JPH1096758A - Electronic circuit substrate with self diagnostic function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric circuit substrate with cheaper, smaller, faster self diagnostic function and calibration function, by fitting PLD on each electronic circuit substrate and by preparing various required programs. SOLUTION: A lot of electronic components are contained on an electronic circuit substrate 5. A connector 8i (i=1, 2..., i...p) is connected with other device 9 and a host processor 10. The electronic circuit substrate 5 is equipped with a PLD 40 for changing a circuit configuration and plural programs are prepared which contain a normal operating program and a self diagnostic program for specifying the circuit configuration. These programs are written into the ROM 41, 42 and are placed in the PLD 40. The PLD 40 is also equipped with a pass/ fail indicator 43 using a LED and a controller 39 using a MPU. Because for the electronic circuit substrate 5 the perfect self diagnostic check and easy calibration are performed, and the device contains the ROM into which the normal operating program, the self diagnostic checking program, and calibration program are written, its operation becomes more correct and faster.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board on which many electronic components are mounted and which is built in an electronic device, and more particularly to an electronic circuit board (also referred to as a "board") having a self-diagnosis function.

[0002]

2. Description of the Related Art At present, electronic devices are assembled with an electronic circuit board on which electronic components are mounted, and individual electronic components and mechanical components. Electronic devices range from large to small. An electronic circuit board used for a small electronic device is relatively small, and its production and inspection are easy. In product inspection of small electronic devices, it is often sufficient to check necessary checkpoints while operating.

[0003] In a product inspection in the case of a voltage measuring instrument or a frequency measuring instrument of an electronic measuring instrument, for example, a known reference voltage or a reference frequency conforming to a national standard is given after assembling the measuring instrument, and a display of the measurement result is performed. The pass / fail judgment can be made by comparing with the given reference value. Even in the case of failure, it is relatively easy to estimate the location of the failure because of its small size.

[0004] However, recent electronic circuit boards of large electronic devices have a high degree of integration and low power of semiconductor integrated circuits such as LSIs (large-scale integrated circuits) due to the miniaturization and low power of mounted electronic components. With the increase in the number of components, many components have been mounted on a large multilayer printed circuit board (hereinafter referred to as “electronic circuit board”) at high density. Therefore,
Many electronic circuit boards on which electronic components are mounted have functions equivalent to those of small electronic devices. Therefore, conventionally, an electronic circuit board is first inspected with a board checker or a board tester, and after assembling into a large electronic product, a special diagnostic performance board or the like is connected to inspect the product.

As an example, a configuration of an LSI test system (hereinafter referred to as an “IC tester”) will be described with reference to FIG. FIG. 6A shows an example of an electronic circuit board 5 used for an IC tester. The circuit scale has been increased and the density has been increased due to the sophistication of IC testers. Usually 10
Multi-layer printed circuit board of about layer, area is 600mm × 30
Some are as large as about 0 mm and as large as 1 m square. An electronic component 6i (i = 1 to m) is provided on this electronic circuit board by several tens.
Approximately 0 components are mounted and wired, and connected to other modules (9) other than this board through connectors 8i (i = 1 to p). The electronic circuit board 5 to be inspected by the board tester has check lands 7i (i = 1) at check points.
To h) are arranged, and a number of probe needles are brought into contact with the plurality of check lands 7i to check the circuit operation. Some boards cannot be tested with a board tester.

FIG. 6B is a schematic diagram of an IC tester. The host processor 10 for controlling the test is mainly composed of a CPU (computer), and sends and receives data signals to and from each unit in the system by data buses 15, 16, and 17 for controlling the entire system. Although not shown, each unit such as a timing generation unit and a pattern generation unit is configured in the electronic circuit board 5 i (i = 1 to n) and is incorporated in the housing of the measurement rack 14 and the test head 11. When measuring a device under test (DUT), a performance board 13 for the designated DUT is attached to one surface of the test head 11 to serve as an interface, and the designated DUT is used.
Is measured.

[0007] When performing product inspection, periodic maintenance, or failure repair of the IC tester, the designated DUT performance board is replaced with a diagnostic performance board, and the host processor 10 is operated by the diagnostic to perform a self-diagnosis. ing. Here, the diag (Di
agnostics) refers to a system diagnostic program, which is a program that detects a malfunction, a defective portion, an error, and the like of a system and assists in maintenance of an IC tester.

[0008]

In the case of a large-sized electronic device such as an IC tester, when a failure or malfunction occurs, it is sometimes unclear which circuit part is defective, which electronic component is defective, and the like. In many cases, the electronic circuit board 5 is replaced, a pass / fail judgment is made for each board, a defective electronic circuit board 5 is replaced, and then calibration (fine adjustment) is often performed. For that purpose, a dedicated board such as a diagnostic performance board is required. In addition, since the calibration of the entire apparatus is performed in order for each board, it takes too much time. In particular, an electronic circuit board 5 having a mechanical relay (hereinafter referred to as "mechanical relay")
Since the mechanical relay has a finite life, it often takes time to find the location of the failure.

In recent years, the calibration function has been
Increasingly complex, larger and more densely populated boards. Further, even when the individual electronic circuit boards 5 are adjusted during the calibration of the entire specific device, the calibration of the entire specific device is performed instead of the calibration of the individual electronic circuit boards 5. Therefore, even if the correctly calibrated electronic circuit board 5 is replaced, it is necessary to calibrate the entire specific device again.

The present invention provides a relatively large electronic circuit board 5.
In the above, each board has a self-diagnosis function and a calibration function so that the individually calibrated electronic circuit board 5 can be immediately applied to the device. In other words, each board is calibrated and connected and combined to complete the entire device. Another object of the present invention is to provide an electronic circuit board 5 that can be easily calibrated. In addition, the self-diagnosis function and the calibration function can be reduced in size at low cost, and at a higher speed.

[0011]

In order to achieve the above object, the present invention provides a PLD (Programmab) which has been developed in recent years.
le Logic Device) is mounted on each electronic circuit board, the program is switched, and the PLD is changed to a normal operation circuit, a diagnosis circuit, or a calibration circuit to operate. That is, in the case of the normal operation of the electronic device, the normal operation program is set and the electronic device is operated normally. In the case of inspection and calibration of an electronic circuit board, an automatic diagnosis program or a calibration program is set to perform inspection and calibration of the electronic circuit board.

Here, the PLD will be briefly described. PL
D is an IC to which a user can arbitrarily write, that is, program, a logical specification. Basically AN
Although it is composed of a D array and an OR array, a memory is built in and diversified. PLA (Pro
grammable Logic Array), PAL (Programmable Arra)
y Logic), FPGA (Field Programmable Gate Arr)
ay). Therefore, in this specification, although the names of these manufacturers and the applications for trademark registration have been filed, these names and the names of similar PLDs to be developed in the future are collectively referred to as PLDs. I do.

A typical example is Xilinx (X
ILINX) FPGAs. The logic cell array inside the FPGA is a high-performance, highly-integrated digital integrated circuit, and has three types of circuit functions: an I / O block (IOB), a configurable logic block (CLB), and an internal connection. Consists of elements. Each has a setting element, and all of them can be programmed. The IOB interfaces between internal logic blocks and device package pins. The CLB array also has a memory, and implements a logical function specified by the user. The interconnect elements form a network that propagates signals between blocks.

The logic functions and internal connections are set by a configuration program stored in built-in static memory cells. This configuration program is ROM (read only memory)
Or a floppy disk or a hard disk, and the initialization logic operates when the power is turned on or when a command is issued, so that the program is automatically loaded.

The present invention relates to the above-mentioned FPGA, ie, PL
D (Programmable Logic Device) is mounted on each electronic circuit board, and a program for normal operation, a program for self-diagnosis, and a program for calibration are created and stored. It may be stored on the test processor side and transferred to the FPGA when necessary. However, when there are many types of boards, a ROM in which a program for each board is stored in each board, that is, an electronic circuit board. It is undoubtedly faster to mount and drive with a changeover switch or command.

It is effective to mount a pass / fail indicator, such as a blue-red LED, for indicating pass / fail on the electronic circuit board, since fine adjustment can be performed while checking the pass / fail indicator during calibration. Further, it is more and more effective to mount an MPU (microprocessor) as a controller on the electronic circuit board in order to exchange signals with the outside and control the electronic circuit board at high speed.

At the time of self-diagnosis or calibration, the output signal from the board is converted into a digital value,
A comparison circuit in the FPGA compares the value with the expected value, and performs pass / fail judgment or fine adjustment to a non-defective product. For example, if the output signal from the board is a DC voltage, it is converted to a digital value by an A / D converter, and if the signal is a pulse signal at a frequency or a fixed period interval, the frequency or cycle is converted to a digital value by a counter. I do. The A / D converter and the counter may be incorporated in the board, or a digital measuring device such as a digital voltmeter (digital voltmeter) or a counter may be externally provided, and the result may be provided to the comparison circuit.

A first aspect of the present invention is a basic aspect of the present invention, in which a signal is transmitted / received to / from another department on an electronic circuit board on which electronic components are mounted.
The connector comprises the above-described connector, a PLD whose circuit configuration can be changed to a normal operation circuit, a self-diagnosis circuit, and the like, and a plurality of programs including a normal operation program and a self-diagnosis program for specifying this circuit configuration. According to a second aspect of the present invention, a plurality of programs including a normal operation program and a self-diagnosis program are stored in a ROM in the electronic circuit board according to the first aspect of the present invention and mounted on each board. The initialization of the PLD may be a manual switch or a command from the host processor.

In the third invention, a pass / fail indicator of the board is mounted on these electronic circuit boards, and a pass / fail indication is displayed by, for example, a blue or red LED. At the time of self-diagnosis, the determination can be made at a glance, and the efficiency can be improved by performing fine adjustment while looking at the pass / fail indicator during calibration. In a fourth aspect of the present invention, a controller dedicated to the electronic circuit board is mounted on the electronic circuit board to increase the processing speed. The controller may be an MPU (microprocessor), and is responsible for sending and receiving signals to and from other departments and controlling the board.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings based on embodiments. FIG. 1 illustrates this invention in LC
Electronic circuit board 5 of one embodiment applied to D driver tester
It is. Many electronic components are mounted on the electronic circuit board 5. The CHi 20i (i = 1 to 16) has 16 channels of RVS (Reference Via Source) analog units shown in FIG.

The connector 8i is connected to another department 9 and the host processor 10. This electronic circuit board 5 includes
A PLD 40 capable of changing the circuit configuration is mounted, and a plurality of programs including a normal operation program for designating the circuit configuration and a self-diagnosis program are prepared. In FIG. 1, the plurality of programs are written in the ROMs (41, 42) and mounted. Further, a pass / fail display 43 using LEDs and a controller 39 using MPU are mounted.

[0022] Figure 2, RVS analog part of FIG. 4 is the board of FIG. 1, it is an example of a circuit diagram of a PLD40 self-diagnostic program is set _2. The circuit configuration based on the self-diagnosis program checks the operation of a mechanical relay, an analog switch, and the like. The data transmission in FIG. 2 is performed in 8-bit parallel. The timing generation circuit 44 reads RD (read), ST from the test processor 10 or a CPU (computer) equivalent thereto.
It receives ART, CLK (clock), and RESET signals and transmits appropriate timing signals to necessary circuits.
The address latch 45 and the address decoder 46
It receives 16-bit data of EL (board select) and 8 + 8, and transmits it to necessary circuits.

The address counter 50 generates an address number of each memory based on signals from the timing generation circuit 44 and the address decoder 46, and
1. Output to the expected value data memory 52 and the fail memory 53. The control data memory 51 transmits the data signal in each address through the gate 55 to the RON / ROF
(Reference on / off), output voltage range, IM current (measurement current) range, Cal relay, and other signals are output to control self-diagnosis of the RVS analog unit 20i of the board.

The output voltage of the analog signal is supplied to the A / D converter 5
8 and is compared with the expected value in the expected value data memory 52 by the comparing circuit 54.
It is stored in the memory 53. The A / D converter 58 may be configured in a board, or a digital bol may be installed outside.
In addition, when the output of the analog signal from the board is a pulse with a frequency or a time interval, it may be digitized using a counter. The data in the fail memory 53 is sent to the host processor 10 through the gate 56, and at the same time, the result of the pass / fail is sent to the pass / fail indicator 43 of the board and displayed.

That is, in this circuit operation, the operation of the relay is set in the control data memory 51, and the expected value of the analog signal output of the board is set in the expected value data memory 52. The expected value data and the data of the actual operation result are compared by the comparing circuit 54, and the data is stored in the fail memory 53, and the pass / fail of the board is checked with the data.

[0026] FIG. 3 is a PLD40 circuit diagram of ₁ set normal operation program board of FIG. Similarly to FIG. 2, data from the host processor 10 or a CPU equivalent thereto is transmitted in two 8-bit parallel signals, that is, 16 bits. Address data is transmitted first, and the output from the address decoder 46 is One of 55 registers is designated. Then, 8 + 8 1
6-bit data is sent and stored in the designated register. Each stored data is stored in a timing generation circuit 4
At timings from 4, necessary signals are output through buffers 57 and 59.

FIG. 4 is a circuit diagram of the RVS analog section 20i (i = 1 to 16) mounted on the board of FIG. The power supply 21 outputs an analog voltage of ± 5 V by a D / A converter based on the reference voltage 30. The analog switches are switched through the filter 22 and the RON / ROF switch circuit 23 so that the output voltage range switching circuit 24 can output any of ± 5 V, ± 10 V, and ± 20 V. The selected voltage passes through the resistances of the current clamp circuit 25 and the current measurement circuit 26, and is output to the output terminal 29 while maintaining the voltage in the voltage follower circuit 27. The mechanical switches and analog switches used in this circuit have a limited life and must be inspected periodically.

FIG. 5 shows another example of a circuit under test, which is a circuit of a waveform digitizer. An input voltage is input to an arbitrary waveform digitizer circuit by a switch circuit 61 and a range switching circuit 62
To switch to an appropriate range, select an appropriate filter from a plurality of filter groups 63 having different filter frequencies, and pass it through.
A / D conversion is performed by the A / D converter 64, the data is stored in the memory 65, and output. Also in this case, periodic inspection is necessary because many mechanical switches are used. These inspections are performed by a PLD and a self-diagnosis program for each electronic circuit board.

[0029]

As described in detail above, conventionally, the inspection of the electronic circuit board 5 on which a large number of electronic components 6i are mounted is checked with a board checker or a board tester, or after the product is commercialized, a performance board for diagnosis is used. Using
The processor was running in diagnostics to perform self-diagnosis and calibration. Therefore, complete self-diagnosis and calibration of the electronic circuit board 5 alone could not be performed.

According to the present invention, the PLD 40 is mounted on the electronic circuit board 5 on which a large number of electronic components 6i are mounted, and at least a normal operation program and a self-diagnosis program are prepared. Self-diagnosis and calibration have become easier. The normal operation program, the self-diagnosis program, and the calibration program are stored in a ROM and mounted on the board, so that the operation is definitely performed at a high speed.

By mounting the pass / fail indicator 43 on the board, self-diagnosis and calibration become easier, and by mounting the dedicated controller 39 on the board, the speed is further increased. Then, only by assembling the individual circuits 5 completely calibrated, the apparatus can be operated immediately. Thus, the technical effects of the present invention are great.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of an electronic circuit board of the present invention.

FIG. 2 is a circuit configuration diagram at the time of a self-diagnosis function of the PLD of the present invention.

FIG. 3 is a circuit diagram of the PLD of the present invention in a normal operation.

FIG. 4 is a diagram showing the electronic device when the LCD driver tester is used.
FIG. 6 is a circuit diagram of an RVS analog unit which is CHi of FIG.

FIG. 5 is a circuit diagram when CHi in FIG. 1 is a waveform digitizer tester.

FIG. 6A is a configuration diagram of an electronic circuit board of a conventional device, and FIG. 6B is a schematic diagram of a conventional IC tester.

[Explanation of symbols]

5, 5i Electronic circuit board (board) 6, 6i Electronic components 7, 7i Check land 8, 8i Connector 9 Other departments 10 Host processor 11 Test head 13 Performance board 14 Measurement rack 15, 16, 17 Data bus 20, Reference Signs List 20i RVS (Reference Vias Source) analog unit 21 Power supply 22 Filter 23 RON / ROF switch circuit 24 Output voltage range switching circuit 25 Current clamp circuit 26 Current measurement circuit 27 Voltage follower circuit 28 Switch circuit 29 Output terminal 30 Reference voltage source 40, 40i PLD (Programmable Logic Devic)
e) 41 ROM for normal operation 42 ROM for self-diagnosis 43 Pass / fail indicator 60 Waveform digitizer

Claims (4)

[Claims] An electronic circuit board (5) on which an electronic component (6i) is mounted, at least one connector (8i) for transmitting and receiving signals to and from a host processor (10) and another department (9). )
And PLD (Programmable Logic De
vice) (40), and a plurality of programs including a normal operation program for specifying a circuit configuration and a self-diagnosis program, the electronic circuit board having a self-diagnosis function. 2. A plurality of programs, including a normal operation program and a self-diagnosis program for designating a circuit configuration according to claim 1, are stored in ROMs (41, 42) and mounted on the electronic circuit board (5). An electronic circuit board having a self-diagnosis function. 3. An electronic circuit board having a self-diagnosis function, wherein a pass / fail indicator (43) for indicating pass / fail is mounted on the electronic circuit board (5) according to claim 1. 4. An electronic circuit board (5) according to claim 1, 2 or 3, further comprising a host processor (10) and another section (9).
An electronic circuit board having a self-diagnosis function, comprising a controller (39) for sending and receiving signals and controlling the electronic circuit board (5).