JPH1138079A - Testing method for ball grid array type integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm the connection of all terminals to a printed board when multiple terminals are connected by providing current input/output terminals on the printed board, feeding a current, providing voltage measuring terminals, and measuring the voltage between the terminals. SOLUTION: The reference resistance value ΣRre between electrodes 8a, 8b, when the electrode 8a of the electrode group 8 of a printed board 3 connected with power terminals is electrically separated from the other electrode group, is measured in advance with a reference integrated circuit having the same circuit structure as that of a ball grid array type integrated circuit 1 subject to test and normally connected with the terminals to the printed board 3. The electrode 8a of the circuit 1 subject to test is separated, the resistance value ΣR between the electrodes 8a, 8b is measured, ΣRre and ΣR are compared, and the connection state of the power terminals to the electrode group 8 is tested. A current source is connected between an input terminal 4 and an output terminal 6, a current is fed, a voltmeter is connected between the terminals 5, 7, and the voltage between the terminals 5, 7 is measured. The resistance value between the terminals 5, 7 can be thus measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a ball grid array type integrated circuit having two or more power supply terminals, and more particularly to a method for testing solder ball connection to a printed circuit board.

[0002]

[Prior art]

[1] Boundary scan test method (IEEE standar
d 1149.1 (JTAG)) The boundary scan test method is a method of inputting / outputting data so that all external input / output terminals of an integrated circuit are sequentially scanned (scanned). The functions proposed by this method are as follows. Verify the normality of the connection between the integrated circuits mounted on the board. Verifies the normality of the function of the integrated circuit itself mounted on the board. The normal operation of each integrated circuit is monitored while mounted on the board.

FIG. 3 is a diagram showing a configuration of a conventional boundary scan circuit. In FIG. 3, four (or five) test access ports (hereinafter, TAP)
TCK, TMS, (TRST), TDI,
The TDO inputs and outputs instructions, test data, and execution results to and from the test logic.

[0004] This boundary scan test method comprises:
This is a test method for input / output signal terminals.
It is not enough to confirm the D terminal. That is, in recent integrated circuits handling high-speed signals, the number of power supply terminals and GN
The number of D terminals is 2 or more, respectively.
When the scan test is applied to the power supply terminal and the GND terminal of the integrated circuit, the plurality of power supply terminals and the plurality of GNDs
The test is performed by regarding each D terminal as one terminal.

[2] X-ray transmission test method FIG. 4 is a diagram illustrating an X-ray transmission test method in a conventional example. The X-ray transmission test method shown in FIG. 4 is a method in which the connection of the power supply solder bump group 2 of the ball grid array type integrated circuit 1 to the printed circuit board 3 is confirmed through X-rays.

[0006]

The first problem is that the boundary scan test method cannot test all of the power supply terminals and the GND terminals, each of which is multi-connected to two or more terminals. That is.
The reason is that the boundary scan test method is a test method for confirming the operation of the input / output signal, and therefore, each of the power supply terminal has at least two terminals and one of the GND terminals is connected to the printed circuit board. This is because the test is normally performed even if the remaining power supply terminal and the GND terminal are not connected to the printed circuit board.

The second problem is that the X-ray transmission test method cannot sufficiently verify whether or not the solder bump group is attached to the printed board without any problem in reliability. In addition, when a component or the like is mounted on the back surface of the printed circuit board, it cannot be applied. The reason is that the X-ray transmission test method is a radiographic confirmation using X-rays, and the characteristics are not electrically confirmed.

An object of the present invention is to easily confirm connection of all terminals to a printed circuit board when a plurality of terminals are multi-connected.

[0009]

SUMMARY OF THE INVENTION A ball grid array type integrated circuit testing method according to the present invention is a ball grid array type integrated circuit having a plurality of first terminals having the same electrical characteristics. Electrically separating a second electrode of the first electrode group of the printed circuit board to which each of the first terminals is connected from a third electrode of the first electrode group;
A first resistance value between the second electrode and the third electrode is measured, and each terminal has the same circuit configuration as that of the integrated circuit and each terminal is normally connected to each electrode of the printed circuit board. Measuring a second resistance between an electrode corresponding to the second electrode and an electrode corresponding to the third electrode of the reference integrated circuit, and determining the first resistance and the second resistance; And a connection state between the first terminal and the first electrode group is tested.

The ball grid array type integrated circuit testing method of the present invention is a ball grid array type integrated circuit having a plurality of power supply terminals, and a printed circuit board to which a power supply solder bump group of the integrated circuit is connected. Electrically separates one second electrode of the first electrode group from a third electrode group other than the second electrode of the first electrode group; Forming two first wirings,
A current input terminal is connected to one of the first wirings, a first voltage measuring terminal is connected to the other of the first wirings, and two fourth electrodes are connected to one fourth electrode of the third electrode group. 2 wiring,
A current output terminal is connected to one of the second wires, a second voltage measurement terminal is connected to the other of the second wires, and a current source is connected between the current input terminal and the current output terminal. And the first
A voltmeter is connected between the voltage measuring terminal and the second voltage measuring terminal, and a first voltage between the second electrode and the fourth electrode is connected.
Of the reference integrated circuit having the same circuit configuration as that of the integrated circuit and having each terminal normally connected to each electrode of the printed circuit board. 4
Measuring a second resistance value between the electrode corresponding to the electrode of
The connection between the power supply terminal and the first electrode group is tested by comparing the first resistance value with the second resistance value.

The above-described method for testing a ball grid array type integrated circuit according to the present invention can be applied not only to a power supply terminal but also to a GND terminal or a common signal terminal.

The measurement of the resistance value is performed by applying a four-terminal measurement method used for low resistance measurement. Specifically, a current source is connected between a current input terminal and a current output terminal to flow a current, and a voltmeter is connected between voltage measurement terminals to measure a voltage. In this manner, the reference resistance ΔRre can be calculated by ΔRre = V / I.

When the number of power supply terminals is N, assuming that the resistances R of the respective power supply terminals are all equal, the resistance ΣRre when the power supply terminals are multi-connected is as follows: ΣRre = R + R / (N−1) (1) ).

The resistance ΣR * when a part of the power supply terminals are not connected is as follows: ΣR * = R + R / (N−1−n) (2) where n is the number of power supply terminals not connected. Therefore, the resistance value is larger when there is a power supply terminal that is not connected than when all the power supply terminals are connected, and ΔRre <ΔR *. Therefore, if the reference resistance .DELTA.Rre in a state where all the power terminals are connected to the printed circuit board is measured in advance, the connection state of the solder bump group to the printed circuit board can be tested.

[0015]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a method of testing a ball grid array type integrated circuit according to an embodiment of the present invention, and shows a case where a power supply terminal is tested. FIG.
As shown in FIG. 1, when a ball grid array type integrated circuit 1 having two or more power supply terminals is connected to a printed circuit board 3 through a power supply solder bump group 2, the printed circuit board 3
Power supply electrode group 8 and one electrode 8 of the electrode group 8
a, a current input terminal 4 provided on one of the two wires formed on the electrode 8a, a voltage measurement terminal 5 provided on the other of the two wires formed on the electrode 8a, and one electrode 8b of the electrode group 8. Current output terminal 6 provided on one of the two formed wirings
And a voltage measurement terminal 7 provided on the other of the two wires formed on the electrode 8b.

In such a configuration, the electrodes 8a of the electrode group 8 of the printed circuit board 3 to which each of the power supply terminals is connected.
The resistance ΣRre, which is the reference between the electrodes 8a and 8b when electrically separated from other electrode groups, is set to the same circuit configuration as the ball grid array type integrated circuit 1 to be tested. The measurement is performed in advance by using a reference integrated circuit in which each terminal is normally connected to a printed circuit board. Then, the electrode 8a of the ball grid array integrated circuit 1 to be tested is electrically separated from the other electrode groups, and the resistance ΔR between the electrode 8a and the electrode 8b is measured.
The connection state of the power supply terminal to the electrode group 8 is tested by comparing ΣRre and ΣR.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram for explaining a method of testing a ball grid array type integrated circuit according to one embodiment of the present invention, and shows a case where a power supply terminal is tested. FIG. 2 shows an electrical connection of a portion for testing the ball grid array integrated circuit shown in FIG.

In the configuration shown in FIG. 1, in FIG. 2, the resistance value is measured by applying a four-terminal measurement method used for low resistance measurement. Specifically, a current source is connected between the current input terminal 4 and the current output terminal 6 to flow a current, and a voltmeter is connected between the voltage measurement terminal 5 and the voltage measurement terminal 7 to connect the voltage measurement terminal. Measure the voltage between 5 and 7. In this manner, the resistance ΔR between the power supply terminals can be measured.

The resistance ΣRre between the power supply terminals of the integrated circuit and the resistance 間 の R between the power supply terminals measured in the test, which are the reference values measured in advance before the test, are calculated by the equation (1) described in the section for solving the problem. And Equation (2).

Here, assuming that R1 is a solder bump resistance including a printed circuit board wiring resistance, R2 is a wire bonding resistance including a case wiring resistance, and R3 is a wiring resistance between power supply pads in an integrated circuit, R = R1 + R2 + R3 ( 3)

When the values of the resistors R are all equal at each terminal, ΔRre = R + R / (N−1). When n of the power supply solder bump groups 2 are not connected to the printed circuit board, ΔR * = R + R / (N−1−n), and the resistance is higher than when all power supply terminals are connected. The value increases. Therefore, if the resistance value ΔRre as a reference when all the power supply solder bump groups 2 are connected to the electrode groups 8 of the printed circuit board 3 is measured first,
By comparing with ΔR calculated from the measurement result in the test, the connection state of the power supply solder bump group 2 to the electrode group 8 of the printed circuit board 3 can be tested.

If a method similar to the test method described in the embodiments and examples of the invention is used for the GND terminal,
The connection state of the GND terminal to the printed circuit board can be tested. Further, if the same technique is used for the common signal terminal, the connection state of the common signal terminal to the printed circuit board can be tested.

[0025]

The first effect is that, in a ball grid array type integrated circuit having a plurality of terminals having the same electric characteristics, the connection state of the solder bump group to the printed circuit board can be tested. is there. The reason is,
Provide current input / output terminals on the printed circuit board to allow current to flow,
This is because a four-terminal measurement method used for low resistance measurement is performed by providing a voltage measurement terminal and measuring the voltage between the terminals.

The second effect is that it is possible to verify the reliability of the connection between the solder bump and the printed circuit board, which cannot be found by the X-ray transmission test method. The reason for this is that the connection between the solder bumps and the printed circuit board is confirmed not by seeing through but by electrical measurement.

In this manner, when a plurality of terminals are multi-connected, it is possible to easily confirm whether all the terminals are connected to the printed circuit board.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for testing a ball grid array integrated circuit according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a test method of a ball grid array integrated circuit according to one embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a boundary scan circuit in a conventional example.

FIG. 4 is a diagram illustrating an X-ray transmission test method in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball grid array type integrated circuit 2 Power supply solder bump group 3 Printed circuit board 4 Current input terminal 5, 7 Voltage measurement terminal 6 Current output terminal 8 Electrode group 8a, 8b Electrode

Claims (4)

[Claims] 1. A ball grid array integrated circuit having a plurality of first terminals having the same electric characteristics, wherein the first terminals are connected to each other in a first electrode group of a printed circuit board. Is electrically separated from the third electrode of the first electrode group, and a first resistance value between the second electrode and the third electrode is measured. .. Corresponding to the second electrode and the third electrode of the reference integrated circuit having the same circuit configuration as the integrated circuit and having each terminal normally connected to each electrode of the printed circuit board. Measuring a second resistance value between the first and second electrodes; comparing the first resistance value with the second resistance value;
A method for testing a ball grid array type integrated circuit, wherein a connection state between the terminal and the first electrode group is tested. 2. A ball grid array type integrated circuit having a plurality of power supply terminals, wherein a second electrode of one of a first electrode group of a printed circuit board to which a power supply solder bump group of the integrated circuit is connected. And a third electrode group of the first electrode group other than the second electrode is electrically separated, and two first wirings are formed on the second electrode, A current input terminal is connected to one of the first wirings, a first voltage measurement terminal is connected to the other of the first wirings, and two fourth electrodes are connected to one fourth electrode of the third electrode group. 2
And a current output terminal is connected to one of the second wires, a second voltage measurement terminal is connected to the other of the second wires, and the current input terminal and the current output terminal are connected to each other. A current source is connected between the first and second voltage measuring terminals, and a voltmeter is connected between the first and second voltage measuring terminals, so that a first voltage between the second and fourth electrodes is measured. 1 is measured, and an electrode corresponding to the second electrode of the reference integrated circuit having the same circuit configuration as the integrated circuit and having each terminal normally connected to each electrode of the printed circuit board, and A second resistance value between an electrode corresponding to a fourth electrode is measured, the first resistance value is compared with the second resistance value, and the power terminal and the first electrode group are compared. 2. The test method for a ball grid array type integrated circuit according to claim 1, wherein a connection state with the circuit is tested. 3. A ball grid array type integrated circuit having a plurality of ground terminals, wherein one second electrode of a first electrode group of a printed circuit board connected to a ground solder bump group of the integrated circuit. And a third electrode group of the first electrode group other than the second electrode is electrically separated, and two first wirings are formed on the second electrode, A current input terminal is connected to one of the first wirings, a first voltage measurement terminal is connected to the other of the first wirings, and two fourth electrodes are connected to one fourth electrode of the third electrode group. 2
And a current output terminal is connected to one of the second wires, a second voltage measurement terminal is connected to the other of the second wires, and the current input terminal and the current output terminal are connected to each other. A current source is connected between the first and second voltage measuring terminals, and a voltmeter is connected between the first and second voltage measuring terminals, so that a first voltage between the second and fourth electrodes is measured. 1 is measured, and an electrode corresponding to the second electrode of the reference integrated circuit having the same circuit configuration as the integrated circuit and having each terminal normally connected to each electrode of the printed circuit board, and A second resistance value between an electrode corresponding to a fourth electrode is measured, the first resistance value is compared with the second resistance value, and the ground terminal and the first electrode group are compared. 2. The test method for a ball grid array type integrated circuit according to claim 1, wherein a connection state with the circuit is tested. 4. A ball grid array type integrated circuit having a plurality of common signal terminals, wherein a second one of a first electrode group of a printed circuit board connected to a common signal solder bump group of the integrated circuit. Is electrically separated from a third electrode group other than the second electrode of the first electrode group, and two first wirings are formed on the second electrode, A current input terminal is connected to one of the first wires, a first voltage measuring terminal is connected to the other of the first wires, and two wires are connected to one fourth electrode of the third electrode group. Second
And a current output terminal is connected to one of the second wires, a second voltage measurement terminal is connected to the other of the second wires, and the current input terminal and the current output terminal are connected to each other. A current source is connected between the first and second voltage measuring terminals, and a voltmeter is connected between the first and second voltage measuring terminals, so that a first voltage between the second and fourth electrodes is measured. 2 of the reference integrated circuit having the same circuit configuration as that of the integrated circuit and having each terminal normally connected to each electrode of the printed circuit board, and an electrode corresponding to the second electrode of the reference integrated circuit. Measuring a second resistance value between an electrode corresponding to a fourth electrode, comparing the first resistance value with the second resistance value, and comparing the common signal terminal with the first electrode; 2. The method for testing a ball grid array integrated circuit according to claim 1, wherein a connection state with the group is tested.