The selection of material properties is based on the functionality and performance of the circuit. They are divided into multi chip module substrate IC, rigid, flexible, and ceramic. The placement of the IC substrate and processor is shown in the following figure.

Multi chip module IC carrier board: Multi chip modules have high manufacturing costs, but can be used as substrates for packaging multiple ICs. This type of substrate is thin, lightweight, and compact. Due to the use of multiple chips on the substrate, the performance of multi chip IC substrates is slightly inferior and thermally unstable.

Rigid IC substrates: Resin is used to manufacture these substrates, typically using epoxy resin, but there are also several other types such as ABF (Ajinomoto Thickening Film), BT (Bismaleimide Triazine), with a thermal expansion coefficient between 12 and 17 ppm per degree Celsius.

Flexible IC substrate: The substrate is similar to a flexible printed circuit board and uses polyamide resin or polyimide as the substrate. The range of thermal expansion coefficient is 13 to 27 ppm/Celsius, which can provide better performance and thermal management.

Ceramic IC substrate: Ceramic substrates are made of aluminum nitride, silicon carbide, or aluminum oxide, with a low temperature coefficient of 6 to 8 ppm per degree Celsius.

There are three manufacturing processes for IC carrier boards: subtractive process (SP), additive process (AP), and modified semi additive process (MSAP). Each manufacturing process depends on the application and manufacturing cost.

The subtraction process is similar to the PCB manufacturing process of coating a layer of copper on a laminated board. Apply a dry film to protect the wiring and etch the remaining parts of the copper sheet. The manufacturing capability determines the minimum spacing, as it affects the width of the wiring and the accuracy of the plated holes. The minimum manufacturing space is 2 mil, and they are used for high-speed and high-density PCBs.

Another process is to chemically coat copper on top of the substrate and expose a thin film on top. Exposed to chemical components until reaching thickness. This process is additional, so the accuracy can reach 1 mil. This method is costly and requires more complex processes.

Copper clad laminates are laminated using copper electroplating. Add circuits and regions that require higher precision. Etch the next layer of copper and place a negative film on top of it. Flash corrosion may be more corrosive. This is a combination of subtraction and addition. This can improve production efficiency and cost-effectiveness, and can be adjusted according to board to board or application type.

Remove the copper pattern required for the circuit and deposit a thin film on the laminated board. High precision copper plating using chemical processes. The thickness and shape of copper plating can be automatically adjusted.

The solder mask layer is composed of an IC substrate and printed by filling the holes on the copper plating cover. For better and easier processing, the thickness of copper plated circuits should be kept below 10 millimeters.

The most common surface treatment is EMIG or ENEPIG of gold alloys to achieve appropriate conductivity and uniform thickness surface treatment.

In the final stage, the IC substrate undergoes quality inspection to test its reliability and internal connectivity. The testing method includes using Gigs or end of line testers for reliable integration testing.

When it comes to IC substrate design, design considerations are crucial for understanding various parameters such as material composition, alloy type, lamination, lead, and substrate type. Adhesive tape and rigid substrates also have different characteristics, which provide necessary performance, reliability, lifecycle, and durability for applications.

Material composition: IC carrier boards are composed of different electrical, mechanical, and chemical properties. The material of the lead frame is made of gold or silver and connected by spot welding. The lead frame and laminated packaging are made of the same material.

Alloy: The solder pad is protected by plastic packaging, providing relative permeability for performance, especially for surface mount packaging.

Terminal: The terminal cannot match the performance of tin or other materials, and the industry uses gold or silver coating packaging to comply with industry standards. The operating frequency is mainly affected by the selection of leads.

Laminated materials: The laminating technology on ceramic substrates and the technology applicable to organic substrates not only have high temperature resistance (thermal reliability), but also have lower costs. Electrical durability is higher than other ceramic substrates.

If pursuing cost-effective FPC manufacturing services, choosing a Chinese manufacturer is the best choice. As a manufacturing powerhouse, China has abundant resources, cheap labor, and a large number of technical personnel. We recommend Haibo, a Chinese FPC assembly service provider with over 10 years of experience, who has performed outstandingly in various aspects

Efficient and reasonable quotation:There is an efficient quotation process to assist you in making decisions, providing reasonable prices and highly competitive quotes in China.
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