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Celerity Research Pte. Ltd.

Ase Electronics (m) Sdn Bhd

Robert M Hilton

Sabran Bin Samsuri

Mark L DiOrio

A probing system or process for electrical testing of a device fabricated on a wafer also conditions terminals such as solder balls on the device to improve uniformity of the heights of the terminals and improve the reliability of connections to an interconnect substrate in a flip-chip package or to a printed circuit board in a chip-on-board application. The system can employ a probe card that is a printed circuit board and/or is substantially identical to interconnect substrates used in flip-chip packaging. The probe card can be replaceable on a test head to allow for quick changes the reduce ATE downtime and to accommodate device changes such as a die shrink. Probe tips on the probe card can be the contact pads or bumps that are the normal electrical contact structures of the interconnect substrates.

Wafer probing that conditions devices for flip-chip bonding

A dam or barrier around the periphery of a die in a flip-chip package changes the shape of the underfill to reduce stress resulting from edge effects. The dam can include a treated region of a substrate having an affinity to an underfill material. The treated region causes liquid underfill material to bead, thereby controlling the wetting angle of the underfill material and shaping the underfill to eliminate sources of stress such as underfill fillet regions that are subject to significant shrinkage. The dammed underfill additionally avoids or reduces the extent of areas having thermal coefficients of expansion that differ from the optimal level because of low filler particle concentration.

Flip-chip package with underfill dam for stress control

A flip-chip packaging method for a semiconductor device treats a portion of an interconnect substrate so that a fill material when liquid beads on the treated portion of the interconnect substrate. When the fill material is dispensed on the interconnect substrate to fill a gap under the semiconductor device, the beading of the fill material prevents formation of fillets that might otherwise create a variation in the thermal coefficient of expansion of fill material and/or warp the interconnect substrate. The treated portion of the interconnect substrate can be roughened or coated with a material that differs from other portions of the interconnect substrate and thereby causes beading.

Flip-chip packaging method that treats an interconnect substrate to control stress created at edges of fill material

A flip-chip package uses a substrate having bond pad spacing that matches terminal spacing on a chip at an elevated temperature that is an expected operating temperature of the chip. The elevated temperature can be the midpoint of the desired temperature cycle of the chip so that deformations of the electrical connections in one direction balance deformations in the opposite direction during temperature cycling. Matching spacing at an elevated temperature, even a temperature less than the bonding temperature, permits a better alignment at the bonding temperature for formation of stronger bonds.

Flip-chip package containing a chip and a substrate having differing pitches for electrical connections

A flip-chip package and packaging method use a substrate having bond pad spacing that matches terminal spacing on a chip at an elevated temperature, such as the temperature of the chip during bonding to the substrate, the melting point of solder used on the chip, a temperature within the range of thermal cycling of the chip, or an operating temperature of the chip. Matching spacing at an elevated temperature permits a better alignment at the bonding temperature for formation of stronger bonds.

Pitch compensation in flip-chip packaging

A process for fabricating a BGA flip chip package containing a stiffener or heat spreader monitors edges of the adhesive that attaches the stiffener or heat spreader. The monitoring ensures that the adhesive extends beyond the centers of the outermost solder balls in the BGA. Stress at the edge of the adhesive thus does not cause warping or variations within the BGA.

Growing community of inventors

Queensland, Australia

Robert M Hilton