JP4731232B2 - Surface mount base for electronic devices - Google Patents

Description

  The present invention relates to a surface mount base for an electronic element for supporting an electronic element such as an LED or a crystal resonator and facilitating surface mounting on a set substrate, and more particularly to a surface mount base easy to manufacture.

  A surface mount type package in which a crystal resonator is mounted on a surface mount base is small and light in weight, and is therefore widely used especially in portable electronic devices. Usually, this type of package is sealed by mounting a crystal resonator on a surface mount base. For example, Patent Literature 1 describes a surface mount base that considers compatibility with a set substrate on which a crystal resonator is mounted.

  FIG. 2 shows a cross section of a crystal resonator package using the surface mount base described in Patent Document 1. Although not shown, the planar shape is a rectangle, and FIG. 2 shows a longitudinal section thereof. Reference numeral 21 denotes a surface mount base, which includes an insulating support member 22, a pair of metal lead terminals 23, and a sealing glass 24. A crystal resonator 25 is mounted on the upper surface of the surface mount base 21, and an upper portion thereof is covered with a cover 26.

  The support member 22 is made of ceramic, for example, and has a pair of through holes 27 at both ends. The lead terminal 23 includes an element connection terminal 23 a, a lead portion 23 b, and a mounting terminal 23 c, and is attached to the support member 22 with the lead portion 23 b penetrating the through hole 27. The through hole 27 is filled with a sealing glass 24, and the lead terminal 23 is sealed in the through hole 27, thereby ensuring the airtightness of the surface mount base 21. The element connection terminal 23a of the lead terminal 23 is located facing the upper surface side of the support member 22, and is connected to the electrode of the crystal unit 25 by a conductive adhesive or the like. The mounting terminal 23c is disposed so as to face the bottom surface side of the support member 22, and is used as a terminal when mounted on the set substrate. The element connection terminal 23a and the mounting terminal 23c are bent in opposite directions in the horizontal direction with respect to the vertical lead portion 23b.

  As the sealing glass 24, solid glass is filled into the through-hole 27 and fired integrally with the support member 22 and the lead terminal 23. As a result, the solid glass is melted and integrated with the support member 22 and the lead terminal 23 to form the surface mount base 21.

  The cover 26 is made of an insulating material such as ceramic, and is joined to the outer periphery of the surface mount base 21 by, for example, glass sealing.

In such a package, the mounting terminals 23c of the lead terminals 23 are joined to a circuit terminal portion (not shown) of the set substrate by soldering, for example, by transporting a high-temperature furnace. At that time, since the metal mounting terminal 23c has elasticity, it absorbs a difference in expansion coefficient between the ceramic support member 22 and the set substrate (glass epoxy substrate or the like). Therefore, the external impact applied to the joint between the two due to heat cycle or the like is alleviated, and for example, cracks and chips generated in the solder are prevented.
JP 2003-297453 A

  In the step of manufacturing the surface mount base 21 having the above-described configuration, when the lead terminal 23 is attached to the support member 22, the lead terminal 23 is inserted into the through hole 27 and fixed using a jig or the like. Fill the shape glass. However, in order to facilitate the insertion of the lead terminal 23, the through-hole 27 must be made sufficiently large, so that the lead portion 23b of the lead terminal 23 is unstable in the through-hole 27 and unstable in positioning. Therefore, handling in the manufacturing process was difficult.

  Furthermore, along with the miniaturization of electronic devices such as capacitors and diodes and ICs mounted on the same set substrate (glass epoxy substrate or the like), the surface mount base for electronic devices tends to be miniaturized. For this reason, the region where the metal mounting terminal 23c is formed is dimensionally restricted, the elasticity is lowered, the action of mitigating the external impact acting on the lead terminal 23 is lowered, and the surface mounting base and the mounting substrate are joined. The risk of the joints being destroyed due to external stress applied to the surface increased.

  The present invention has a structure that is positioned in a state in which detachment and backlash of the lead terminal with respect to the support member are suppressed during assembly, is easy to manufacture, and can improve the mounting position accuracy of the lead terminal, Moreover, it is an object of the present invention to provide a surface mount base in which the elasticity of the lead terminal 2 is ensured and the external impact can be sufficiently mitigated.

The surface mount base for an electronic device according to the present invention includes an insulating support member having a through hole, an element connection portion disposed in an inner region of the through hole, a mount portion disposed outside the support member, and A lead terminal having a lead portion connected between the element connection portion and the mounting portion and inserted into the through-hole, and filled in the through-hole of the support member and sealing the lead portion in the through-hole Sealing glass. The lead portion sandwiches the support member and includes a non-sealing region protruding from the sealing glass in the through hole toward the mounting portion in the through hole .

  According to the configuration of the surface mount base of the present invention, the lead terminal is securely held by the support frame by abutting against and pressing the support frame. As a result, during assembly, positioning is performed in a state where detachment and backlash of the lead terminal with respect to the support frame are suppressed, and in that state, the sealing glass can be filled and baked, and the lead terminal is easy to manufacture. It is possible to improve the mounting position accuracy.

  Furthermore, the lead terminal formed of a metal plate such as an Fe-Ni-Co alloy has an electronic element assembly process, a mounting process on a glass-epoxy-based board, and a board mounting process due to the elasticity of the non-sealing region provided in the lead part The structure is designed to mitigate impacts acting on the lead terminals from the outside due to the cooling and heating cycle. Therefore, the strength against external stress is improved and long-term reliability can be maintained.

  In the surface mount base of the present invention, it is preferable that the length of the non-sealing region in the through direction of the through hole is 0.1 mm to 0.5 mm.

  Moreover, it is preferable to have a gap of 0.05 mm to 0.3 mm between the surface of the lead portion and the inner surface of the support member.

    Hereinafter, the surface mount base in the embodiment of the present invention will be specifically described with reference to FIG. 1A is a plan view of a surface mount base, FIG. 1B is a side view, FIG. 1C is a cross-sectional view taken along line AA in FIG. 1A, FIG. 1D is a rear view, and FIG. It is -B sectional drawing. The surface mount base is composed of an insulating support frame 1, a pair of metal lead terminals 2, and a sealing glass 3.

  The support frame 1 is made of, for example, ceramic, has a substantially rectangular frame shape, and forms a lumen by the inner peripheral surface 1a. The lead terminal 2 is formed of a metal plate such as an Fe-Ni-Co alloy and has an element connection terminal 2a, a lead part 2b, and a mounting terminal 2c. The lead part 2b is inserted into the inner cavity of the support frame 1 and supported. Mounted on the frame 1. The inner cavity of the support frame 1 is filled with a sealing glass 3, and the lead terminals 2 are sealed in the support frame 1, whereby the airtightness between the front and back surfaces of the surface mounting base is maintained.

  The element connection terminal 2a of the lead terminal 2 is located facing the upper surface side of the support frame 1, and is connected to the electrode by a conductive adhesive or the like when the electronic element is mounted. The mounting terminal 2c is disposed so as to face the bottom surface side of the support frame 1, and is used as a terminal when mounted on the set substrate.

  The lead portion 2b of the lead terminal 2 has an unsealed portion 2b 'that is not sealed to the glass seal 3 with a length of 0.1 to 1.0 mm. Due to the action of the protrusion 4 provided on the lead portion 2b, the non-sealing portion 2b 'and the support frame 1 are separated from each other and have a gap of 0.05 mm to 1.5 mm. The bent portion located between the non-sealing portion 2b ′ and the mounting terminal 2c has a radius of curvature R of 0.01 mm to 1.0 mm, and can increase the elasticity to mitigate external impact. .

  The length of the non-sealed portion 2b ′ is 0.5 mm, the gap between the non-sealed portion 2b ′ and the support frame 1 is 0.15 mm, and the bent portion is located between the non-sealed portion 2b ′ and the mounting terminal 2c. The radius of curvature R is preferably 0.1 mm.

  Further, by providing a bent portion or a stepped portion in the non-sealing portion 2b ', it is possible to further increase the elasticity for reducing the external impact.

  The mounting terminal 2c of the lead terminal 2 extends along the outer peripheral surface 1b through the bottom surface of the support frame 1 and forms an outer surface facing portion 2d. The lead portion 2 b of the lead terminal 2 is disposed so as to face the inner peripheral surface 1 a of the support frame 1. The outer surface facing portion 2d and the lead portion 2b are configured such that the support frame 1 is sandwiched therebetween. That is, the interval between the outer surface facing portion 2d and the lead portion 2b is formed slightly smaller than the thickness between the inner peripheral surface 1a and the outer peripheral surface 1b of the support frame 1. Therefore, if the support frame 1 is inserted between the outer surface facing portion 2d and the lead portion 2b, the lead terminal 2 is bent to generate a pressing force for clamping the support frame 1, and the lead terminal 2 is engaged with the support frame 1. Match. More precisely, the interval between the outer surface facing portion 2d and the lead portion 2b is the distance between the inner surface of the outer surface facing portion 2d facing the outer peripheral surface 1b of the support frame 1 and the support frame 1 formed on the lead portion 2b. The distance from the protrusion 4 protruding toward the inner peripheral surface 1a. The distance between the inner surface of the outer surface facing portion 2 d and the protrusion 4 of the lead portion 2 b is formed smaller than the thickness of the support frame 1.

  After the lead terminals 2 are elastically held on the support frame 1 by the above-described clamping action, the solid glass as the sealing glass 3 is filled in the lumen of the support frame 1 and baked. Thereby, the lead terminal 2 is integrated with the support frame 1 by the sealing glass 3, and an airtight structure is formed.

  As described above, according to the structure of the present embodiment, since the sealing process can be performed in a state where each lead terminal 2 is securely held on the support frame 1, the lead terminal can be performed without requiring a jig. 2 and backlash can be suppressed. Therefore, it is easy to manufacture and it is possible to improve the accuracy of the mounting position of the lead terminals.

  Although it is not essential to provide the protrusion 4 on the lead portion 2b, the following effects can be obtained. That is, by providing the protrusion 4, a gap is generated between the inner peripheral surface 1 a of the support frame 1 and the lead portion 2 b. The gap makes it easy for molten glass to enter between the inner peripheral surface 1a and the lead portion 2b, and it becomes easy to ensure airtightness at the location. Furthermore, in the present embodiment, the lead portion 2b of the lead terminal 2 appears in FIG. 1 (e) or the like in order to make it easier for molten glass to enter between the inner peripheral surface 1a and the lead portion 2b. Thus, the width is narrower than the element connection terminal 2a.

  Further, the outer surface facing portion 2d can be given a bent shape so as to be convex toward the outer peripheral surface 1b of the support frame 1. In this case, the distance between the outer surface facing portion 2d and the lead portion 2b is the distance between the apex of the bent shape on the inner surface of the outer surface facing portion 2d and the protrusion 4 formed on the lead portion 2b. The shape of the outer surface facing portion 2d may be any shape as long as the mounting of the lead terminal 2 to the support frame 1 is easy and the conditions for generating a pressing force due to elastic deformation after mounting are satisfied. For example, it may be a protrusion or a U-shape that forms a bend in a bent portion.

  In the present embodiment, the upper surfaces of the element connection terminals 2 a and the sealing glass 3 are recessed from the upper end surface of the support frame 1, and a cavity 5 is formed in the upper part of the support frame 1. When the cavity 5 is formed, the element connection terminal 2a is accommodated inside the support frame 1 and does not protrude outside, so that an effect of avoiding damage or the like before the element is mounted can be obtained. It is also possible to configure so that the electronic element is mounted in the cavity 5.

  Such a cavity 5 is formed by a simple linear support frame 1 in the present embodiment. That is, no step is formed on the inner peripheral surface 1 a of the support frame 1, and the support frame 1 is linear in the vertical direction. Therefore, manufacture of the support frame 1 is easy, and when the surface mounting base is assembled, the front and back of the support frame 1 need not be identified, and the manufacturing process is simple.

  Further, an outer surface groove 6 is formed on the outer peripheral surface 1 b of the support frame 1. The outer surface facing portion 2 d of the lead terminal 2 is engaged with the outer surface groove 6. That is, the step formed by the outer surface groove 6 restricts the outer surface facing portion 2d from moving on the outer peripheral surface 1b of the support frame 1 in the lateral direction. Thereby, the effect of positioning the lead terminal 2 with respect to the support frame 1 is obtained.

  In the above embodiment, the support frame 1 has a flat plate shape. However, the support frame 1 may have a shape that forms a recess, for example.

  According to the surface mount base for an electronic device of the present invention, when assembling, the lead terminal can be prevented from being detached or rattled from the support frame, and can be easily manufactured, and the lead terminal mounting position accuracy can be increased. . Therefore, it is suitable for use in a surface mounting package on which an electronic element such as an LED or a crystal resonator is mounted.

It is a figure which shows the surface mounting base for electronic devices by one Embodiment of this invention, (a) is a top view, (b) is a side view, (c) is AA sectional drawing in (a), (d ) Is a back view, and (e) is a cross-sectional view along BB in (a). Sectional view of a surface mount base for a conventional electronic device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support frame 1a Inner peripheral surface 1b Outer peripheral surface 2 Lead terminal 2a Element connection terminal 2b Lead part 2b 'Non-sealing part 2c Mounting terminal 2d Outer surface opposing part 3 Sealing glass 4 Protrusion 5 Cavity 6 Outer surface groove 21 Surface mounting base 22 Support Member 23a Element connection terminal 23b Lead part 23c Mounting terminal 24 Sealing glass 25 Crystal resonator 26 Cover

Claims (3)

An insulating support member having a through hole;
An element connection portion disposed in an inner region of the through hole, a mounting portion disposed outside the support member, and a lead portion connected between the element connection portion and the mounting portion and inserted into the through hole A lead terminal having
A sealing glass filled in the through hole of the support member and sealing the lead portion in the through hole;
The lead part sandwiches the support member , and includes an unsealed region protruding from the sealing glass in the through hole toward the mounting part in the through hole. Surface mount base for.   The surface mount base for an electronic device according to claim 1, wherein a length of the non-sealing region in a through direction of the through hole is 0.1 mm to 0.5 mm.   The surface mount base for an electronic device according to claim 1 or 2, wherein a gap of 0.05 mm to 0.3 mm is provided between the surface of the lead portion and the inner surface of the support member.

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