Name: DOWSIL ME 1140 Silicone Adhesive
Brand: Dow Silicones Corporation
SKU: DOWSIL ME 1140

Main features

Solvent-Free Bonding Formulation
60-Minute 130 deg C Cure
Low-Modulus Cured Bonding

Product Description

DOWSIL™ ME-1140 Adhesive is a one-part, heat-curing, translucent polydimethylsiloxane adhesive formulated for fine, precise jet dispensing. Its solvent-free, low-viscosity formulation combines thixotropy with controlled flow, while the cured silicone elastomer has a low Young's modulus for stress-relieving attachment and encapsulation. The product is documented for die attach, glob-top encapsulation, and sealing or bonding within PCB system assemblies. It is supplied as a single-component material and has a standard thermal cure condition of 60 minutes at 130°C.

Key features

Fine jet dispensing: Low-viscosity, solvent-free PDMS with a documented balance of thixotropy and flow for fine, precise material deposition.
One-part heat cure: Single-component format with a standard cure condition of 60 minutes at 130°C.
Low-modulus cured elastomer: Typical Young's modulus of 2.5 MPa and Shore A hardness of 40 for applications requiring stress relief.

Applications / Suitable for

Fine, precise application by jet dispensing
Die attach bonding
Glob-top encapsulation
Sealing and bonding in PCB system assemblies

TDS, SDS & Technical Documents

Technical Specifications

General Properties

Appearance

Translucent

Chemistry Type

Polydimethylsiloxane

Color

Colorless

Density

1.01 kg/m3

Physical Properties

Thixotropic index

3.0

Viscosity

4400 mPa.s

Mechanical Properties

Elongation

120 %

Additional Information

One-Part Heat-Cure Silicone Adhesive

DOWSIL ME-1140 Adhesive Clear

DOWSIL ME-1140 Adhesive is a one-part, heat-curing, translucent polydimethylsiloxane adhesive developed for fine, precise jet dispensing. Its solvent-less, low-viscosity formulation combines thixotropy with controlled flow, while the cured silicone elastomer provides a low Young's modulus. Dow documents the product for die attach, glob-top encapsulation, and sealing, encapsulation, or adhesive use in PCB system assemblies.

One-part heat cure

Jet dispensable

4.4 Pa s viscosity at 10/s

2.5 MPa Young's modulus

Translucent PDMS

As-Supplied Properties

Dispensing-focused material characteristics

ME-1140 is supplied as a translucent, one-part PDMS adhesive. Dow characterizes it as solvent-less and low viscosity with balanced thixotropic and flow properties for fine, precise patterning by jet dispensing.

Product Form

One-part

No component mixing is required before application.

Viscosity

4.4 Pa s

Reported at a shear rate of 10/s.

Thixotropic Index

3.0

Viscosity ratio at 10/s to 100/s.

Appearance

Translucent

Polydimethylsiloxane formulation.

Typical values are not intended for use as product specifications.

Property	Value	Unit	Method / condition
Product form	One-part	N/A	As supplied
Appearance	Translucent	N/A	As supplied
Viscosity	4.4	Pa s	Shear rate 10/s
Thixotropic index	3.0	N/A	Viscosity ratio at 10/s / 100/s
Viscosity rise	101	%	25 deg C for 24 hours

Preparation and Cure

Processing and cure

ME-1140 is a one-part addition-curing silicone adhesive, so component mixing is not required. Dow documents fine, precise patterning by jet dispensing and a standard heat-cure condition of 60 minutes at 130 deg C. The cure rate is accelerated by heat, and the final process should be validated for the actual assembly and equipment.

1. Prepare surfaces

Thoroughly clean and degrease bonding surfaces. Dow notes that residual oils can interfere with adhesion.

2. Dispense

Apply the one-part material using the dispensing process appropriate to the assembly. Jet dispensing is specifically documented for fine, precise patterning.

3. Assemble

Position the component or complete the encapsulation or sealing operation while maintaining the required material geometry for the application.

4. Heat cure

The documented standard condition is 60 minutes at 130 deg C. Validate the actual material temperature and cure result for the assembly.

Cure-related property	Value	Unit	Condition
MDR TC10	170	s	120 deg C / 10 min test
MDR TC50	180	s	120 deg C / 10 min test
Standard heat cure	60	min	130 deg C

Material Handling

Storage and handling

Refer to the product label for the required storage temperature. Dow instructs that containers be kept tightly closed and in cold storage, with the material retained in its original packaging to avoid contamination.

Use the product by the Use Before date shown on the product label and follow the current product and safety documentation before handling.

Technical Guidance

Surface preparation, adhesion and cure compatibility

Adhesion and cure behavior depend on the substrate and assembly environment. Dow recommends evaluating the actual materials and surface conditions before production use.

Surface cleanliness

Thorough cleaning and degreasing are recommended. Dow notes that acetone or IPA alone may not remove oils effectively, although a final wipe with acetone or IPA can be useful after appropriate cleaning.

Substrate adhesion

Dow describes unprimed adhesion to many reactive metals, ceramics and glass, plus selected laminates, resins and plastics. Difficult or non-reactive surfaces may require treatment or primer evaluation.

Addition-cure inhibition

Organotin and other organometallic compounds, sulfur-containing materials, unsaturated hydrocarbon plasticizers, and some solder-flux residues are identified as potential cure inhibitors. Compatibility testing is recommended for questionable materials.

Cured Material

Mechanical and physical properties after cure

The cured silicone elastomer combines Shore A 40 hardness with a typical Young's modulus of 2.5 MPa and 120% elongation. These are typical material-property values and should not be interpreted as guaranteed joint or assembly performance.

Young's Modulus

2.5 MPa

Hardness

Shore A 40

Tensile Strength

1.7 MPa

Elongation

120%

Property	Value	Unit	Method / context
Density	1.01	g/cm^3	Typical property
Hardness	40	JIS Type A	Cured material
Young's modulus	2.5	MPa	Cured material
Tensile strength	1.7	MPa	Cured material
Elongation	120	%	Cured material
Linear CTE	300	ppm/deg C	TMA
Lap shear adhesion	50	N/cm^2	Aluminum substrate

Typical values are not intended for use as product specifications.

Reported Impurity Levels

Ionic impurity data

Ion	Reported result	Unit
Na+	< 2.0	ppm
K+	< 2.0	ppm
Cl-	< 2.0	ppm

These are reported typical impurity values and are not presented as proof of assembly-level corrosion performance.

Use Considerations

Temperature and solvent exposure

Useful temperature guidance

Dow states that for most uses silicone adhesives should be operational from -45 to 200 deg C for long periods. Performance near either end can be application-dependent and should be verified for the actual parts or assembly.

Solvent exposure

The adhesive is intended to survive splash or intermittent solvent exposure. Dow states that it is not suited for continuous solvent or fuel exposure and recommends application-specific testing.

Documented Use Contexts

Applications

Dow documents ME-1140 for fine, precise jet dispensing and for bonding, encapsulation and sealing functions in electronic assemblies.

Fine jet dispensing

Fine, precise material patterning by jet dispensing.

Die attach

Silicone adhesive attachment for documented die-attach applications.

Glob-top encapsulation

Localized encapsulation where the documented flow and cured elastomer properties fit the assembly requirements.

PCB system assemblies

Sealing, encapsulation and adhesive functions within PCB system assemblies.

Next Steps

Evaluate DOWSIL ME-1140 for your dispensing and assembly process

Krayden can help review dispensing method, pattern geometry, substrate preparation, cure conditions, adhesion requirements, cure-inhibition risks and the mechanical requirements relevant to evaluating ME-1140 for die attach, glob-top encapsulation or PCB assembly applications.