Advanced Packaging

Advanced Packaging

Flip Chip, Wafer level and 3D memories

CSP, BGA, PoP, Fan in, Fan out

Flip Chip BGA

Ball grid arrays are one of the most prominent technologies at the moment and are the main connectivity type for flip chips. Flip chip assemblies are much smaller than traditional carrier-based systems. The chip sits directly on the circuit board, and is much smaller than the carrier both in area and height. Having no wires greatly reduces inductance, a property that allows higher-speed signals and better heat conductivity. Flip chips are not suitable for easy replacement, or manual installation. They also require very flat mounting surfaces, which is not always easy to arrange, and they are sometimes difficult to maintain as the boards heat and cool. Also, the short connections are very stiff, so the thermal expansion of the chip must be matched to the supporting board or the connections can crack.
 

Flip Chip BGA (FCBGA) packages are assembled around state‑of‑the‑art, single unit laminate or ceramic substrates: (1) Flip Chip Organic BGA - Laminate or build-up organic substrate offers better electrical performance than wire-bond type BGA package especially in high frequency applications; (2) Flip Chip Ceramic BGA - Alumina ceramic substrate offers better moisture resistance, electrical insulating property and higher thermal conductivity than organic substrate. FCBGA is used primarily for high-reliability commercial applications (e.g. CPU). By combining flip chip interconnect with ultra advanced substrate technology, FCBGA packages can be electrically tuned for maximum electrical performance with a high routing density. 

 
 

 Key Features

  • High performance and low cost package solutions
  • Superior thermal peformance with copper or aluminum lid/heat spreader
  • Package sizes from 10 mm to 67.5 mm 
  • Pb-free, and Cu pillar as bumps
  • SMT components on top or bottom side
  • Multi-die capability
 
APPLICATIONS
  • Computing: Memory, CPU, APU, GPU, HDD storage
  • Network: small cell base station, network storage driven by cloud computing and high speed processors
  • Comsumer: DTVs, STBs, game consoles and IOT
RELIABILITY
  • Moisture Sensitivity Level: JEDEC Level 4 or  3@260°C
  • Temperature Cycling Test: -55°C/125°C, 1000 cycles 
  • High Temperature Storage: 150°C, 1000hrs
  • Highly Accelerated Stress Test: 130°C, 85%RH, 2 atm, 96 hrs 

The above are typical condition numbers.

Product Recommendation For FCBGA Assembly
Semicondutor Capillary Underfill (CUF) Board Level Underfill Lid Attach Adhesive For BGA

Locitite ECCOBOND NCP5209

Locitite ABLESTIK NCF218 

Locitite ECCOBOND UF8830S

Loctite ECCOBOND FP4526

UF8828

FP4511

FP4549 (HT)

Conductive Lid Attach
Non conductive Lid Attach
  • Bump protection of flip-chip devices, with bump pitches less than 100 µm and gaps less than 40 µm
  • Enables fine pitch, narrow gap Cu pillar TSV, Die to die & Die to substrate
  • Achieves MSL L3/L2A and passes all reliability requirements
  • Excellent wettability to different substrates
  • Mechanical reinforcement and improve the thermal cycling performance.
  • Absorb the CTE mismatch between the die and the substrate the die is placed on.
  • Distribute stress across the surface of the die or the substrate instead of being concentrated in the solder balls, especially during thermal cycling.
  • For capillary flow on flip chip applications with excellent reliability

 

 

BGA Lid attach.

Conductive Lid Attach
 
Non conductive Lid Attach

BGA Encapsulation


Integrated circuits are extremely vulnerable packages that need protection from the outside world. They need to be thermally, mechanically and electrically insulated in order to endure operational conditions.
 
Nearby components can be too warm or too dense for the die that needs to be covered and protected from dust, heat, moisture and ensure the environmental protection and mechanical strength needed.
 
Encapsulants for BGA packages:


Ball Grid array underfills

Ball grid arrays rely on microscopic and extremely precise connections to keep things running. Soldes spheres have their own mechanical and thermal properties, but normal operating conditions for most devices are too rough to handle for most components and are even worse for those hundreds of tiny (down to 0.100mm) solder balls. Even one failed connection can mess with the entire circuit and make the device unusable. To solve these issues while maintaining all of the BGA advantages, we came up with the underfills. Underfills go between the solder balls and create a solid surface with great properties that help our devices withstand the daily struggle. 

Additionally, underfills help with thermal expansion that can also cause serious issue and cracks.  The underfill material acts as an intermediate between the difference in CTE of the chip and board providing the leeway and flexibility required under thermal stress.


Underfills for BGA packages.
In principle most underfills should work for Ball grid arrays but some popular products are: