JPH04150504A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To evaluate an RF characteristic in a wafer state by providing a resistor whose one end is connected to wiring and a probing pad connected to the other end of the resistor. CONSTITUTION:Output wiring 11 for leading out the output of an oscillation block 9 formed in an IC pellet 2 to an output pad 10 is branched halfway, and the resistor 12 connected to this branch is formed, and further, the probing pad 13 for an on-wafer-probing is installed at the other end of this resistor 12. At the time of the evaluation of the RF characteristic of this oscillator in the wafer state, the probe for the on-wafer-probing is brought into contact not with the output pad 10 but with the probing pad 13. Thus, oscillation output can be taken out not directly from 50OMEGA but through the resistor 12 in series. In this case, the oscillation output is lowered compared with the case that original load is connected, but such trouble as the stop of oscillation or the jump of frequency, etc., is never caused. Accordingly, the RF characteristic of the oscillator can be evaluated in the wafer state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device, and particularly to an integrated circuit microwave voltage controlled oscillator that is used by connecting a high impedance load.

[Conventional technology]

Conventionally, this type of microwave voltage controlled oscillator (hereinafter referred to as an oscillator) has been designed on the premise that a high impedance load is connected as a load.

For this reason, when evaluating the RF characteristics, if a measurement system with a characteristic impedance of 50Ω, which is widely used to measure the characteristics of microwave circuits, is connected, problems such as oscillation stoppage and oscillation frequency jumps will occur.

To avoid this, measurements are usually performed by inserting a resistor of several hundred to several ohms in series between the oscillator output and the measurement system, although this varies depending on the oscillator circuit type and load conditions.

When considering the application of on-wafer probing, which is the most efficient method in terms of man-hours and cost, as a method for evaluating the RF characteristics of an oscillator, if the characteristic impedance of the probe used for this is high, then this The evaluation method is applicable.

However, in the microwave band, especially at frequencies above the X band, the probe behaves like a distributed constant, so it is extremely difficult to put a high impedance probe into practical use.

For this reason, the on-wafer blow pink probes currently in practical use have a characteristic impedance of 50Ω.
Most of them are not suitable for evaluation of this type of oscillator which assumes a high impedance load.

Therefore, at present, after scribing a wafer, it is common to evaluate individual IC pellets mounted on a chip carrier or ceramic package.

FIG. 3 shows an example of mounting an IC pellet on a chip carrier and evaluating it.

In this case, first, an IC pellet 2. is placed on a chip carrier 1 made of one metal plate. The microchip capacitor 3 and ceramic substrates 4a and 4b are mounted using a brazing material or a conductive adhesive.

Next, each pad on the IC pellet 2 and the microchip capacitor 3. 50Ω wire F for output ratio on ceramic substrate 4a! @5 and power supply or bias supply line 6
are connected by bonding wires 7.

Here, a thin film resistor 8 is inserted between the output pad on the IC pellet 2 and the 50Ω line 5 on the ceramic substrate 4a for the purpose of increasing the impedance on the 50Ω line side.

Conventionally, IC pellets were mounted as shown above and 500M
After increasing the roadside impedance, the RF characteristics of this IC pellet were evaluated using a probe with a characteristic impedance of 50Ω.

Note that the microchip capacitor 3 is used to prevent high frequency waves from entering the power supply or bias line.

[Problem to be solved by the invention]

The conventional method for evaluating the RF characteristics of an oscillator described above requires assembly as shown in FIG. 3 for each evaluation, resulting in a large evaluation cost.

In addition, in the past, this type of oscillator was fully inspected for RF characteristics while individually mounted on a paragauge, and only non-defective products were shipped. In order to downsize and reduce costs, several circuit blocks such as a low-noise amplifier, two frequency rationalizers, one oscillator, and an intermediate frequency amplifier are individually integrated into integrated circuits, and these are combined in pellet form to create a low-noise amplifier. There is also a movement toward configuring noise converters.

However, since the above-mentioned conventional evaluation method is a destructive test, it is not possible to judge whether all IC pellets are good or bad like on-wafer blobbing, and a pilot judgment must be made by sampling.

Therefore, when multiple IC pellets are combined and mounted as described above, it is not possible to guarantee the characteristics of each individual IC pellet, and a certain percentage of defective products end up being shipped. .

[Means to solve the problem]

A semiconductor integrated circuit device according to the present invention includes a wiring for leading an output from a high-frequency oscillation section to an output pad, a resistor connected at one end to the wiring, and a probe connected to the other end of the resistor. It is characterized by having a pad.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

As shown in FIG. 1, in this embodiment, the output wiring 11 for feeding the output of the oscillation block 9 formed in the IC pellet 2 to the output pad 10 is branched in the middle, and the output wiring 11 is connected to this branch. A resistor 12 is formed, and further this resistor 1 is
A probe pad 13 for on-wafer probing is provided at the other end of 2.

FIG. 2 shows the pattern layout of the output section of the embodiment shown in FIG. Note that in FIG. 2, the oscillation block 9 is omitted.

In Fig. 2, the resistance value of the resistor 12 varies depending on the circuit type of the oscillator and its load conditions;
The number is on the order of Ω.

This resistor 12 is usually formed by ion implantation, but if the resistance value is as high as described above, its dimensions can be made sufficiently small compared to the wavelength of the oscillation frequency by selecting the ion implantation conditions. can do.

Note that this resistor 12 is connected to the output wiring 11 and the probe pad 1 via an ohmic metal and a through hole 14.
Connected to 3.

When evaluating the RF characteristics of this oscillator in the wafer state, a probe for on-wafer probing is brought into contact with the probe pad 13 instead of the output pad 10. By doing so, the oscillation output can be taken out not directly through the 50Ω but through the resistor 12 in series.

In this case, the oscillation output is lower than when the original load is connected, but problems such as oscillation stop or frequency jump do not occur.

Therefore, the RF characteristics of the oscillator can be evaluated in the wafer state.

Regarding the aforementioned drop in oscillation output, we first investigated the correlation between the oscillation output measured with a probe with a characteristic impedance of 50Ω via a series resistor and the oscillation output in the operating state with the original load connected. The criteria for determining pass/fail shall be determined.

〔Effect of the invention〕

As explained above, according to the present invention, in an integrated circuit microwave voltage controlled oscillator designed assuming a high impedance load, a probe with a characteristic impedance of 50Ω is used when evaluating the RF characteristics of this oscillator. Since problems such as oscillation stoppage and oscillation frequency jumps do not occur even if the wafer is used, the RF characteristics can be evaluated in the wafer state.

This eliminates the need for components such as chip carriers and ceramic packages, which were required because conventional RF characteristics could only be evaluated with IC pellets mounted.It also reduces the number of assembly steps, reducing evaluation costs. can be reduced.

Furthermore, since all IC pellets on a wafer can be judged as good or bad, the RF characteristics of each IC pellet can be guaranteed.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing a pattern layout of the output section of the embodiment shown in Fig. 1, and Fig. 3 is a diagram showing the pattern layout of the output section of the embodiment shown in Fig. It is a figure showing an outline of a jig used. 1... Chip carrier, 2... IC pellet, 3.
... Microchip capacitor, 4a, 4b... Ceramic substrate, 5... 50Ω line, 6... Power supply or bias supply line, 7... Bonding wire, 8...
... Thin film resistor, 9... Oscillation block, 1o... Output pad, 11... Output wiring, 12... Resistor, 13...
...Probe pad, 14...Ohmic metal and through hole.

Claims (1)

[Scope of Claims] Wiring for leading the output from the high-frequency oscillator to an output pad, a resistor connected at one end to the wiring, and a probe pad connected to the other end of the resistor. A semiconductor integrated circuit device comprising: