KR20110053896A - Protection element - Google Patents

Abstract

PURPOSE: A protection element is provided to improve reliability by miniaturizing and thinning, with a fusible alloy fuse surely operated in response to the heating of a resistance heating element. CONSTITUTION: A protection element includes a ceramic chip body(12), a fusible alloy fuse element disposed on the surface thereof, a resistance heating element disposed in a through-hole, and leading-out leads(15-17) disposed on the back thereof. Since the heating element comprises a resistor having a predetermined resistance value, and is embedded and filled in the through-hole, heating of the resistor accurately and speedily operates the fusible alloy fuse element through the ceramic chip body having good heat conductivity.

Description

Protective element {PROTECTION ELEMENT}

The present invention provides a miniaturized and thin protection element, in particular a resistive heating element, which is surface-mounted with a soluble alloy fuse element that withstands a reflow process on a ceramic chip body on which a pattern electrode is formed. It is related with the protection element which provided in the hall, and provided the lead-out terminal in the back surface side, and the protection apparatus using the same.

Non-returnable protection elements which operate by detecting excessive heat generated by the overcurrent of the device to be protected or by reacting to abnormal overheating of the ambient temperature are operated at a predetermined operating temperature in order to ensure the safety of the device. Shut off electrical circuits. As one example, there is a protection element that generates a resistance by a signal current that detects an abnormality occurring in the device, and operates the fuse element by the heat generation. In Japanese Patent Application Laid-Open No. 07-153367 (Patent Document 1) and Japanese Patent Application Laid-Open No. 08-161990 (Patent Document 2), protection using a film resistance provided with a resistance that generates heat on an abnormal time on a ceramic substrate Protection device which prevents performance deterioration and ignition by the dendrite produced | generated on the electrode surface in the overcharge mode of a lithium ion secondary battery using this protection element, or prevents a battery from being charged more than predetermined voltage at the time of charge. Is disclosed.

In general, a portable information terminal device uses a high-density lithium ion secondary battery or a lithium polymer secondary battery having excellent storage characteristics and leakage resistance for a main power source. It is more likely to be released in a dangerous state. In order to prevent overcharge and overdischarge in such a secondary battery and to ensure safety, dual protection circuits of return type and non-return type are provided. For example, Japanese Unexamined Patent Application Publication No. 10-056742 (Patent Document 3) discloses a return-type protection circuit that cuts off a charging current when the battery voltage exceeds a set voltage, and when this protection circuit does not work for any reason. A protection device having a non-returnable protection circuit for a thermal fuse to be used is disclosed. Regarding the thermal fuse with a resistance, a protection element designed to reduce the cost by using a glass epoxy resin in an insulating substrate is disclosed in Japanese Patent Application Laid-Open No. 2005-129352 (Patent Document 4), and the resistor is made of a lead-free soluble alloy. A fuse is disclosed in Japanese Patent Laid-Open No. 2005-150075 (Patent Document 5). Further, Japanese Patent Laid-Open No. 2006-221919 (Patent Document 6) discloses a fuse with a resistor in which a heat generating resistor is laminated in an insulating substrate and a soluble metal piece is provided on an insulating substrate on the resistor.

Patent Document 1: Japanese Patent Application Laid-Open No. 07-153367 Patent Document 2: Japanese Patent Application Laid-Open No. 08-161990 Patent Document 3: Japanese Patent Application Laid-Open No. 10-056742 Patent Document 4: Japanese Patent Application Laid-Open No. 2005-129352 Patent Document 5: Japanese Patent Application Laid-Open No. 2005-150075 Patent Document 6: Japanese Patent Application Laid-Open No. 2006-221919

In recent years, with the rapid spread of small mobile PCs, the use of surface mounting techniques and the miniaturization and thinning of battery packs used are demanded, and the demand for chipping of protection elements is increasing. The above-mentioned Patent Documents 1, 2, and 6 refer to a combination of a fuse element and a resistive film using some kind of alloy, but either of them forms the resistive film in the horizontal direction of the substrate, that is, in the direction along the main surface of the substrate. Doing. Usually, since a battery voltage is applied to this resistive film at the time of abnormality, since it should be designed so that it may have an area with the likelihood with respect to the voltage range, there was a limit in the dimension reduction of a horizontal direction. In the fuse with resistance shown in Patent Literature 5, a single or two low melting point fusible alloy fuse elements are mounted on the surface of a ceramic insulating substrate, and the rear surface of the fuse together with a lead generates heat of a thick film resistor. An element is mounted and comprised. In this fuse with resistance, the soluble alloy is mounted between the electrodes on the substrate in a foil state of a flat plate, and since the film resistance is provided on a relatively large area, a necessary mounting area is inevitably large, so that it is suitable for attachment as a protective element. Large space is required. Therefore, it is unsuitable for application to portable information devices and the like requiring miniaturization and thinning, and there is a problem in assembling and manufacturing. On the other hand, in forming a film-shaped resistor, it is difficult to print a ruthenium oxide paste and to bake at a temperature exceeding 800 ° C. to obtain a uniform thick film resistance and at the same time to obtain a desired resistance value in terms of characteristics. Reconciliation was laborious and difficult to reduce costs. In addition, the resistance film is small in volume, the electric power resistance is small, and the resistance film cannot be baked onto the organic substrate. In addition, since it is formed on the rear surface side to which the lead for drawing is attached, it is not possible to provide a miniaturization and thinning protection element that requires an insulation treatment and satisfies it, and it is difficult to achieve compactness as low as possible. . Therefore, it is desired to provide an improved protective element including manufacturing processability and a protective device for an equipment circuit using the same as a protective element operating at a stable operating temperature.

Accordingly, the present invention has been proposed in view of the above-described drawbacks, and focuses on arranging a resistive heating element in a through hole of a chip substrate, and uses a fusible alloy fuse element that withstands reflow treatment on a ceramic substrate on which a pattern electrode is formed. It is an object of the present invention to provide a chip type protection element which is surface mounted, is chip-divided after plural elements are processed in a batch, and is miniaturized and thinned.

Another object of the present invention is to provide a protection device such as a battery pack using the protection element, in which a heat generating element is disposed in a through hole of a ceramic substrate, and a lead terminal is provided on the back side. Specifically, another object of the present invention is to provide resistance to through-holes formed in the ceramic chip body while disposing an soluble alloy fuse element on one surface of the ceramic chip body, an electrode portion or lead for leading out on the other surface. A new and improved protection device with a heating element provided, simplified manufacturing and improved work efficiency, both cost reduction and miniaturization, improved performance and effective utilization of mounting space It is to provide a protective device and a protective device using the same.

According to the present invention, a surface is mounted between a ceramic chip body having a plurality of through holes, one of which includes a resistance heating element, and a plurality of pattern electrodes disposed on both front and rear surfaces thereof, and a surface pattern electrode which is one surface of the ceramic chip body. A soluble alloy fuse element connected by a reflow soldering and a plurality of lead leads for connection arranged on a back pattern electrode which is a surface in the other direction of the ceramic chip body, and a through-hole or A protection element is provided, which is connected by a conductive half through hole and heats up the soluble alloy fuse element by directing heat generation of the resistance heating element directly or through thermal conduction of a ceramic material. Here, the resistive heating element is a chip resistor arranged in one through hole or a resistive filler having a predetermined resistance value. The resistance value is adjusted by the selection of the resistance material to fill the through hole. As the soluble alloy fuse element on the front side, a soluble alloy which is not affected by the reflow process and a flux material which assures smooth melt operation are selected and connected to the pattern electrode on the back side. In this way, the structure of the wiring is simplified. That is, the fusible alloy fuse element is not melted by the reflow process and does not impair the fuse function even after the reflow process. Moreover, the fuse element consists of two or more soluble alloys as needed, and the temperature which each soluble alloy melts can be selected to the same or different temperature. Moreover, Preferably, the lead for derivation consists of a flat conductor and the flat surface is solder-connected to the pattern electrode of the other surface.

As a metal and soluble alloy specifically selected as a material of a fuse element, 97Bi-3Zn (255 degreeC), 99.3Bi-0.5Ag-0.2Cu (258 degreeC), 97Bi-3Ag (262 degreeC), Bi (272 ° C), 78Zn-22Al (275 ° C), 95Zn-5A1 (382 ° C), 54Ge-46Al (424 ° C), and the like. In addition, the number has shown the compounding ratio (weight%) of an alloy. Since the protection element using these lead-free alloys can endure reflow soldering of 245 degreeC or more, it can be collectively soldered together with other devices as surface mounting components.

In addition, flux coating is required on the surface of the soluble alloy in order to ensure smooth melting operation of the protection element, which withstands the reflow temperature described above and ensures the melting operation without flowing down from the surface of the alloy even at an operating temperature of 250 ° C or higher. For this purpose, a high temperature flux having a configuration shown below is used. This flux is to a solid component which acts as a coating agent. Rosin-modified maleic acid resin or rosin-modified in which 10 to 50 parts of Hazen 100 or more pale-color grade acid-modified hydrogenated rosin excellent in heat resistance and a softening point thereof are selected in the range of 120 to 190 ° C. 5 to 30 parts of phenol resin, 20 to 50 parts of montanic acid wax or stearic acid amide or behenic acid amide as dispersion modifier, 0.5 to 10 fumed silica or organic modified fumed silica as thixotropic agent to prevent thermal sagging. In addition, 0.5-1 part of diphenylamine or dicyclohexylamine is added as antioxidant, and it heat-mixes to make a base material. Also as an active agent there are 2 to 10 parts of saturated straight chain aliphatic dicarboxylic acid having 4 to 12 carbon atoms, 2 to 10 parts of saturated straight chain amino acid having 4 to 12 carbon atoms, aliphatic hydroxy monocarboxylic acid having 1 to 6 carbon atoms or hydroxy. Solid flux in which 2 to 10 parts of dicarboxylic acid or hydroxytricarboxylic acid is added and sufficiently kneaded and dispersed is used.

According to another aspect of the present invention, there is provided a ceramic chip body having a plurality of through holes, a plurality of pattern electrodes provided on both front and rear surfaces of the ceramic chip body, a fusible alloy fuse element solder-connected between the surface pattern electrodes, and a plurality of through At least two of a resistive heating element disposed in at least one through-hole among the holes, a plurality of lead leads for connection to the pattern electrodes on the rear surface of the ceramic chip body, and a plurality of through holes for connecting the pattern electrodes on both sides of the front and back The non-return type | mold provided with the conductor embedded in the above-mentioned through-hole, and the protection element which activates heat-sensitizing an soluble alloy fuse element by the heat conduction of a ceramic chip body by the heat conduction of a ceramic chip body, and a control element which detects an abnormal signal. In the protection device, the control element heats up the ceramic chip body via the control current to the heat generating element, and fuses mounted in the vicinity thereof. It discloses a protective device, comprising a step of operation. Here, the control element is used for overcharge prevention which detects the abnormal state of the charge / discharge control circuit for battery packs.

According to the present invention, there is provided a novel protection element in which a resistive heat generating element is disposed in a vertical direction in a through hole of a ceramic chip body, thereby achieving miniaturization by lateral shortening in the horizontal direction and thinning by omission of the resistive film thickness. In addition, a pattern electrode is provided in a ceramic chip body having a through hole, and a soluble alloy fuse element that withstands reflow treatment on the surface, a lead electrode portion or a lead on the back surface is provided, so that the through hole conducts between the pattern electrodes on both sides of the front and back. In addition, it is easy to assemble as a protection device and can be simplified, and heat is rapidly transmitted to the fusible alloy fuse element through the heat conduction of the ceramic chip body, and the melting of the fusible alloy is accelerated to ensure the predetermined operation of the fusible alloy fuse element. Let's do it.

On the other hand, since the soluble alloy which is not melted by reflow process and which does not impair fuse function after reflow process is selected for the soluble alloy fuse element of a protection element, it helps to reduce the trouble which arises with assembly of a protection apparatus. This improves workability by simplifying the manufacturing. Connecting the electrode pattern between the front and back of the chip body by making the through hole of the ceramic chip body into the conductive through hole by embedding the conductive material makes it possible to reliably and easily wire the protective device. In particular, since the heat generation of the heat generating element is transmitted to the soluble alloy fuse element by the heat conduction of the ceramic chip body, and the soluble alloy is quickly heated and sensed, the soluble alloy fuse element detects the heat generation of the heat generating element and responds quickly to ensure the fuse function. To achieve. In addition, since the heat generating element is embedded in the through hole and connected to the pattern electrode on both sides, the resistance heat is transmitted through the heat conducting pattern electrode or the ceramic chip body to raise the available alloy fuse element to increase the temperature and to reliably and quickly Activate the melt. At the same time, the resistance heating element in the through hole increases the withstand power, thereby achieving a practical effect that is advantageous for low magnification and small thickness by effective use of space.

1 is a front perspective view of a protective element according to Embodiment 1 of the present invention.
2 is a perspective view of a protection element corresponding to an assembling process;
3 is a perspective view of a protection element before fuse element mounting;
4 is a perspective view illustrating a mounting structure of a protection element according to the second embodiment.
Fig. 5 is a perspective view of a protection element before fuse element mounting according to the second embodiment.

According to the present invention, a plurality of protective elements are collectively processed, and thus, the green sheet for ceramics prepared in advance is composed of a plurality of chip bodies, and a plurality of through holes are formed, respectively. On both surfaces of the chip body, pattern electrodes are formed of a paste containing silver as a main component. In addition, ruthenium oxide paste is embedded in at least one through hole of each chip body, and a resistive heating element having a desired resistance value is provided. The sintering operation is baked at a temperature of about 850 ° C. for about 0.5 hours, and a ceramic insulating substrate including a plurality of chip bodies is produced. This prepared ceramic insulating substrate is provided with many ceramic chip bodies which have a through-hole and a resistance heating element. In addition, the ceramic chip body includes a plurality of pattern electrodes formed on both surfaces, a conductive through hole for electrically connecting the pattern electrodes on the front and back, and a through hole in which a resistance heating element is embedded. It is what is called a chip segment, and is specifically equipped with the resistance heating element arrange | positioned in the at least 1st through hole, and the 2nd through hole which consists of at least 2 conducting through holes. The fuse element and the lead lead are attached to this segment to form a protection element.

Lead-out leads and fuse elements are assembled to the back electrode of the ceramic insulated substrate via the reflow process. Here, the fuse element is a Pb-free soluble alloy material, a material which is not melted by the reflow process and which endures the reflow which does not impair the fuse function even after the reflow process is selected, Maintain performance and maintain safety. Specifically, a fuse element is selected from the following soluble alloys. 97Bi-3Zn (255 ° C), 99.3Bi-0.5Ag-0.2Cu (258 ° C), 97Bi-3Ag (262 ° C), Bi (272 ° C), 78Zn-22Al (275 ° C), 95Zn-5Al (382) ° C) and 54 Ge-46Al (424 ° C). Since the protection element using these lead-free alloys can endure reflow soldering of 245 degreeC or more, it can collectively solder together with other devices as surface mounting components. Here, the number before each element symbol has shown the compounding ratio (weight%) of an alloy, and has shown the elution temperature in the parenthesis after an element symbol. The selected soluble alloy has a solder foil shape and is fixed by reflow soldering between the pattern electrodes on the surface side. If necessary, a plurality of conductive pattern electrodes provided on both sides of the front and back are insulated, or a fusible alloy fuse element mounted on the surface is sealed with a ceramic cap. Moreover, the cover range which seals a cap contains the pattern electrode of the surface of a ceramic chip body, and a soluble alloy, and the coating area becomes smaller than the area of the whole ceramic chip body. In addition, it is preferable to reduce the thickness and thickness by using a flat copper wire for the lead for lead.

On the other hand, in order to ensure the smooth fusion | melting operation | movement of a soluble alloy fuse element, a flux film is provided in the surface of the soluble alloy to be used. In this case, it is necessary for the flux material to withstand the reflow temperature described above and to maintain the coating state without flowing on the surface of the soluble alloy even at an operating temperature of 250 ° C. or higher, and to ensure the melting operation. For that purpose, the high temperature flux of the structure shown next is used. That is, rosine-modified maleic acid resins or rosin-modified phenols selected from a range of 10 to 50 parts of Hazen 100 or more pale color grade acid-modified hydrogenated rosin excellent in heat resistance and a softening point in the range of 120 to 190 ° C. 5 to 30 parts of resin, 20 to 50 parts of montanic acid wax or stearic acid amide or behenic acid amide as a dispersion modifier, 0.5 to 10 parts of fumed silica or organic modified fumed silica as a thixotropic agent to prevent thermal sagging, and antioxidant As a base material, 0.5-1 part of diphenylamine or dicyclohexylamine is added, and it heat-mixes as a base material. 2 to 10 parts of saturated straight chain aliphatic dicarboxylic acid having 4 to 12 carbon atoms, 2 to 10 parts of saturated straight chain amino acid having 4 to 12 carbon atoms, and aliphatic hydroxy monocarboxylic acid having 1 to 6 carbon atoms or hydroxy. A solid flux obtained by adding 2 to 10 parts of dicarboxylic acid or hydroxytricarboxylic acid and sufficiently kneading and dispersing is used.

The above-mentioned protection element of this invention is a protection device which is another embodiment, and comprises the charge / discharge control apparatus for battery packs using a protection element. In other words, when the control element detects an abnormality and energizes the signal current to the above-described heat generating element, it is a non-return type protection circuit that generates resistance heat to melt the low melting point soluble alloy of the soluble alloy fuse element. In addition, the protection element used here is a soluble alloy soldered to the ceramic chip body which has several through-holes for connecting the pattern electrode and double-sided pattern electrode on both surfaces mentioned above, and the pattern electrode arrange | positioned at the surface side of this ceramic chip body. It consists of a fuse element and the heat generating element of the chip-shaped resistor body arrange | positioned in a through hole.

Example 1

EMBODIMENT OF THE INVENTION Hereinafter, the 1st Example which concerns on this invention is described in detail, referring drawings. The protective lead 10 of the axial lead type according to the present invention is a soluble alloy fuse element of the ceramic chip body 12 and the mounting components mounted on the surface side, as shown in FIG. The case cover 14 of the package which protects the resistance heating element etc. in a through-hole, and the lead lead 15-17 connected to the pattern electrode on the back surface side are provided. Here, pattern electrodes are formed on both surfaces of the ceramic chip body 12, and the resistance heating element is mounted in the fusible alloy fuse element on the front side, the lead for extraction on the back side, and the chip through hole, respectively. FIG. 2 shows a perspective view in a state before the case cover 14 of the package is mounted, and on the pattern electrodes 21 to 23 provided in the ceramic chip body 12, a fusible alloy fuse element 20 having a flux deposited on the surface thereof. Is disposed, and both ends thereof are soldered with the pattern electrodes 22 and 23, and the intermediate point is connected to the resistance heating element (not shown) via the pattern electrode 21. FIG. 3 shows a perspective view of a state before mounting of the fusible alloy fuse element 20 of FIG. 2. The first pattern electrode 21 at the center of the surface side of the ceramic chip body 12, the pair of second pattern electrodes 22 and 23 on both sides thereof, the first through hole 24 formed at each pattern electrode position, and one Pairs of second through holes 26 and 27 are formed. Among them, the resistive heating element 25 is disposed in the through hole 24, and the conductive materials 28 and 29 are embedded in the through holes 26 and 27. Although not shown, the three pattern electrodes formed on the back surface side of the chip body 12 correspond to the surface side pattern electrodes 21 to 23, and the resistive heating element 25 and the conductive materials 28 and 29. It is electrically connected with.

On the other hand, the lead 15-17 for lead attached to the back surface side is a flat copper wire, and is soldered to the pattern electrode. The ceramic chip body 12 becomes a predetermined shape at the stage of the green sheet before a sintering process, and the desired through hole is processed. After the sintering treatment, the pattern printing of the conductive pattern and the filling treatment of the resistor are performed in the through holes. In the ceramic chip body, a plurality of predetermined pattern electrodes and resistors are formed at the same time, and are separated and divided into individual components after a predetermined processing step. The ceramic chip body may be an insulating material other than alumina as long as it maintains good insulation, and pattern electrodes are formed in predetermined shapes on each surface of the insulating substrate. For example, a conductor is provided in two through holes at predetermined positions, and is electrically connected to the pattern electrodes on both sides via a resistor through one through hole. Note that the resistor disposed in the through-hole does not require a space on the surface side and contributes to the miniaturization and can obtain a larger volume than the conventional membrane resistor. Therefore, the power resistance can be increased, the baking necessary for the film-shaped resistor can be omitted, and no external injury occurs. There are no accidents or defects in handling and long-term stabilization is achieved.

[Example 2]

Another embodiment of the present invention is a chip type protection element 30 shown in the perspective view of FIG. 4. Fig. 4 shows a perspective view of the surface side excluding the protective cover, and is constructed by attaching a fusible alloy fuse element 35 to the surface of the ceramic chip body 32, and can be treated as a surface mount chip component. In the chip type protection element 30, the first pattern electrode 41 and the second pattern electrodes 42 and 43 are formed on both surfaces of the ceramic chip body 32, respectively, and on the end face side thereof. The side pattern electrode is mounted on the printed board as it is and soldered to and between the pattern electrodes. 5 is a perspective view showing a state before mounting of the protective cover and the fusible alloy fuse element. In FIG. 5, the pattern electrode group provided in the surface of the ceramic chip body 32 is shown, The 1st pattern electrode 41 is formed in the center, and the pair of 2nd pattern electrodes 42 and 43 are formed in the cross section side. The first through hole 44 is formed in the first pattern electrode 41, and the conductor grooves 46 and 47 are formed in the ceramic chip body 32 in the second pattern electrodes 42 and 43, respectively. . Here, the resistance heat generating element 45 adjusted to a predetermined resistance value is embedded in the through hole 44 corresponding to the center pattern electrode 41 shown in FIG. 5. Further, conductor grooves 46 and 47 are formed on the end faces of the electrode patterns 42 and 43 of the ceramic chip body 32 so as to conduct conductive connection of both pattern electrodes. The first pattern electrode 41 in the center of the substrate is also formed on both surfaces, and is electrically connected to each other via the resistance heating element 45 provided in the through hole 44.

The above-mentioned ceramic chip body is processed into a plurality of connected states with each other in the manufacturing process until just before mounting a fusible alloy fuse element, a resistance heating element, and a protective cover. That is, the plurality of ceramic chip bodies are manufactured by batch processing in the state where the alumina-based ceramic chips are connected, and are separated and separated for individualization in the process immediately before completion. By processing a plurality of ceramic chips in a connected state, the variation between products is reduced, and the characteristics and performance between the products can be equalized. Therefore, the formation of the conductor grooves 46 and 47 in the cross section of the ceramic chip body is also after embedding the conductive material in the through holes formed in the plurality of chip assemblies. It is performed by separating and cutting through the through hole. As shown in FIG. 4, the soluble alloy fuse element 35 which flux-coated the low melting-melting soluble alloy on the surface side of the ceramic chip body 32 is arrange | positioned by soldering both ends with a pattern electrode. Similarly, the back side pattern electrodes are electrically connected to each other via the conductor grooves 46 and 47 of both end faces, and the lead electrodes can be provided by soldering the lead terminals to the back pattern electrodes. In this way, the surface mounting wiring board and the electric circuit are constructed. The fusible alloy fuse element 35 may be sealed with a ceramic cap or an insulating coating material as necessary to form a package. Here, since the heat generating element 45 of the resistor embedded in the through hole 44 of the ceramic chip body 32 is disposed integrally with the ceramic chip body 32 to maintain a thermally coupled state, the heat generation of the resistor is directly generated from the ceramic chip body. Heated to the available alloy fuse element, whereby it can be operated at a predetermined operating temperature quickly and accurately. Here, each component is formed and processed to be as thin as possible. For example, the diameter φ of the through hole is formed to be 0.2 mm, for example. In addition, the resistance material, the through-hole dimension, etc. are adjusted so that the resistance value of a heat generating element may be a desired resistance value, for example, -100 ohms between the electrode patterns of both front and back of the through hole 44.

In the above-described embodiment, three pattern electrodes are connected to each other on both front and back sides of the ceramic chip body through respective through holes, and a resistive heating element is disposed in one of the through holes. The soluble alloy fuse element is bridge | crosslinked in the shape which bridge | crosslinks and welds with three pattern electrode to the three pattern electrodes of the surface side, and, thereby, the 1st soluble body part of a low melting-point alloy, and a 2nd soluble body It becomes a dual type soluble alloy fuse element having a portion. Flux is deposited on the soluble part of the low melting point alloy welded to each pattern electrode to form a soluble alloy fuse element. If necessary, the cover is covered with an insulating ceramic cap which is slightly smaller than the ceramic chip body, including the pattern electrode. The low melting point alloy of the soluble alloy fuse element may be a single type of soluble body, but in the case of a dual type of soluble body, the operating temperatures of the respective soluble bodies can be the same or different. In the dual type of other operating temperatures, it is preferable to keep the temperature difference within the range of the deviation of the operating temperature.

Leading leads and lead terminals are attached to the three pattern electrodes formed on the rear surface side of the ceramic chip body and connected to the device to be protected. The heat generating element is disposed in the first through hole and is connected to the first pattern electrode. The protection element is, for example, a standard DC 32 V, 10 A, an operating temperature of 135 ° C., and a heat generating resistance of 50?, And the ceramic chip body can be made extremely small in terms of the external dimensions of the finished product. In addition, the rectangular ceramic chip body 12 is an alumina substrate having a thickness of 0.4 mm, and the size of the alumina ceramics is greatly reduced by miniaturization, so that an economic merit in terms of cost can be obtained. At the time of implementation, economic effects in manufacturing are also obtained, such as being a small substrate, which allows a plurality of printing processes to be performed simultaneously in one printing. Moreover, since the lead members 15-17 used flat Sn plating copper wire of width 0.7-1.0 mm and thickness 0.2-0.4 mm, it contributes to thickness reduction of a main-body part, and helps thinning.

Example 3

The mounting structure of the protection element which concerns on this invention is applicable to the overcharge protection circuit of a secondary battery. Between the active elements, such as the M0SFET mounted on the main printed circuit board, the ceramic cap side is attached to the bottom side so as to be indented. As described above, the protective element for sealing one surface of the ceramic chip body with the package of the ceramic cap can be mounted close to the heat-sensitive portion of the active element. In addition, by mounting the protection element by using the gap space between the circuit component elements, it is advantageous for miniaturization and it becomes suitable for the compact portable information communication apparatus in which this kind of protection circuit is used. In the case where two or more resistive heating elements are used, by arranging them in parallel in the through-holes of the ceramic chip body, it is possible to achieve uniform heat transfer to the soluble alloy fuse element and to improve accuracy. In addition, by miniaturization of the components, the space between the control elements of the protection circuit can be effectively used on the mounting, thereby achieving an effect of making the entire protection device compact.

The embodiments and examples disclosed herein are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is shown by above-described not description but Claim, and it is intended that the meaning of a claim and equality and all the changes within a range are included.

10, 30: protection element
12, 32: ceramic chip body
14 case cover (cap)
15, 16, 17: lead drawn
20, 35: available alloy fuse element
21, 41: first pattern electrode
22, 23, 42, 43: second pattern electrode
24, 44: First through hole
25, 45: resistance heating element (chip resistance)
26, 27: second through hole
28, 29: conductive material
46, 47: cross section side conductor groove

Claims (7)

A soluble alloy fuse element selected from a ceramic chip body having a plurality of through holes, a plurality of pattern electrodes provided on both front and back surfaces of the chip body, and a material which is not affected by the reflow process soldered between the pattern electrodes on one surface; A plurality of resistive heating elements arranged in at least one through hole among the plurality of through holes, a plurality of lead leads for connection connected to the pattern electrodes on the other side of the ceramic chip body, and a plurality of pattern electrodes connected between the front and back surfaces A protective element comprising a conductor embedded in at least two through holes in the through hole, and conducting heat generation of the resistance heating element directly to the fusible alloy fuse element through a ceramic chip body, and actuating temperature-sensitive. The method of claim 1,
The soluble alloy fuse element is composed of at least two or more soluble portions, the protection element, characterized in that the melting temperature of each of the soluble portion selected at the same or different temperature. 3. The method according to claim 1 or 2,
The heat generating element is a chip resistor disposed in the first through hole, the resistance of which is adjusted by selection of a resistance material, and is provided to the lead terminals of the fusible alloy fuse element on the front side of the ceramic chip body and the pattern electrode on the back side. The protection element characterized by the above-mentioned. The method of claim 3, wherein
The lead-out terminal is connected to a flat lead conductor extending in the same direction, and is connected to a solder along the flat surface of the wiring board. A single center pattern electrode and a pair of pattern electrodes are provided on both sides of the front and back sides of the insulated ceramic chip body, and a protection element of a low melting point soluble alloy and a pair of pattern electrodes on the back side are provided between the pair of pattern electrodes on the front side. The lead-out terminal is provided at the bottom, and the resistor of the heating element is embedded in the through hole formed at the corresponding position of the center pattern electrode on both sides of the front and back, and electrically connected to the center pattern electrode on both sides, and between the pair of pattern electrodes. Electrically conducting through the cross-sectional side conduction grooves, electrically connecting the roughly central portion of the fusible alloy fuse element to the center through hole on the surface side, and providing a second lead terminal in the center pattern electrode on the back side; A non-returnable protective device characterized in that the electric alloy is cut off by melting the soluble alloy in response to heating by an electric current. 6. The method of claim 5,
The current passing through the heat generating element is used for preventing overcharge and discharge generated by a control element that detects an abnormality in the charge / discharge control circuit for a battery pack. 6. The method of claim 5,
The conduction of a cross-sectional through hole is formed by the outer layer surface conductor provided in the edge part of a through hole, The protection apparatus characterized by the above-mentioned.

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