JPH1026647A - Method and device for inspecting substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the extraction of the position relationship of a probe with respect to each lead and the discrimination of the presence or absence of the lose connection of the lead by constituting the non-contact probing by a multiple-electrode probe for the lead group of an IC under inspection, and capturing the weak electromagnetic field. SOLUTION: An AC signal flows into a connecting-lead group 7, and the weak electromagnetic field is generated. A filter 110 of a waveform processing circuit 10 removes the noises of the received detected signal. The signal is amplified in an amplifier 111 and outputted to an A/D converter 11. Then, the detected signal after the waveform processing is inputted into a personal computer 12. When there is loose connection in the lead 7, the received level becomes smaller than the reference value. Therefore, the presence or absence of the loose connection can be discriminated by the level difference. Then, the channel of the AC signal inputted into a contact probe 3 is changed, the same operation is repeated and the received levels are measured, respectively. Thus, where the each electrode of a multiple-electrode probe 8 is located in the vicinity of which lead 7 of an IC under inspection 6 and the position itself can be frond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a board inspection method and apparatus for performing a floating test (good or bad soldering) of a lead of a surface-mounted IC by non-contact probing, and more particularly to a lead group of an IC to be inspected. A non-contact probing with a multi-electrode probe is configured to access (supply or receive / detect) an electronic circuit, and the electrical state is determined by the positional relationship of the multi-electrode probe with respect to each lead of the IC under test and the conductor pattern. The present invention relates to a board inspection method and apparatus for extracting a plurality of leads to be connected together with a one-to-many connection relationship.

[0002]

2. Description of the Related Art Conventionally, non-contact probing has been constructed in a foot lifting test of a lead of a surface mount type IC, with a one-to-one positional relationship or a connection relationship between a conductor pattern and a lead group of an IC to be tested. An inspection method for extracting an electrical state during the period is known.

For example, JP-A-5-264672 discloses that
A capacitive coupling probe (probe chip) used for an in-circuit test of a high-density mounting board is disclosed. Here, non-contact means coupling without ohmic contact and is used interchangeably with capacitive. That is, capacity (gender)
The means of coupling is a capacitor.

In terms of the use of capacitive (sexual) coupling, as disclosed in Japanese Patent Laid-Open No. 4-309875,
2. Description of the Related Art There is known an in-circuit test apparatus in which an electrode (so-called solid probe) made of metal foil is placed on a C package via an insulator.

[0005]

However, all of the above-mentioned prior arts employ non-contact probing. However, positioning is required in each approach to the lead group of the IC to be inspected. It was not possible to determine which portion of the conductor pattern connected to the foot lift of the lead to a certain position together with the one-to-many (at least about 1 to 3 to 5) connection relationship.
Therefore, by arranging the multi-electrode probe close to the lead group of the IC to be inspected and enabling energization (access to the electronic circuit), positioning in probing becomes unnecessary,
In addition, it is reasonable to determine the floating of the lead group with respect to the conductor pattern in a one-to-many relationship, and it is expected to be industrially useful.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to a lead group of an IC to be inspected which is related to an inspection of a floating of a lead of a surface-mounted IC (goodness of soldering).
A non-contact probing is configured by a multi-electrode probe to access (supply or receive / detect) an electronic circuit, and the electrical state of the probe is determined based on the positional relationship of the probe with respect to each lead of the IC under test and a plurality of conductor patterns. It is an object of the present invention to provide a board inspection method and apparatus improved so that leads are extracted together with a one-to-many connection relationship.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for determining the presence or absence of a foot lift of a lead of an IC to be inspected with respect to a pitch of the lead group of the IC to be inspected. A non-contact probing with a narrower pitch multi-electrode probe arranged close to it to access (supply or receive / detect) an electronic circuit by capturing a weak electromagnetic field (or electromagnetic wave) and change its electrical state A board inspection method and apparatus for extracting a positional relationship of a multi-electrode probe with respect to each lead of an IC to be inspected and a one-to-many connection relationship with respect to a plurality of leads connected to a conductor pattern.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method according to the preferred embodiment of the present invention is to sequentially and individually supply an alternating current signal to individual electrodes to be inspected of a conductor pattern via a contact probe, and to connect the respective electrodes to be inspected. Non-contact power reception and detection of the electromagnetic field generated in each lead of the IC for each corresponding region of a multi-electrode probe consisting of a plurality of electrodes opposed to each lead, evaluate the level difference of the detection signal from each electrode, and inspect The position relationship of the multi-electrode probe with respect to each lead of the IC is grasped, and the presence or absence of foot lifting is determined together with the one-to-many connection relationship with the conductor pattern.

In addition, by inverting the configuration on the power supply / reception side, an alternating current signal is supplied to the multi-electrode probe to generate an electromagnetic field and to perform non-contact power supply to a group of leads of the IC to be inspected, thereby forming a conductor pattern. Each of the electrodes to be inspected is sequentially and individually supplied with power via a contact probe to form an energized state, and a multi-electrode probe comprising a plurality of electrodes opposed to each lead of the IC to be inspected connected to the conductor pattern in each energized state. For each corresponding area, the level difference of the detection signal from each electrode is evaluated, the positional relationship of the multi-electrode probe with respect to each lead of the IC to be inspected is grasped, and whether or not the foot is lifted is determined in one pair with respect to the conductor pattern. It may be determined together with various connection relationships.

According to a preferred embodiment of the present invention, a contact probe connected to each of the electrodes to be inspected of a conductor pattern, the probe drive control relay, and an IC to be inspected are provided. A multi-electrode probe and a probe drive control relay disposed in close proximity to the lead group, and a level difference of an electromagnetic field detected by the multi-electrode probe are evaluated via a waveform processing circuit, and the multi-electrode for each lead of the IC under test is evaluated. Measuring means for grasping the positional relationship of the probe and discriminating the presence / absence of foot lifting together with the one-to-many connection relationship with the conductor pattern is provided.

Here, an oscillator is connected to the contact probe drive control relay, the test target electrode group of the conductor pattern is a contact type individual power supply side, and the lead group of the IC to be tested is a non-contact type power receiving / detection. Side may be configured.

Further, an oscillator is connected to the multi-electrode probe driving relay, the leads of the IC to be inspected are used as a non-contact type power supply side and a detection side at the time of energization, and the group of electrodes to be inspected of the conductor pattern is a contact type. It may be configured as an individual power receiving side.

Accordingly, a multi-electrode probe having a pitch smaller than the pitch of the lead group of the IC to be inspected is arranged close to the lead group (constituting non-contact probing), and an AC signal is supplied to the conductor pattern so that the non-contact probe is provided. By generating an electromagnetic field in the part, capturing it and evaluating the electrical state of the electronic circuit, the positional relationship of the multi-electrode probe with respect to each lead of the IC to be inspected can be grasped, and whether or not the foot is lifted is determined. It can be determined together with the one-to-many connection relation to the conductor pattern.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a schematic view of a device configuration according to an embodiment of the present invention. In the configuration mode, a conductor pattern is a contact type individual power supply side, and a lead group of an IC to be inspected is a non-contact type. This is the power receiving / detecting side.

Here, 1 is an oscillator (AC power supply), 2 is a contact probe drive control relay, 3 is a contact probe, 4 is a substrate, 5 is a conductor pattern, 6 is an IC to be inspected,
7 is a lead (foot) of the IC to be inspected, 8 is a multi-electrode probe,
9 is a multi-electrode probe drive control relay, 10 is a waveform processing circuit, 110 is a filter, 111 is an amplifier, 11 is an A / D converter, 12 is a personal computer (measurement means) and X
Is a substrate inspection device.

As shown, an AC signal [voltage] from an oscillator (1) is applied to a contact probe drive control relay (2).
To enter. At this time, the contact probe drive control relay (2) has one channel (hereinafter abbreviated as ch) of the conductor pattern (5) of the substrate (4). ] Conducts to the contact probe (3), and the other channels are grounded (hereinafter abbreviated as GND). ] Is done. This drive control is performed by a personal computer (12) as a measuring means [hereinafter referred to as a personal computer. ]. (Individual power supply)

The AC signal flows through the conductor pattern (5) and the connection leads (7) [group] of the IC (6) to be inspected. At this time, a weak electromagnetic field [electromagnetic wave] is generated [radiated] in the connection lead (7) [group] of the IC under test (6).
These are received one by one sequentially through the multi-electrode probe (8). [Power reception / detection]

At this time, the relevant electrode of the multi-electrode probe (8) that has received the signal is connected to the waveform processing circuit (10) by the multi-electrode probe drive control relay (9), and the other electrodes [group] are connected to GND. Connected. This drive control is also performed by the personal computer (12).

The waveform processing circuit (10) includes a filter (110) and an amplifier (111). The filter (110) removes noise from the received detection signal and outputs the signal to the amplifier (111). This is amplified and output to the A / D converter (11). Then, the detection signal after the waveform processing is sent to a PC (12)
Is input to The reception level at this time becomes the determination value.
Here, if the lead (7) has a foot lift, the reception level thereof is much lower than the reference value, so that the presence or absence of the foot lift can be determined based on the level difference.

Next, the above operation is repeated by changing the channel of the AC signal input to the contact probe (3).
By measuring the reception level, it is possible to know the position of each electrode of the multi-electrode probe (8) that is adjacent to which lead (7) of the IC under test (6). Can be. That is, it can be said that the electrode having a high reception level is located near the lead (7) of the IC (6) to be inspected, while the electrode having a low reception level is located at the IC (6).
Can be said to be located between (the spaces of) the leads (7).
[Hereinafter, this automatic positioning method is referred to as a self-alignment method. ]

According to the self-alignment method, the number (the number of channels) of the multi-electrode probe (8) to be actually received is determined. The number is the electrode [lead] of the IC (6) to be inspected.
Although it depends on the width of (7), it is usually about 3 to 5 per electrode [lead] (7).

The conductor pattern (5) and the IC to be inspected
For each channel between the leads (7) in (6), the number of channels (probe address area) to be received by the multi-electrode probe (8) is set. For example, 3-5 ch of the multi-electrode probe (8) for the first lead [illustrated] of the IC to be inspected (6), and 10ch of the multi-electrode probe (8) for the second lead [illustrated].
Set the number of channels (probe address area) to ~ 12ch.

Therefore, the actual inspection of the foot lift of the IC (6) to be inspected is based on the number of the leads (7) of the IC (6) to be inspected and the number of channels (the number of electrodes) of the multi-electrode probe (8) determined by the self-alignment method. ), That is, the electromagnetic field generated in the lead (7) is captured (received / detected) in a one-to-many relationship. This is important and is extremely beneficial in the following respects. See also FIG.

Positioning in probing becomes unnecessary, and in a normal product, by receiving and detecting power one by one, characteristics of each level difference and position can be obtained.
Therefore, it can be determined which probe of the multi-electrode probe is opposed to (in the vicinity of) which lead. [FIG. 2 (a)
(B)]

It is possible to determine which part (connection part) of the conductor pattern connected to several leads has the lead floating (foot lifting or defective solder). [FIG. 2 (c)]

[0027]

According to the present invention, since the non-contact probing with the multi-electrode probe is configured for the lead (group) of the IC to be inspected, the position of the probe with respect to each lead can be known and the conductor pattern can be obtained. It is possible to determine which of the plurality of leads connected to the cable is a leg floating or soldering failure. In addition, since a compact automated board inspection apparatus that does not require a positioning means can be configured, it is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a device configuration of an apparatus according to an embodiment.

FIG. 2 is an explanatory diagram of an inspection mode by a self-alignment method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oscillator (AC power supply) 2 Contact probe drive control relay 3 Contact probe 4 Substrate 5 Conductor pattern 6 IC to be inspected 7 Lead (foot) of IC to be inspected 8 Multi-electrode probe 9 Multi-electrode probe drive control relay 10 Waveform processing circuit 110 Filter 111 Amplifier 11 A / D converter 12 Personal computer (measurement means) X board inspection device

Claims (5)

[Claims] In an improvement of a board inspection method in which a foot lift inspection of a lead of a surface mount type IC is performed by non-contact probing, a multi-electrode probe having a narrower pitch than a pitch of the lead group of an IC to be inspected is arranged close to the lead group. A board inspection method for controlling power reception / detection by sequentially supplying an AC signal to each electrode to be inspected of a conductor pattern via a contact probe, and connecting the respective ICs to be inspected. Non-contact power reception / detection for each corresponding region of a multi-electrode probe composed of a plurality of electrodes opposed to each lead, and evaluates the level difference of the detection signal from each electrode to evaluate the IC under test. The positional relationship of the multi-electrode probe with respect to each of the leads, and the presence / absence of foot lifting together with the one-to-many connection relationship with the conductor pattern A board inspection method characterized by determining. 2. An improvement in a board inspection method in which a foot lift inspection of a lead of a surface mount type IC is performed by non-contact probing, wherein a multi-electrode probe having a narrower pitch than a pitch of the lead group of an IC to be inspected is provided. A board inspection method in which a power supply and a detection at the time of energization are controlled in close proximity to each other, wherein an AC signal is supplied to a multi-electrode probe to generate an electromagnetic field and to control a lead group of an IC to be inspected. Contact power is supplied, and the individual electrodes to be inspected of the conductor pattern are sequentially and individually received via contact probes to form an energized state, and a plurality of opposing electrodes are connected to the leads of the IC under test connected to the conductor pattern in each energized state. Evaluate the level difference of the detection signal from each electrode for each corresponding region of the multi-electrode probe consisting of electrodes, and apply it to each lead of the IC under test. A board inspection method comprising: grasping a positional relationship of a multi-electrode probe with respect to the multi-electrode probe, and determining whether or not the foot is lifted together with a one-to-many connection relationship with the conductor pattern. 3. An improvement in a board inspection apparatus for performing a foot lift inspection of a lead of a surface mount type IC by non-contact probing, wherein a multi-electrode probe having a narrower pitch than a pitch of the lead group is applied to a lead group of an IC to be inspected. An electronic circuit is accessed by forming a non-contact probing arranged in close proximity, and its electrical state is determined by a one-to-many relationship between the position of the multi-electrode probe with respect to each lead of the IC under test and a plurality of leads connected to the conductor pattern. A board inspection apparatus configured to be extracted together with a connection relation, wherein a contact probe connected to an individual inspection target electrode of a conductor pattern and the probe drive control relay are arranged in close proximity to a lead group of an IC to be inspected. The multi-electrode probe, the probe drive control relay, and the level difference of the electromagnetic field detected by the multi-electrode probe are subjected to waveform processing. Evaluated through the logic circuit and inspected IC
And a measuring means for grasping the positional relationship of the multi-electrode probe with respect to each lead and determining whether or not the foot is lifted together with the one-to-many connection relationship with the conductor pattern. 4. An oscillator connected to a contact probe drive control relay, wherein a group of electrodes to be inspected of a conductor pattern is a contact type individual power supply side, and a group of leads of an IC to be tested is a non-contact type power receiving / detecting side. The substrate inspection apparatus according to claim 3, wherein 5. An oscillator connected to a multi-electrode probe driving relay, wherein a lead group of an IC to be inspected is a non-contact power supply side and a power-on detection side, and an electrode group to be inspected of a conductor pattern is a contact type. 4. The board inspection apparatus according to claim 3, wherein the board is an individual power receiving side.