JPH0299877A - Integrated circuit part and contact inspection thereof - Google Patents

Abstract

PURPOSE:To enable inspection of a junction between a circuit board and a chip by switching a normal operation mode over to a junction inspection mode in an integrated circuit chip. CONSTITUTION:A circuit is provided between a bonding pad section 21 and an input/output buffer circuit of an integrated circuit chip to switch a normal operation mode over to a junction inspection mode and a terminal 26 is used as control terminal. Then, when the terminal 26 is high, transistors (TR) 22 and 23 are turned ON while TRs 24 and 25 are turned OFF while the TRs 24 and 25 are turned ON to enter the junction inspection mode and a circuit part 20 for normal operation is separated electrically from a signal terminal. At this point, as a wire pattern for inspection is pulled out at each signal terminal of the chip on a circuit board, a probing head of an inspector is pressed on the wire pattern. Thus, by measuring a conducting state, a junction condition can be inspected in a soldering between the chip and the circuit board.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides an integrated circuit component equipped with a connection inspection circuit, and a method for connecting the integrated circuit component and a circuit board on which the integrated circuit component is mounted using the circuit. The present invention relates to a connection inspection method for inspecting connection status.

[Conventional technology]

Solder is generally used to connect integrated circuit components to the circuit board on which they are mounted. Conventionally, the state of bonding between this type of integrated circuit component and a circuit board has been visually inspected. Note that incorporating an interconnection defect detection circuit into an integrated circuit chip and detecting interconnection defects and internal defects between integrated circuit chips in a normal operation mode is described in, for example, Japanese Patent Laid-Open No. 180140/1982. .

[Problem to be solved by the invention]

As for the external shape of the integrated circuit component, as shown in FIG.
4, the signal terminal 33 is protruded from the periphery of the integrated circuit component body 31 in order to be directly attached to the surface of the circuit board 32 with solder 34 as shown in FIG. There are flat types, but in all of these, the bonded state of the solder 34 can be seen with the naked eye when viewed from the direction of arrow A, and visual inspection is possible.

However, with the increase in the density of components, as shown in FIG. type, or the integrated circuit chip 45 itself as shown in FIG.
6, the so-called Control Co11a
A pse bond type is used, and in all of these, even when viewed from the direction of arrow B, the state of solder joint cannot be confirmed, and visual inspection is impossible. Conventional visual inspection is not possible in these mounting formats, so the bonding state of individual components to the circuit board is generally not inspected, but abnormalities are detected by testing the functionality of the device with the components installed. We are currently inspecting whether or not there are any.

An object of the present invention is to make it possible to electrically inspect the connection state of each part to the circuit board even in the case where the parts are mounted as shown in FIG. 4 above.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a circuit for switching between a normal operation mode and a bond inspection mode between a bonding pad section of an integrated circuit component and an input/output buffer circuit section.

In other words, depending on the state of a specific signal terminal of the integrated circuit component, the normal operation mode and bonding inspection mode are switched, and when the bonding inspection mode is selected, any signal terminals of the integrated circuit component are electrically connected. The circuit configuration is such that the integrated circuit component is mounted, and the continuity between arbitrary signal terminals is inspected from the circuit board on which the integrated circuit component is mounted, and the bonding between the circuit board and the integrated circuit component is inspected.

[For production]

A specific terminal of an integrated circuit component is used as a control terminal, for example,
When the control signal terminal is in the rHighJ state, a switch circuit provided between the bonding pad section and the crowd cover sofa section switches to the normal operation mode for each signal terminal of the integrated circuit component. - On the other hand, the control signal terminal is rLo
When in the wJ state, the switch circuit switches to a bonding inspection mode, so that the signal terminal group of the integrated circuit component is electrically connected. At this time, the human output buffer circuit for normal operation and the junction inspection circuit are electrically separated without affecting each other.

The integrated circuit component is bonded to the circuit board at the signal terminal portion using a medium such as solder. On the circuit board, a wiring pattern for inspection is tapped off from a normal signal pattern and drawn out for each signal terminal of the integrated circuit component. By press-contacting the blobbing head of the testing device to this wiring pattern for testing and measuring the continuity state,
Inspect the state of solder joints between integrated circuit components and circuit boards.

That is, a voltage or current is supplied by the inspection device to a tap-off wiring pattern for inspection of an arbitrary signal terminal on the circuit board, and the supplied voltage or current is measured using a tap-off wiring pattern for inspection of another arbitrary signal terminal. Since the signal terminal group is electrically connected on the integrated circuit component, the supply voltage or current can be propagated to the signal terminal portion with a normal connection state and detected. On the other hand, the supply voltage or current cannot be detected at the signal terminal portion where the connection is abnormal.

In this way, it is possible to electrically inspect the state of the solder joint between the integrated circuit component and the circuit board.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall view of one embodiment of an integrated circuit chip equipped with a test circuit of the present invention. In FIG. 1, 10 is an integrated circuit chip, 11 is a bonding pad, 12 is an input/output buffer circuit area, and 13 is an internal circuit area. The test circuit according to the present invention is provided in twelve human output buffer areas.

FIG. 2 is an enlarged view of part 0 of FIG. 1, showing its circuit configuration. In FIG. 2, 20 is a normal input/output buffer circuit, and 21 is a bonding pad. Also,
26 is a control terminal (TEST pin) for switching between the normal mode and the bonding test mode, and 27 is a driver circuit to the switch circuit. The switch circuit is a transistor 23
and 24.25.

When TEST pin 26 is rHighJ, transistors 22 and 23 are turned on and transistors 24 and 25 are turned off. The equivalent circuit at this time is shown in FIG. 5(a). At this time,
Integrated circuit chip 10 operates in a normal operating mode. On the other hand, when TEST pin 26 is rLowJ, transistor 2
2.23 is turned off and transistor 24.25 is turned on. The equivalent circuit at this time is as shown in FIG. 5(b). At this time, the integrated circuit chip 10 is configured into a circuit for inspecting the bonding between the integrated circuit component and the circuit board, and a circuit 2 for normal operation.
0 is electrically disconnected from the signal terminal.

FIG. 6 shows a diagram illustrating the bonding state between the integrated circuit component and the wiring board. FIG. 6(a) is a cross-sectional view of an integrated circuit component, in which 50 is an integrated circuit chip, 56 is a circuit board, and 52
5 is a bonding wire and a wiring pattern on the package, 53 is a lead pan (signal terminal), 54 is solder for joining the lead pin 53 and the circuit board 56, and 55 is a drawing pattern for inspection.

In contrast to FIG. 6(a), FIG. 6(b) shows a simplified image diagram of the circuit configuration in the inspection mode. 50 to 55 correspond to the same figure (a). 59 is a closed circuit realized on the integrated circuit chip 50 when in the bonding inspection mode, and each signal terminal pad 51, bonding wire and pattern 52 on the package, lead pin (signal terminal) 53, and circuit board 56 It is connected to a probing pad 57 via a pull-out pattern 55 . The bonding inspection is performed on the circuit board 5.
6. Apply the prober of the inspection device to the probing pad 57 on the top 6. At this time, TEST pin (57x pin)
When put into the rLowJ state and apply voltage V using the 57n bin as the test voltage supply pin, 57a, 57b
, 57c, − pins, etc., a voltage V is detected when the joint portion 54 is normal. Further, for example, if the connection state of the 54m pin is abnormal, the voltage V will not be detected in the test lead-out pattern for the 57m pin, and the abnormality will be revealed.

58 is a normal signal pattern, but when multiple integrated circuit components are mounted on the circuit board, the output circuits of other integrated circuit components connected to the normal signal pattern are in a high impedance state or the integrated circuit concerned Same T as chip
It is necessary to set it to EST mode (test mode).

Figure 7 shows an image of probing work during joint inspection. Reference numeral 64 indicates the main body of the integrated circuit component to be inspected, reference numeral 65 indicates a lead pin, reference numeral 66 indicates a drawing pattern, and reference numeral 67 indicates solder for joining. 62 is a probe, 6° is a probe fixing mold, 63 is an inspection device main body, and 61 is a cable.

〔Effect of the invention〕

According to the invention, the integrated circuit package is Butt 5
The effect of being able to electrically inspect the bonding of circuit boards and integrated circuit components that cannot be inspected visually, such as older types and CCB types that bond integrated circuit chips to circuit boards with solder bumps. There is. Furthermore, since inspection can be performed in terms of DC characteristics, it is possible to detect abnormalities even in the case of a very high resistance bonded state.

[Brief explanation of the drawing]

FIG. 1 is an overall diagram of an integrated circuit chip that is an embodiment of the present invention, FIG. 2 is a partial circuit configuration diagram of FIG. 1, and FIG. 3 is a diagram showing the mounting form of conventional integrated circuit components. FIG. 4 is a diagram showing an implementation form to which the present invention is applied, FIG. 5 is a diagram showing an equivalent circuit according to the control state of the circuit in FIG. 2, and FIG. 6 is a diagram showing the physical state of an integrated circuit component according to an embodiment of the present invention. FIG. 7 is a diagram showing an image of a circuit configuration, and FIG. 7 is a diagram showing an image of a bonding inspection method in a state where an integrated circuit component according to an embodiment of the present invention is mounted on a circuit board. 10... Integrated circuit chip, 11... Bonding pad, 12... Input/output buffer circuit area,
13... Internal circuit area, 20... Human output buffer circuit, 21... Bonding pad, 22.23
,24.25...1-runpasta for switch circuit,
26...Ponding pad for control signal input, 2
7... Driver circuit group for switch circuits. (ω TEST 56 njigarari toi 5 几 (sr-11ko (I))

Claims (2)

[Claims] (1) In an integrated circuit component equipped with an input/output signal terminal group and a power supply terminal group, by inputting a control signal in the first state to a specific signal terminal of the integrated circuit component, the normal state of the integrated circuit component can be adjusted. When setting the input/output signal terminal group to a state where operation is possible, and inputting a control signal in the second state to the specific signal terminal, arbitrary signal terminals of the integrated circuit component can be electrically connected to each other. An integrated circuit component that is equipped with a circuit that can switch between being electrically conductive and electrically disconnected from functional parts that operate normally so as not to affect each other. (2) In a circuit board on which the integrated circuit component is connected and mounted using the input/output signal terminal group and the power supply terminal group of the integrated circuit component as described in claim (1) as connecting portions, a specific signal of the integrated circuit component is provided. By inputting a control signal to the terminal from the lead wiring section provided on the circuit board,
Arbitrary signal terminals other than specific signal terminals of the integrated circuit component are set to be electrically connected to each other, and a lead-out wiring section provided on the circuit board is connected to an arbitrary pin of the electrically connected signal terminal group. The connection between the integrated circuit component and the circuit board is established by inputting an electrical signal from the integrated circuit component and detecting the propagation state of the electrical signal to any other signal terminal from a lead-out wiring section provided on the circuit board. A connection inspection method characterized by inspecting a state.