Electro Scientific Industries, Inc.

Synektron Corporation

Robert M Pailthorp

Mark Alan Unrath

Donald R Cutler

Hisashi Matsumoto

Glenn Simenson

Joseph J Stupak, Jr

William J Jordens

Weisheng Lei

David A Watt

Brandon John McCurry

Mark A Bortnem

Howard V Goetz

Bruce E Edson

Thomas W Richardson

Alan J Cable

Randall B Elliott

Thermoelectric effects that occur during laser trimming of resistors () are resolved by taking voltage measurements. The voltage attributed to laser heating on a resistor () during a low-power simulated trim () is used to determine a relatively thermal-neutral location () on the resistor (). A trimming-to-value operation can then be performed on all like resistors (). Voltage measurements can also be taken before and after every pulse in a trimming operation to establish thermal deviation information that can be used to offset the desired trim value against which resistor measurement values are compared. Spatially distant or nonadjacent resistors () in a row or column can also be trimmed sequentially to minimize heating effects that might otherwise distort resistance values on adjacent or nearby resistors ().

Resolving thermoelectric potentials during laser trimming of resistors

High speed removal of material from a specimen employs a beam positioner for directing a laser beam axis along various circular and spiral laser tool patterns. A preferred method of material removal entails causing relative movement between the axis of the beam and the specimen, directing the beam axis at an entry segment acceleration and along an entry trajectory to an entry position within the specimen at which laser beam pulse emissions are initiated, moving the beam axis at a circular perimeter acceleration within the specimen to remove material along a circular segment of the specimen, and setting the entry segment acceleration to less than twice the circular perimeter acceleration.

Methods for processing holes by moving precisely timed laser pulses in circular and spiral trajectories

A compound switching matrix (30) operates in cooperation with a resistance measuring system (20) and a laser (22) to quickly and accurately trim resistors (12) to predetermined values while they are being measured. The compound switching matrix is implemented with dry reed relays (34-81, 101-164) and includes a probe switching matrix (90-97) and a configuration matrix (32) that reduce the average number of relay contacts required per probe to implement two-, three-, and four-terminal measurements with or without guarding. Moreover, the separate probe switching and measurement configuration matrices effectively separate the high and low sides of the measurement to reduce the effects of stray resistances and capacitances on measurement speed and accuracy. A switchable grounding configuration (82-89) further improves measurement accuracy. The compound switching matrix of this invention enables sequential resistance measurements of individual resistors in the array, with two-, three-, and four-terminal measurement configurations being adapted to resistors having values ranging from less than 0.1 ohm to greater than 100 Megohms.

Compound switching matrix for probing and interconnecting devices under

A multi-rate, multi-head positioner (150) receives and processes unpanelized positioning commands to actuate slow stages (56, 58) and multiple fast stages (154) that are mounted on one of the slow stages to simultaneously position multiple tools (156) relative to target locations (162) on multiple associated workpieces (152). Each of the fast stages is coupled to a fast stage signal processor (172) that provides corrected position data to each fast stage positioner to compensate for fast stage nonlinearities and workpiece placement, offset, rotation, and dimensional variations among the multiple workpieces. When cutting blind via holes in etched circuit boards (ECBs), improved throughput and process yield are achieved by making half of the tools ultraviolet ('UV') lasers, which readily cut conductor and dielectric layers, and making the other half of the tools are infrared ('IR') lasers, which readily cut only dielectric layers. The UV lasers are controlled to cut an upper conductor layer and a portion of an underlying dielectric layer, and the IR lasers are controlled to cut the remaining dielectric layer without cutting through or damaging a second underlying conductor layer. The throughput is increased by cutting conductor layers in unprocessed ECBs while concurrently cutting dielectric layers in ECBs that have already had their conductor layer cut. The process yield is increased by performing a workpiece calibration prior to each cutting step to account for any ECB placement, offset, rotation, and dimensional variations.

Multi-tool positioning system

A multi-rate positioner system (50) receives unpanelized positioning commands from a database subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

Apparatus and method for coordinating the movements of stages in a

A multi-rate positioner system (50) receives unpanelized positioning commands from a database storage subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

High speed, high accuracy multi-stage tool positioning system

A light beam positioning system (10) has the capability of generating accurately positioned beam paths at programmed velocities between any two positions on a target surface (18). The beam positions correspond to beam position and velocity command data processed by a system control computer (22). The invention employs an error correction processor (52) that receives X and Y position coordinate signals (X and Y signals) produced by a conventional position data generator and develops compensated X and Y position coordinate signals (X.sub.c and Y.sub.c signals) for delivery to a light beam positioner (12). The X.sub.c and Y.sub.c signals are derived from a calibration map of an addressable field representing the positions to which the light beam can be commanded on the target surface. The X.sub.c and Y.sub.c signals represent polynominal functions of the X and Y signals and offset beam position errors resulting from the light-directing properties of the system optical components (26, 28, 30). The error correction processor allows the use of a single command data file in the system control computer,

Light beam positioning system

A variable reluctance actuator, of either the linear or rotary type, having a moving element operated by a solenoid, is controlled by a Hall effect sensor signal representative of flux density in the magnetic circuit of the actuator. The actuator may be operated in either a constant-force control mode, or a position-sensing or control mode. Substantially constant force, independent of position of the actuator's movable element, is obtained by varying, rather than stabilizing, the sensed magnetic field during movement. Position sensing, independent of actuator force, is obtained by variably controlling the magnitude of the excitation current of the Hall effect sensor in response to the magnitude of the coil current and Hall sensor output.

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Portland, OR, United States of America

Robert M Pailthorp