JPH0595058U - Surface mount type electronic component container - Google Patents

Abstract

(57) [Summary] [Purpose] Applying solder plating to the tip surface of the lead terminal,
To improve the reliability of soldering at the time of mounting and to easily confirm the soldering state. [Structure] A plurality of lead terminals 11a are bridged to the frame portion 11c via the bridging portion 11b. A portion of the lead terminal 11a of the lead frame 11 is molded with a thermoplastic resin and solder-plated to remove the bridging portion 11b from the bridging portion 11b. In a structure in which electronic parts are housed in a resin base 12 in which a plurality of lead terminals 11a are cut out and extended from the bottom surface and sealed with a metal lid, the bridging portion 11b is a side portion of the lead terminal 11a. It is characterized by being entangled.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a surface mount type electronic component container in which a soldering state during mounting can be easily checked.

[0002]

[Prior Art]

 Recently, piezoelectric vibrators, especially inexpensive and high-performance quartz vibrators, are widely used as a reference for frequency and time in various electronic devices. In addition, a large number of crystal oscillators that have a compact crystal resonator and a semiconductor integrated circuit oscillating circuit integrated in a container in order to achieve compact size, high reliability, and high-precision frequency Manufactured and used. In this type of conventional crystal oscillator, for example, a quartz piece having an oscillation circuit made of a semiconductor integrated circuit and electrodes formed on a base made of an insulating substrate such as ceramic is placed, and a cover is placed over them to make it airtight in a vacuum. It is designed to be sealed. In this way, the electrode formed on the plate surface of the crystal piece can be shielded from the outside air, so that the inside of the container can be kept in a stable state chemically and physically for a long period of time. High accuracy can be maintained. Further, in recent electronic devices, it is particularly desired that the shape is small and lightweight, and efforts are being made to automate the assembly process as much as possible. For this reason, active devices such as transistors and ICs, and passive devices such as resistors and capacitors are often of the surface mount type. This type of surface mount device can be made small in size and can be automatically arranged at a predetermined position on a printed circuit board using a parts feeder or the like. After placing all components on the printed circuit board, they are passed through a reflow oven, etc., and the solder applied to the terminals of each component is melted and mounted, so that electronic devices can be installed with almost no human intervention. The assembly can be performed, and the productivity can be remarkably increased.

For this reason, there is also a demand for a surface mount type crystal oscillator that is smaller in size and has no lead terminal than a crystal oscillator housed in a metal container which has been widely used in the past and in which the lead terminal is led out. As such a surface mount type crystal oscillator, for example, a surface mount type oscillator using a base formed by molding a lead frame formed with lead terminals of a predetermined shape with a thermoplastic resin has been considered. FIG. 2 is an assembly perspective view showing an example of such an oscillator, in which a small crystal unit 1 housed in a metal container is mounted on an insulating substrate 3 together with circuit components 2 constituting an oscillation circuit. It is placed on the substrate 4 and electrically connected to the lead terminal 5 so that the cover 6 is covered and sealed. 3 is a plan view showing an example of the lead frame 6 made of a thin metal plate, in which a plurality of lead terminals 5 are bridged to the frame portion 6b via the bridge portion 6a. That is, the tip portion of the lead terminal 5 is bridged to the frame portion 6b of the lead frame 6 through the bridge portion 6a, and the base end portion of the lead terminal 5 is molded with a thermoplastic resin to form the base 4. I am trying to mold it. Then, for example, the exposed portion of the lead frame 6 is plated with solder or the like, and the bridging portion 6a is cut so that the lead frame 6 is cut off and the lead terminal 5 is extended from the bottom surface of the base 4. .. In FIG. 3, reference numeral 6c is a holding piece, which is bent substantially vertically and is soldered to, for example, a side portion of the cover to fix the cover 6 to the base 4. Further, the hatched portion is molded with a molding material so that the lead terminals 5 are held on the bottom surface of the base 4 insulative from each other.

By the way, since the solder plating for the lead frame 6 is performed by electroplating, it is necessary to electrically connect the parts to be plated in common. Therefore, when the frame portion 6b of the lead frame 6 is cut off, the lead terminals 5 are electrically separated from each other. Therefore, for example, resin is molded to form the base 4 and electroplating is performed with each lead terminal 5 electrically connected in common via the lead frame 6, and then the bridge portion 6a is cut. Then, it is rational to cut off each lead terminal 5 from the frame portion 6b. However, in this way, the bare metal of the lead frame is directly exposed on the tip surface of the lead terminal, and the wettability of the solder is poor depending on the material, and the tip surface of the lead terminal is actually mounted on the printed circuit board. The solder may not adhere to the. Therefore, when such a surface mount type electronic component is mounted on the substrate, there is a problem in the reliability of soldering because the solder does not rise on the front end face of the terminal. When checking the soldering state, the easiest and most reliable method is to visually check that the solder has reached the tip surface of the lead terminal. However, when the bare metal on the front end surface of the lead frame is exposed, there is a problem that it is difficult to visually confirm the soldering state because the solder does not adhere to here.

[0005]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and it is possible to provide a surface mount type electronic component in which the tip surface of the terminal can be plated with solder and the soldering state at the time of mounting can be easily confirmed. It is intended to provide a container.

[0006]

[Means for Solving the Problems]

 In the present invention, a plurality of terminals are bridged to the frame via the bridging section. The lead frame terminals are molded with a thermoplastic resin and solder-plated. An electronic part is housed in a resin base that is extended and sealed with a metal lid, and the bridging part is characterized by bridging to the side part of the terminal.

[0007]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the plan view of the lead frame shown in FIG. In the figure, reference numeral 11 denotes a lead frame made of a thin metal plate, and a plurality of terminals 11a provided at intervals in the center by press working, etching, etc. are provided on the peripheral frame via bridging portions 11b. It is connected to the section 11c. The bridging portion 11b bridges the side portion of the terminal 11a. The shaded portion in FIG. 1 is the base 12, which is molded with a molding material such as an epoxy-based synthetic resin so as to fill the center portion of the lead frame 11, and the bottom portion and the bottom portion are formed in the same manner as in the conventional example shown in FIG. A side wall is formed so as to rise from the peripheral edge of the bottom. Then, each lead terminal of the lead frame 11 is led out from the bottom surface of the base 12, and the bottom surface of the lead terminal is formed so as to be flush with the bottom surface of the base 12. Then, after the molding with the molding material is completed, the bridging portion 11b of the lead frame 11 is cut from the position shown by the broken line in the figure to electrically separate the lead terminals 11a individually. Then, for example, a conductive pattern having a predetermined shape is formed by etching or the like on the plate surface of an insulating substrate such as ceramics, and electronic components such as semiconductor integrated circuits, C, R, and crystal oscillators are mounted on the conductive pattern. An oscillation circuit is configured and placed on the base to electrically connect with each lead terminal. Then, the opening of the lid formed by pressing a thin metal plate is fitted to the outside of the side wall of the base 12 to seal it.

With such a configuration, the side portions of the terminals are bridged to the frame portion via the bridging portions, and at least the tip surfaces of the terminals are solder-plated. Solder goes up to the tip surface of the terminal when it is mounted, and the reliability of soldering is improved, and the state of soldering can be easily confirmed visually.

[0009]

[Effect of the device]

 As described in detail above, according to the present invention, when the surface mounting is performed, the solder is deposited on the tip surface of the lead terminal, the reliability of the soldering can be improved, and the soldering state can be visually checked easily. To provide a container for surface-mounted electronic components that can be confirmed, has good flatness of the terminals on the mounting surface, is easy to assemble, has excellent productivity, and can be downsized. You can

[0010]

[Brief description of drawings]

FIG. 1 is a plan view showing a lead frame used in a container according to an embodiment of the present invention.

FIG. 2 is an assembled perspective view showing a conventional surface mount piezoelectric oscillator.

FIG. 3 is a plan view showing a lead frame used in the piezoelectric oscillator shown in FIG.

[Explanation of symbols]

 11 lead frame 11a lead terminal 11b bridge portion 11c frame portion 12 base

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H03B 5/32 H 8321-5J // B65D 85/38 L 8921-3E H05K 1/18 F 9154- 4E (72) Inventor Takayuki Takaishi 2 at 1275 Kamihirose, Sayama City, Saitama Prefecture Nikkagen Denpa Kogyo Co., Ltd. Sayama Plant

Claims (1)

[Scope of utility model registration request] 1. A lead frame in which side portions of a plurality of lead terminals are bridged to a frame-shaped frame via bridging portions, and at least tip surfaces of each terminal are plated with solder, and each terminal of the lead frame. A surface mount type electronic component, comprising: a base whose base end is molded with a thermoplastic resin; an electronic component housed in the base; and a metal lid which covers the base. Container.