JPH03142382A - Characteristic measuring instrument for high frequency device - Google Patents

Abstract

PURPOSE:To control the oscillation for DC characteristic measurement to improve the precision and the workability of device test for mass production by storing an object to be measured in an electromagnetic absorber to perform measurement. CONSTITUTION:A measuring jig main body 1 consists of the electromagnetic absorber, and mounting positions 4 are formed as recessed parts by which plural high frequency devices 3 are easily mounted and positioned. A metallic electrode 5 connecting source electrodes 3s of devices 3 in common is provided in parts, where electrodes 3s are placed, around the main body 1. An enclosure 2 consists of an electromagnetic absorber also, and it is surely coupled to the main body 1 by respective projecting parts 7 and recessed parts 6. Mounting spaces of devices 3 are shielded from the outside to control the oscillation in this manner. A measuring signal is supplied to devices 3, and measuring terminal leading-in holes 8 and 9 reaching the electrode 5 are formed and probe needles are inserted through them, and measurement is performed by successive switching.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring characteristics of high frequency devices, and more particularly to a jig for mounting a device under test.

In recent years, the performance of compound semiconductor MESFETs has rapidly improved, including the HE model that effectively utilizes the properties of GaAlAs/GaAs. Efficient mass production of semiconductor devices is being considered.

By the way, in the mass production of devices, it is necessary for the devices that have completed the process to exhibit predetermined characteristics, and each device undergoes a characteristic test and selection based on the results before shipping. Particularly in high-frequency devices such as HEMTs, DC characteristics are an essential test item, and therefore, at the end of the process, a test signal is input to each device to test the DC characteristics.

When measuring the DC characteristics of a device such as a HEMT that has high gain up to a high frequency band, an unexpected loop is formed with the measurement jig used for normal semiconductor devices, and feedback from this loop causes an undefined frequency. An oscillation phenomenon occurs in this method, and the direct current characteristics of the device cannot be measured accurately.

The cause of the above oscillation phenomenon is that noise power such as white noise is fed back, and conventionally, in order to remove unnecessary AC signals, coil capacitors or ferrite beads, etc. are connected to the input/output terminals, and measurements are taken. Measurement jigs have been proposed that are designed to terminate at the characteristic impedance of the system to prevent the generation of unnecessary reflected waves.

Problems to be Solved by the Invention Even with the above devised measuring jig, the cutoff frequency is several tens of G11z.
In high-frequency devices such as IIEMT, which spans over There was a problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a DC characteristic measuring device that can be used for mass production of high frequency devices.

In order to achieve the above object, the present invention provides a main body made of an electromagnetic absorber forming positions for mounting a plurality of high frequency devices, and a high frequency device mounted on the main body. A measuring jig is constituted by a lid body made of an electromagnetic absorber that covers the body, and a measurement terminal introduction hole formed in at least one of the main body or the lid body and reaching the electrode of the high frequency device at the mounting position.

Because the in-situ measurement jig is made of an electromagnetic absorber, noise is blocked, and therefore it hardly reaches the input/output terminals of the device under test, making it possible to measure DC characteristics without oscillation. can.

Furthermore, since multiple device mounting positions are formed on the main body, the same measurement process can handle multiple devices, making it suitable for measuring characteristics during mass production.

The measurement jig according to this embodiment consists of a main body and a lid covering the main body, and a high-frequency device, which is an object to be measured, is housed in the space formed between the two, and the DC characteristics are measured. Ru.

FIG. 1(a) shows a plan view of the main body l of the measuring jig.
Figure (b) shows a plan view of the lid body 2. The main body l is made of an electromagnetic absorber, and positions 4.4 for mounting a plurality of high frequency devices 3.3 are formed on the substantially flat upper surface. This position 4 is formed as a depression corresponding to the external shape of the device so that the high-frequency device 3 can be more easily mounted and aligned, as shown in the cross-sectional view of FIG. 2(a). At the portion where the source electrodes 3s of the device 3 mounted at each position 4 are located, a metal electrode 5 for commonly connecting the source electrodes 33 is provided.
It is provided in a form that goes around the periphery of the main body l. The main body 1 is also provided with a positioning recess 6 in an area that does not interfere with the mounting of the device 3 in order to ensure the connection with a lid 2 which will be described later.

For the main body l having the above structure, the lid body 2 is also made of an electromagnetic absorber, and when attached to the main body l, shields the device mounting space of the main body l from the outside. In order to ensure the connection with the main body 1, the four parts 6 are attached as shown in FIG. 2(b).
A convex portion 7 that fits into is provided. In order to supply measurement signals to the devices 4 mounted on the main body 1, the lid body 2 is further formed with measurement terminal introduction holes 8 corresponding to the gate and drain electrode positions of each device 4, and a common source electrode. A measurement terminal introduction hole 9 is formed that reaches the metal electrode 5.

The probe needles of the measuring device are passed through the measurement terminal introduction holes 8 and 9, and the tip contacts each electrode to transfer a signal for measuring the DC characteristics. In order to enhance the positioning and fixing function of the device 4 mounted on the main body 1, the lid body 2 can also be formed with a pressing member 33 corresponding to the shape of the device 4, as shown in FIG.

FIG. 3 is a block diagram of a DC characteristic measuring apparatus for a high frequency device using the above measuring jig. The electrodes of the high-frequency device 3 attached to each position 4 of the measurement jig 21 are connected to the tips of probes 22d, 22g, and 22s inserted through the measurement terminal introduction holes 8 and 9 formed in the lid 2 of the jig 21. An electrical connection is made in abutment and a test signal is supplied. The probes 22d, 22g, and 22S are probers 22
The switch 23 is supported by the switch 23, and wired between the switch 23 and the changeover switch 23. The changeover switch 23 is arranged to efficiently carry out measurement work in response to the fact that a plurality of high frequency devices 3 are attached to the measurement jig 21.

That is, the measurement signals of a set of drain D, gate G, and source S electrodes for device testing outputted from the DC characteristic measuring device 24 are sequentially switched to each device 3 mounted on the jig 21 for manual input. It is set in. The switching of the switch is performed in synchronization with the measuring device 24 according to a command from the controller 25, and the output from the device 3 is given to the measuring device 24 as a measured value.
Determination and ranking are performed as to whether the device ensures predetermined characteristics or not. In this manner, the measurement apparatus described above can perform measurement and evaluation on a plurality of devices in one operation.

In the above embodiment, the tips of the probes 22d, 22g, and 22s are directly inserted into the holes formed in the lid of the jig. The metal column 31 can also be provided with the dimensions adjusted so that the tip thereof protrudes toward the main body and reaches the electrode of the device at the mounting position. In this structure, probes 22d, 22g,
It is desirable to form a recess 32 so that the tip of the 22s can be easily attached.

As described above, according to the present invention, the object to be measured can be housed in an electromagnetic absorber for measurement, so oscillations when measuring DC characteristics can be sufficiently suppressed. In addition to being able to perform accurate measurements and improve accuracy, it also allows for a large number of objects to be measured at the same time, greatly improving throughput and facilitating device testing during mass production. Workability can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment according to the present invention, Fig. 2 is a sectional view taken along line A-A of the embodiment, Fig. 3 is a block diagram of a DC characteristic measuring device to which the embodiment is applied, and Fig. 4 is a sectional view of essential parts of another embodiment according to the present invention. 1-Main body, 2-Lid body, 3-High frequency device. 4-Mounting position, 5-Metal electrode. 6-Alignment recess, 7- Alignment. Convex portion. 8.9-One electrode terminal introduction hole.

Claims (1)

[Claims] (1) A main body made of an electromagnetic absorber that forms positions for mounting a plurality of high-frequency devices, a lid made of an electromagnetic absorber that covers the high-frequency devices mounted on the main body, and at least one of the main body or the lid. A measurement terminal introduction hole that reaches the electrode of the high-frequency device at the mounting position, the measurement terminal introduction hole being formed in the mounting position of the high-frequency device.