JP2013030695A - Package for electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the occurence of cracks in solder.SOLUTION: A package for an electronic device includes: a flat plate like substrate part; a frame part provided at an outer periphery of the substrate part and forming a recessed part; a pair of two mounting pads provided at an area located in the recessed part and in the substrate part; and an external connection terminal electrically connecting with the pair of two mounting pads and provided on a main surface of the substrate part which is the opposite side of a main surface where the frame part is provided. The external connection terminal is formed into a substantially square shape, and each corner part is formed into a curved line shape.

Description

  The present invention relates to an electronic device package on which element parts are mounted.

  Conventionally, an electronic device includes, for example, an element component, a package on which the element component is mounted, and a lid member that seals the element component. A crystal resonator will be described as an example of the electronic device.

As shown in FIG. 5A, the crystal resonator 200 includes an element mounting member 210 that is an electronic device package, a crystal resonator element 220 that is an element component, and a lid member 230 that seals the crystal resonator element 220. (For example, refer to Patent Document 1).
The crystal resonator element 220 includes a plate-shaped crystal piece 221 processed with a predetermined cut angle, an excitation electrode 222 provided to face both main surfaces of the crystal piece 221, and a crystal piece connected to the excitation electrode 222. 221 includes a pair of connection terminals 223 provided so as to be routed to one end of the 221. By applying a voltage to these connection terminals 223, the portion provided with the excitation electrode 222 is vibrated.
The crystal resonator element 220 configured as described above is mounted on the element mounting member 220 having the recess 211 via the conductive adhesive D.

The element mounting member 210 that is a package for an electronic device is made of, for example, ceramic and has a concave portion 211 on one main surface, and a mounting pad P for mounting the crystal resonator element 220 in the concave portion 211 is provided. Two are provided.
The element mounting member 210 is provided with at least two external connection terminals 212 on the other main surface. Each external connection terminal 212 is electrically connected to the mounting pad P separately via an internal wiring (not shown) provided inside the element mounting member 210.

  The lid member 230 is made of, for example, a flat metal member and has a size that closes the recess 211 of the element mounting member 210. The lid member 230 is bonded to the element mounting member 210 in a vacuum atmosphere, for example, and seals the recess 211.

  Therefore, the crystal resonator 200 has the recess 211 formed by the lid member 230 in a state where the crystal resonator element 220 is mounted on the mounting pad P provided in the recess 211 of the element mounting member 210 via the conductive adhesive D. It is in a sealed state.

Here, the external connection terminal 212 provided in the element mounting member 210 will be described.
As shown in FIG. 5B, the external connection terminal 212 is formed in a square shape, for example, and is formed close to the short side of the element mounting member 210. Further, the mounting pad for an electronic device having a rectangular shape provided on a substrate such as a mother board on which the crystal resonator is mounted is provided larger than the external connection terminal 212 of the crystal resonator. Therefore, the external connection terminal 212 is formed in a quadrangular shape, so that the crystal resonator 200 can be accommodated in a mounting pad for an electronic device provided on a substrate (not shown) such as a motherboard using glass-epoxy. There is an effect that the mounting becomes easy.

For mounting the crystal resonator 200 on the substrate, for example, the external connection terminal 212 provided on the element mounting member 210 of the crystal resonator 200 and the electronic device mounting pad L provided on the substrate are bonded via solder. Is done.
For example, specifically, the crystal resonator 200 is mounted by applying cream solder to a predetermined electronic device mounting pad L provided on the substrate by screen printing, and the crystal resonator element on the cream solder. A mounting member is placed. When heated at a predetermined temperature in this state and then cooled, the cream solder is solidified to bond the substrate and the crystal unit.
At this time, the cream solder tends to spread over the entire surface of the electronic device mounting pad L and the external connection terminal 212 due to heating, and to approach the center side of the range wetted and spread during cooling.

  Here, the solder wets and spreads over the entire surface of the mounting pad L for the electronic device, the entire surface of the external connection terminal 212, and a part of the side surface of the element mounting member 210 of the crystal resonator element when heated. Become.

JP 2006-005027 A

Since the element mounting member, which is an electronic device package, is made of a different material from the substrate, the coefficient of thermal expansion is also different.
As shown in FIG. 6, the mounting pad L for the electronic device and the external connection terminal 212 are formed in a quadrangular shape, so that the solder located at the corners of the quadrangular shape during the cooling is also in a range where the solder spreads. Presumed to approach the center side. Accordingly, it is considered that the stress increases in the corner portion 213 of the external connection terminal 212 after the electronic device package 210 used in the conventional crystal resonator 200 is mounted on the substrate.
In addition, an element mounting member that is a package for a conventional electronic device, for example, is repeatedly heated and cooled in an environment where the electronic device is used. L, the electronic device package 210, and the external connection terminal 212 are repeatedly expanded and contracted. Due to the repeated expansion and contraction, it is estimated that the solder cracks from the corner portion of the external connection terminal 212 and spreads.
If the solder is cracked, it is difficult for electricity to flow from the substrate to the crystal resonator, or there is a risk that the electricity will not flow and the crystal resonator will not oscillate.

  Therefore, an object of the present invention is to provide an electronic device package that solves the above problems and reduces the occurrence of cracks in solder.

  The electronic device package of the present invention includes a flat substrate portion, a frame portion provided on the outer periphery of the substrate portion to form a recess, and a pair of two mountings provided in the substrate portion within the recess. A pad and an external connection terminal electrically connected to the two mounting pads and provided on a main surface opposite to the main surface on which the frame portion of the substrate portion is provided, and the external connection terminal Is formed in a substantially quadrangular shape, and the corner portion is formed in a curved shape.

  In addition, the electronic device package of the present invention is electrically connected to the flat substrate portion, the two pairs of mounting pads provided in one main surface of the substrate portion, and the two pairs of mounting pads. And an external connection terminal provided on the other main surface opposite to the one main surface of the substrate portion, wherein the external connection terminal is formed in a substantially square shape, and a corner portion is formed in a curved shape. It is characterized by.

According to such an electronic device package of the present invention, since the corner portion of the external connection terminal is curved, the concentration of stress on the corner portion of the external connection terminal is reduced when the solder is mounted on the substrate. ,
It is possible to prevent cracks from entering the solder.

(A) is a perspective view which shows an example of the front side of the package for electronic devices which concerns on 1st embodiment of this invention, (b) is the back side of the package for electronic devices which concerns on 1st embodiment of this invention. It is a perspective view which shows an example. It is a schematic diagram which shows an example of the external connection terminal of the package for electronic devices which concerns on 1st embodiment of this invention. It is a conceptual diagram which shows an example of the state which provided the solder in the external connection terminal. (A) is a perspective view which shows an example of the front side of the package for electronic devices which concerns on 2nd embodiment of this invention, (b) is the back side of the package for electronic devices which concerns on 2nd embodiment of this invention. It is a perspective view which shows an example. (A) is sectional drawing which shows an example of the crystal resonator which is a conventional electronic device, (b) is a schematic diagram which shows an example of the external connection terminal of the crystal resonator which is a conventional electronic device. It is a conceptual diagram which shows an example of the state which provided the solder in the external connection terminal of the crystal oscillator which is a conventional electronic device.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. For the sake of clarity, the configuration of the invention is exaggerated.

(First embodiment)
As shown in FIGS. 1A and 1B, the electronic device package 100 according to the first embodiment of the present invention mainly includes a substrate part 10, a frame part 20, a mounting pad 30, and an external connection terminal 40. It is configured.

The substrate unit 10 is made of, for example, ceramic and is formed in a flat plate shape.
This substrate portion is provided with a concave casteration on the short side, and is formed in a state where the end of the caster and the long side are close to each other. For example, the width between the end portion and the long side of the castellation is preferably close enough that the strength of the substrate portion 10 does not decrease.
Note that the length of the castration is a part of the short side of the substrate unit 10.
The frame portion 20 is made of, for example, ceramic, and is provided along the outer periphery of the substrate portion 10 to form the recess 21. In addition, the board | substrate part 10 and the frame part 20 are integrally formed.

The mounting pads 30 are provided in pairs, and are provided close to the short side of the substrate unit 10 in the recess 11.
The mounting pad 30 is made of, for example, gold and is formed on the surface of the base metal provided on the surface of the substrate unit 10.

  The external connection terminal 40 is provided on the main surface opposite to the main surface on which the frame portion 20 of the substrate unit 10 is provided by being electrically connected to the pair of mounting pads 30. The external connection terminal 40 is formed in a substantially square shape, and the corner portion is formed in a curved shape.

  Here, the external connection terminals 40 are provided in pairs, for example, and one external connection terminal 40 is electrically connected to one mounting pad and an internal wiring (not shown) provided in the substrate unit 10. The other external connection terminal 40 is electrically connected to the other mounting pad via another internal wiring (not shown) provided in the substrate unit 10.

As shown in FIG. 2, such external connection terminals 40 are provided one by one on two short sides of the substrate portion 10 formed in a quadrangular shape. At this time, the external connection terminal 40 is formed by aligning one side of the substantially square shape with the edge of the short side of the substrate unit 10. In the present embodiment, the length of one side of the external connection terminal 40 is determined in accordance with the length of the casteration. Further, the external connection terminal 40 is formed in a curved shape without being formed at a right angle at two corner portions located inside the substrate portion 10. For example, the corner portion can form a curved shape with a predetermined radius R.
Further, the corner portion of the external connection terminal 40 that has a right angle is reduced, and the increase in stress on the corner portion of the external connection terminal 40 can be reduced. In addition, since the corner | angular part used as the right angle provided in the short side of the board | substrate part 10 of the external connection terminal 40 is connected with the solder | pewter which protrudes outside when it mounts in the board | substrate which is not illustrated, the generated stress becomes small.

In such an electronic device package 100 according to the first embodiment of the present invention, as shown in FIG. 3, the corner portions of the external connection terminals 40 are curved, so that the degree of expansion varies with the same temperature change. Even in such a case, stress can be reduced from concentrating on the corner portion of the external connection terminal 40 having a curved shape at the corner portion of the external connection terminal 40.
The degree of expansion of the electronic device package 100 and the substrate such as the mother board is almost always different even at the same temperature change, and can reduce the stress on the solder when expanding and the stress on the solder when contracting. it can.
Therefore, cracks can be reduced in the solder.
In addition, the corner portion of the external connection terminal 40 provided on the substrate portion 10 at a right angle is reduced, and an increase in stress on the corner portion of the external connection terminal 40 can be reduced.

(Second embodiment)
As shown in FIGS. 4A and 4B, the electronic device package 101 according to the second embodiment of the present invention has no frame portion, and is mainly composed of the substrate portion 10, the mounting pads 30, and the external connection terminals 40. It differs from 1st embodiment by the point comprised by.

The substrate portion 10 is formed in a rectangular shape and a flat plate shape, and two pairs of mounting pads 30 are provided in one main surface, and is electrically connected to the mounting pads 30 and is connected to one of the substrate portions 10. External connection terminals 40 are provided on the other main surface opposite to the main surface.
The external connection terminal 40 is formed in a substantially square shape, and the corner portion is formed in a curved shape.

The configurations of the mounting pad 30 and the external connection terminal 40 provided on the substrate unit 10 are the same as those in the first embodiment.
Therefore, even when the electronic device package 101 according to the second embodiment of the present invention is configured as described above, the same effects as those of the first embodiment can be obtained.

In addition, this invention can be changed suitably and used.
For example, the electronic component mounted on the mounting pad may be mounted with a chip component such as an integrated circuit element, a capacitor, a thermistor, or a piezoelectric element other than a quartz crystal, in addition to the crystal vibrating element.
In addition, the external connection terminal may be provided with a curved corner portion on the short side on the substrate part 10 side.
Further, the electronic device package of the present invention may be used as a connection component on the mounting side of the electronic device used in the module to the substrate.

DESCRIPTION OF SYMBOLS 100 Electronic device package 10 Board | substrate part 20 Frame part 30 Mounting pad 40 External connection terminal

Claims (2)

A flat substrate portion;
A frame portion provided on the outer periphery of the substrate portion to form a recess;
A pair of mounting pads provided in the recess and in the substrate portion;
An external connection terminal provided on a main surface opposite to a main surface on which the frame portion of the substrate unit is electrically connected to the pair of mounting pads;
With
A package for an electronic device, wherein the external connection terminals are formed in a substantially square shape, and corner portions are formed in a curved shape. A flat substrate portion;
A pair of mounting pads provided in one main surface of the substrate portion;
An external connection terminal electrically connected to the two pairs of mounting pads and provided on the other main surface opposite to one main surface of the substrate portion;
With
A package for an electronic device, wherein the external connection terminals are formed in a substantially square shape, and corner portions are formed in a curved shape.

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