3M Innovative Properties Company

Teresa M Goeddel

Mikhail L Pekurovsky

Kara A Meyers

Saagar A Shah

Ankit Mahajan

Jeremy K Larsen

Thomas J Metzler

Jonathan W Kemling

Roger W Barton

Matthew R D Smith

Kayla C Niccum

James Zhu

Michael A Kropp

Christopher Bland Walker, Jr

Graham M Clarke

Vivek Krishnan

Lyudmila A Pekurovsky

Kevin T Reddy

Gino L Pitera

Jessica Chiu

Ankit Mahajan, Jr

Thomas P Klun

Richard John Pokorny

Matthew S Stay

Shawn C Dodds

Daniel J Theis

Ann M Gilman

Benjamin R Coonce

Chad M Amb

Christopher G Walker

Joseph E Hernandez

A method comprises: providing a layer of curable adhesive material () on a substrate (); forming a pattern of microstructures () on the layer of curable adhesive material (); curing a first region () of the layer of curable adhesive material () at a first level and a second region () of the layer of curable adhesive material () at a second level greater than the first level; providing a solid circuit die () to directly attach to a major surface of the first region () of the layer of curable adhesive material (); and further curing the first region () of the layer of curable adhesive material () to anchor the solid circuit die () on the first region () by forming an adhesive bond therebetween. The pattern of microstructures () may include one or more microchannels (), the method further comprising forming one or more electrically conductive traces in the microchannels (), in particular, by flow of a conductive particle containing liquid () by a capillary force and, optionally, under pressure. The at least one microchannel () may extend from the second region () to the first region () and have a portion beneath the solid circuit die (). The solid circuit die () may have at least one edge disposed within a periphery of the first region () with a gap therebetween. The solid circuit die () may have at least one contact pad () on a bottom surface thereof, wherein the at least one contact pad () may be in direct contact with at least one of the electrically conductive traces in the microchannels (). Forming the pattern of microstructures () may comprise contacting a major surface of a stamp () to the layer of curable adhesive material (), the major surface having a pattern of raised features () thereon. The curable adhesive material () may be cured by an actinic light source such as an ultraviolet (UV) light source ('), wherein a mask may be provided to at least partially block the first region () of the layer of curable adhesive material () from the cure. The stamp () may be positioned in contact with the curable adhesive material () to replicate the pattern of raised features () to form the microstructures () while the curable adhesive material () is selectively cured by the actinic light source such as the ultraviolet (UV) light source (). The first region () of the layer of curable adhesive material () may be cured at the first level to allow a bottom surface of the solid circuit die () to be fluidly-sealed by the major surface of the first region (). The second region of the layer of curable adhesive material () may be cured at the second level such that the second region () is fully cured. The further curing may be any suitable curing such as thermal curing, radiation curing (e.g., by actinic radiation, such as ultraviolet (UV) radiation) or self-curing at room temperature without using a thermal or radiation curing source.

Circuits including micropatterns and using partial curing to adhere dies

A method includes placing an electronic device on a pliable mating surface on a major surface of a mold such that at least one contact pad on the electronic device presses against the pliable mating surface. The pliable mating surface is on a microstructure in an arrangement of microstructures on the major surface of the mold. A liquid encapsulant material is applied over the electronic device and the major surface of the mold, and then hardened to form a carrier for the electronic device. The mold and the carrier are separated such that the microstructures on the mold form a corresponding arrangement of microchannels in the carrier, and at least one contact pad on the electronic device is exposed in a microchannel in the arrangement of microchannels. A conductive particle-containing liquid is deposited in the microchannel, which directly contacts the contact pad exposed in the microchannel.

Methods for registration of circuit dies and electrical interconnects

A stretchable conductor includes a substrate with a first major surface, wherein the substrate is an elastomeric material. An elongate wire is on the first major surface of the substrate; the wire includes a first end and a second end, and further includes at least one arcuate region between the first end and the second end. At least one portion of the arcuate region of the wire in the region has a first surface area portion embedded in the surface of the substrate and a second surface area portion unembedded on the substrate and exposed in an amount sufficient to render at least an area of the substrate in the region electrically conductive. The unembedded second surface portion of the arcuate region may lie above or below a plane of the substrate. Composite articles including a stretchable conductor in durable electrical contact with a conductive fabric are also disclosed.

Stretchable conductors

Flexible devices including conductive traces with enhanced stretchability, and methods of making and using the same are provided. The circuit die is disposed on a flexible substrate. Electrically conductive traces are formed in channels on the flexible substrate to electrically contact with contact pads of the circuit die. A first polymer liquid flows in the channels to cover a free surface of the traces. The circuit die can also be surrounded by a curing product of a second polymer liquid.

Flexible device including conductive traces with enhanced stretchability

Processes for automatic registration between a solid circuit die and electrically conductive interconnects, and articles or devices made by the same are provided. The solid circuit die is disposed on a substrate with contact pads aligned with channels on the substrate. Electrically conductive traces are formed by flowing a conductive liquid in the channels toward the contact pads to obtain the automatic registration.

Automatic registration between circuit dies and interconnects

A stretchable conductor includes a substrate with a first major surface and an elongate wire, wherein the substrate is an elastomeric material, the elongate wire is on the first major surface of the substrate, the wire includes a first end and a second end, and further includes at least one arcuate region between the first end and the second end. At least one portion of the arcuate region of the wire in the region has a first surface area portion embedded in the surface of the substrate and a second surface area portion unembedded on the substrate and exposed in an amount sufficient to render at least an area of the substrate in the region electrically conductive. The unembedded second surface portion of the arcuate region may lie above or below a plane of the substrate. Additionally, different methods of preparing said stretchable conductor are disclosed. Composite articles including said stretchable conductor in durable electrical contact with a conductive fabric are also disclosed.

Method of making a stretchable conductor

Growing community of inventors

Saint Paul, MN, United States of America

Teresa M Goeddel