SU1443213A1 - Contact device for probing inspection of articles - Google Patents

Abstract

The invention is in the field of electronics and is intended for probe monitoring of the parameters of semiconductor wafers. The contact device comprises a table 2 for the test article 3, which is fixedly connected to the holder 4, which forms a probe head with the L-shaped elastic probes 5. The table 2 is sun-shaped in the form of a vibrating channel, conjugated X 8 5 / J / 7/7 with the case by means of inclined springs 6 with a vibration drive, made, for example, in the form of a vertical electromagnet 7. At the same time, the resonant natural frequency of the probe oscillations is equal to the operating frequency vibrator. The contact is made at the beginning of the throwing phase, in which the controlled product 3 is pressed by force of inertia to the table 2, which allows to ensure reliable contacting and control of the product parameters without stopping during the through transport system. The contact device can be used in a batch transport system mode. A contact device of this design allows you to reliably determine current distortion and the type of conductivity of a semiconductor wafer. 1 hp f-ly, 2 ill. i (Л С X | i ij 00 К) 00 ///// (Рig.1

Description

The invention relates to instrumentation engineering and is intended for probe control of a parameter in semiconductor wafers during their mass production.

The purpose of the invention is to increase the reliability of contact and the performance of the control.

Figures 1 and 2 schematically depict a contact device in two projections.

The device consists of case 1 and table 2 for the controlled article 3. With table 2, the holder 4 is fixedly connected, which forms a probe head with the L-shaped elastic probes 5.

Table 2 is made in the form of a vibrating channel coupled to the body by means of inclined springs 6 and equipped with a vibrating actuator, for example, in the form of a vertical electromagnet 7. Probes 5 are inserted into the holes in the holder 4 with the possibility of adjusting axial movement and fixed thereto screws 8.

Before starting work, a preliminary one-time adjustment of the device is necessary, which consists in the fact that after the electromagnet 7 has been fed to the coil of an alternating variable pump. the frequency coinciding with the mechanical resistance of the springs 6 and probes 5, precisely adjusts the length of the unchipped portion of the horizontal section until the resonant frequencies of the mechanical oscillations of the probes 5 and the vibrator drive coincide to obtain the maximum amplitude and minimum phase difference of the oscillations of the working condos of the contact items. After that, the required amplitude of oscillations of the probes 5 is set by varying the magnitude of the supply voltage of the electromagnet 7. The oscillation amplitude is chosen such that, within 1 / 3-1 / 4 of the oscillation period, the working end of the probe 5 is located above the plane of contact with the lower surface of the product. The device works as follows.

Table 3 receives the product 3, for example, a semiconductor base. The vibrating conduit, which gives the oscillatory system formed by table 2 and the crust 6, a plane-parallel oscillatory motion, is turned on.

The article 3 moves rto to the table 2 from left to right and is above the vibrating probes 5. The contact is made at the beginning of the throwing phase, in which the product 3 is pressed by force of inertia to the table 2, which ensures reliable contacting and control of the product parameters without stopping it through the through mode transport system.

The proposed device can be used in the mode of a periodic action transport system. In this design of the device, there are no relative movements of the probe 5 and the product 3 being monitored, and independent adjustment of the speed of movement of the product 5 and the amplitude of vibrations of the probes 5 is possible, since the speed r1 of displacement is determined by the horizontal component of the table oscillations 2, and the amplitude of vibrations is only a vertical component vibrations.

The contact device provides contact with the unfixed transported plate. It does not require compensation for the plate deflection and wear of contact elements. Since the maximum amplitude of oscillations of the contact elements is 2–3 mm longer than the distance to the surface of the contacting plate, when the plate oscillates damping, the amplitude of oscillations of the working ends of the contact elements automatically changes in accordance with the profile of the contacting surface of the plate. Since the deflection of the plates is no more than 100 µm, the change in the contact time and the instantaneous speed of the contact element at the moment of contact with the plate surface is irrelevant for the device to work. Since the measurement of the electrical parameters of the plates is carried out at frequencies exceeding the resonant frequency of the contact elements, the contact time equal to 1 / 3-1 / 4 of the oscillation period of the contact element is sufficient to carry out the measurement cycle. For example, the measurement of the conductivity type of semiconductor wafers, carried out by the method of rectifying current through a contact element — a semiconductor wafer, is carried out at a frequency ff, on the order of 10 MHz. . At the resonant frequency of the contact element frank 100 Hz, the contact time t will be equal to

 - t

1 fn

eleven

A f

2.5-10, -.

During this time, a number N of periods is analyzed, equal to

N 25000 periods

l i.

which is sufficient to reliably determine the current shape distortion and determine the type of plate conductivity.

Claims (2)

1. A contact device for probe inspection of products consisting of a housing, a table for a controlled article, a probe head, including a holder with L-shaped elastic probes and actuators of the probe head, characterized in that, in order to increase the reliability of contact and performance , the drive of the zodovoy head is made in the form of a vibrator, on a movable element of which a fixedly mounted holder and A table for a controlled product made in the form of a vibrating channel, while the resonant frequency of the probe's own oscillation is equal to the working frequency of the vibrator. five 2. The device according to claim 1, characterized in that the drive is in the form of a vertical electromagnet, the chute is coupled to the housing by means of inclined springs, and the T-on0 different elastic probes are installed in a hole x holder with adjustable axial displacement .