# US 7,744,802 B2 · Dielectric film with low coefficient of thermal expansion (CTE) using liquid crystalline resin

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- Number: US 7,744,802 B2
- Document ID: US7744802B2
- Status: Granted
- Kind: B2
- Application number: 10/876,508
- Filed: 2004-06-25
- Published: 2005-12-29
- Granted: 2010-06-29
- Earliest claimed: 2004-06-25
- Assignees: Intel Corporation
- Inventors: James C. Matayabas, Jr.
- Web page: https://patentgrep.com/patent/US7744802B2

## CPC

- H10W 20/47: comprising two or more dielectric layers having different properties, e.g. different dielectric constants
- H05K 3/4626: {characterised by the insulating layers or materials (H05K3/4688 takes precedence)}
- H10W 20/097: {by thermally treating}
- H10W 20/48: Insulating materials thereof
- H05K 2201/0141: Liquid crystal polymer [LCP]
- H05K 2201/068: wherein the coefficient of thermal expansion is important
- H05K 2203/104: Using magnetic force, e.g. to align particles or for a temporary connection during processing
- H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills}
- H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills
- Y10T 428/25: Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An embodiment of the present invention is a technique to provide a dielectric film material with a controllable coefficient of thermal expansion (CTE). A first compound containing a first liquid crystalline component is formed. The first compound is cast into a first film. The first film is oriented in an magnetic or electromagnetic field in a first direction. The first film is cured at a first temperature.

## Claims

### Claim 1

A method comprising:
forming a first compound containing a first liquid crystalline component;
casting the first compound into a first film;
orienting the first film in a magnetic or electromagnetic field in a first direction to control a coefficient of thermal expansion (CTE) of the first film;
curing the first film at a first temperature;
forming a dielectric layer including the cured first film; and
depositing the dielectric layer on a substrate layer in a semiconductor package, the substrate layer having a CTE that matches with CTE of the dielectric layer;
wherein forming the dielectric layer comprises:
forming a second compound containing a second liquid crystalline component;
casting the second compound into a second film;
orienting the second film in the magnetic or electromagnetic field in a second direction different than the first direction; and
forming a multilayer as the dielectric layer including at least the first and second films.

### Claim 2 (depends on 1)

The method of claim 1 further comprising:
adding at least an additive to at least one of the first compound and the second compound.

### Claim 3 (depends on 2)

The method of claim 2 wherein adding the additive comprises:
adding at least one of a catalyst, an adhesive, an adhesion promoter, a mold release agent, a flame retardant, a stabilizer, and a colorant.

### Claim 4 (depends on 1)

The method of claim 1 further comprising:
adding a filler to at least one of the first compound and the second compound.

### Claim 5 (depends on 1)

The method of claim 1 wherein depositing the dielectric layer comprises:
laminating at least one of the first film and the second film onto the substrate layer.

### Claim 6 (depends on 1)

The method of claim 1 wherein forming the first compound comprises:
forming the first compound including a rod-like liquid crystalline component and at least an element selected from a group of oxygen, carbonyl, carboxyl, oxycarbonyl, and amine; and (CH2)n, n being from 1 to 20.

### Claim 7 (depends on 1)

The method of claim 1 wherein forming the first compound comprises:
forming the first compound including a rod-like liquid crystalline component and at least first and second elements, each being independently selected from a group of oxygen, carbonyl, carboxyl, oxycarbonyl, and amine; and (CH2)n, n being from 2 to 20.

### Claim 8 (depends on 1)

The method of claim 1 further comprising:
curing the second film at a second temperature.

### Claim 9 (depends on 8)

The method of claim 8 wherein at least one of the first and second temperatures is above a melting point of one of the first and second compounds.

### Claim 10 (depends on 1)

The method of claim 1 wherein forming the second compound comprises:
forming the second compound including a rod-like liquid crystalline component and at least an element selected from a group of oxygen, carbonyl, carboxyl, oxycarbonyl, and amine: and (CH2)n, n being from 1 to 20.

### Claim 11 (depends on 1)

The method of claim 1 wherein forming the second compound comprises:
forming the second compound including a rod-like liquid crystalline component and at least first and second elements, each being independently selected from a group of oxygen, carbonyl, carboxyl, oxycarbonyl, and amine; and (CH2)n, n being from 2 to 20.