CURRENT SENSING MODULE FOR CURRENT SENSOR AND METHOD FOR MANUFACTURING CURRENT SENSING MODULE

The present invention provides a current sensing module for a current sensor and a method for manufacturing the current sensing module. The current sensing module includes a spacer layer including a through hole and being annular in shape, and a circuit board electrically connected to the current sensor and includes at least two structural layers. The two structural layers cover the spacer layer and each of the structural layers includes at least one metal wire layer insulated from the spacer layer. The two metal wire layers are conducted to form a loop coil surrounding the spacer layer. When a wire is located in the through hole, an external power supply power to the circuit board, such that the circuit board has a detection state in which a sensing current is outputted due to magnetic induction generated by the loop coil during the wire is electrically conducted.

FIELD OF THE INVENTION

The present invention relates to a current sensing module and a method for manufacturing the current sensing module, and particularly to a current sensing module for a current sensor and a method for manufacturing the current sensing module.

BACKGROUND OF THE INVENTION

Conventional current sensors mostly adopt the form of a clamp meter, and a wire is inserted into the clamp meter to detect an alternating current flowing in the wire.

Current commercially available current sensors are roughly divided into four categories. A current sensor of the first category is for measuring a supply current value of a power supply system, and is applied to such as electricity companies, buildings and households, with a measurement range approximately between 0.1 A to 1000 A. A current sensor of the second category is for measuring a large alternating current value of a supply system, and is applied to electricity companies and buildings, with a measurement range reaching as high as several thousand amps, wherein the method for measuring an extremely large alternating current value is performed by using a Rocowsky coil. A current sensor of the third category is for measuring leakage alternating current of power supply systems and leakage alternating current of electrical appliances, with a measurement range approximately between 10 μA and 100 A. A current sensor of the fourth category is for measuring direct current signals transmitted between interfaces of industrial controllers, with a measurement range approximately between 20 mA to 4 mA and a resolution of 1 μA.

A current clamp current sensor, for example, “Clamp Jaw Assembly” disclosed by the U.S. Pat. No. 8,159,211, includes a first clamp jaw and a second clamp jaw. The first clamp jaw comprises therein a first jaw clamp core and a first non-conductive shield, and the second clamp jaw comprises therein a second jaw clamp core and a second non-conductive shield. The first clamp jaw further comprises therein a flexible printed circuit board (PCB) so as to use the flexible PCB to detect conductive properties of the first clamp jaw and the second clamp jaw.

For another example, the U.S. Pat. No. 8,914,249 discloses “Resistance Measuring Apparatus”, including a clamp sensor. The clamp sensor includes an injection clamp unit and a detection clamp unit. Each of the injection clamp unit and the detection n clamp unit includes arc-shaped core, a bobbin installed outside the arc-shaped core and a coil wound around the bobbin. The injection clamp unit and the detection clamp unit are enclosed in a housing.

Further, the U.S. Pat. No. 6,191,673 discloses “Current Transformer”, including two transformer units. Each of the transformer units includes an iron core and a secondary winding wound outside the iron core, and a shield winding is further wound outside the transformer units.

In the above patents, the clamp meter is primarily formed by winding a coil around a magnetic component, such that a current value of the wire is measured through the magnetic component and the coil when the wire is located at the clamp meter. Most conventional coils are accomplished through winding copper wires. Further, to mutually separate the coil from the magnetic component, different spaces for respectively accommodating the coil and the magnetic component are usually formed in the clamp meter. Thus, the overall volume of the clamp meter is enlarged and material costs of materials used are also increased.

SUMMARY OF THE INVENTION

In view of the above, it is a primary object of the present invention to provide a current sensing module for a current sensor and a method for manufacturing the current sensing module.

According to the above object, the present invention provides a current sensing module for a current sensor. The current sensing module includes at least one spacer layer and at least one circuit board. The spacer layer is annular in shaped, and includes a through hole at a center thereof for a wire to pass through. The circuit board is electrically connected to a current sensor, and includes at least of two structural layers for covering the spacer layer. Each of the structural layers includes an insulation layer, and a metal wire layer provided on the insulation layer and mutually insulated from the spacer layer. The two metal wire layers are mutually electrically to form at least one loop coil, which surrounds the spacer layer. When the wire is located in the through hole and electrically conducted, the circuit board has a detection state in which the circuit board a sensing current is outputted due to magnetic induction generated by the loop coil.

In one embodiment, the current sensing module further includes a magnetic separation layer for covering the external of the circuit board.

In one embodiment, the circuit board further includes four of the structural layers, which are a first structural layer, a second structural layer opposite the first structural layer, a third structural layer located between the first structural layer and the second structural layer, and a fourth structural layer located between the third structural layer and the second structural layer. The spacer layer is located between the third structural layer and the fourth structural layer.

In one embodiment, the spacer layer is selected from a group consisted of a magnetic material and a non-magnetic material.

In one embodiment, the spacer layer is insulated from the first structural layer and the second structural layer.

In one embodiment, the first structural layer includes thereon a first metal wire layer, the second structural layer includes thereon a second metal wire layer mutually electrically connected to the first metal wire layer, the third structural layer includes thereon a third metal wire layer, and the fourth structural layer includes thereon a fourth metal wire layer mutually electrically connected to the third metal wire layer.

According to the above object, the present invention further provides a method for manufacturing a current sensing module, the method including the following steps.

In a spacer layer manufacturing step, at least one a spacer layer includes a through hole and being annular in shape is provided.

In a structural layer manufacturing step, at least two structural layers are provided, and each of the structural layers includes an insulation layer and a metal wire layer.

In a combining step, the space layer is arranged between the two structural layers and the two insulation layers insulate the spacer layer from the two metal wire layers, the two structural layers are mutually combined to fix the spacer layer, the two metal wire layers on the two structural layers are mutually electrically connected to form a circuit board, and a loop coil for covering the spacer layer is formed by the two metal wire layers, and the circuit board is electrically connected to an external power providing a power. When the wire is located in the through hole and electrically conducted, the circuit board has a detection state in which a sensing current is outputted due to magnetic induction generated by the loop coil.

In one embodiment, the method further includes a magnetic separation layer manufacturing step, in which a magnetic separation layer is formed at an external of the circuit board and the magnetic separation layer covers the external of the circuit board.

In one embodiment, the structural layer manufacturing step further includes four of the structural layers, which are a first structural layer, a second structural layer opposite the first structural layer, a third structural layer located between the first structural layer and the second structural layer, and a fourth structural layer located between the third structural layer and the second structural layer. The spacer layer is located between the third structural layer and the fourth structural layer.

In one embodiment, the spacer layer is selected from a group consisted of a magnetic material and a non-magnetic material.

In one embodiment, the spacer layer is insulated from the first structural layer and the second structural layer.

In one embodiment, the first structural layer includes thereon a first metal wire layer, the second structural layer includes thereon a second metal wire layer mutually electrically connected to the first metal wire layer, the third structural layer includes thereon a third metal wire layer, and the fourth structural layer includes thereon a fourth metal wire layer mutually electrically connected to the third metal layer.

As described, the present invention provides following effects compared to the prior art.

1. In the manufacturing process of the circuit board of the present invention, the spacer layer is directly disposed onto the circuit board, such that insulation is directly formed between the spacer layer and the loop coil on the circuit board, thus effectively reducing the volume of the detection component and at the same time lowering material costs of the detection component.

2. The direct formation of the circuit board and the spacer layer of the present invention increases the manufacturing yield rate, allowing the present invention to be better applicable for mass production.

3. In the loop coil of the present invention, the number of turns of the loop coil is increased by increasing the number of the structural layers, thus enhancing overall magnetic field sensing amount.

4. The present invention provides the loop coil with better uniform wire distribution, which is capable of minimizing externally generated current interference during measurement process.

5. The circuit board of the present invention adopts designs in various shapes to match the shape of the detection component, and thus is able to be applied to a greater scope.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Details and technical contents of the present invention are given with the accompanying drawings below.

Referring toFIGS. 1, 2 and 3, as seen from the drawings, the present invention provides a current sensing module30adapted to be installed in a current sensor10. The current sensor10includes a detection body11and a detection component12located on the detection body11. The detection component12is annular in shape, and includes at least one detection hole13for a wire20to pass through. The current sensing module30is arranged in the detection component12, and includes a spacer layer40, a circuit board50, and a magnetic separation layer60covering an external of the circuit board50and blocking between the circuit board50and the detection component12.

The spacer layer40is made of a magnetic material or a non-magnetic material, appears as an annular shape relative to the detection component12, and includes at a central part thereof a through hole41located concentrically as the detection hole13. The magnetic material refers to a highly magnetically conductive material, and the non-magnetic material refers to a non-magnetic conductive material such as glass fiber.

The circuit board50is for electrically connecting to the detection body11, and includes at least two structural layers51for covering the spacer layer40. Each of the structural layers51includes an insulation layer52, a metal wire layer53located on the insulation layer52, and a plurality of conductive channels59. More specifically, the plurality of conductive channels59include a first conductive channel591and a second conductive channel592; each of the metal wire layers53is distributed with a plurality of conductive wires, which are not yet connected. Further, the plurality of conductive wires need to be connected on other metal wire layers53via other conductive channels59. The connection of the metal wire layers53and the conductive channels59form a loop coil54. In this embodiment, four of the structural layers51are used as a main implementation form, and are respectively a first structural layer511, a second structural layer512opposite the first structural layer511, a third structural layer513located between the first structural layer511and the second structural layer512, and a fourth structural layer514located between the third structural layer513and the second structural layer512. The spacer layer40is located between the third structural layer513and the fourth structural layer514. Further, the first structural layer511includes a first insulation layer521and a first metal wire layer531located on the first insulation layer521, the second structural layer512includes a second insulation layer522and a second metal wire layer532located on the second insulation layer522, the third structural layer513includes a third insulation layer523and a third metal wire layer533located on the third insulation layer523, and the fourth structural layer514includes a fourth insulation layer524and a fourth metal wire layer534located on the fourth insulation layer524. The first metal wire layer531is mutually electrically connected to the second metal wire layer532via the first conductive channel591, and the third metal wire layer533is mutually electrically connected to the fourth metal wire layer534via the second conductive channel592, such that the first metal wire layer531, the second metal wire layer532, the third metal wire layer533and the fourth metal wire layer534form the loop coil54, surround an external of the spacer layer40, and are mutually insulated from the spacer layer40through the first insulation layer521, the second insulation layer522, the third insulation layer523and the fourth insulation layer524. The circuit board50further includes a first electrode contact55and a second electrode contact56, wherein the first electrode contact55and the second electrode contact56are mutually electrically connected to the metal wire layer53and the detection body11, respectively.

Accordingly, when the wire20is inserted in the detection hole13and a current passes through the wire20, the loop coil54formed by the first metal wire layer531, the second metal wire layer532, the third metal wire layer533and the fourth metal wire layer534on the circuit board50generates magnetic induction due to the current passing through the wire20, and hence a sensing current is generated. The sensing current is transmitted to the detection body11, which then provides the current value at the present time according to the sensing current. In an implementation of the embodiment, when the spacer layer40is the magnetic material, a smaller current is detected, wherein the detected current value has a higher resolution. When the spacer layer40is a non-magnetic material, a larger current is detected.

Again referring toFIGS. 1, 4A and 4B, in one embodiment, the circuit board50is further provided with two of the loop coils54, including a first loop coil541and a second loop coil542provided around an external of the first loop coil541. In this embodiment, the spacer layer40is provided in the first loop coil541, and no spacer layer40is provided in the second loop coil542. The first loop coil541and the second loop coil542are mutually electrically connected to the detection body11via the circuit board50, respectively.

Again referring toFIGS. 1, 5 and 6, in one embodiment, a pressing component14linked with the detection component12is further provided at an external of the detection body11, the detection component12includes a first annular portion121and a second annular portion122, and at least one disconnected portion123is formed at an adjacent position of the first annular portion121and the second annular portion122. When the pressing component14on the detection body11is pressed, the distance of the disconnected portion123between the first annular portion121and the second annular portion122is increased, allowing the wire20to pass through the disconnected portion123to enter the detection hole13. The circuit board50includes a first circuit board501corresponding to the first annular portion121and a second circuit board502corresponding to the second annular portion122. The first circuit board501and the second circuit board502are semi-annular in shape. The loop coil54is disposed on each of the first circuit board501and the second circuit board502, and the spacer layer40is covered by each of the loop coils54.

In one embodiment, as shown inFIG. 6, the first loop coil541and the second loop coil542are respectively formed on the first circuit board501and the second circuit board502, and the spacer layer40is provided in the first loop coil541but not provided in the second loop coil542. In this embodiment, the first loop coil541and the second loop coil542are shaped correspondingly to the shapes of the first annular portion121and the second annular portion122, and are both semi-annular.

In other words, the loop coil54of the circuit board50of the present invention may be in an enclosed annular shape as shown inFIG. 2A, or in a non-enclosed annular shape as shown inFIG. 6. When the loop coil54is in the enclosed annular shape, optimization for reducing outer peripheral current interference is minimized. When the loop coil54is in the non-enclosed annular shape, the density of the loop coil54at disconnected parts is increased to compensate non-uniformity generated by the discontinuity at the disconnected parts of the loop coil54, similarly reducing the outer peripheral current interference.

Again referring toFIGS. 7 and 8, in one embodiment, the detection component12further includes a first detection hole131, which is spaced from the detection hole13. An aperture of the first detection hole131is smaller than an aperture of the detection hole13, so as to allow the wire20and a first wire21having a line width smaller than that of the wire20to respectively pass through the detection hole13and the first detection hole131. And the detection hole13and the first detection hole131detect current values of the wire20and the first wire21, respectively.

In this embodiment, as shown inFIGS. 7 and 8, an extension circuit board503is for fried at a position of the circuit board50corresponding to the first detection hole131. The extension circuit board503is mutually electrically connected to the circuit board50, and is provided thereon with a third loop coil543, wherein the spacer layer40is provided in the third loop coil543. Accordingly, with the loop coil54provided on the circuit board50correspondingly to the detection hole13and the extension circuit board503provided correspondingly to the first detection hole131, the current values of the wire20and the first wire21is detected respectively through the detection hole13and the first detection hole131.

Again referring toFIGS. 1, 2A, 2B, 3 and 9, the present invention further provides a current sensing module manufacturing method for manufacturing the current sensing module30. The current sensing module manufacturing method includes a spacer layer manufacturing step S001, a structural layer manufacturing step S002, a combining step S003and a magnetic separation layer step S004.

In the spacer layer manufacturing step S001, a magnetic material or a non-magnetic material is primarily used to manufacture the annular-shaped spacer layer40, and the through hole41is formed on the spacer layer40.

In the structural layer manufacturing step S002, at least two of structural layers51for covering the spacer layer40are provided. Each of the structural layers51includes the metal wire layer53formed on the insulation layer52via electroplating, coating or printing.

In the combining step S003, the spacer layer40is provided between the two structural layers51so as to the two insulation layers52insulate the spacer layer40from the two metal wire layers53. The two insulation layers52of the two structural layers51are mutually combined through adhesion or pressing to fix the spacer layer40, two of metal wire layers53on the two structural layers51are mutually electrically connected to form the circuit board50, and the loop coil54for covering the spacer layer40is formed by the two metal wire layers53and the conductive channels59. When the wire20is located in the through hole41, the circuit board50has a detection state in which a sensing current is outputted due to magnetic induction generated by the loop coil54when the wire20is electrically conducted.

In the magnetic separation layer manufacturing step S004, a magnetic separation layer60is formed at the external of the circuit board50and the magnetic separation layer60covers the external of the circuit board50, thereby the circuit board50blocked from the detection component12by the magnetic separation layer60therebetween.

It should be noted that, during a manufacturing process of the circuit board50, the spacer layer40of the present invention is arranged between the two structural layers51via a pressing process of the two structural layers51. Further, the two insulation layers52of the two structural layers51are connected through hot-pressing or adhesion such that the two metal wire layers53are insulated from the spacer layer40through the two insulation layers52Next, using a manufacturing step in the manufacturing process of the circuit board50, such as drilling, exposure, etching, electroplating, cleaning, applying or printing, the two metal wire layers53are electrically connected to form the loop coil54, allowing the loop coil54to surrounded the spacer layer40and thus completing the manufacturing of the current sensing module30.

Thus, not only the volume of the current sensing module30is reduced but also the manufacturing yield rate is increased, making the present invention be better applicable for mass production. Further, the number of turns of the loop coil54is able to be increased by increasing the number of the structural layers51, and the circuit board50is manufactured by a multi-layer circuit board process, thus further enhancing a magnetic field sensing amount of the detection body11. Further, the circuit board50provides the loop coil54with more uniform wire distribution, such that current interference generated by an external environment is minimized during measurement process. Moreover, the circuit board50adopts designs of various shapes to match the shape of the detection component12, and thus is applied to a greater scope.