This means dramatic changes for IC design and production. Achieving the critical 3D shrinks depends on cutting-edge 28nm, 20nm and 14/16nm wafer process technology, as well as “More-than-Moore” advanced packaging technologies, like Cu pillars and 2.5D/3D probing.
Such changes present big wafer test challenges for SoCs and memory ICs. Take low-power DRAM devices (LPDDR2 and LPDDR3) for example. Here, the mandate is to reduce mobile memory power even as memory arrays grow larger. That’s where high-frequency test-at-probe (HFTAP) can be a big success driver. FormFactor leads this effort with new technology that enables mobile DRAM wafer test speeds of up to 2.4Gb/s – the highest specification testing possible for LPDDR2 and LPDDR3 devices – and an unprecedented enabler of full Known Good Die test capability.
Key Probing Essentials for Mobile ICs
- Advanced packaging technologies (like solder bump and Cu pillars, and ultimately 2.5D and 3D TSV) and rapidly reduced bump pitch
- Grid-array packaging pitch, once static, is now rapidly evolving: 150µm -> 130µm -> 100 -> 80µm -> sub-50µm
- Multi-sites to reduce cost of test
- At one time, X4 sites or less was the norm; now, X8 to X16 is becoming common
- This trend is sending the pin-count-per-cards above 20,000 to 30,000 pins – a soaring increase.
- Mandatory low-power test environments require stringent power-distribution integrity
- Balancing power distribution among multi-sites is critical for optimal test yield
- Low probe force to avoid bump/pillar damages
- With each pitch shrink, the feature size of the Cu pillar or solder bumps must also shrink to fit into the tight array area. Gentle probing is essential to ensure minimum disturbance on the delicate bonding structures and ensure down-stream packaging reliability.
FormFactor’s Products for Mobile ICs
Apollo™ Vertical and Vertical MEMS
Apollo is the probe of choice for baseband and application processors in mobile devices. Valued for its “Right First Time” reliability, Apollo is known for its unique electrical/ mechanical design/modeling capability to ensure optimal yield in multi-site testing environments.
A variety of probe options are available – from traditional Cobra-style wires to fine-pitch vertical MEMS, and space transformer options. Collectively, they’re designed to ensure lowest cost of test production configuration for mobile device testing.
- Minimum grid-array pitch of 80µm
- Supports high multi-site testing (X8–X16) with ultra-high pin count (20 – 30k pins)
- Ultra low-force vertical MEMS probe options for Cu pillar probing, 1.5 to 2.5 g/probe
SmartMatrix™ for Mobile DRAM Sort
The SmartMatrix™ probe card provides full-area 300-mm wafer testing for advanced mobile DRAM devices, like LPDDR2 and LPDDR3. Built for massively high-parallelism testing (more than 1000 sites testing in parallel) to dramatically reduce the cost of test.
- Superior thermal operation to reduce soak time and improve scrub performance
- Excellent contact and electrical performance to optimize yield
- FFI proprietary custom-designed advanced TRE ICs to increase test native parallelism of testers
FormFactor’s HFTAP™ probe cards support wafer testing at frequencies up to 2.4 Gb/sec. This is an ideal test option for LPDDR2 and LPDDR3, the memory technologies of choice for mobile devices like tablets and smart phones. This capability allows device manufacturers to validate performance at the wafer level, an important component in Known Good Die testing.
FormFactor’s HFTAP product family includes these speed options:
- K3 (333MHz or 667Mb/s)
- K5 (533MHz or 1066Mb/s)
- K8 (800MHz or 1.6Gb/s)
- K10 (1GHz or 2Gb/s)
- K12 (1.2GHz or 2.4Gb/s)
High-speed product to test wireless RF ICs. Superior signal integrity delivered in a robust production-worthy vertical MEMS probe architecture, the Vx-RF offers a >2x cost-of-test reduction when compared to competitive advanced probe cards.
- Minimum in-line pitch of 80µm and grid-array pitch 135µm
- High-speed testing, up to 6GHz @-3dB bandwidth
- Ultra-compliance vertical MEMS architecture for high particle tolerance and long lifetime