Integrated laser voltage probe pad for measuring DC or low frequency AC electrical parameters with laser based optical probing techniques

Patent metadata

Field	Value
Publication number	US-11079432-B2
Application number	US-201916279304-A
Country	US
Kind code	B2
Filing date	Feb 19, 2019
Priority date	Feb 19, 2019
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A semiconductor or integrated circuit block including a sense node and a converter circuit, in which the sense node develops a low frequency electrical parameter that is constant or varies at a frequency below a predetermined frequency level, and in which the converter circuit converts the low frequency electrical parameter into an alternating electrical parameter having a frequency at or above the predetermined frequency level sufficient to modulate a laser beam focused within a laser probe area of the converter circuit. The converter may include a ring oscillator, a switch circuit controlled by a clock enable signal, a capacitor having a charge rate based on the low frequency electrical parameter, etc. The laser probe area has a frequency level based on a level of the low frequency electrical parameter to modulate the reflected laser beam for measurement of the electrical parameter by a laser voltage probe test system.

First claim

The invention claimed is:

1. An integrated circuit block, comprising:
a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and
a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate from a laser beam focused on a point within said laser probe area, a reflected laser beam generated from said laser beam focused on a point within the laser probe area striking said laser probe area are being reflected as the reflected laser beam from said laser probe area.

2. The integrated circuit block of claim 1 , wherein:
said low frequency electrical parameter comprises an electrical current; and
wherein said converter circuit comprises:
a current mirror that mirrors said electrical current as a mirrored current; and
a ring oscillator coupled in series with said current mirror, wherein said ring oscillator oscillates at a frequency based on a magnitude of said mirrored current.

3. The integrated circuit block of claim 1 , wherein:
said low frequency electrical parameter comprises an electrical voltage; and
wherein said converter circuit comprises:
a conversion device that converts said electrical voltage into an electrical current; and
a ring oscillator coupled to said conversion device, wherein said ring oscillator oscillates at a frequency based on a magnitude of said electrical voltage.

4. The integrated circuit block of claim 1 , wherein:
said low frequency electrical parameter comprises an electrical voltage; and
wherein said converter circuit comprises:
an electronic device incorporating said laser probe area and coupled between a detect node and a supply voltage, wherein said electronic device develops said alternating electrical parameter;
a plurality of switches comprising a sense switch and at least one reference switch;
wherein said sense switch is coupled between said sense node and said detect node;
wherein each of said at least one reference switch is coupled between said detect node and a corresponding one of at least one reference voltage node, wherein each said at least one reference voltage node has a known voltage level; and
a switch control circuit that sequentially closes said plurality of switches for each of a plurality of cycles.

5. The integrated circuit block of claim 4 , wherein said electronic device comprises a PN junction.

6. The integrated circuit block of claim 4 , wherein said at least one reference switch comprises:
a first reference switch coupled between said detect node and a first reference voltage node; and
a second reference switch coupled between said detect node and a second reference voltage node.

7. The integrated circuit block of claim 1 , wherein:
said low frequency electrical parameter comprises an electrical current; and
wherein said converter circuit comprises:
a current mirror that mirrors said electrical current as a mirrored current;
a capacitor coupled in series with said current mirror; and
a transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal.

8. The integrated circuit block of claim 1 , wherein:
said low frequency electrical parameter comprises an electrical voltage; and
wherein said converter circuit comprises:
a first transistor having a control input receiving said electrical voltage and having a current path that converts said electrical voltage into an electrical current;
a capacitor coupled in series with said current path of said first transistor; and
a second transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal.

9. An integrated circuit block, comprising:
a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and
a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area;
wherein said low frequency electrical parameter comprises an electrical voltage; and
wherein said converter circuit comprises:
an electronic device incorporating said laser probe area and coupled between a detect node and a supply voltage, wherein said electronic device develops said alternating electrical parameter;
a plurality of switches comprising a sense switch and at least one reference switch;
wherein said sense switch is coupled between said sense node and said detect node;
wherein each of said at least one reference switch is coupled between said detect node and a corresponding one of at least one reference voltage node, wherein each said at least one reference voltage node has a known voltage level; and
a switch control circuit that sequentially closes said plurality of switches for each of a plurality of cycles.

10. The integrated circuit block of claim 9 , wherein said electronic device comprises a PN junction.

11. The integrated circuit block of claim 9 , wherein said at least one reference switch comprises:
a first reference switch coupled between said detect node and a first reference voltage node; and
a second reference switch coupled between said detect node and a second reference voltage node.

12. An integrated circuit block, comprising:
a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and
a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area;
wherein said low frequency electrical parameter comprises an electrical current; and
wherein said converter circuit comprises:
a current mirror that mirrors said electrical current as a mirrored current;
a capacitor coupled in series with said current mirror; and
a transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal.

13. An integrated circuit block, comprising:
a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and
a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area;
wherein said low frequency electrical parameter comprises an electrical voltage; and
wherein sai

Assignees

• Npx B V
• Nxp Bv

Inventors

• Nierop Pieter Gustaaf
• Boon Gerben
• Kerver Harry Bernardus Antonius

Classifications

• H10P74/27

  Structural arrangements therefor · CPC title

• G01R31/31728 Primary

  Optical aspects, e.g. opto-electronics used for testing, optical signal transmission for testing electronic circuits, electro-optic components to be tested in combination with electronic circuits, measuring light emission of digital circuits (probes having electro-optic elements G01R1/071; electro-optic sampling for oscilloscopes G01R13/347; contactless testing of individual semiconductor devices by optical means G01R31/2656) · CPC title

• G01R31/2601

  Apparatus or methods therefor (G01R31/2607, G01R31/2642 take precedence) · CPC title

• G01R31/318505

  Test of Modular systems, e.g. Wafers, MCM's · CPC title

• G01R15/12 Primary

  Circuits for multi-testers {, i.e. multimeters}, e.g. for measuring voltage, current, or impedance at will · CPC title