JPH046846A - Semiconductor integrated circuit for analog scanning test - Google Patents

Abstract

PURPOSE:To obtain a semiconductor integrated circuit by which the wafer of a semiconductor integrated circuit chip having a fine bonding pad pitch at a pitch of 75 to 50mum or lower can be tested by a method wherein a specific semiconductor switch, a specific control circuit and a specific terminal for test use are provided. CONSTITUTION:The following are provided: semiconductor switches 6 connected to terminal parts 2 for external connection on a semiconductor integrated circuit chip 1; a circuit 7 used to control the semiconductor switches 6; a terminal 14, for test, connected to said semiconductor switches 6; and a terminal 14, for test use, used to input a signal, from the outside, to said circuit 7 used to control the semiconductor switches 6. For example, an input signal 8 to a control circuit 7 used to control analog switches 6 is sent from a contact probe 3 for chip test and a pad 14 for test. The control circuit 7 makes one out of many existing analog switches 6 conductive according to the input signal 8. Then, a voltage is applied, from the outside, to an input signal line 13 of an operational amplifier 10, and a voltage of an output signal line 12 of the operational amplifier 10 is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit that facilitates wafer testing of semiconductor integrated circuit chips, particularly analog scan testing of input terminal leakage current, etc.

[Conventional technology]

FIG. g is a plan view for explaining a conventional wafer test method for semiconductor integrated circuit chips. In the figure, +1
1 is a semiconductor integrated circuit chip, and 21 is a contact needle for chip testing that connects to an external connection terminal (hereinafter referred to as a bonding pad) 31 made on the semiconductor integrated circuit chip fil. . 14) is Pondaig Pad! The input circuit 1, 61 connected to the pad 1 is an output circuit connected to the bonding pad 12).

Next, the operation will be explained.

Human power on semiconductor integrated circuit chip +11 to be measured - #8
The characteristics of F+41 and the output circuit 11 were measured by connecting them to a semiconductor integrated circuit calibration device (not shown) via a contact needle (31t) for chip testing. Since the semiconductor integrated circuit chip test was configured as described above, the test could not be carried out unless the contact needle for the chip test was always in contact with the bonding/rad.

10,000, the spacing between the bonding pads #'i was 160μ in the past.
m pitch was the standard, but improvements in bonding ink technology have made it possible to imitate i-bonding with a pinch of 75 to 50 μm or less.
There is a problem in that it is difficult to fabricate a fine bonding pad with a pitch of 75 to 50 μm or less and make contact with a fine bonding pad having a pitch of 75 to 50 μm or less.

Does this invention have the above problems? This was done to solve the problem that testing could not be carried out unless the contact needle for chip testing made contact with the bonding pad, and it was developed to solve the problem of semiconductor integrated circuits with fine bonding pad pinches with a pitch of 75 to 60 μm or less. The purpose of this invention is to obtain a semiconductor integrated circuit that can perform chip wafer testing.

[Means and operations for solving the problem] The semiconductor integrated circuit according to the present invention has a circuit for analog scan testing and a small number of bonding pads for testing built into the chip, so that contact for chip testing can be improved. Solved the drawback that tests could not be performed unless the needles were in contact with each other.

Wafer testing of semiconductor integrated circuit chips with any fine bonding pad pitch can be performed.

〔Example〕

The Kazufu-It diagram of this invention will be explained below. @
In Figure 1, 1lr1 semiconductor integrated circuit chip, +! I
Bonding pad made on H semiconductor integrated circuit chip III, contact needle for t:11i chip test, (4)
is the input circuit connected to the pumping unit Rad 121,
15) is the bonding pad: 2) is the output circuit, 161 is the semiconductor switch (hereinafter referred to as analog switch) connected to the bonding pad (2), +7
1 is the control circuit that controls the analog switch 16), (8) is the control circuit 10 (input signal to 71, (9) is the analog switch) 61 commonly connected signal line, +1
01 is the operational amplifier built in the semiconductor integrated circuit chip Tadochi, dll is the feedback element of the operational amplifier 11Ql, U power is the output signal line of the operational amplifier +101, (131 is the input signal line of the operational amplifier till, and a41 is the semiconductor integrated circuit This is a test pad made from chip clay.

Next, the operation will be explained. Contact needle 1 for chip test
3) and test pad 04, analog switch 1
6) Control circuit to control; input signal to 7) (
8) will be sent. The 1lla circuit (7) is composed of a circuit such as a shift register, and turns on one of the many analog switches 16) in response to the input signal 18). For example, when measuring the total input leakage current of the input circuit 4, the analog switch (6) connected to the input circuit 4 is turned on.

Then, a voltage is applied to the operational amplifier 1010 input signal amplification from outside the semiconductor integrated circuit. The voltage of the input signal line α4 is applied to the input circuit 141, and if there is a current from the input circuit nuc'J-, the leakage current flows through the analog switch (6).
Through the operational amplifier @ tlol , the feedback element Lu1l
The current is converted into voltage and measured by the output signal line +121 of the operational term UO+. Output side 1it! r+6
Similarly, when there is a leakage current in 1, the IC and IJ currents are converted into voltage by the operational amplifier U[, feedback element Uυ] through the analog switch (6), and then converted into the operational amplifier dα.
#I is determined from the output signal line 'J2+.

In addition, functional tests of semiconductor integrated circuits are conducted using the background scan method. By using the background scan method, it is possible to perform a functional test on a semiconductor integrated circuit using only a small number of test pads without contacting each band on the chip.

Note that in the above embodiment, the feedback element ul of the operand @
Although the case where l is constituted by a diode is shown, it may be a resistor. Also, in the above practical case, the operand @ device: 1
01, Feedback element 0 Although the case where the feedback element is built into the semiconductor integrated circuit chip is shown, it may be attached externally and the same effect as the above-mentioned actual result can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a wafer test of a semiconductor integrated circuit chip with am bonding pad pitch is carried out by making a semiconductor integrated circuit for analog scan test. We can manufacture inexpensive VC test equipment that can perform wafer testing of circuit chips, and also provide highly accurate testing*
111 can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view of a semiconductor integrated circuit for analog testing according to one embodiment of the present invention, and FIG. 2 is a plan view for explaining a conventional method of wafer testing of semiconductor integrated circuit chips. 111 is a semiconductor integrated circuit chip, (21 is a bonding pad, j3 is a contact needle for chip testing, (41 is an input circuit, 15) is an output circuit, 161 is an analog switch, (7) is a control circuit % (81 is control (b)
(9) Commonly connected signal line of the analog switch * tlQl is the operational amplifier, ULl is the feedback element of the operational amplifier, and the same is the output signal line of the operational amplifier. The opposite side shows the input signal line of the operational amplifier, and α4 shows the test pad. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A semiconductor switch connected to an external connection terminal on a semiconductor integrated circuit chip, a circuit that controls this semiconductor switch, a test terminal connected to the semiconductor switch, and a circuit that controls the semiconductor switch from the outside. A semiconductor integrated circuit for analog scan testing, comprising a test terminal for inputting a signal.