BT stands for bismaleimide triazine. This laminate sheet has impacted the chip packaging industry. Chip packaging is crucial in PCB assembly. Laminated materials for circuit boards usually comprise several layers of impregnated and dried glass fiber cloth pressed onto the chip substrate. However, a thermal-hardened bismaleimide triazine (BT) resin material was introduced. This material offers great electrical and thermal properties and is low cost.
BT resin laminate has been playing a crucial role in the development of electronic equipment and information technology.
What is a BT PCB?
BT stands for bismaleimide triazine. It is one of thermoset resins utilized in manufacturing PCBs. Also, this component is a primarily a mixture of epoxy resin and BT resins. The epoxy resin is a common raw material used for PCBs. Also, the BT resins are majorly a mixture of bismaleimide, used as a common raw material for circuit boards and cyanate ester. BT resin is a combination of strongly basic molecules.
BT resin features great properties like excellent electrical properties and high thermal resistance. These features increased the standard for high-performance semiconductors. Also, the low cost of BT laminate makes it an ideal option for chip packaging. Therefore, BT laminate is contributing to technological advances for electronic devices.
To date, BT laminate remains a good standard for chip packaging. Before the introduction of BT laminate, the laminate used for high-performance chips was high-cost ceramic. However, BT became an alternative with great electrical and thermal properties. When the chip manufacturing industry noticed this material, the BT resin was used for chip packaging in 1985.
This material became to gain acceptance in Japan and across the world when the chip manufacturing industry accepted the cost savings. Furthermore, BT resin made the chip fabrication process much simpler. To date, BT resin is a popular laminate material for chip packaging. BT PCB is a mixture of epoxy resin and bismaleimide.
Applications of BT PCB
Any devices featuring electronic components feature one or more computer chips. Device makers constantly look for how to make their products better by making them lighter and smaller. Also, they make these devices more sophisticated. An example of this is the smartphone technology that keeps evolving each model while becoming more powerful, lighter, and more versatile.
The manufacturers of the chips in these devices keep improving their chip technology to meet the demands of manufacturers for advanced functionality. Also, chip manufacturers need to put more parts into a chip to make devices lighter and more efficient. Therefore, these manufacturers make use of denser materials that can reduce spacing between the traces.
Spacing of traces has reduced from more than 100 microns to less than 20 microns. Furthermore, the greatest challenge during PCB fabrication is avoiding curvature or deformation caused by temperature variation. Also, PCB fabrication involves processes that alternate cold and hot. Therefore, the chip must comprise materials that must keep their shape in these conditions. The bismaleimide triazine resin is a low cost material that features high performance in all aspects.
Also, chips function under conditions with incessant contraction and expansion. Therefore, they must be able to keep their performance specifications without any form of degradation throughout their life span. The bismaleimide triazine resin is a primary material in chips that function in electronic devices of today.
Also, the complexity of today’s technology keeps demanding for a dramatic revolution in the semiconductor industry. Bismaleimide triazine resin is the breakthrough these technologies need. Therefore, the industry keeps improving BT laminate and anticipating the future demands of chip makers.
Properties of BT Epoxy
BT epoxy is widely used in fabricating printed circuit boards due to their exceptional electrical and mechanical properties. Also, BT features excellent thermal properties. This laminate is ideal for lead-free PCB assembly. Also, BT epoxy resin is primarily used in multilayer PCB applications. BT epoxy offers great features like high heat resistance, exceptional electromigration, and insulation resistance.
Furthermore, BT epoxy features high bond strength at extremely high temperatures. BT epoxy resin is widely used across several industries since they offer a great level of protection. BT epoxy is listed in some standards in the world due to its properties. For example, IPG4101-1997 listed it as “No. 30” board while EC 249-2-1994 listed it as “18” board
In addition, BT epoxy features a high glass transition temperature and low dielectric constant. Therefore, BT resin substrate can improve the interconnection of printed circuit boards. BT stands for Bismaleimide triazine. This common raw material features low thermal expansion and exceptional dielectric properties. Therefore, this makes it ideal for high-density interconnect (HDI).
The properties of BT epoxy includes:
- Exceptional thermal shock resistance
- Great ion migration resistance
- Exceptional dielectric performance, Dk is within 2.8 and 3.5
- Great electrical properties
- Excellent dimensional stability and curing shrinkage
- Good wettability and low melt viscosity
Factors that Determine the Performance of BT PCB
BT resin as a common raw material for PCB fabrication varies from low-viscosity liquid to solid based on the ratio and variety of CE and BMI. There are several factors determine the performance of BT PCB. These factors include:
Development of lead-free soldering technology
The majority of PCB manufacturer integrate led-free soldering technology. This has become the mainstream of the industry. Higher temperature reflow soldering related with this technology will put more heat resistance requirements on PCB production.
Packaging technology development
Traditional semiconductor packaging products like DIP and QFP should connect the chip to the lead frame and utilize gold wire to link the aluminum pad on the chip. The utilization of organic substrates with internal pin, connection PBGA, EBGA, and packaging methods like TAB are increasing. Also, many new technologies like WLSCP, CSP, and chip packaging soil are increasing as portable products need component volume miniaturization.
The information and communication technology has enhanced its working frequency. For instance, mobile phones’ standard has evolved over time. Also, the operating frequency of the CPU has changed over time. The emergence of different digital communications and the development of MHz and now GHz are part of the development.
BT PCB is highly preferred among electronics manufacturers due to its electrical and mechanical properties. Also, the low cost of BT laminate makes it an ideal option for chip packaging.