JPH0282646A - Semiconductor integrated circuit and discriminating method thereof - Google Patents

Abstract

PURPOSE:To discriminate kinds in a short time by measuring the high-frequency characteristics of a microstrip line for discrimination formed onto a substrate composed of a semiconductor or a derivative. CONSTITUTION:Circuits 7 and a microstrip line 16 for discrimination are formed onto a substrate 4. The microstrip line 16 consists of a transmission line 2, a stab 1, ground patterns 3, etc. A high-frequency probe 17 is used for measuring the high-frequency characteristics of the microstrip line 16. A metallic pad 15 for transmission is brought into contact with regions 18a, 18b and a metallic pad 13 for grounding with regions 19a, 19b in order to measure high-frequency characteristics by employing the high-frequency probe. When the transmission line 2 has characteristic impedance matched with a measurement system, the microstrip line 16 functions as a band lamitation filter, attenuation of which is maximized at frequency where the length of the stab 1 is brought to the quarter of a wavelength. Accordingly, when the length of the stab 1 is changed in response to the kind of a semiconductor integrated circuit, the kind of the semiconductor integrated circuit can be discriminated only by acquiring maxi mum attenuation frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a semiconductor integrated circuit whose type can be automatically identified during the manufacturing process.

(a) Conventional technology Conventionally, as a semiconductor integrated circuit whose type can be automatically identified, (i) a semiconductor integrated circuit with a type name or a pattern representing the type; (1) a plurality of electrodes for identification; A semiconductor integrated circuit (
(See Japanese Patent Laid-Open No. 145764/1983) has been proposed.

In the semiconductor integrated circuit (i), humans can identify the pattern by observing the pattern, and in the semiconductor integrated circuit (ii), the connection state (short circuit or open) between the electrodes is all detected using a switching matrix. It is identified by its silk combination.

(...) Problem to be Solved by the Invention The semiconductor integrated circuit of (i) requires personnel for identification, and there is a problem in that the process cannot be fully automated.

In addition, in the semiconductor integrated circuit (ii), although full automation is possible, the number of types that can be identified is determined by the number of ti, so it is necessary to provide more TL poles to support a wide variety of products. There is. Therefore, short! /There is a problem that it takes a long time to detect an open state.

The present invention has been made in view of the problems mentioned above, and it is an object of the present invention to provide a semiconductor integrated circuit and a method for identifying the semiconductor integrated circuit, which can be completely self-developed and can identify the type in a short time.

(d) Means for Solving the Problems The present invention provides a semiconductor integrated circuit using a substrate made of a semiconductor or a dielectric, characterized in that a microstrip line for identification is provided on the substrate. It is a circuit.

Further, the present invention also provides a substrate made of a semiconductor or a dielectric material.
This is a semiconductor integrated circuit identification method characterized in that the type is identified by measuring the high frequency characteristics of an identification microstrip line provided in the semiconductor integrated circuit.

(N) Function According to the present invention, since a microstrip line for identification according to the type of semiconductor integrated circuit is added on the substrate, the type can be identified by measuring the high frequency characteristics of the microstrip line. can.

(f) Example FIGS. 1(a), (b), and (c) show a semiconductor integrated circuit, FIG. 1(a) is a top view, and FIG. 1(b) is an f- A 1-line sectional view, FIG. 1(c) is a sectional view taken along the line II--II in FIG. 1(a).

(4.) is a substrate made of semiconductor or dielectric material,
A circuit (7) and an identification microstrip line (16) are provided on this substrate (1). The microstrip line (16) is a transmission line (2), a stub (1)
), a grounding pattern (3), a connecting conductor (6), and a back grounding conductor (5).

By the way, to measure the high frequency characteristics of the microstrip line (16), a high frequency probe is used as shown in FIGS. 2(a) and 2(b). Figure 2 (a) is a top view of the high frequency probe, Figure 2 (b) is the III in Figure 2 (a).
-III line sectional view, (11) is a probe body made of ceramic, (14) is a signal line pattern, (
12) is the ground pattern, (15) is the transmission metal pad,
(13) is a grounding metal pad.

At high frequencies, one of the key points in determining whether accurate measurement values can be obtained is whether or not the grounding is properly established. ) is connected to the back surface ground conductor (5) by the connecting conductor (6) formed in the through hole on the
) is provided with a grounding pattern (3) connected to the ground pattern (3).

In addition, if a high frequency probe that can reliably contact the back surface ground conductor (5) of the board (4) is used, the microstrip line (16) can be connected to the transmission line (2), the stub (1),
and a back ground conductor (5).

To measure high-frequency characteristics using such a high-frequency probe, place the transmission metal pad (15) in the area (1) shown in Figure 1(a).
8a) (18b), the grounding metal pad (13) may be brought into contact with the areas (19a) (19b) shown in FIG. 1(a). FIG. 3 shows a state in which the high frequency probe (II) is brought into contact with the semiconductor integrated circuit.

In addition, Fig. 4 shows an example of the configuration of an automatic inspection system, and (1
01) is a computer, (102) is an integrated circuit measuring device for measuring circuit characteristics, (103) is a blow μ, (
104) is a measurement probe that can touch the circuit;
5) is a network analyzer to which a high frequency probe (17) is connected. This automatic inspection system blow μ
The above-mentioned high frequency probe (17) is brought into contact with the semiconductor integrated circuit installed at (103), the high frequency characteristics are measured by the network analyzer (105), and this measurement data is transferred to the computer (011) based on the principle described later. ), the type of the semiconductor integrated circuit can be identified.

Next, the principle and specific example of identifying the type of semiconductor integrated circuit using the microstrip line (16) described above will be described in detail below.

Assuming that the transmission line (2) has a characteristic impedance (usually 50Ω) that matches the measurement system (high frequency probe, network analyzer), the microstrip line (1
6) is a stub (
1) The length is exactly the wavelength (the wavelength is the wavelength; the property of li 14,
This is a value converted according to the dimensions of the microstrip line, etc., and is not the same as the value in vacuum. ) becomes a band rejection filter with maximum attenuation at a frequency of 18. Therefore, if a specific microstrip line (16) is provided in a specific semiconductor integrated circuit, the length of the stub (1) (wavelength 174) can be known (
Although two or more attenuation peak frequencies appear depending on the length of the stub (1), the lowest peak frequency is taken as the maximum attenuation frequency. ) That is, by providing a microstrip line (band rejection filter) (16) with a stub (1) of different length depending on the type of semiconductor integrated circuit on the substrate (4) of the semiconductor integrated circuit, the maximum attenuation frequency can be increased. The type of semiconductor integrated circuit can be identified just by asking.

The parameter that determines the maximum attenuation frequency of the microstrip line is the length L of the stub (1) as described in 17iI.
Parameters that affect the reproducibility of this maximum attenuation frequency include the substrate thickness H1 ratio jR, the ratio ε1, and the width W of the transmission line (2). The smaller the error between the design value and the actual value of these parameters, the smaller the error in the length of the stub calculated by back calculation from the measured value of the maximum attenuation frequency, and the better the identification sensitivity becomes. If there is no error and the network analyzer has high resolution, it is possible to identify hundreds of types up to 26 GHz. However, in reality, errors of about ±5% in the substrate thickness H, ±3% in the dielectric constant ε7, and ±10% in the width W of the transmission line may occur, and there are errors in the design of the maximum attenuation frequency. A deviation of .1 GHz or less occurs. Therefore, even if you set the length of the stub to identify in units of about 0.5 GHz to ensure sufficient safety, the 26 GHz
Approximately 30 varieties can be distinguished.

Semiconductor integrated circuits include MMIC (monolithic microunib IC), in which multiple elements are fabricated on a semiconductor substrate, and MIC (monolithic microunib IC), in which MMIC and single components are mounted on a dielectric TL substrate according to a designed circuit. Microwave IC), and the present invention is applicable to both. Examples of design values and maximum attenuation frequencies when a GaAs semiconductor substrate is used in the MM IC and an alumina ceramic dielectric substrate is used in the MIC are shown below.

Design value of microstrip line Maximum attenuation frequency of microstrip line FIG. 6 is a top view of a semiconductor integrated circuit of another embodiment. It is a smaller version of . In the case of this embodiment, if the stub (1) has the same length, the maximum attenuation frequency will be about 1 GHz smaller than in the embodiment described in iii, but the reproducibility will not change at all. The total number of distinguishable species is reduced by only a few percent.

Note that the microstrip line pattern is not limited to a band-stop filter, and for example, a band-pass filter, an inductance, etc. can be used.

(G) Effects of the Invention It is clear from the above description that the present invention is a fully automated method for manufacturing semiconductor integrated circuits, especially small-volume, high-mix semiconductor integrated circuits, using microstrip lines for identification. In addition, by performing high-frequency measurement only once, the measurement data can be processed by a computer to identify the circuit in question, so the type can be identified very quickly. With just one foot, it is possible to save labor, achieve high efficiency, and reduce manufacturing costs.

[Brief explanation of the drawing]

1(a), 1(b), and 1(c) show a semiconductor integrated circuit, FIG. 1(a) is a top view, FIG. 1(b) is a sectional view taken along line I-r in FIG. 1(a), FIG. 1(c) is a sectional view taken along the line II--II in FIG. 1(a). Figure 2 (a) (b)
shows a high-frequency probe, FIG. 2(a) is a top view,
FIG. 2(b) is a sectional view taken along the line III--III in FIG. 2(a). FIG. 3 is a side view showing a state in which a high frequency probe is brought into contact with a semiconductor integrated circuit. FIG. 4 is a diagram showing an example of the configuration of an automatic inspection system. FIG. 5 is a diagram showing the transfer characteristics of the microstrip line. FIG. 6 is a top view of a semiconductor integrated circuit according to another embodiment. (1)...Stub, (2)...Transmission line, (3)
...Ground conductor pattern, (4)...Substrate, (5)...
- Back ground conductor, (16)...Microstrip line, (17)...High frequency probe. Figure 1

Claims (1)

[Scope of Claims] 1. A semiconductor integrated circuit using a substrate made of a semiconductor or a dielectric, characterized in that a microstrip line for identification is provided on the substrate. 2. A method for identifying a semiconductor integrated circuit, characterized in that the type is identified by measuring the high frequency characteristics of a microstrip line for identification provided on a substrate made of a semiconductor or dielectric.