JP4702383B2 - Electronic components - Google Patents

Description

  The present invention relates to a resin-sealed electronic component.

As a resin-encapsulated electronic component, a substrate, an electronic element disposed on one surface of the substrate, a resin sealing member disposed on one surface of the substrate so as to cover the electronic element, and the other of the substrate There is known a device including a terminal electrode formed on a surface and electrically connected to an electronic element (see, for example, Patent Documents 1 and 2).
JP-A-8-148302 JP 2000-286151 A

  By the way, the resin-encapsulated electronic component as described above is required to increase the molding pressure of the resin-encapsulated member in order to improve the durability of the resin-encapsulated member. Moreover, when the terminal electrode of an electronic component is soldered to a mounting substrate, it is required that the joining state of the terminal electrode by solder can be easily visually confirmed.

  Therefore, the present invention has been made in view of such circumstances, and can increase the molding pressure of the resin sealing member, and can easily recognize the joining state of the terminal electrode by solder. The purpose is to provide parts.

  In order to achieve the above object, an electronic component according to the present invention includes a substrate on which a notch from one surface to the other surface is formed, an electronic element disposed on one surface, and a notch. A covering member disposed on one surface so as to cover, a resin sealing member disposed on one surface so as to cover the electronic element and the covering member, and formed on the other surface so as to correspond to the notch portion. And a terminal electrode electrically connected to the electronic element, and the covering member has a first layer facing the notch and a second layer laminated on one side of the first layer. The first layer is made of a thermoplastic resin, and the second layer is made of a thermosetting resin.

  In this electronic component, an electronic element is arranged on one surface and a terminal electrode is formed on the other surface, and a notch extending from one surface to the other surface is formed so as to correspond to the terminal electrode. Has been. As a result, when the terminal electrode is soldered to the mounting substrate, a solder fillet is formed in the notch, so that the joining state of the terminal electrode by solder can be easily visually confirmed. In addition, a covering member is disposed on one surface of the substrate so as to cover the notch, and the covering member includes a first layer made of a thermoplastic resin facing the notch, and a first layer. And a second layer made of a thermosetting resin laminated on one side. As a result, the strength of the covering member increases, so that the covering member and the resin sealing member are prevented from entering the notch, and the resin seal disposed on one surface of the substrate so as to cover the electronic element and the covering member is covered. The molding pressure of the stop member can be increased.

  In the electronic component according to the present invention, the covering member preferably has a third layer laminated on one side of the second layer, and the third layer is preferably made of a thermoplastic resin. In this case, the second layer made of the thermosetting resin is sandwiched between the first layer and the third layer made of the thermoplastic resin, and the adhesion strength between the layers in the covering member is increased, so that the strength of the covering member is improved. Can be made.

  At this time, the covering member has a fourth layer laminated on one side of the third layer, and the first layer and the third layer are made of the same thermoplastic resin, and the second layer And the fourth layer are preferably made of the same thermosetting resin. In this case, the covering member can be easily multilayered.

  According to the present invention, the molding pressure of the resin sealing member can be increased, and the joining state of the terminal electrodes by solder can be easily visually confirmed.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a longitudinal sectional view of a solid electrolytic capacitor as an embodiment of an electronic component according to the present invention, and FIG. 2 is an exploded perspective view around a conductive member of the solid electrolytic capacitor of FIG. As shown in FIGS. 1 and 2, a solid electrolytic capacitor (electronic component) 1 includes a capacitor element laminate 3 in which a plurality of capacitor elements (electronic elements) 2 (here, four layers) are laminated. The capacitor element laminate 3 is disposed on one surface of the printed circuit board 4 and is sealed with a resin sealing member 5.

  3 is a longitudinal sectional view of the capacitor element of the solid electrolytic capacitor of FIG. As shown in FIG. 3, the capacitor element 2 has a rectangular thin plate (or rectangular foil shape) anode layer 6 made of aluminum. The surface of the anode layer 6 is roughened to increase the surface area and is porous. Dielectric layers 7 made of aluminum oxide formed by chemical conversion are laminated on the surfaces on both sides of the anode layer 6. In the chemical conversion treatment, for example, a voltage of 6 V is applied in a state where the anode layer 6 is immersed in an aqueous solution of ammonium adipate to cause anodization. Note that one end 6 b in the longitudinal direction of the anode layer 6 is narrower than the main body 6 a of the anode layer 6.

  The resist layer is interposed via the dielectric layer 7 on the surfaces on both sides of the outer edge portion on the end portion 6b side of the main body portion 6a of the anode layer 6 so as to extend along the direction orthogonal to the longitudinal direction of the anode layer 6. 8 are stacked (see FIG. 2). The resist layer 8 is formed, for example, by applying an epoxy resin or the like by a screen printing method or the like. Further, the cathode layer 9 including the solid polymer electrolyte layer 11, the graphite paste layer 12, and the silver paste layer 13 is disposed on the outer surface of the dielectric layer 7 in the main body portion 6a of the anode layer 6 so as to cover the end surface portion of the main body portion 6a. Are laminated together. The resist layer 8 electrically isolates the anode layer 6 and the cathode layer 9 by separating the outer edge portion of the cathode layer 9 from the anode layer 6.

  The solid polymer electrolyte layer 11 is laminated on the outer surface of the dielectric layer 7 in a state where it enters a fine hole formed by roughening the anode layer 6. The solid polymer electrolyte layer 11 is formed, for example, by impregnating the anode layer 6 on which the dielectric layer 7 is laminated with a polymerization solution to cause chemical oxidative polymerization. The graphite paste layer 12 is laminated on the outer surface of the solid polymer electrolyte layer 11, and the silver paste layer 13 is laminated on the outer surface of the graphite paste layer 12. The graphite paste layer 12 and the silver paste layer 13 are formed by, for example, an immersion method (dip method). In the resist layer 8, when the anode layer 6 on which the dielectric layer 7 is laminated is immersed in the polymerization solution, the polymerization solution enters the end 6b side of the anode layer 6 by capillary action on the porous surface. It has a function to prevent this.

  As shown in FIGS. 1 and 2, the capacitor element 2 is laminated by bonding the cathode layers 9 facing each other with a conductive adhesive 14 at a predetermined interval. Then, the cathode layer 9 of the capacitor element 2 located on the outermost layer on the printed circuit board 4 side in the capacitor element laminated body 3 is connected to the wiring electrode 16 formed on one surface of the printed circuit board 4 and the conductive adhesive 14. Is glued by. The wiring electrode 16 is connected to the terminal electrode 18 formed on the other surface of the substrate 15 through the through hole 17. That is, the terminal electrode 18 is electrically connected to the cathode layer 9 of each capacitor element 2.

  One end face in the longitudinal direction of the anode layer 6 of each capacitor element 2 (that is, one end face of the end portion 6b in the longitudinal direction of the anode layer 6) is connected to the conductive member 19 by laser welding. The conductive member 19 has a main body 19 a that is erected on the printed circuit board 4 and to which one end face of the anode layer 6 is connected. A base end portion 19b extending inward (that is, the capacitor element 2 side) is provided at an end portion of the main body portion 19a on the printed circuit board 4 side, and an inner end portion is provided on the opposite end portion of the main body portion 19a. A distal end portion 19c is provided. The main body 19 a and the base end 19 b have the same width as the main body 6 a of the anode layer 6, and the distal end 19 c has the same width as the end 6 b of the anode layer 6. In addition, the main-body part 19a, the base end part 19b, and the front-end | tip part 19c are formed by bending the plate-shaped member which consists of iron, nickel, copper, or these alloys etc., for example.

  The base end portion 19b of the conductive member 19 is connected to the wiring electrode 21 formed on one surface of the substrate 15 in the printed circuit board 4 by laser welding. The wiring electrode 21 is connected to the terminal electrode 23 formed on the other surface of the substrate 15 through the through hole 22. That is, the terminal electrode 23 is electrically connected to the anode layer 6 of each capacitor element 2. The connection between the base end portion 19b and the wiring electrode 21 by laser welding is that the width of the end portion 19c and the end portion 6b of the anode layer 6 is narrower than the width of the base end portion 19b and the wiring electrode 21. This is performed by irradiating laser light along the stacking direction of the capacitor element 2 on both sides of 19c and the end 6b of the anode layer 6 (see FIG. 2).

  In the printed circuit board 4, a notch 24 extending from one surface to the other surface is formed on the edge of the substrate 15 so as to be adjacent to the terminal electrodes 18 and 23. That is, the terminal electrodes 18 and 23 are formed so as to correspond to the cutout portions 24. A covering member 25 is disposed on one surface of the substrate 15 so as to cover each notch 24. The covering member 25 is covered together with the capacitor element laminated body 3 by the resin sealing member 5 disposed on one surface of the printed circuit board 4.

  The covering member 25 has a multilayer structure (here, a four-layer structure), and a first layer 26 facing the notch 24 and a second layer 27 stacked on one surface of the first layer 26. The third layer 28 is laminated on one surface of the second layer 27, and the fourth layer 29 is laminated on one surface of the third layer 28. The first layer 26 and the third layer 28 are made of the same thermoplastic resin such as an acrylic resin, and the second layer 27 and the fourth layer 29 are the same such as an epoxy resin. It consists of a thermosetting resin.

  In the solid electrolytic capacitor 1 configured as described above, the capacitor element laminated body 3 is disposed on one surface and the terminal electrodes 18 and 23 are formed on the other surface. A notch 24 is formed so as to correspond to the terminal electrodes 18 and 23. Accordingly, as shown in FIG. 1, when the terminal electrodes 18 and 23 are soldered to the wiring electrodes 32 and 33 of the mounting substrate 31, solder fillets 34 are formed in the notches 24. The joining state of the terminal electrodes 18 and 23 can be easily visually confirmed. In addition, a covering member 25 is disposed on one surface of the substrate 15 so as to cover each notch 24, and each covering member 25 is a first layer made of a thermoplastic resin facing the notch 24. 26 and a second layer 27 made of a thermosetting resin laminated on one surface of the first layer 26. As a result, the strength of the covering member 25 is increased, so that the covering member 25 and the resin sealing member 5 are prevented from entering the notch 24 and the substrate 15 is covered so as to cover the capacitor element laminate 3 and the covering member 25. It is possible to increase the molding pressure of the resin sealing member 5 disposed on one surface of the.

  Further, since the first layer 26 and the third layer 28 are made of the same thermoplastic resin, and the second layer 27 and the fourth layer 29 are made of the same thermosetting resin, the thermoplastic resin layer If the sheet | seat of the 2 layer structure which laminated | stacked the thermosetting resin layer on this is prepared and this sheet | seat is laminated | stacked, the coating | coated member 25 can be multilayered simply.

  The present invention is not limited to the embodiment described above.

  For example, a plurality of notches 24 may be formed for the terminal electrodes 18 and 23. The covering member 25 is not limited to a four-layer structure, and the number of layers may be appropriately set according to the molding pressure of the resin sealing member 5. As an example, when the covering member 25 has a three-layer structure having a first layer 26, a second layer 27, and a third layer 28, the second layer 27 made of a thermosetting resin is made of a thermoplastic resin. Since the adhesion strength between the layers of the covering member 25 is increased by being sandwiched between the first layer 26 and the third layer 28, the strength of the covering member 25 can be improved. The present invention is not limited to a solid electrolytic capacitor, but can be applied to various surface mount components such as a coil, an IC, and a transistor.

It is a longitudinal cross-sectional view of the solid electrolytic capacitor which is one Embodiment of the electronic component which concerns on this invention. FIG. 2 is an exploded perspective view around a conductive member of the solid electrolytic capacitor of FIG. 1. It is a longitudinal cross-sectional view of the capacitor | condenser element of the solid electrolytic capacitor of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Solid electrolytic capacitor (electronic component), 2 ... Capacitor element (electronic element), 5 ... Resin sealing member, 15 ... Board | substrate, 18, 23 ... Terminal electrode, 24 ... Notch part, 25 ... Cover member, 26 ... 1st layer, 27 ... 2nd layer, 28 ... 3rd layer, 29 ... 4th layer.

Claims (3)

A substrate having a notch formed from one surface to the other surface;
An electronic element disposed on the one surface;
A covering member disposed on the one surface so as to cover the notch,
A resin sealing member disposed on the one surface so as to cover the electronic element and the covering member;
A terminal electrode formed on the other surface so as to correspond to the notch and electrically connected to the electronic element,
The covering member has a first layer facing the notch, and a second layer laminated on one side of the first layer,
The electronic component according to claim 1, wherein the first layer is made of a thermoplastic resin, and the second layer is made of a thermosetting resin. The covering member has a third layer laminated on one side of the second layer,
The electronic component according to claim 1, wherein the third layer is made of a thermoplastic resin. The covering member has a fourth layer laminated on one side of the third layer,
3. The first layer and the third layer are made of the same thermoplastic resin, and the second layer and the fourth layer are made of the same thermosetting resin. The electronic component described.

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