,
- wherein the anisotropic adhesive polymer layer is coated to have a thickness of 100 nm to 500 nm, and a thickness of the metal conductor is 50 nm to 300 nm,
- wherein a function of the effective interfacial potential is expressed as a following Equation 1:
- Φ
-
- (
- h
- )
- =
- c
- h
- 8
- +
- Φ
- vd
-
- (
- h
- )
- =
- c
- h
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- 2
- <
-
- Equation
-
-
- 1
-
- >
- wherein in the Equation 1, h represents the thickness of the anisotropic adhesive polymer layer covering the metal conductor, c represents a short-range interaction strength between the anisotropic adhesive polymer layer and the metal conductor, A represents an effective Hamaker constant of the metal conductor, Φvd (h) denotes a function of van der Waals force based on the thickness h,
- wherein c in the Equation 1 is obtained from a following Equation 2:
- Φ
-
- (
- h
- *
- )
- =
- c
- h
- *
- 8
- -
- A
- 12
-
-
- π
-
-
- h
- *
- 2
- =
- σ
-
- [
- 1
- -
- (
- 1
- +
- tan
- 2
-
- θ
- )
- -
- 1
- 2
- ]
- <
-
- Equation
-
-
- 2
-
- >
- wherein in the Equation 2, θ represents a contact angle between the metal conductor and the anisotropic adhesive polymer layer, σ represents a surface tension of the anisotropic adhesive polymer layer, and h* denotes an equilibrium film thickness of the anisotropic adhesive polymer layer as a thickness that is formed by the spinodal dewetting,
- wherein, in the metastable state, a value of the function of the effective interfacial potential changes from a negative value to a positive value as a value of h increases and, then, a slope of the function of the effective interfacial potential is changed to a negative value, and
- wherein a minimum thickness of the adhesive polymer layer at the interface location is defined as the thickness h at which the slope of the function of the effective interfacial potential changes from positive to negative.
96 more elements
Dependencies are inferred from the claim text.