Determination of the dispersion of an electronic component

Patent metadata

Field	Value
Publication number	US-11249133-B2
Application number	US-202016745813-A
Country	US
Kind code	B2
Filing date	Jan 17, 2020
Priority date	Jan 22, 2019
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A value representative of a dispersion of a propagation delay of assemblies of electronic components is determined. A component test structure includes stages of components and a logic circuit connected in a ring. Each stage includes two assemblies of similar components configured to conduct a signal. A test device is configured to obtain values of the component test structure and to perform operations on these values.

First claim

The invention claimed is:

1. An apparatus for determining a value representative of dispersion of a propagation delay of assemblies of electronic components, comprising:
at least one component test structure, wherein each component test structure comprises stages of components and a logic circuit connected in a ring, wherein each stage comprises two assemblies of electronic components configured to propagate a signal, the two assemblies of electronic components being formed by same components coupled in a same way but having different characteristics as a result of manufacturing differences; and
a test device configured to obtain values of the at least one component test structure related to propagation delay of the signal propagated through the two assemblies of electronic components, and to perform operations on these values to thereby determine the value representative of the dispersion of the propagation delay of the signal through the two assemblies of electronic components.

2. The apparatus of claim 1 , comprising a wafer of electronic chips, each electronic chip of the wafer comprising at least one of the at least one component test structures.

3. The apparatus of claim 1 , wherein each component test structure comprises four terminals of connection to the test device and two power supply terminals.

4. The apparatus of claim 1 , wherein each stage comprises a comparator, a memory circuit configured to store data, and a multiplexer.

5. The apparatus of claim 4 , wherein the comparator is formed from the two assemblies of electronic components.

6. The apparatus of claim 4 , wherein at least a portion of the multiplexer is formed from two assemblies of electronic components.

7. A method of determining a value representative of dispersion of a propagation delay of assemblies of electronic components, wherein the method is implemented by a device comprising: at least one component test structure, wherein each component test structure comprises stages of components and a logic circuit connected in a ring, wherein each stage comprises two assemblies of electronic components configured to conduct a signal; and a test device configured to obtain values of the at least one component test structure and to perform operations on these values; wherein each pair of assemblies of electronic components is formed by the two assemblies of electronic components of a stage; wherein each stage comprises a comparator, a memory circuit configured to store data, and a multiplexer, the method comprising:
calculating a difference between a sum of longest propagation delays of each pair among pairs of assemblies of electronic components, and a sum of shortest propagation delays in each pair among pairs of assemblies of electronic components, the pairs of assemblies of electronic components being formed by same components coupled in a same way but having different characteristics as a result of manufacturing differences;
sending a signal into the stages;
comparing with the comparator of each stage to determine a path where the signal propagates faster; and
storing information resulting from comparing in the memory circuit.

8. The method of claim 7 , wherein the value representative of the dispersion is obtained by:

D
=

1
N

⁢

(

∑

i
=
1

N

⁢

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a
⁢
i

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-

∑

i
=
1

N

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b
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)

where N is equal to a number of stages, and where values ai and bi are, for a pair of assemblies of electronic components i, the propagation delays of the assemblies of electronic components, value ai being greater than value bi.

9. The method of claim 7 , comprising:
generating a periodic signal running through the stages, the multiplexer of each stage being configured to conduct the signal through one among the assembly of electronic components having the longest propagation delay and the assembly of electronic components having the shortest propagation delay, the signal having a first oscillation period value after a passage through all the stages; and
generating a periodic signal running through the stages, the multiplexer of each stage being configured to conduct the signal through the other one among the assembly of electronic components having the longest propagation delay and the assembly of electronic components having the shortest propagation delay, the signal having a second oscillation period value after a passage through all the stages.

10. The method of claim 9 , wherein the test device calculates the value representative of the dispersion of the propagation delay from the first and second oscillation period values.

11. The method of claim 7 , wherein each component assembly belongs to a single pair of assemblies.

12. The method of claim 7 , wherein part of the calculation of the value representative of the dispersion is performed by the electronic components.

13. The method of claim 7 , wherein the value representative of the dispersion is obtained by the following formula:

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=

1
N

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∑

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=
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N

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a
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i

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Assignees

• St Microelectronics Crolles 2 Sas

Inventors

• Carminati Yann

Classifications

• G01R31/2882

  Testing timing characteristics · CPC title

• G01R31/31922

  Timing generation or clock distribution (G01R31/3191 takes precedence) · CPC title

• G01R31/3016

  Delay or race condition test, e.g. race hazard test · CPC title

• G01R31/2894

  Aspects of quality control [QC] (G01R31/31718 takes precedence; program control for QC G05B19/41875) · CPC title

• G01R31/2884 Primary

  using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence) · CPC title