RU2311653C1 - Method for dividing analog integration chips on basis of reliability - Google Patents

Abstract

FIELD: microelectronics, namely, methods for determining potentially unreliable analog integration microchips in process of production, and also during manufacture of radio-electronic equipment.

SUBSTANCE: on integration chips of operational amplifier type, made using complementary metal-oxide-semiconductor structure technology, coupled according to repeater circuit with grounded non-inverting input, average quadratic voltage of noise is measured on outputs "power to common point" at 1 kHz frequency with frequency band of 200 Hz and averaging time 2s with minimal and maximal value of power voltage matching technical conditions without letting current impulse through. Coefficient

is determined, where

- average quadratic noise voltage at maximal and minimal power voltage, respectively. On basis of value coefficient K, integration chips are divided reliability-wise.

EFFECT: increased trustworthiness.

Description

The invention relates to microelectronics, and in particular to methods for determining potentially unreliable analog integrated circuits (ICs) during the manufacturing process, as well as in the manufacture of electronic equipment.

The known method [1], applicable for monitoring IP and including the cyclical effect of high and low temperatures, as well as the calculation of the informative parameter (area of the hysteresis loop), obtained on the basis of critical stresses.

The disadvantages of this method: high complexity, the use of more than one informative parameter, the complexity of the automation process.

The closest analogue is the method [2], which consists in the fact that they measure the noise intensity before and after passing a current pulse that is 1.5-5 times higher in amplitude than the maximum permissible value according to technical specifications (TU), and then in relation to two measurements judge the potential reliability of the instruments.

The disadvantage of this method is the supply of a pulse that is 1.5-5 times higher in amplitude than the permissible TU value for the device, which can cause irreversible processes in the structure of the devices, which can lead to insufficient reliability of the results and to catastrophic device failures in operation.

The invention is aimed at improving the reliability and expansion of functionality.

This is achieved by the fact that in the proposed method for separating analog integrated circuits by reliability, the noise intensity is measured twice in the circuits at the minimum and maximum value of the supply voltage according to the technical specifications (TU).

The method is as follows.

On a representative sample of analog ICs of the same type, the rms noise voltage was measured from the “power-to-common point” terminals at the minimum and maximum supply voltage according to specifications without passing a current pulse. Then they found a coefficient characterizing the reliability of analog ICs:

,

- значение шума при максимальном и минимальном напряжении питания соответственно.Where

,

- the noise value at the maximum and minimum voltage, respectively.

Higher reliability will have those ICs that have a minimum value of this coefficient.

Noise measurement at supply voltages according to TU without applying a current pulse does not cause irreversible processes in the structure of devices and allows to increase the degree of reliability.

An example implementation of the method.

измерялось методом прямого измерения [3] по выводам "питание-общая точка" на частоте 1 кГц. Ширина полосы измерения частот Δf=200 Гц, время усреднения τ=2 с. Схема включения ИС-повторитель (инвертирующий вход соединен с выходом) с заземленным неинвертирующим входом.By random sampling, 12 integrated circuits of the OPA735 type were selected (an operational amplifier made using CMOS technology with a range of supply voltage values from TU from 2.7 to 12 V) in an 8-pin DIP package. RMS noise voltage

was measured by the direct measurement method [3] according to the conclusions "power-common point" at a frequency of 1 kHz. The frequency measurement bandwidth is Δf = 200 Hz, the averaging time is τ = 2 s. Switching circuit IC repeater (inverting input connected to the output) with a grounded non-inverting input.

The measurement results of 12 ICs at power supply voltages of 2.7 and 12 V, i.e. the minimum and maximum values for TU are presented in the table, where the values of the relative change in K, calculated by the expression (1), are also given.

Table IP number

, мкВ², при напряжении питания, В

, μV ² , at supply voltage, V TO 2.7 12 one 2.14 2.72 1.27 2 2.18 2.80 1.28 3 2.22 3.11 1.40 four 2,30 2.88 1.25 5 2,30 2.86 1.24 6 2.20 3.23 1.47 7 2,30 2.67 1.16 8 2.27 2.75 1.21 9 2.25 2.74 1.22 10 2,30 3.37 1.46 eleven 2.27 2.90 1.28 12 2.24 2.67 1.19

If we select the criterion that for reliable circuits K <1.4, then circuits 3, 6, 10 will be potentially unreliable.

It is possible to divide a batch according to reliability into three groups: IS having a higher reliability with a value of K≤1,2 (schemes No. 7, 12); ICs with reliability corresponding to technical conditions, having values 1.2 <K <1.4 (circuits No. 1, 2, 4, 5, 8, 9, 11) and ICs that are potentially unreliable having a value of K≥1.4 (circuits No. 3, 6, 10).

Experimental confirmation of the separation of the batch of ICs into reliable and potentially unreliable was obtained as a result of reliability tests (500 h, elevated temperature, maximum permissible load), when IS No. 3, 6, 10 had a parametric failure.

Information sources

1. Pat. Russia №2018148, G01R 31/28, publ. 1994.

2. USSR Copyright Certificate No. 490047, G01R 31/28, 1976.

3. Van der Zil A. Noise - sources, description, measurement: Trans. from English / Ed. A.K. Naryshkina. M.: Soviet Radio, 1973. 178 p.

Claims (1)

A method for separating analog integrated circuits (ICs) by reliability, according to which the rms noise voltage is measured twice, characterized in that the rms voltage is measured on a representative sample of ICs such as operational amplifiers made using CMOS technology and connected according to a repeater circuit with a grounded non-inverting input noise according to the findings "power-common point" at a frequency of 1 kHz with a frequency band of 200 Hz and an averaging time of 2 s at the minimum and maximum values of the supply voltage eskim conditions without passing current pulse ratio are

Where

,

- rms noise voltage at maximum and minimum supply voltages, respectively, and by the value of the coefficient K, the IPs are divided by reliability.