What is the role of adhesives in the miniaturization of electronic devices?

Adhesives play a crucial role in the miniaturization of electronic devices. Electronics miniaturization refers to the manufacturing of increasingly smaller electronic products and devices and is driven by factors such as the need for enhanced performance and functionality, size and weight reduction, improved efficiency and cost-effectiveness, and the development of new, more compact devices such as wearables, medical technology, and automotive electronics. Electronics miniaturization is essential because the exponential growth of transistor density and computing power, as described in Moore’s Law, requires electronics to become smaller, faster, and more energy-efficient.

Adhesives play a crucial role in the miniaturization of electronic devices, enabling the assembly of thinner, lighter, and more flexible devices. Specific properties offered by adhesives such as high flexibility, low thickness, and the ability to bond to different substrates are essential for miniaturization. Advancing the future of small-scale electronics, electronic-grade adhesives can address microelectronics production areas that traditional techniques such as soldering cannot. Adhesives provide a precise and controlled method for attaching miniature components to PCBs and other electronic assemblies. These electronic-grade adhesives come in different formulations with controlled viscosity allowing secure bonding of microscopic components, the ability to apply complex geometries with precision and control, and a level of durability ensuring long-term performance, even under harsh operating conditions.

Adhesive Properties for Miniaturization in Microelectronics There are many properties to consider when looking for an adhesive compatible with microelectronics production and assembly, including:

• High thermal and electrical conductivity: Adhesives with high thermal conductivity effectively dissipate heat in miniaturized electronic devices. Thermally conductive adhesives often contain formulated fillers to enhance heat transfer.
• Low outgassing: Adhesives used in microelectronics must have low outgassing to avoid contamination of sensitive electronic components. Volatile solvents are typically avoided in modern adhesive formulations.
• Precise dispensing capabilities: The ability to precisely dispense adhesives is crucial for assembling small, complex microelectronic devices. Adhesives must have the right level of fluidity and viscosity to allow for precise and controlled application.
• High-temperature stability: Adhesives must be able to withstand the high temperatures encountered during the manufacturing process as well as the operating temperatures of the final device.
• Strong adhesion and reliability: Adhesives must provide robust bonding between different substrates to ensure structural integrity and long-term reliability of microelectronic devices.

Silicone Adhesives – Dowsil™ for Electronic Miniaturization

Dow, with its DOWSIL, offers a wide range of silicone adhesives perfectly suited to the challenges of electronic miniaturization, including flexibility and conformability, proper gap filling, and moisture resistance. Using DOWSIL silicone adhesives ensures strong, reliable, and thermally efficient bonding of components in miniaturized electronic devices.

• DOWSIL™ 3140, formerly known as DOW CORNING® 3140 Clear, is a one-component silicone sealant offering exceptional properties for bonding and sealing. With its self-leveling formulation and room temperature vulcanization (RTV) capability, it ensures easy application and reliable results. Featuring a skin formation time of just 15 minutes, it offers a Shore A34 hardness and impressive tensile strength of 3 MPa, with an elongation of 419%. This product is FDA approved, UL 94 V-1, UL 746 E, UL RTI 105, IPC-CC-830B, and Mil Spec certified, ensuring compliance with the strictest standards. With a temperature range of -50 to 180°C, it can be used in a variety of applications. Its neutral and transparent formulation makes it suitable for various uses, and chemical equivalence certificates are available for consultation, ensuring its quality and compatibility.

• DOWSIL™ 3145, formerly known as DOW CORNING® 3145 Clear, is a leading one-component silicone sealant designed specifically for bonding and sealing, offering high mechanical strength. Its room temperature vulcanization (RTV) capability ensures convenient and efficient application. With a skin formation time of just 15 minutes, it exhibits a Shore A51 hardness and impressive tensile strength of 7.1 MPa, accompanied by an elongation of 670%. Approved to MIL-A-46146 and UL RTI 200 standards, this product ensures optimal performance even in extreme conditions, with a temperature range of -55 to 180°C. Its neutral and transparent formulation makes it ideal for a wide range of applications, while available chemical equivalence certificates attest to its quality and compatibility.

• DOWSIL™ SE 9186 is a preferred choice for ensuring the sealing of electronic equipment and modules, as well as for attachment to printed circuit boards. This white electronic silicone has a viscosity of 66,100 mPas, a Shore A20 hardness, and a tensile strength of 2.5 MPa, with an elongation capacity of 550%. As a low-VOC product, it meets the strictest environmental standards. Its one-component formulation and room temperature vulcanization (RTV) by condensation make it a convenient and reliable choice. Additionally, its self-leveling nature ensures uniform application and optimal adhesion. Dow Corning SE 9186 thus offers an effective solution for both adhesion and sealing in demanding electronic environments.

• DOWSIL™ SE 9189 is specially designed for module assembly and attachment to printed circuit boards. This white electronic silicone has a viscosity of 22,000 mPas and a Shore A33 hardness. With a working time of 8 minutes, it offers flexibility of use while ensuring optimal adhesion. Its tensile strength of 2.2 MPa makes it perfectly suited for applications requiring strong mechanical holding. Approved UL94 V-0 at UL RTI 105, it meets the strictest safety standards. With reduced VOC emissions, it aligns with responsible environmental practices. As a one-component product, its application is simplified, while its room temperature vulcanization (RTV) by condensation ensures reliable and durable bonding. Its self-leveling nature ensures uniform distribution and effective sealing, making Dow Corning SE 9189L an ideal choice for assembly and attachment requirements in the electronic field.

UV durcissable – Permabond & Born2Bond

• PERMABOND UV610 is a single-component UV adhesive ideally designed for fast bonding of glass and metal, particularly for glass/glass and glass/metal assemblies. With a viscosity of 800 to 1000 mPa.s, this adhesive ensures smooth and precise application. It offers remarkable tensile strength of 17 MPa and an elongation capacity of 95%, ensuring strong and flexible adhesion. Its Shore D70 hardness allows it to maintain the integrity of bonds under various conditions, ranging from -55 to +120°C. This UV acrylic adhesive is solvent-free, making it environmentally friendly. Its high resistance on glass and metal makes it a reliable choice for a wide range of applications. Despite its low viscosity, it ensures optimal adhesion, offering an effective solution for bonding requirements in glass and metal applications.

• PERMABOND UV625 is a single-component UV instant adhesive specifically formulated for efficient bonding of glass and metal, especially for glass/glass and glass/metal bonds. With a gel viscosity, this adhesive ensures strong and durable adhesion. It has a tensile strength of 16 MPa and an elongation capacity of 40%, providing excellent mechanical strength. Its Shore D65 hardness allows it to maintain bond integrity over a wide range of conditions, from -55 to +120°C. This UV acrylic adhesive is solvent-free, making it environmentally friendly. Its high viscosity allows for easy application, even on vertical surfaces, and it is suitable for situations requiring significant gap filling between the surfaces to be bonded. In summary, this adhesive offers an efficient and versatile solution for glass and metal bonding applications, while meeting the highest quality and performance requirements.

• Born2Bond Light Lock HV is a dual-cure adhesive that is both cyanoacrylate and UV, designed to provide fast curing and strong adhesion. Its low blooming and low odor formula makes it user-friendly. With a viscosity of 800 mPa.s and a maximum gap of 0.2 mm, it is suitable for a variety of applications. Its curing time is 60 seconds, but reduced to just 5 seconds under UV exposure. Resistant to temperatures from -40 to +80°C and offering a tensile strength of 29 MPa, it ensures durable results. Its dual curing system allows for fast bonding under UV and contact curing, even between opaque substrates.

Époxy – Huntsman Araldite

• ARALDITE® 2011 PL is a standard, versatile, and fluid two-component epoxy resin offering extended open time for convenient use. With a mixing ratio of 1:1 and a viscosity of 30 to 45 Pa.s, this resin has a characteristic pale yellow color. It offers a generous pot life of 100 minutes, allowing for efficient work even on large projects. With a modulus of elasticity (E-modulus) of 1900 N/mm², it exhibits robust mechanical strength, with a rupture elongation of 9% and a shear strength of 26 N/mm². Versatile and resistant to dynamic loads, it is ideal for a wide range of applications. Additionally, its excellent chemical resistance ensures durable performance even in demanding environments. In summary, Araldite 2011 PL is a reliable choice for projects requiring strong adhesion, ease of use, and exceptional resistance.

• ARALDITE® 2012 PL is a versatile two-component epoxy adhesive, designed for self-leveling application and fast curing. With a mixing ratio of 1:1 and a viscosity of 30,000 mPa.s, this resin offers excellent fluidity for precise application. Its pot life is 6 minutes, while the setting time is just 20 minutes, ensuring increased productivity. Shear strength reaches 18 MPa, with a rupture elongation of 4% and a modulus of 2500 MPa, ensuring strong and durable adhesion in a variety of applications. With a temperature resistance range of -40 to +70°C, it can be used in diverse environments. Its yellow color allows for clear visualization during application. As a structural two-component epoxy adhesive, Araldite 2012 PL offers exceptional versatility in applications requiring fast curing and low viscosity, making it an ideal choice for projects requiring high adhesion and mechanical strength.