A device and method to test microelectronic parts to determine whether the parts are compromised by active illumination in a testing fixture by analysis of emission metrics.

An apparatus for detecting a wiring short in a substrate includes a voltage source configured to apply a rising or falling measurement voltage to a first wiring of a substrate, a plurality of electrodes including first and second electrode elements capacitively coupled to the first and second wirings of the substrate, respectively, a sensing circuit configured to generate an output voltage based on a voltage or a current between the first and second electrode elements, and a processor configured to determine whether a short circuit connection having a resistance value greater than a reference resistance value is present between the first and second wirings based on a change rate of the output voltage after application of the measurement voltage. Methods for detecting wiring shorts in the substrate are further provided.

A sensor device is provided for testing electrical connections in a DUT using contactless fault detection. The sensor device includes main traces for conducting an RF signal supplied by a signal source; at least one inductor connected to at least one of the main traces; and a slit formed between opposing conductor portions at a tip of the sensor device for sensing open circuits and/or short circuits in portions of the DUT located in a sensing region below the slit, the tip being at an end of the sensor device opposite ends of the main traces connected to the signal source. An electric field, generated by the sensor device in response to the RF signal, substantially concentrates in the slit, enhancing the sensing of the open and/or the short circuits during the contactless fault detection.

A sensor device is provided for testing electrical connections in a DUT using contactless fault detection. The sensor device includes main traces for conducting an RF signal supplied by a signal source; at least one inductor connected to at least one of the main traces; and a slit formed between opposing conductor portions at a tip of the sensor device for sensing open circuits and/or short circuits in portions of the DUT located in a sensing region below the slit, the tip being at an end of the sensor device opposite ends of the main traces connected to the signal source. An electric field, generated by the sensor device in response to the RF signal, substantially concentrates in the slit, enhancing the sensing of the open and/or the short circuits during the contactless fault detection.

A capacitance detection area sensor includes capacitance sensor elements arranged in a two-dimensional array, is shaped into an appropriate shape, and capacitively coupled to an external electrode. To the external electrode, a sensing signal having a potential difference is supplied. The first and second sensor output signals are acquired from a capacitance sensor element capacitively coupled to the external electrode, at the timing of the sensing signal being a first signal and being a second signal, respectively. A differential signal is generated from a difference between the acquired first and second sensor output signals, and an image indicating the shape of the external electrode is generated based on the level of the differential signal, in different colors or different tones.

The invention relates to a test needle for measuring electrically conductive layers in holes of printed circuit boards, as well as to a test probe equipped with such a test needle and to a flying probe tester for testing printed circuit boards equipped with such a test needle or such a test probe.

The test needle has a capacitive measuring body, which is connected via a cable to a capacitive measuring device. The cable is shielded so that only the capacitive measuring body can form a capacitive coupling with other electrically conductive bodies. This makes it possible to determine this capacitive coupling with a high local resolution.

The invention relates to a test needle for measuring electrically conductive layers in holes of printed circuit boards, as well as to a test probe equipped with such a test needle and to a flying probe tester for testing printed circuit boards equipped with such a test needle or such a test probe.

The test needle has a capacitive measuring body, which is connected via a cable to a capacitive measuring device. The cable is shielded so that only the capacitive measuring body can form a capacitive coupling with other electrically conductive bodies. This makes it possible to determine this capacitive coupling with a high local resolution.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters. Spectral filtering is used to improve measurement contrast and LED defect detection. External light irradiation is used to excite the LED array and improve onset of charge injection light emission and throughput.

During frequency detection, a constant current source outputs an output current to charge a variable capacitor for multi-period. In a calibration mode, according to a comparison result between a cross voltage of the variable capacitor and a reference voltage, a capacitance value of the variable capacitor is adjusted. In a monitor mode, according to a reference frequency and the cross voltage of the variable capacitor, a frequency under test of a circuit under test is detected.