摘要:
Disclosed is a system that determines whether input and output leads of semiconductor components are present and properly soldered to a printed circuit board. The system includes a signal source which is connected to a wiring trace on the printed circuit board, which is soldered to the lead being tested. A capacitive test probe is placed on top of the component and connected to a capacitance measuring device. The signal source signal is capacitively coupled through the lead of the integrated circuit package being tested to the capacitive test probe, so if a predetermined capacitance is measured by the capacitance measuring device, the lead is connected to the circuit assembly. As the capacitances being measured are small, the capacitive test probe may include an amplifier, a shield or a buffer circuit to reduce stray capacitance.
摘要:
The present invention is an improved printed circuit board test system in which test probes are positioned to electronically engage a selected device or printed circuit board section on a printed circuit board for testing the printed circuit board for manufacturing defects. The printed circuit board test system uses a bed-of-nails test fixture to ground and excite predetermined sites on a first side of the printed circuit board and a robot to mechanically position test probe(s) at selected test sites on a second side of the printed circuit board. A controller is used to control the movement of the robotic tester and the selection of spring probes in the bed-of-nails fixture to be exited, grounded or measured.
摘要:
Feedback control loop systems are provided that enhance output-signal switching times without degrading other loop performance parameters. The systems reduce “kick-back” voltages that are generated in a loop filter by drive currents which rapidly drive a control loop oscillator to a loop acquisition range. This reduction reduces a frequency step in the oscillator output signal which would otherwise have to be driven to eliminate the frequency step with a consequent increase in the output-signal switching time. Structures are provided that reduce the kick-back voltage to thereby enhance output-signal switching times.
摘要:
Feedback methods and systems are provided to achieve rapid switching of oscillator frequencies without compromising operational feedback loop bandwidths that filter out spurious tones and phase noise to thereby enhance loop spectral and noise performance. The methods respond to frequency changes in a reference signal by providing an open-loop drive current to drive a feedback signal towards the reference signal. The drive current is terminated and the feedback control loop closed when the feedback signal is within a predetermined acquisition range of the reference signal. This is determined by successively comparing a feedback frequency of the feedback signal to a destination frequency of the reference signal over a comparison window of time. The invention also provides a feedback control system that practices the invention's methods.
摘要:
Disclosed is a system that determines whether input and output pins of semiconductor components are present and properly soldered to a printed circuit board. The system uses an oscillator which supplies a signal, typically ten kilohertz (10 kHz) at 0.2 volts, to the pin under test. A conductive electrode is placed on top of the component package. The electrode is connected to a current measuring device. Another pin of the component is connected to the common signal return. Typically the other pin is chosen to be a power or ground pin of the component.
摘要:
One aspect provides a system including a sensor adjustment component comprising: a memory device having adjustment information stored therein; signal source capable of producing a signal detectable by a sensor to be adjusted; and one or more processors; wherein the one or more processors are configured to execute program instructions to operate the signal source to produce a predetermined signal pattern detectable by a measurement component of the sensor to be adjusted; and wherein the predetermined signal pattern comprises the adjustment information. Other aspects are disclosed.
摘要:
The present invention relates to the field of circuit assembly testing systems and provides improved systems and methods for debugging circuit test systems and diagnosing faults in circuit assemblies. An expert system derives possible root causes of test failures, predicts test results based on these possible root causes and uses factual observations to refute inconsistent hypothetical root causes. Tests useful in refuting inconsistent hypothetical root causes are devised and run automatically by the system.
摘要:
Disclosed is a system that determines whether input and output pins of semiconductor components are present and properly soldered to a printed circuit board. The system uses an oscillator which supplies a signal, typically ten kiloHertz (10 kHz) at 0.2 volts, to the pin under test. A conductive electrode is placed on top of the component package. The electrode is connected to a current measuring device. Another pin of the component is connected to the common signal return. Typically the other pin is chosen to be a power or ground pin of the component.
摘要:
Disclosed is a novel electrical probe that stores probe-specific information. A probe implemented in accordance with the invention includes a processor, memory, and a communications interface. Probe-specific information such as a probe identifier and/or calibration parameters that affect the true value of a measurement are stored in the probe memory. The probe-specific information may be retrieved by the processor from the probe memory via the communications interface.
摘要:
An adaptive delay learning algorithm is presented that reduces the amount of delay before making test measurements in an automated test that requires a delay of any type to be completed before a measurement is made in order to remove the possibility that a tester component lying in the measurement path has not achieved a ready state. In the execution of an automated test, a current delay time is set to an initial delay value. Test execution does not begin until the current delay time elapses. If, upon execution, the test fails, the current delay time is set to a different delay time, and the test is reexecuted only after the updated current delay time has elapsed.