JP2007311657A - Noise resistance evaluating circuit substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise-resistance evaluating circuit substrate which can easily make an exchange of a noise controlling chip member without causing the damage of a substrate when doing an EMI measurement, etc. <P>SOLUTION: The noise-resistance evaluating circuit substrate includes a chip holder 15 for detachably mounting a noise-controlling chip member 13, which holder is attached to a land for mounting the noise-controlling chip member 13 formed on the circuit substrate, wherein the chip holder 15 has: a pair of electrode portions 16 and 17 electrically connecting with the land, while being in ohmic contact with a pair of terminals 13a of the noise-controlling chip member 13; and a holder B for holding the noise controlling chip member by an elastic stress. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a circuit board for noise resistance evaluation used when EMI measurement is performed on an electronic device such as a copying machine in which a control board or the like is incorporated.

  In general, an evaluation test is performed on whether or not various standards are satisfied with respect to an electronic device that has been developed or mass-produced as a prototype, and adjustments of each part are performed so as to satisfy a predetermined reference value. One such evaluation test is EMI measurement. When measuring EMI, adjust the electrical constants of multiple noise suppression chip components such as resistors, capacitors, and coils mounted on a control board equipped with a microcomputer that uses a high-frequency clock signal to appropriate values. However, it is required to perform the measurement work and the work of measuring and verifying the signal waveform of each part to determine whether the control circuit operates normally with the adjusted noise suppression chip component.

  As such an EMI countermeasure, in Patent Document 1, optimization of the GND connection between a large number of GNDs on a circuit board and a conductive casing (frame) is performed by trial and error, and depending on the result, In order to solve the problem that a complicated work such as retrial of a circuit board with a changed conductor pattern is necessary, the circuit board has a plurality of GND connection points with the housing, and the connection points and the circuit board There has been proposed a liquid crystal display device in which the entire circuit board and the housing are GND-connected only by mounting a chip component composed of a 0Ω resistor to GND.

Japanese Patent Laid-Open No. 11-352509

  Such a control board is usually screwed to the housing to serve as a GND connection, and is further electromagnetically shielded by a thin metal plate covering the board. However, if inconvenience is found as a result of EMI measurement, the control board is soldered. It is necessary to replace the fixed noise suppression chip component with a component having a different electrical constant and perform measurement again.

  In this case, the screwed electronic device decorative panel and the electromagnetic shielding metal thin plate are sequentially removed, the connector inserted into the connector post of the control board is removed, and then the control board is removed from the housing and soldered to the board. It is necessary to remove the noise suppression chip component with a soldering iron and solder the noise suppression chip component with a different electrical constant, and the control board with the replaced component is returned to the original in the reverse procedure. Work is required.

  However, there is a problem that the above-described series of operations is very laborious and extremely inefficient, and when the soldered noise suppression chip parts are replaced many times, the wiring pattern and land are peeled off and the board is removed. There was also a problem of damage.

  In view of the above problems, an object of the present invention is to provide a circuit board for noise resistance evaluation that can easily replace a noise suppression chip component without causing damage to the substrate when performing EMI measurement or the like.

  In order to achieve the above-mentioned object, the characteristic configuration of the circuit board for noise resistance evaluation according to the present invention is such that the noise suppression chip component formed on the circuit board is mounted as described in claim 1 of the claims. A chip holder for detachably mounting the noise suppression chip component is attached to a land for the purpose.

  According to the above configuration, when replacing the noise suppression chip component on the circuit board, the noise suppression chip component supported by the chip holder is picked with a finger or a jig such as dedicated tweezers without using a soldering iron. Since it is only necessary to remove and mount and support a new noise suppression chip component on the chip holder, the workability is greatly improved, and the situation where the wiring pattern and land are peeled off is eliminated.

  In addition to the first characteristic configuration described above, the second holder is configured to provide ohmic contact with a pair of terminals of the noise suppression chip component and the land. It is in the point provided with the holding | maintenance part which hold | maintains a pair of electrode part electrically connected, and the said noise suppression chip component by elastic stress.

  According to the configuration described above, the electrical connection between the noise suppression chip component and the circuit board is ensured through the electrodes, and the noise suppression chip component is held by the elastic stress by the holding portion. It is stably held without detaching from the circuit board.

  As described above, according to the present invention, it is possible to provide a circuit board for noise resistance evaluation that can easily replace a noise suppression chip component without causing damage to the board when performing EMI measurement or the like. became.

  An embodiment of a circuit board for noise resistance evaluation mounted on a copying machine according to the present invention will be described below.

  As shown in FIG. 1, the noise resistance evaluation circuit board 1 is disposed inside an exterior cover 3 that is a decorative panel screwed to the side surface of the copying machine 2, and as shown in FIGS. 2 and 3, It is attached via a spacer 6 on a sheet metal 5 supported between frames 4 provided in the copying machine 2. The circuit board 1 for noise resistance evaluation is further covered with a shield box 10 having a notch 9 for cable wiring formed on the lower side surface, and connected to the connector 7 of the circuit board 1 for noise resistance evaluation. 8 is configured to be connected to another control board or the like through the notch 9.

  The shield box 10 is provided with a plurality of heat release holes 10a for radiating heat generated from the noise-resistant evaluation circuit board 1 to the outside, and folded portions 12a, 12b, 12c provided on the side surfaces thereof. 12d is fixed to the screw hole 12 provided in the metal plate 5 with a screw 12e, and is electromagnetically shielded so that electromagnetic noise generated in the noise-resistant evaluation circuit board 1 does not leak outside the apparatus.

  As shown in FIG. 6, the noise resistance evaluation circuit board 1 protects the base board 20 made of epoxy resin, the wiring pattern 22 printed on the base board 20 with copper, and the wiring pattern 22. A plurality of electronic components are mounted on a land 14 that is an electrode for connecting the components.

  Of the plurality of lands 14 formed on the noise-proof evaluation circuit board 1, a chip holder 15 for detachably mounting the noise suppression chip component is soldered to the land 14 for mounting the noise suppression chip component. Has been. Here, the noise suppression chip component is a chip component having a size of several millimeters for suppressing the generation amount of electromagnetic noise generated from the circuit board 1 for noise resistance evaluation. For example, a passive component such as a resistor, a capacitor, or a coil is used. It is an electrical component.

  As shown in FIG. 4, the chip holder 15 includes an electrode 16 that makes ohmic contact with a pair of terminals 13 a of the noise suppression chip component 13, and a conductive member 17 that electrically connects the electrode 16 and the land 14. A holding portion B that holds the noise suppression chip component 13 by its own elastic stress, and a resin insulating member 18 that holds the electrode 16.

  As shown in FIGS. 5 (a) and 5 (b), the insulating member 18 is formed of a plate-shaped resin molded product in which fitting portions 19b for attaching the conducting member 17 are formed on both ends of the bottom portion. ing. As shown in FIGS. 5 (c) and 5 (d), the conductive member 17 has electrodes 16 projecting from both ends, and a fitting opening 19a for integrally attaching to the insulating member 18 at the center. It is formed of a single metal plate made of a copper alloy that has been punched to be formed, and is bent 90 degrees above each other so that the electrodes 16 at both ends face each other.

  By fitting the fitting portion 19b into the fitting opening 19a, a chip holder 15 composed of the conductive member 17 having the pair of electrodes 16 and the insulating member 18 as shown in FIG. Is done.

  As shown in FIG. 4B, a gap formed between the pair of electrodes 16, that is, a notch A is formed on the side of the chip holder 15, and the chip holder 15 is attached via the notch A. In addition, the abdomen of the noise suppression chip component 13 can be clamped. Therefore, the abdomen of the noise suppression chip component 13 mounted on the chip holder 15 is picked from the notch A with a jig such as a finger or dedicated tweezers, and is placed above the noise-resistant evaluation circuit board 1. It can be easily removed by moving in the direction, and can be easily mounted by moving in the opposite direction.

  As shown in FIG. 4 (c), when one electrode 13a of the noise suppression chip component 13 is inserted between the electrodes 16 facing each other in a substantially vertical posture when the noise suppression chip component 13 is not mounted, As shown in (d), the electrode 16 is biased so as to spread slightly outward, and the noise suppression chip component 13 is held by elastic stress generated at that time. That is, in this embodiment, the electrode 16 becomes the holding part B.

  If the noise-resistant evaluation circuit board 1 having such a chip holder 15 is provided, when the noise suppression chip component 13 needs to be replaced at the time of EMI measurement work, it is not necessary to remove and replace the board. Parts can be easily replaced in a short time. That is, after turning off the power and removing the outer cover 3 and the shield box 10, the parts to be replaced mounted on the chip holder 15 are removed with tweezers, and after inserting a new chip part, the shield box 10 and the It can be done simply by attaching the outer cover 3.

  Similarly, even in the waveform inspection for checking the operation of the circuit board, it is possible to easily replace the chip parts as necessary. In this way, a mass production board is manufactured in which chip components with fixed circuit constants are directly mounted on the board.

  Another embodiment will be described below. In the above-described embodiment, the chip holder 15 that sandwiches the pair of terminals 13a of the noise suppression chip component 13 from both sides thereof by the electrodes 16 as illustrated in FIG. 4 is described. As illustrated in FIG. The electrode 16 may be configured to sandwich both ends of the pair of terminals 13 a of the noise suppression chip component 13. In this case, as shown in FIG. 7B, the electrode 16 is provided at one end and the other end is formed by a pair of conductive metal plates provided with fitting holes 19a for attachment to the insulating member 18. An electrode portion can be formed by bending the conductive member 17 so that the surface provided with the electrode 16 and the surface provided with the fitting opening 19a are perpendicular to each other.

  At this time, when the noise suppression chip component 13 is mounted, as shown in FIG. 7C, in the holding portion B, the noise suppression is performed by the electrode 16 facing the electrode 16 provided on the conductive member 17. Since the chip component 13 is held by the inward elastic stress, the noise suppressing chip component is stably held without detachment.

  In the above-described embodiment, the chip holder 15 in which the pair of electrodes 16 and the conductive member 17 are integrally supported by the insulating member 18 has been described. As the chip holder 15, as shown in FIG. The electrode portion is composed of a conductive member 17 that is provided with an electrode 16 at one end and is bent so that the surface on which the electrode 16 is provided and the other surface are perpendicular to each other, and is supported by different insulating members 18 made of resin. Can be configured separately.

  As shown in FIG. 8C, the chip holder is attached by soldering or the like so that the chip holder 15 faces the land 14 so that the noise suppressing chip component 13 can be attached and detached.

  The above-described embodiments are merely examples of the present invention, and it is needless to say that materials, shapes, sizes, and the like can be appropriately set within a range where the effects of the present invention can be achieved.

Perspective view of copier (A) Front view of shield box fixedly arranged on copier, (b) Lower front view of shield box fixedly arranged on copier (A) Perspective view of shield box fixedly arranged on copier, (b) Perspective view of circuit board for noise resistance evaluation fixedly arranged on copier, (c) Crossing of shield box fixedly arranged on copier Area (A) Top view and side view of chip holder, (b) explanatory diagram of chip holder, (c) explanatory diagram of chip holder, (d) explanatory diagram of chip holder (A) Top surface explanatory diagram of the chip holder component, (b) Side surface explanatory diagram of the chip holder component, (c) Side surface explanatory diagram of the chip holder component, (d) Top surface explanatory diagram of the chip holder component, (A) explanatory diagram of a circuit board for noise resistance evaluation, (b) explanatory diagram of a circuit board for noise resistance evaluation, (c) top view of a circuit board for noise resistance evaluation, (d) a circuit board for noise resistance evaluation Top view Explanatory drawing of another embodiment of a chip holder Explanatory drawing of another embodiment of a chip holder

Explanation of symbols

1: Circuit board for noise resistance evaluation 2: Copier 3: Cover 4: Frame 5: Sheet metal 6: Spacer 7: Connector 8: Cable 9: Cable hole 10: Shield box 11: Folded part 12: Screw hole 12a: Folded part 12b: Folding part 12c: Folding part 12d: Folding part 12e: Screwing 13: Noise suppression chip component 14: Land 15: Chip holder 16: Electrode part 17: Conducting member 18: Insulating member 19: Fitting part 20: Base substrate 21: Electrode protective film 22: Wiring pattern A: Notch B: Holding part

Claims (2)

  A circuit board for noise resistance evaluation, wherein a chip holder for detachably mounting the noise suppression chip component is attached to a land for mounting the noise suppression chip component formed on the circuit board.   The chip holder includes a pair of electrode portions that are in ohmic contact with a pair of terminals of the noise suppression chip component and electrically connected to the land, and a holding portion that holds the noise suppression chip component by elastic stress. The circuit board for noise resistance evaluation according to claim 1.