The specification discloses an electrical discharge machining (EDM) system and method capable of defining an unlimited number of waveforms. The system and method define logical waveforms using a plurality of time slices, each having a voltage and a width. The time slices are applied to the system power section where they are amplified and delivered to the electrode.

Whether or not an inter-electrode voltage exceeds a voltage threshold is determined after a predetermined inter-electrode state determination period has passed since application of an induction voltage (inter-electrode voltage) to an inter-electrode gap. Thus, an inter-electrode gap amount between a wire electrode and a work is estimated. A pause time during which electrical discharge is not performed is changed according to an estimation result of the inter-electrode gap amount.

Whether or not an inter-electrode voltage exceeds a voltage threshold is determined after a predetermined inter-electrode state determination period has passed since application of an induction voltage (inter-electrode voltage) to an inter-electrode gap. Thus, an inter-electrode gap amount between a wire electrode and a work is estimated. A pause time during which electrical discharge is not performed is changed according to an estimation result of the inter-electrode gap amount.

A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece. The wire electric discharge machine includes: a remaining length calculation unit that calculates a remaining length of the wire electrode based on electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin. The electrode winding coefficients depend on a winding density of the wire electrode, an inner width of the wire bobbin, a wire diameter of the electrode wire, and a winding tension of the wire electrode. The bobbin draw-out radius correlation information is correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin.

A method of yielding a thinner product wafer from a thicker base SiC wafer cut from a SiC ingot includes: supporting the base SiC wafer with a support substrate: and while the base SiC wafer is supported by the support substrate, cutting through the base SiC wafer in a direction parallel to a first main surface of the base SiC wafer using a wire as part of a wire electrical discharge machining (WEDM) process, to separate the product wafer from the base SiC wafer, the product wafer being attached to the support substrate when cut from the base SiC wafer.

A machining condition setter in a wire electrical discharge machine, sets up: as machining conditions, a first machining condition for enabling the core fixing function in a first section on the upstream side; a second machining condition for enabling formation of a slot in the workpiece in a second section on the downstream side; and a medial machining condition that is different from the first machining condition and the second machining condition in a medial section located between the first section and the second section.

A machining condition setter in a wire electrical discharge machine, sets up: as machining conditions, a first machining condition for enabling the core fixing function in a first section on the upstream side; a second machining condition for enabling formation of a slot in the workpiece in a second section on the downstream side; and a medial machining condition that is different from the first machining condition and the second machining condition in a medial section located between the first section and the second section.

A wire electrical discharge machine includes: a pulse detection unit configured to detect voltage pulses repeatedly applied between a workpiece and a wire electrode; an instability calculation unit configured to calculate the degree of instability indicating how unstable the discharge state is, by using the number of non-discharge pulses that present no voltage drop due to electrical discharge, among the pulses detected per unit time by a pulse detection unit; and a machining condition changing unit configured to change a machining condition for the workpiece, based on the calculated degree of instability.

A wire electrical discharge machine includes: a pulse detection unit configured to detect voltage pulses repeatedly applied between a workpiece and a wire electrode; an instability calculation unit configured to calculate the degree of instability indicating how unstable the discharge state is, by using the number of non-discharge pulses that present no voltage drop due to electrical discharge, among the pulses detected per unit time by a pulse detection unit; and a machining condition changing unit configured to change a machining condition for the workpiece, based on the calculated degree of instability.

A substrate includes a multilayer substrate body in which a plurality of circuit bodies are laminated in a laminating direction through insulating layers and are interlayer connected via a connected conductor formed on each of the insulating layers, and a magnetic body that is arranged in the laminating direction while at least a part of or all of the magnetic body sandwiches the circuit bodies. Each of the circuit bodies includes at least a first circuit body and a second circuit body. The first circuit body is formed of a first extending portion and a first folding portion. The second circuit body is formed of a second extending portion and a second folding portion.