Use of optoelectronic tweezers in manufacturing—accurate solder bead positioning

Abstract

In this work, we analyze the use of optoelectronic tweezers (OETs) to manipulate 45 μm diameter Sn62Pb36Ag2 solder beads with light-induced dielectrophoresis force and we demonstrate high positioning accuracy. It was found that the positional deviation of the solder beads increases with the increase of the trap size. To clarify the underlying mechanism, simulations based on the integration of the Maxwell stress tensor were used to study the force profiles of OET traps with different sizes. It was found that the solder beads felt a 0.1 nN static friction or stiction force due to electrical forces pulling them towards the surface and that this force is not dependent on the size of the trap. The stiction limits the positioning accuracy; however, we show that by choosing a trap that is just larger than the solder bead sub-micron positional accuracy can be achieved.

Patterned Optoelectronic Tweezers: A New Scheme for Selecting, Moving, and Storing Dielectric Particles and Cells

“…The resulting nonuniform electric field in the medium interacts with the samples in the liquid medium producing either repulsive (negative DEP) or attractive (positive DEP) force depending on the Clausius–Mossotti (CM) factors of the system . Micro‐objects with similar CM factors (i.e., those with similar material properties and operating conditions) behave similarly in OET systems, and the technique has been applied to manipulate micro‐objects with a wide range of different materials, sizes, and shapes . Figure a,b illustrates the process of patterning 10 µm diameter polystyrene beads in a standard OET device (without micropatterns) to form an “Einstein” cartoon pattern at an AC potential of 7 V p–p at 25 kHz.…”

“…To better understand the observed experimental results, numerical simulations were carried out in COMSOL Multiphysics based on a well‐developed 2D simulation model (with details and parameters included in Section S4 in the Supporting Information). The model includes the XZ cross‐section of the p‐OET device, and Figure g shows the simulated electrical potential distribution in the p‐OET device.…”

The optoelectronic microrobot: A versatile toolbox for micromanipulation

“…The technique is straightforward to implement, and we propose will find wide use for the everexpanding list of applications that require micromanipulation of cells. a range of applications (18)(19)(20)(21)(22)(23)(24)(25)(26)(27); here we describe its extension to microrobotics, and propose that this combination may prove useful for a variety of applications.…”

Assembly of Topographical Micropatterns with Optoelectronic Tweezers

“…In recognition of these limitations, a second category of "dry" cleanroom-free methods has been developed, including 3D printing, [8][9][10] laser machining, [11] and "pick-and-place" technologies. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] The new method is a member of the wet cleanroom-free assembly techniques, but lacks many of the limitations indicated previously. [22][23][24][25] These techniques, in which patterns of 3D particles are assembled in a fluidic environment and are later dried for use in TMP applications, are creative and interesting, and preserve many of the advantages of the canonical methods while allowing for accessible, cleanroom-free operation.…”

“…[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] The new method is a member of the wet cleanroom-free assembly techniques, but lacks many of the limitations indicated previously. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] The new method is a member of the wet cleanroom-free assembly techniques, but lacks many of the limitations indicated previously.…”