Thin Small Outline Package (TSOP)

• Precise Gold Finger Processing: The metal contact points (gold fingers) of the SD card require extremely high processing accuracy and durable wear resistance to ensure reliable contact despite repeated insertions and removals.
• Multi-layer PCB Wiring: To meet the requirements for high-speed data transmission (such as the UHS-II standard) and signal integrity, the multi-layer PCB design inside the SD card requires strict control of impedance and crosstalk.
• Structural Strength and Heat Dissipation: While maintaining standard size, the structural strength of the card needs to resist bending. Also, the thermal management during high-speed read and write must be considered.

SD cards are one of the most commonly used storage solutions in digital cameras, camcorders, laptops, game consoles, and many embedded systems.

• Miniaturization of Component Mounting: Mounting the storage chip, controller, and other passive components on the very small PCB area requires extremely precise Surface Mount Technology (SMT).
• High Reliability: The tiny metal fingers and connection points must maintain stable electrical connections even under stress, such as vibration or repeated insertions and removals.
• Heat Dissipation: The high storage density and fast read/write operations generate additional heat, and managing this heat in such a small space poses a significant challenge to the chip and its packaging materials
• Testing Complexity: Due to the small size, designing fixtures for comprehensive electrical performance testing and environmental reliability testing (such as high temperature and humidity) is more complex.

microSD cards are widely used for external storage expansion in smartphones and are also commonly found in action cameras, drones, dash cams, and smartwatches—devices that require compact and portable storage solutions.

• Ultra-High-Density Integration: Achieving large storage capacity in a form factor smaller than the microSD card requires extreme packing density, advanced chip stacking technology, and highly precise controller designs.
• Ultra-Thin Packaging: With a thickness of just 0.7mm (slightly thicker than a Nano SIM card at 0.67mm), the challenge is to thin the chip and substrate materials without compromising mechanical strength. Packaging that is too thick will not fit into the card slot, while packaging that is too thin may lack adequate durability, leading to potential damage.
• Patents and Ecosystem Barriers: As a relatively new proprietary standard, the ecosystem and supply chain for NM cards are not yet as mature as those for SD cards.

The NM card is primarily used in Huawei and Honor smartphones and tablets, offering a unique storage expansion solution within their ecosystem. It provides flexible options for dual SIM or storage expansion, depending on user preferences.