Method and system for inspecting a circuit board equipped with components using a needle adapter

Abstract

A method for inspecting a circuit board equipped with components using a pin adapter, wherein the probes of the pin adapter are connected to a signal electronics device, wherein in a first method step, a sample signal curve is determined, particularly a set signal curve, or a sample spectrum is determined, wherein in a second method step following the first method step, a first contact portion of the circuit board is electrically contacted by the probes, wherein a high-frequency signal is input to the contact portion of the circuit board contacted by the first probe of the pin adapter by means of the first probe, wherein the signal curve thereby generated on another probe of the pin adapter is compared with the sample signal curve, and whether it exceeds an allowable deviation range is monitored, or wherein the spectrum of the signal curve thereby generated on another probe of the pin adapter is compared with the sample spectrum, and whether it exceeds an allowable deviation range is monitored.

Description

Technical Field

[0001] This invention relates to a method and system for inspecting / diagnosing circuit boards equipped with components using pin adapters / probe adapters. Background Technology

[0002] It is well known that high production quality can be achieved by controlling the manufactured products.

[0003] A method for testing circuit boards is known from EP 618 453 A2.

[0004] A system for inspecting circuit carriers is known from DE 10 2006 021 569 A1.

[0005] A method for locating faults on an electronic circuit board is known from DE 10 2007 007 339 A1. Summary of the Invention

[0006] Therefore, the object of the present invention is to improve the method for inspecting circuit boards, wherein comprehensive control of the circuit board can be performed using as few contact points as possible.

[0007] According to the present invention, this objective is achieved by a method according to the features described in claim 1 and a system according to the features described in claim 11.

[0008] In a method for inspecting a circuit board with assembled components using a pin-type adapter, an important feature of the present invention is that the probes of the pin-type adapter are connected to a signal electronics device, and in a first method step, a sample signal curve is determined, particularly a set signal curve, or a sample spectrum is determined, particularly a set spectrum.

[0009] In the second method step, which follows the first method step in time, the probe makes electrical contact with the first contact portion of the circuit board.

[0010] In this process, a high-frequency signal is introduced into and / or input into the circuit board contact area touched by the first probe of the pin-type adapter.

[0011] - This involves comparing the signal curves, particularly the voltage signal curves, generated on additional probes of the pin adapter with the sample signal curve, while simultaneously monitoring whether they exceed the allowable deviation range.

[0012] - and / or wherein the spectrum of the signal curve, particularly the voltage signal curve spectrum, generated thus on another probe of the pin adapter is compared with the sample spectrum, and at the same time, it is monitored whether it exceeds the allowable deviation range.

[0013] The advantage here is that the input high-frequency signal propagates through the printed conductors and components of the assembled circuit board, and the signal curve or signal curve spectrum subsequently formed at other contact points characterizes a characteristic step response. Therefore, this step response is characteristic of the assembled circuit board and changes significantly in the event of a short circuit between two printed conductors, solder joint failure, defective establishment, or defective implementation of components. It is particularly advantageous to compare not only the signal curve with a sample but also the spectrum, because, for example, a signal curve that deviates only within acceptable limits from the sample signal curve but exhibits an unacceptably large deviation in its spectrum from the sample spectrum can be identified as unacceptable, thus identifying a fault.

[0014] In an advantageous design, the high-frequency signal is a Dirac pulse, and / or a voltage signal in the form of a Dirac pulse, and / or a voltage pulse generated by a controllable switch of signal electronics that approximates an ideal Dirac pulse as closely as possible. The advantage here is that all frequencies are input with substantially the same intensity; therefore, the spectrum exhibits frequency-dependent attenuation along the path from the Dirac pulse through its input contact to the contact contacted by another probe (whose signal determines a corresponding spectrum in the spectrum). Faults or variations at solder joints or contacts, or replacement of components with functionally equivalent but structurally different components, will cause changes in the line inductance and capacitance of the printed conductors, thus also causing changes in frequency-dependent attenuation.

[0015] In one advantageous design, the sample signal curve is determined in the first method step by means of electrical contact between the probes of a pin-type adapter and at least one first contact point on a sample circuit board.

[0016] In particular, the sample circuit board is designed to have the same structure as the circuit board.

[0017] In this process, a high-frequency signal is input to the contact area of ​​the sample circuit board that is contacted by the first probe, using the probe or the first probe in the probe of the pin adapter.

[0018] - This involves acquiring and storing the signal curves, particularly voltage signal curves, generated on other probes of the pin adapter as sample signal curves.

[0019] - Alternatively, the spectrum of the signal curves, particularly the voltage signal curves, generated on other probes of the pin adapter are acquired and stored as sample spectra.

[0020] The advantage here is that high-frequency signals, especially Dirac pulses, can propagate over long distances in the assembled circuit board, and therefore the entire sub-region can be monitored for unacceptably large deviations from the set value in a single method step.

[0021] In one advantageous design, the first method step is performed multiple times, wherein, as a sample circuit board, a sample circuit board with the same corresponding structure is used for each step.

[0022] The sample signal curve is determined by averaging the sample signal curves obtained during multiple executions. An advantage of this approach is that an allowable deviation range can be considered. Because a corresponding sample circuit board is used each time the corresponding first method step is executed, the allowable range can be derived from multiple repeated method steps. If this allowable range is exceeded during the execution of the second method step, a warning message will be generated.

[0023] In a favorable design, a warning message is displayed and / or forwarded after the allowable deviation range is exceeded. The advantage here is improved security.

[0024] In an advantageous design, the sample circuit boards, particularly the corresponding sample circuit boards, are assembled and manufactured using defect-free components. The advantage here is that the corresponding sample circuit boards are defect-free, and therefore, when measurements are later taken on the board, it can be determined whether the deviation exceeds the permissible range by comparing with acceptable values.

[0025] In one advantageous design, the signal electronics device has a neural network. A high-frequency signal and signal curves, particularly voltage signal curves, acquired on a probe are fed to the neural network. In a first method step, serving as a learning phase, the neural network learns from the signal curves or spectra of a sample circuit board as a good state. In a second method step, the signal curves or spectra of the circuit board are monitored to ensure they do not exceed permissible deviation ranges. The advantage here is that simple training or learning of the neural network can be achieved in the first method step.

[0026] In an advantageous design, particularly by repeatedly performing the second method steps, a corresponding additional probe of the pin adapter is used instead of the first probe to introduce and / or input high-frequency signals into the circuit board contact areas contacted by the first probe. The advantage here is that further improvements in security can be achieved because the area of ​​the circuit board furthest from the corresponding input area contributes very little to the response, i.e., to the curves or spectrum of these signals.

[0027] In an advantageous design, the method steps are repeated, wherein, instead of the circuit board, another circuit board with the same first contact portion is used, wherein the additional contact portions of the additional circuit board are constructed, in particular, according to different functions. The advantage here is that the entire series of circuit boards can be inspected using a single pin adapter, particularly using the same pin adapter.

[0028] In particular, a key feature of systems used to perform the aforementioned methods is that the system has a circuit board equipped with components and a pin adapter, the probes of which are connected to signal electronics.

[0029] In particular, the probe electrically touches and / or contacts the first contact point of the circuit board.

[0030] In this pin-type adapter, the first probe introduces a high-frequency signal into the contact area of ​​the circuit board that is touched by the first probe.

[0031] The signal electronic device is constructed in a suitable manner as follows:

[0032] - The signal curve, especially the voltage signal curve, acquired by the signal electronics on another probe of the pin adapter is compared with the sample signal curve, and at the same time, it is monitored whether it exceeds the allowable deviation range.

[0033] - Alternatively, the spectrum of the signal curve, especially the voltage signal curve spectrum, acquired by the signal electronics on another probe of the pin adapter is compared with the sample spectrum, and at the same time, it is monitored whether it exceeds the allowable deviation range.

[0034] The advantage here is that a large area of ​​the circuit board can be inspected by inputting a high-frequency signal.

[0035] In an advantageous design, the system includes a sample circuit board, which can also be contacted by the pin adapter at a first contact point, thereby enabling the acquisition and storage of sample signal curves or sample spectra. The advantage here is that the system not only has a pin adapter but also a circuit board and at least one sample circuit board, wherein the signal electronics of the pin adapter store pass values ​​or knowledge about pass values, and thus subsequently perform checks by comparing them with actual values ​​acquired on the circuit board.

[0036] Further advantages are provided by the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, particularly for purposes proposed and / or proposed by comparison with the prior art, other reasonable combinations of features of the claims and / or individual claims and / or description features and / or drawings are possible. Attached Figure Description

[0037] The invention will now be described in more detail with reference to the illustrative drawings:

[0038] exist Figure 1 The system for performing quality checks on the assembled circuit board 4 according to the present invention is schematically shown in a side view.

[0039] exist Figure 2 The corresponding system is shown schematically in a tilted view with the view flipped open. Detailed Implementation

[0040] As shown in the attached figure, the system has a circuit board 4 equipped with components 5, the circuit board being electrically contacted by a pin adapter at a first contact point 3, particularly a solder joint or through hole, the pin adapter having an adapter board 1 equipped with probes 2.

[0041] After contact is established, a potential is applied to one or more probes in probe 2, and the potential established on one or more additional probes 2 of the needle adapter is acquired and compared with the set potential assigned to each probe in probe 2.

[0042] In this way, manufacturing defects during the assembly of circuit board 4 can be identified, and corresponding warnings can be displayed and / or forwarded. Corresponding signal electronics are arranged on the adapter board 1, which generate the potential and transmit it to the corresponding probe 2, or collect the potential formed on another probe 2 and compare it with a set potential.

[0043] Subsequently, in another method step, a potential is applied to one or more additional probes, and the potential formed on the remaining contact points, particularly solder joints or vias, contacted by probe 2 is again acquired.

[0044] Instead of electric potential, a time-potential curve can also be used, where the acquired time-potential curve is compared with the set potential curve.

[0045] According to the present invention, several of the contact points arranged on the circuit board 4 are not contacted by the probe 2. Therefore, improved quality control can be achieved by contacting these unused contact points 3.

[0046] However, according to the present invention, not all available contact portions 3 are used, but only a portion of them are used.

[0047] Therefore, a series of circuit boards can be inspected using the same pin adapter, each having a first contact point for contacting the probe 2 of the pin adapter, but differing in other aspects of construction and correspondingly having different functions.

[0048] However, in order to achieve sufficiently high quality with a small number of probes attached to the first contact area, a high-frequency signal, particularly a Dirac pulse, is introduced at the first contact area, and voltage signals formed on the other probe 2, or the spectrum of these voltage signals, are acquired. These voltage signals or spectra are then compared with corresponding set voltage signals or spectra acquired and stored in advance on a defect-free assembled circuit board (i.e., a sample circuit board).

[0049] Therefore, this method monitors whether the response to the Dirac pulse exceeds the permissible high deviation range between the corresponding signal and the sample circuit board with defect-free components.

[0050] Subsequently, in another method step, a Dirac pulse can be input again on another probe 2, and the signal curve or spectrum formed on the other contact point contacted by the pin adapter can be monitored to see if it exceeds the allowable deviation range, especially compared with the signal curve or spectrum of a defect-free sample circuit board.

[0051] Therefore, the advantage of the present invention is that it can utilize the same pin adapter and a small number of probes 2 to perform defect-free control of circuit board series that are assembled differently with very high precision.

[0052] The probe 2 is constructed to gradually taper as the distance from the adapter plate 1 increases. The contact portion 3 is designed as a metallized through-hole, into which the probe can be inserted to establish an electrical contact.

[0053] In another embodiment of the invention, the Dirac pulse is also used as a synchronization signal, wherein the Dirac pulse represents a time zero point or a reference time point, and the acquired signal curve or spectrum is processed based on this time point, wherein the signal or spectrum stored in the defect-free sample circuit board is also based on this time point.

[0054] In another embodiment of the invention, the signal electronics have a neural network trained on a signal or spectrum on a sample circuit board, and the acquired signal or spectrum is then fed into the neural network. Because the number of probes and associated signal curves or spectra is large, only a small amount of programming work is required when using a neural network.

[0055] List of reference numerals in the attached diagram:

[0056] 1 adapter board

[0057] 2 probes

[0058] 3. Contact areas, especially solder joints or through holes

[0059] 4 circuit boards

[0060] 5 components

Claims

1. A method for inspecting a circuit board equipped with components using a pin adapter, wherein the probes of the pin adapter are connected to signal electronics. in, In the first method step, the sample signal curve is determined, particularly the set signal curve, or the sample spectrum is determined, particularly the set spectrum. In the second method step, which follows the first method step in time, the probe makes electrical contact with the first contact portion of the circuit board. Its features are, A high-frequency signal is introduced into and / or input to a circuit board contact area contacted by the first probe of the pin adapter. - This involves comparing the signal curves, particularly the voltage signal curves, generated on additional probes of the pin adapter with the sample signal curve, while simultaneously monitoring whether they exceed the allowable deviation range. - and / or wherein the spectrum of the signal curve, particularly the voltage signal curve spectrum, generated thus on another probe of the pin adapter is compared with the sample spectrum, and at the same time, it is monitored whether it exceeds the allowable deviation range.

2. The method according to claim 1, Its features are, High-frequency signals are voltage signals in the form of Dirac pulses. And / or, High-frequency signals are voltage pulses generated by the controllable switches of signal electronics devices, which are as close as possible to the ideal Dirac pulse.

3. The method according to any one of the preceding claims, Its features are, In the first method step, the sample signal curve is determined by electrically contacting at least one first contact point on the sample circuit board with a probe of a pin adapter. In particular, the sample circuit board is designed to have the same structure as the circuit board. In this process, a high-frequency signal is input to the contact area of ​​the sample circuit board that is contacted by the first probe, using the probe or the first probe in the probe of the pin adapter. - This involves acquiring and storing the signal curves, particularly voltage signal curves, generated on other probes of the pin adapter as sample signal curves. - Alternatively, the spectrum of the signal curves, particularly the voltage signal curves, generated on other probes of the pin adapter are acquired and stored as sample spectra.

4. The method according to any one of the preceding claims, Its features are, The first method step is executed multiple times, wherein sample circuit boards with identical structures are used as sample circuit boards for each step. Specifically, the sample signal curve is determined by averaging the sample signal curves obtained during multiple executions.

5. The method according to any one of the preceding claims, Its features are, If the deviation exceeds the allowable range, display and / or forward a warning message.

6. The method according to any one of the preceding claims, Its features are, The sample circuit boards, especially the corresponding sample circuit boards, are assembled and manufactured using defect-free components.

7. The method according to any one of the preceding claims, Its features are, The signal electronic device has a neural network, to which high-frequency signals and signal curves, particularly voltage signal curves, are collected on a probe. In the first method step, which is the learning phase, the neural network learns the signal curves or spectra of the sample circuit board as a good state. In the second method step, it monitors whether the signal curves or spectra of the circuit board exceed the allowable deviation range.

8. The method according to any one of the preceding claims, Its features are, In particular, the second method steps are repeated multiple times, wherein, instead of the first probe, a corresponding additional probe of the pin adapter is used to introduce and / or input a high-frequency signal into the circuit board contact area contacted by the first probe.

9. The method according to any one of the preceding claims, Its features are, Repeat the method steps, wherein, instead of the circuit board, use another circuit board that also has the first contact portion, wherein the other contact portion of the other circuit board is constructed in particular according to different functions.

10. The method according to any one of the preceding claims, Its features are, The system has a sample circuit board, which is also contacted by a pin adapter at the first contact point, thereby acquiring and storing sample signal curves or sample spectra.

11. A system, particularly a system for performing the method according to any one of the preceding claims, in, The system has a circuit board equipped with components and a pin adapter, the probes of which are connected to signal electronics. In particular, the probe electrically touches and / or contacts the first contact point of the circuit board. Its features are, The first probe in the pin-type adapter introduces a high-frequency signal into the circuit board contact area touched by the first probe. The signal electronic device is constructed in a suitable manner as follows: - The signal curve, especially the voltage signal curve, acquired by the signal electronics on another probe of the pin adapter is compared with the sample signal curve, and at the same time, it is monitored whether it exceeds the allowable deviation range. - Alternatively, the spectrum of the signal curve, especially the voltage signal curve spectrum, acquired by the signal electronics on another probe of the pin adapter is compared with the sample spectrum, and at the same time, it is monitored whether it exceeds the allowable deviation range.

12. The system according to claim 11, Its features are, The system has a sample circuit board, which can also be contacted by a pin adapter at the first contact point, thereby enabling the acquisition and storage of sample signal curves or sample spectra.

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