JPH02231704A - Electrode structure of surface mounted electronic part - Google Patents

Abstract

PURPOSE:To facilitate the confirmation of the connecting state after solder connection and to reduce a mounting height by forming an attachment which is engaged with a part from the bottom surface of a base to the extruding part at the edge of the base so that the outer surface of a thin planar metal core is covered with an insulating material. CONSTITUTION:An attachment 11 is engaged with a part from the bottom part of a base 10 to the extruding part of the edge of the base. An electrode pattern 15 is formed from the bottom surface to the side surface of the attachment 11. The tip part of a lead 12 which is made to penetrate through the attachment 11 is electrically connected to the electrode pattern 15. The attachment is formed by covering the outer surface of a thin planar metal core with an insulating material. The electrical and mechanical connection between the electrode pattern 15 and the tip part of the lead 12 is performed by using solder connection or a conductive bonding agent. Thus, the confirmation of the connecting state after the solder connection can be made easy and ensured, and the mounting height can be also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in the electrode structure of surface-mount electronic components mounted on a printed circuit board by soldering. (Prior art) Electronic circuit units used in various communication devices, electronic devices, etc. are made by mounting surface-mounted electronic components such as piezoelectric devices, capacitors, and resistors on wiring patterns on printed circuit boards by soldering, etc. In recent years, there has been an increasing demand for miniaturization of various communication devices, electronic devices, etc. FIGS. 3(a) and 3(bl) are an explanatory diagram of the internal structure and a bottom view of a piezoelectric device as an example of an electronic component for surface mounting, and this piezoelectric device includes a base l made of a conductor block subjected to the required molding process, A ceramic pedestal 2 integrated into the bottom surface of the base l, a pair of leads 3 that hermetically penetrate the base 1 and the ceramic pedestal 2 and are electrically insulated from the base, and a crystal oscillator etc. supported on the top of the leads 3. a cap 7 that hermetically seals the upper space of the base containing the piezoelectric element 5; and metallization formed by vapor deposition on the bottom surface of the ceramic pedestal 2 and electrically connected to the leads 3 exposed from the bottom surface. When mounting an electronic component having such a configuration on a printed circuit board P, the metallized region 8 is formed on the connecting conductor (land) II of the printed circuit board P via solder paste. Electrical and mechanical connections are completed by reflowing the base 1. Figures 4(a) and 4(b) show another conventional example, in which a plastic tube integrated into the bottom of the base 1 is used. It has a configuration in which each lead 3 extends downward through the pedestal l3 and extends outward. According to these electrode structures, the lead wires are inserted into the through holes of the printed circuit board and connected by soldering. The mounting work can be made more efficient because the mounting can be carried out by soldering in a reflow set without going through complicated processes such as Thickness is 0.5m each
More than m. Therefore, there was a problem in reducing the overall height of the component, which went against the request to reduce the mounting height6.Furthermore, if these pedestals were made too thin,
This creates a problem in that it becomes difficult to confirm the solder connection state after two rows of soldering, and it becomes easy to detect poor connections.

(Objective of 9! Ming) The present invention was made in view of the above, and is a surface mounting method that makes it possible to reduce the mounting height while making it easy and reliable to confirm the connection state after soldering. The purpose of this research is to provide electrode structures for electronic components.

(Summary of the Invention) - In order to achieve the above object, the present invention provides a surface mounting electronic component comprising a base and a lead penetrating the base.
The attachment is locked from the bottom surface of the base to the peripheral protruding portion, and an electrode pattern is formed from the bottom surface to the side surface of the base, and the lead tip portion passing through the attachment is electrically connected to the electrode pattern. is characterized in that the outer peripheral surface of a thin plate-shaped metal core is coated with an insulating material.

(Example) The present invention will be described in detail below based on an example shown in the accompanying drawings. FIGS. 1(a), 1(b), and 1(c) are a front view, a bottom view, and a side view showing the configuration of an embodiment of the present invention, and this surface-mounted electronic component is attached to the base IO and the bottom surface of the base 10.・
A pair of leads 12 that pass through the base 10 and the attachment 1l in an airtight manner and are electrically insulated from the base, and a piezoelectric element such as a crystal resonator (not shown) supported on the upper part of the lead 12. ．． It has a cap l4 that hermetically seals the space F of the base containing the piezoelectric element, and an electrode pattern I5 formed on the bottom surface of the attachment 1l and exposed from the bottom surface or electrically connected to the bottom surface of the lead 12. Attachment 11
is a plate-like body with a thickness of 0.3 mm or less, which is made by integrally covering the outer peripheral surface of a thin copper plate as a core material with a heat-resistant plastic resin such as polyimide, and the copper plate as a core material improves bending workability. By bending both ends of this core member at right angles in the direction F as shown in the figure, and then further bending its tip toward the cap 14, the attachment I1 can be fixedly attached to the protruding portion of the base periphery. In addition to bending both ends of the plate-shaped attachment 11 and engaging the base periphery as described above, the attachment 11 may be configured to have claws or the like extending from both ends and be engaged by the claws. You can.

Note that if the lead 12 and the copper plate in the attachment 11 come into contact, a short circuit will occur, so an opening is formed in the copper plate part where the lead passes through to prevent short circuits. and mechanical connections are made by soldering or conductive adhesive. The electrode pattern 15 extends from the position where the tip of the lead 12 on the bottom of the attachment is exposed to the side surface of the first bent portion +1a. By extending and forming the electrode pattern portion 15a on the side surface of the bent portion l1a, it becomes easy to check the state of solder development when this mounted component is soldered to a printed circuit board L (not shown). FIG. 2 shows an example of an attachment used in the present invention, in which a non-copper plate area 2N is formed in the center of a steel plate 20, a pair of lead insertion holes 22 are formed in the non-copper plate area 2I, and a pattern is formed between each hole 22. A coil 23 is provided, and the outer peripheral surface of the coil 23 is coated with an insulating resin film 24.

The coil 23 has a continuous U-shaped bent shape,
By forming the coil in this way, the parallel capacitance can be canceled and the capacity ratio can be reduced. Also,
By coating the upper and lower surfaces of the coil pattern 23 with an insulating film 24, it can be combined with the copper plate 20. In addition, as in the above embodiment, the attachment 11
By bending the base, a mechanical connection can be obtained between the base and the attachment, and at the same time, the base and the attachment may be bonded with adhesive to be reinforced. By reinforcing it with adhesive in this way, the thickness of the attachment itself can be made even thinner. In this way, by using a thin-walled attachment, the present invention can obtain an electrode structure suitable for reflow soldering without increasing the mounting height. (Effects of the Invention) As described in Part 2, according to the present invention, it is possible to reduce the mounting height while making it easy and reliable to confirm the connection state after soldering.

[Brief explanation of the drawing]

Fig. 1 (al (b) and (cl) are a front view, a bottom view, and a side view showing the configuration of an embodiment of the present invention, and Fig. 2 is shown. 10...Base I1...Attachment 12...
・Lead l4...Cap l5...Electrode pattern patent applicant Toyo Tsushinki Co., Ltd.

Claims (1)

[Claims] In a surface-mounted electronic component comprising a base and a lead penetrating the base, an attachment is locked from the bottom surface of the base to a peripheral protrusion, and an electrode pattern is formed from the bottom surface to the side surface of the attachment. A surface mount electronic device, characterized in that a lead tip portion passing through the attachment is electrically connected to an electrode pattern, and the attachment is formed by coating an outer peripheral surface of a thin plate-shaped metal core material with an insulating material. Part electrode structure.