Die-Attach-Adhesives (Die-Attach-Adhesives)
Die-attach adhesives are now used in many important industries, including the electronics and semiconductor industry, the aerospace industry, the telecommunications industry, the automotive industry, the medical technology industry and the consumer electronics industry.
In the following article, we explain what die attach adhesives are, what types there are, some of the most important material properties, what you should consider when choosing the right die attach adhesive, what challenges and solutions exist with die attach adhesives and which industry standards regulate the use of die attach adhesives, among other things.
What are die attach adhesives?
Die-attach adhesives are adhesives that are used to attach chips to a substrate, such as a printed circuit board or a semiconductor.
The term “die attach” comes from the English word “die”, which in the semiconductor industry refers to a single unpackaged semiconductor chip. The meaning of the word “attach” is “to fasten”.
A distinction is made in particular between the following types of die attach adhesives:
- electrically conductive die attach pastes
- Non-conductive die attach pastes
- Soft solder paste and soft solder wire for high-performance applications (Die-Attach Soft Solder)
- Electrically conductive die attach adhesive films
- Non-conductive die attach adhesive films
- Fully sintered die attach adhesives
- Semi-sintered die attach adhesives
The adhesive manufacturer Henkel also offers die attach adhesives, both as pastes and as adhesive films.
Also read our article on Henkel’s die attach adhesive “Loctite Ablestik 84-1LMI (Thettach-Epoxy-adhesive)“.
Material properties
The effect of die attach adhesives in the respective application depends, among other things, on the material properties of these adhesives, whereby the most important material properties of die attach adhesives include the following:
- Thermal conductivity: Dissipating heat prevents overheating in appliances; thermally conductive die attach adhesives can also help to prevent overheating.
- Thermal resistance: Thermal resistance, also known as thermal resistance, indicates the extent to which an adhesive, for example, hinders the flow of heat. Thermal resistance is the reciprocal of thermal conductivity. A low thermal resistance therefore reduces the temperature rise in appliances.
- Electrical conductivity: There are conductive die attach adhesives that contain conductive materials and there are non-conductive die attach adhesives, and it depends on the application which type of adhesive should be used.
- Adhesive strength: Die attach adhesives also differ in terms of their adhesive strength. How firmly a chip must adhere to its substrate with the help of the adhesive depends on the respective application.
Selecting the right die attach adhesive
When selecting the right die attach adhesive for the respective application, the following points, among others, should be taken into account:
- Material compatibility: The die attach adhesive must be compatible with both the materials of the chip and the materials of the substrate, but also with other materials that may be used, such as underfill materials and encapsulation materials.
- specific requirements of the respective application: When choosing the right die attach adhesive, it is also important to consider the exact application for which it will be used, which determines the mechanical, thermal and electrical requirements, for example. The respective application also determines whether a paste or an adhesive film should be used.
- long-term reliability: When selecting the right die attach adhesive, you should also ensure that it is reliable in the long term under the specific operating conditions of the component or device. Among other things, the extent to which the adhesive remains resistant to environmental factors, such as moisture, temperature fluctuations and chemical stresses, must be taken into account.
Challenges and solutions for die attach adhesives
There are several challenges that can be faced when using die attach adhesives, including the following:
- Cavity formation
- Cracking
- Delamination (chip detachment)
Among other things, these events can jeopardize the functionality and longevity of semiconductor components.
The following measures are available as solutions to overcome the challenges:
- Selecting the right die attach adhesive
- Correct control of dosing parameters such as temperature, pressure and dosing needle size
- Correct curing conditions, including correct temperature, pressure and curing time
- Implementation of strict quality control measures, such as X-ray and ultrasound examinations to detect defects at an early stage
Industry norms (standards)
There are various industry standards that regulate chip mounting with adhesives, and therefore also the use of die attach adhesives. These standards include the following:
MIL-STD-883
Standard from the US Department of Defense, including test methods and test procedures for microelectronic devices; this standard also regulates aspects relating to chip mounting
ISO 16525-1:2014
Standard of the International Organization for Standardization including test methods for isotropic electrically conductive adhesives
IPC-A-610
Standard from the American National Standards Institute (ANSI) with, among other things, visual inspection requirements for chip mounting processes
Advice on die attach adhesives
The Swiss specialist wholesaler abovo has been an authorized distributor for the Henkel Adhesive Technologies division Henkel Elektronik (Henkel Electronic Material) for over 15 years and, since 2022, also for the Henkel Industrial division.
We will be happy to advise you on die attach adhesives and support you in selecting the right Henkel die attach adhesive for your application.
Simply contact our Henkel-Loctite experts by phone or e-mail without obligation:
- Telephone number: +41 32 552 44 44
- E-mail: info@abovo.ch
