Electronic Packaging

Manufacturing Technologies

The Electronic Packaging technologies in the ThinFilm, Vacuum, and Packaging Department are aresource for all aspects of microelectronic packag-ing. From design and layout to fabrication of proto-type samples, the staff offers partners the opportu-nity for concurrent engineering and developmentof a variety of electronic packaging concepts. Thisincludes assistance in selecting the most appropri-ate technology for manufacturing, analysis of per-formance characteristics and development of newand unique processes.

Capabilities

1. Network Fabrication

• Low Temperature Co-Fired Ceramic (LTCC)

• Thick Film

• Thin Film

2. Packaging and Assembly

• Chip Level Packaging

• MEMs Packaging

• Hermetic Sealing

• Surface Mount Technology

3. Integrated Passive Components

• Resistors

• Capacitors

• Inductors

4. Laser Processing

• Machining Ceramic

• Resistor Trimming

• Serialization

NETWORK FABRICATION

Network fabrication is accomplished by patterningmetals and dielectrics onto a free-standing sub-strate to form the base of a microcircuit. A varietyof substrates, processes, and metals are used todo this. Several options are available for produc-ing networks depending on requirements for circuitsize, heat produced, operating frequency, cost andother factors.

Low Temperature Cofire Ceramic (LTCC)

LTCC networks are produced using screen printedconductors and resistors on multiple layers ofgreen ceramic tape. Up to 50 layers of ceramiccan be printed and then cofired for high densitynetworks. An advantage of LTCC is the ability tomanufacture 3-dimensional electronic packages.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a LockheedMartin Company,for the United States Department of Energy’s National Nuclear

Security Administration under contract DE-AC04-94AL85000.

A high density LTCC multi-chip module

Thick Film Networks (TKN )

A TKN network is comprised of a ceramic sub-strate which has been screen printed and firedwith conductor, resistor, and dielectric elements.This type circuit allows double-sided multilayerpatterning for higher circuit density.

Thin Film Networks (TFN)

A TFN is produced with vacuum deposited resistorand conductor layers which are then photo-processed into circuit elements. Several TFN sub-strate materials are selectable including alumina,aluminum nitride, diamond, silicon, etc. A majoradvantage is the precision patterning consistentwith higher frequency circuits.

PACKAGING AND ASSEMBLY

This department has the capabilities to fabricate avariety of integrated chip (IC) carrier assemblies,hybrid microcircuits, multi-chip modules and otherunique electronic assemblies. The focus in pack-aging and assembly is two-fold: 1) development ofadvanced concepts in packaging and assemblyand 2) providing technology and production over-sight to Sandia organizations.

Chip Level Packaging

A broad term identifyingprocesses used toattach IC’s to a varietyof IC packages or circuitboards and to provideinterconnectionsbetween the IC’s andthe package or circuitboard. These processesare commonly called dieattach and wire bond-ing, respectively.

Hermetic Sealing

A method of sealing IC package so that the pack-age is gastight. This method uses a solder or weldprocess to create the hermetic seal. Plastic encap-sulation is another method of sealing, howeverthis approach is non-hermetic.

Surface Mount Technology

A method of assembling hybrid circuits and printedwiring boards, where component parts are sol-dered onto a variety of interconnect circuit boardsrather than into the circuit board (as in pin-through-hole soldering).

INTEGRATED PASSIVE COMPONENTS

This technology focuses on the use of silicon chippassive components and screen printing to fabri-cate small RCL type networks required to achieveminiaturization of electronic systems. Compared todiscrete surface mount type components thispackaging approach will allow up to 4X reductionin network size. This department’s engineeringresources and manufacturing capabilities promotedesign and rapid prototyping of these passivecomponent assemblies in a concurrent engineer-ing environment.

Resistors

Depending on the level of inte-gration required, resistors canbe realized using thick filmmaterials or through the use ofdiscrete silicon chip resistors. Awide range of resistor valuescan be attained with eitherapproach.

Capacitors

Commercially available highdielectric constant thick filmmaterials for manufacturingintegrated capacitors are limit-

A thick film MCM for hightemperature use

ed thereby restricting the range of capacitor val-ues possible. Discrete chip capacitors, as small as20 mils square, are available in a wide range ofvalues and can be combined with direct write orchip resistors to form integrated RC networks.

Inductors

Integrated inductors are primarily realized usingscreen printing or direct write techniques and canbe combined with resistors and/or capacitors toform RLC networks. This technology also allowsrealization of integrated multilayer transformers.

LASER PROCESSING

Using CO2 and ND-YAG lasers this departmenthas developed capabilities for machining complexgeometries, hole drilling and scribing both firedand "green" alumina and other materials. The useof a PC controlled ND-YAG laser system, incorpo-rating a "flying probe" system, enhances our laserprocessing capabilities to include passive andactive trimming of thick and thin film resistors to1% as trimmed tolerance. In addition the ND-YAGlaser system has been extensively used for alpha-numeric serialization of a wide variety of compo-nents types ranging from Neutron Tube ceramicpiece parts to high carbon steel tool tips.

Resources

• Complete processes and facilities for designand prototyping of LTCC, precision microwaveand high-density thick and thin film networks.

• Broad range of die attach, wire bonding, her-metic sealing and process testing equipmentconducted in class 1000 and 10,000 cleanrooms and laboratories.

• CO2 and YAG laser for marking, resistor trim-ming and machining various materials.

Accomplishments

• Developed capability to fabricate hermeticallysealed, LTCC multi-chip modules.

• Realization of first packaged MEMs deviceusing LTCC technology.

• Application of LTCC technology for high densitysatellite program.

Contact:

Fernando Uribe, (505) 845-8802furibe@sandia.gov

Ken Peterson, (505) 845-8549peterska@sandia.gov

SAND2003-3883P