Piezoresistive Stress Sensors for Structural Analysis of Electronic
                    Packages

Bittle, David; Suhling, Jeffrey C.; Beaty, R.E.; Jaeger, R.C.; Johnson, Richard W.

doi:10.1115/1.2905397

Cited by 175 publications

(72 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wire bonder ultrasound oscillation is along the yaxis. Only the stress fields r xx , r yy , r zz , and r xy can be detected by piezoresistors on a (100) wafer [35]. The integrated sensor consists of x-, y-, and z-force sensor elements.…”

Section: Sensor Principlesmentioning

confidence: 99%

“…Doped silicon can be used as piezoresistive material [85]. In particular, the source/drain diffusions of CMOS processes are suited as piezoresistive in situ stress sensors [35]. Details of the piezoresistance of silicon are discussed in the literature [25,36].…”

Section: Silicon Piezoresistorsmentioning

confidence: 99%

“…Various test chips are commercially avail-able [38][39][40]. On these chips, p-n junctions [32] and aluminum resistors [30,41] serve as temperature sensors, while piezoresistors are used as stress detectors [11,[35][36][37]. Piezoresistive sensors were used to investigate thermal stress on the chip [11].…”

Section: Packaging Characterization By Microsensorsmentioning

confidence: 99%

See 2 more Smart Citations

Microelectronic Bonding Processes Monitored by Integrated Sensors

Mayer¹,

Schwizer

2002

Sensors Update

View full text Add to dashboard Cite

Real-time monitoring methods are beneficial for the control, optimization, and failure analysis of microelectronic packaging processes. The focus of this chapter is on the real-time monitoring of two widely used processes, soft solder die bonding and thermosonic ball bonding. The methods presented here use uniquely developed microsensors integrated on custom-made test chips using commercial double-metal CMOS processes.For the soft solder die bonding process, nine aluminum-based resistive temperature detectors were integrated on various locations on a test chip. The temperature was monitored during the placement of the test chip on the leadframe. The experimental results describe the wetting and spreading effects of the molten solder under the drip. Together with numerical results obtained with a transient thermal finite element model, the beginning of wetting can be quantified. For the soft solder PbSn10, wetting occurred around 30 ms after touch down. This method hence can be used to determine wetting times under different process conditions. The wetting time determines an upper limit of the throughput of the process.For the thermosonic ball bonding process, temperature and force sensors were integrated on test chips. The sensors are aluminum resistors and piezoresistive p + -and n + -diffused resistors placed around bond pads. A bond quality parameter can be derived from the temperature signal variation during bonding. The piezoresistive sensors permit the measurement of forces in the x-, y-, and z-directions simultaneously. The ultrasonic tangential force signal reached a typical value of 0.12 N on a 50 lm diameter contact zone and revealed significant process characteristics. Four process phases are identified which are necessary for a successful ball bond formation. These phases are assigned to initial stiction, sliding, bond growth, and deformation effects.

show abstract

Section: Sensor Principlesmentioning

confidence: 99%

Section: Silicon Piezoresistorsmentioning

confidence: 99%

See 1 more Smart Citation

Microelectronic Bonding Processes Monitored by Integrated Sensors

Mayer¹,

Schwizer

2002

Sensors Update

View full text Add to dashboard Cite

show abstract

“…In a conventional plastic encapsulated package the surface of a semiconductor chip is exposed to inplane mechanical stress [21,22]. For inplane normal stress , and inplane shear stress components on a (100) silicon chip it holds [23] = 0 (1 + 11 + 12 + 44 2…”

Section: Similarities Of Piezoresistance and Hall Effectmentioning

confidence: 99%

An Analytical Theory of Piezoresistive Effects in Hall Plates with Large Contacts

Ausserlechner

2018

Advances in Condensed Matter Physics

View full text Add to dashboard Cite

Four-terminal transducers can be used to measure the magnetic field via the Hall effect or the mechanical stress via the piezoresistance effect. Both effects are described by an anisotropic conductivity tensor with small offdiagonal elements. This has led other authors to the conclusion that there is some kind of analogy. In both cases the output voltage depends on the geometry of the device and the size of the contacts. For Hall plates this influence is accounted for by the Hall-geometry factor. The alleged analogy proposes that the Hall-geometry factor also applies to four-terminal stress transducers. This paper shows that the analogy holds only for a limited class of devices. Moreover, it is shown that devices of different geometries may have identical magnetic field sensitivity but different mechanical stress sensitivities. Thus, shape optimization makes sense for mechanical stress sensors. In extreme cases the output voltages of vertical Hall-effect devices may have notable magnetic field sensitivity but zero mechanical stress sensitivity. As byproduct, exact analytical formulae for the equivalent resistor circuit of rectangular and circular devices with two perpendicular mirror symmetries are given. They allow for an accurate description of how mechanical stress and deformation affect the output offset voltage and the magnetic sensitivity of Hall-effect devices.

show abstract

“…Piezo-resistive stress sensors, which have widespread applications as sensing elements in various transducers [1][2][3][4][5][6][7][8][9][10][11], are powerful tools for the experimental structural analysis of electronic packages. Such sensors are to be used to measure stress.…”

Section: Introductionmentioning

confidence: 99%