JPH0680744B2 - Leadless package - Google Patents

Description

[Detailed Description of the Invention] [Table of Contents] -Outline-Industrial application field-Conventional technology (Figs. 5 and 6) -Problems to be solved by the invention-Means for solving problems- Operation ・ Examples (Figs. 1, 2, 3, 4) ・ Effects of the invention [Overview] In the insulation hermetically sealed (hermetically sealed) leadless package, the flat part for connecting the electrode body (18) ( 18
By disposing a) away from the lower surface of the glass (6) through the protrusion (18b) continuous with the flat portion (18a), the glass (6) is mounted when the package is mounted on the printed wiring board. Since it can be mounted in a form in which it is separated from the printed wiring board and floated, cracks in the soldering part and conductor patterns caused by the difference in thermal expansion coefficient between the glass (6) and the printed wiring board (11). Peeling / breaking of (12), destruction of fusion interface between electrode body (18) and glass (6), glass (6)
It is possible to reliably prevent cracks in the situation.

[Industrial application field]

TECHNICAL FIELD The present invention relates to an insulating hermetically sealed (hermetically sealed) type leadless package for accommodating a crystal oscillator (crystal element), an integrated circuit (IC) substrate, a composite element circuit substrate, other elements, etc. It concerns embedded structures.

Conventionally, a hermetically sealed package is formed with a plurality of lead wires extending downward from the package body, and when mounting the package on a printed wiring board, these lead wires are small holes provided on the printed wiring board. It was inserted into and was automatically soldered. In such a package, the problem that it is necessary to purposely provide a small hole in the printed wiring board, the problem that the solder is not sufficiently filled in the small hole and the electrical continuity is damaged, and the lead wire is bent There is a problem in that careless force is applied during the repair to break the fusion interface between the lead wire and the glass, and in the case of a large number of leads, it is difficult to insert the lead wire into the printed wiring board due to lead deformation.

Therefore, recently, a leadless package having an electrode on the lower surface of the package and capable of directly connecting the electrode to a printed wiring board has been developed and has been widely used.

[Conventional technology]

5 and 6 are views for explaining a conventional example, FIG. 5 (a) is a perspective view (partially cutaway) of the conventional example, and FIG. 5 (b) is (a) A ₁ -A. FIG. 6 is a cross-sectional view taken along line _{2 and} FIG. 6 is a diagram showing a conventional example mounted on a printed wiring board.

As shown in FIG. 5, the body 1 is made of a plate material such as iron / nickel / cobalt alloy (commonly known as Kovar) processed by a press molding machine into a rectangular planar shape. Is formed with a flange portion 3 for mounting, and a concave area 4 having a rectangular planar shape is formed in the central portion. The recessed region 4 has a bottom wall 4a and a side wall 4b, and four small holes 5 (5a) for inserting an electrode body are formed through the bottom wall 4a. Of these small holes 5 (5a), three small holes 5 have a relatively large hole diameter, and one small hole 5a has a relatively small hole diameter. The glass 6 has a concave portion corresponding to the outer surface and the lower surface of the concave region 4 of the container 1 using glass powder, and a through hole (not shown) at a position corresponding to the small holes 5 and 5a of the container 1. It is press-molded in advance into a block shape having. Then, the block-shaped glass 6 is fitted into the body 1 from the lower side, and then the electrode body 8 is inserted into the four small holes 5 and 5a, and the assembly is stored in a carbon jig (not shown). Then, a conductive material (for example, silver braze) 7 is added to the inner lead portion of one of the four electrode bodies 8 (the electrode body to be inserted into the small hole 5a) to become a ground electrode, and the heating furnace is added. The glass 6 and the conductive material 7 are heat-welded (not shown), and FIG.
A hermetically sealed leadless package 10 as shown in is obtained.

As shown in FIG. 5 (b), the glass 6 is the bottom wall 4 a of the body 1.
Is sealed from the lower surface to the outer surface of the side wall 4b. on the other hand,
The electrode body 8 is a flat portion 8a for connection which is welded to the lower surface of the glass 6.
And a small hole in the body 1 that penetrates the inside of the glass 6
It extends on the body 1 through 5, 5a. The other electrode bodies 8 except the ground electrode body passing through the small hole 5a are insulated from the body 1 through the glass 6, and the ground electrode body 8 passing through the small hole 5a is connected through the conductive material 7 to the body body. 1 is electrically connected. A crystal element, an IC board, a composite element circuit board, and other elements are mounted on the completed package 10, and after connecting to the electrode body 8, the lid 2 is attached to the body 1 by a method such as resistance welding.

The package 10 thus formed is mounted on the printed wiring board 11 as shown in FIG. In FIG. 6, reference numeral 12 is a conductor pattern provided on the printed wiring board 11, and 13 is solder. When the package 10 is mounted on the printed wiring board 11, the solder 13 is used for the conductor pattern 12
By previously coating on either the top or the connection flat portion 8a, the flat portion 8a is aligned and arranged on the conductor pattern 12, and is heated in a heating furnace (not shown) to melt the solder 13, The package 10 is soldered onto the printed wiring board 11. In this conventional example, since the glass 6 is directly attached to the printed wiring board 11 via the flat portion 8a, the glass 6 and the printed wiring board 11 are mechanically directly restrained from each other. .

[Problems to be solved by the invention]

In the above-mentioned conventional example, the glass 6 is directly attached to the printed wiring board 11 via the electrode body 8 (flat portion 8a), so that the glass 6 and the printed wiring board 11 are directly restrained from each other. Therefore, concentrated stress acts due to the difference in the amount of thermal expansion (or the amount of contraction during cooling) due to the difference in the coefficient of thermal expansion between the glass 6 and the printed wiring board (substrate material) 11, cracks in the soldered portion, and conductor patterns. There is a problem that peeling and disconnection of (12), breakage of the fusion bonding interface between the electrode body (8) and the glass (6), cracks of the glass (6) itself, and the like are likely to occur. In particular, when the base material of the printed wiring board (11) is a resin-based material, the above-mentioned problems are likely to occur because the difference in coefficient of thermal expansion is large.

The present invention was created in view of the above problems, and a leadless package capable of solving the above problems even if the difference in the coefficient of thermal expansion between the glass used for the package and the printed wiring board is large. It is intended to be provided.

[Means for solving problems]

As a means for solving the above problems, in the present invention,
A body 1 having a flange portion 3 for mounting the lid 2 on the periphery and made of a metal plate, a glass 6 as an insulating material provided on at least the lower surface of the body 1, and a lower surface side of the glass 6 for connection It has a flat portion 18a and the inside of the glass and the body 1
In a leadless package in which a plurality of electrode bodies 18 penetrating through and extending over the body 1 are hermetically sealed and insulated, the electrode body 18 has a connecting flat portion 18a.
A leadless package characterized in that the leadless package is arranged apart from the lower surface of the glass 6 through a continuous protruding portion 18b.

[Work]

The glass (6) is arranged on the printed wiring board by arranging the connecting flat portion (18a) of the electrode body (18) at a distance from the lower surface of the glass (6) via the projection (18b) continuous with the flat portion (18a). The package (20) can be mounted on the printed wiring board in a state of being separated from and floating on the printed wiring board, whereby the difference in thermal expansion amount or contraction amount between the glass (6) and the printed wiring board is caused by the protruding portion (18b). Since they can be absorbed, the glass (6) and the printed wiring board can individually and freely perform the thermal expansion action or the contraction action at the time of cooling without being directly restrained to each other.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 are views for explaining the embodiment and the modification of the present invention. In these figures, the same or corresponding portions as those in FIGS. 5 and 6 described above are designated by the same reference numerals.

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 1 (a) is a perspective view (partially cut away), and FIG. 1 (b) is a view of (a).
B ₁ is a _two-wire cross section -B. FIG. 2 is a diagram showing a form in which the embodiment of FIG. 1 is mounted on a printed wiring board (11).

As shown in FIG. 1, the body 1 is made of a plate material such as iron / nickel / cobalt alloy (commonly known as Kovar) processed by a press molding machine into a rectangular planar shape. Is formed with a flange portion 3 for mounting, and a concave area 4 having a rectangular planar shape is formed in the central portion. The recessed region 4 has a bottom wall 4a and a side wall 4b, and four small holes 5 (5a) for inserting an electrode body are formed through the bottom wall 4a. Of these small holes 5 (5a), three small holes 5 have a relatively large hole diameter, and one small hole 5a has a relatively small hole diameter. The glass 6 has a concave portion corresponding to the outer surface and the lower surface of the concave region 4 of the container 1 using glass powder, and a through hole (not shown) at a position corresponding to the small holes 5 and 5a of the container 1. It is press-molded in advance into a block shape having. Then, the block-shaped glass 6 is fitted into the body 1 from the lower side, and then the electrode body 18 is inserted into the four small holes 5 and 5a, and the assembly is stored in a carbon jig (not shown). Then, a conductive material (for example, silver braze) 7 is added to the inner lead portion of one of the four electrode bodies 18 (the electrode body to be inserted into the small hole 5a) to become a ground electrode, and the heating furnace is added. The glass 6 and the conductive material 7 are heated and welded (not shown), and FIG. 1 (b) is shown.
A hermetically sealed leadless package 20 as shown in is obtained.

As shown in FIG. 1 (b), the glass 6 is the bottom wall 4 a of the body 1.
Is sealed from the lower surface to the outer surface of the side wall 4b. The electrode body 18 has a protruding portion 18b protruding from the lower surface of the glass 6.
Has a connection flat portion 18a which is arranged apart from the lower surface of the glass 6 through the glass 6, penetrates the inside of the glass 6, and extends on the container 1 through the small holes 5 and 5a of the container 1. . The other electrode bodies 18 except the electrode body passing through the small hole 5a are insulated from the body 1 through the glass 6, and the electrode body 18 passing through the small hole 5a.
Are electrically connected to the body 1 via the conductive material 7. After the package 20 is completed, a crystal element, an IC board, a composite element circuit board, and other elements are mounted, and after electrically connecting to the electrode body 18, the lid 2 is resistance welded (projection) to the flange portion 3 of the body 1. (Eg, welding), soldering, gold welding, laser welding, or the like (see FIG. 1A). As the material of the glass 6, borosilicate powder glass, borosilicate glass containing filler, or other suitable glass is used. Further, as the metal material of the container body 1 and the electrode body 18, in addition to the above Kovar, copper clad Kovar, iron-nickel alloy, and other materials capable of glass sealing can be used.

The package 20 thus formed is mounted on the printed wiring board 11 as shown in FIG. In FIG. 2, reference numeral 12 indicates a conductor pattern formed on the printed wiring board 11, and 13 indicates solder. When mounting the package 20 on the printed wiring board 11, the solder 13 is connected to the flat portion 18 for connection.
The flat portion 18a is preliminarily applied on either the a or the conductor pattern 12, the flat portion 18a is aligned and arranged on the conductor pattern 12, and the solder 13 is melted by heating in a heating furnace (not shown). The package 20 is mounted on the printed wiring board 11 by soldering the portion 18a onto the conductor pattern 12. Therefore, in this example, as compared with the above-described conventional example (FIG. 6), the glass 6 is indirectly provided on the printed wiring board 11 via the protruding portion 18b of the electrode body 18, that is, a predetermined amount is provided on the printed wiring board 11. It is mounted in a floating form at intervals.

In this example, the glass 6 is configured so as to be mounted on the printed wiring board 11 via the protruding portion 18b of the electrode body 18 in such a manner that the glass 6 and the printed wiring board 11 can be mounted.
Even if the difference in the coefficient of thermal expansion between the two is large, the difference in the amount of thermal expansion between the two (or the amount of contraction during cooling) is calculated as
Can be absorbed by b. Therefore, in this example, the glass 6 and the printed wiring board 11 can individually and freely perform expansion or contraction without being restricted by each other.
Therefore, in this example, it is possible to prevent the occurrence of concentrated stress in the glass 6, the printed wiring board 11, the soldered portion, etc.
Therefore, it is possible to reliably prevent cracks in the soldered portion, peeling / breaking of the conductor pattern 12, breakage of the fusion interface between the electrode body 18 and the glass 6, cracks in the glass 6 itself, and the like. Further, in this example, the lower surface S ₁ of the glass 6 and the side surface S ₂ excluding the fused edge portion with the container 1 are formed into extremely good flat surfaces by a unique manufacturing method. As a result, in this example, when the lid 2 is welded to the body 1, etc., the stress distribution inside the glass 6 is made uniform with respect to the mechanical and thermal loads applied to the glass 6, so that the glass 6 itself It is possible to reliably prevent breakage, enhance the commercial value, and prevent cracks, peeling, disconnection, and breakage at each of the above-mentioned locations even better.

FIGS. 3A to 3J are views showing various modifications of the shape of the electrode body 18 and the built-in structure. In the present invention, as described above, the connection flat portion 18a of the electrode body 18 is arranged apart from the lower surface of the glass 6 via the protruding portion 18b. In FIG. 3, (a) shows the tip portion of the flat portion 18a bent upward, and (b) and (c) show the electrode portion by increasing the bent portion in the middle portion up to the flat portion 18a. The area of the contact portion between 18 and the glass 6 is increased to improve the adhesion strength and airtightness between the two, and (d) and (e) are the above (b),
Compared to (c), the length of the protruding portion 18b is further increased, and the protruding portion 18b is also protruded on the side surface to increase the degree of freedom of the protruding portion 18b (stress absorbing function). )
Reduces the manufacturing cost by forming the flat portion 18a and the protruding portion 18b separately from the upper portion of the electrode body 18 and forming the electrode body 18 by brazing them and integrally connecting them by welding or the like. (G) and (h) are flat portions 18a.
And the projecting portion 18b is formed so as to be located inside the side surface position of the glass 6 so as to facilitate the attaching step (welding etc.) of the lid 2 (FIG. 1) to the flange portion 3. Further, (g) is a glass 6 cut out in order to make the length of the free portion of the protruding portion 18b longer than in the case of (b), and (h) is the same as (f) above. The manufacturing cost is reduced, and (i) and (j) are flat portions 18a.
Also, the thickness of the protruding portion 18b is made thinner than the thickness of the upper portion of the electrode body 18 to increase the flexibility (degree of freedom) of the protruding portion 18b.

4 (a), (b) and (c) are views showing various modifications of the three-dimensional structure of the electrode body 18. As shown in FIG. In FIG.
(A), (b), and (c) are not formed by simply bending a strip plate, but are formed into a slightly complicated three-dimensional structure as shown in the drawing, so that the glass 6 (FIG. 1) is formed. It is formed to further increase the adhesion and airtightness with.

〔The invention's effect〕

As described above, according to the present invention, the glass (6) of the package (20) is connected to the protrusion (18) of the electrode body (18).
The glass (6) and the printed wiring board (11) are individually and freely subjected to thermal expansion or contraction by being mounted on the printed wiring board (11) in a floating form via b). The protrusion (18b) absorbs the difference between the expansion amount and the contraction amount between the two, and the concentrated stress in the glass (6), the printed wiring board (11), the soldered portion, etc. It is possible to reliably prevent the occurrence. Therefore, according to the present invention, cracks in the soldering portion, peeling / breaking of the conductor pattern (12), destruction of the fusion interface between the electrode body (18) and the glass (6), cracks in the glass (6) itself, etc. It is possible to obtain the preferable effect of reliably preventing the occurrence of Further, in the above-mentioned embodiment, since the outer surface (S ₁ , S ₂ ) of the glass (6) is formed into a very good flat surface by a unique jig and manufacturing method,
The above effect can be further enhanced, and the commercial value of the package can be enhanced.

[Brief description of drawings]

1 (a) and 1 (b) are views showing an embodiment of the present invention, FIG. 2 is a view showing a form in which the embodiment of FIG. 1 is mounted on a printed wiring board (11), and FIG. 3 ( a) to (j) are views showing various modifications of the shape and built-in structure of the electrode body (18), and FIGS. 4 (a), (b) and (c) are three-dimensional structures of the electrode body (18). FIGS. 5 (a) and 5 (b) are views showing a conventional example, and FIG. 6 is a view showing a form in which the conventional example of FIG. 5 is mounted on a printed wiring board (11). Is. In FIGS. 1, 2, 3, and 4, 20 is a leadless package according to the present invention, 1 is a body, 2 is a lid, 3 is a flange portion, 4 is a concave region, 5 and 5a are small holes, and 6 is glass. 7 is a conductive material, 11 is a printed wiring board, 12 is a conductor pattern, 13 is solder, 18 is an electrode body, 18a is a flat portion for connection, and 18b is a protruding portion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Ando, 4-20 Komunishi-cho, Sachi-ku, Kawasaki-shi, Kanagawa Fuji Denka Co., Ltd. 20-chome, Fuji Denka Co., Ltd. (72) Inventor Tadashi Nishimura 4-chome, Komukai-nishimachi, Saiwai-ku, Kawasaki-shi, Kanagawa 4-chome, Fuji Denka Co., Ltd.

Claims (1)

[Claims] 1. A container body (1) made of a metal plate and having a flange portion (3) around which a lid (2) is attached, and an insulating material provided on at least a lower surface of the container body (1). A plurality of glass (6), and a plurality of flat parts (18a) for connection on the lower surface side of the glass (6), which penetrate the inside of the glass and the body (1) and extend onto the body (1); In a leadless package in which the electrode body (18) is hermetically sealed and insulated, the electrode body (18) has a protrusion (18b) in which the connection flat portion (18a) is continuous with the flat portion (18a). ), And is arranged apart from the lower surface of the glass (6) via the leadless package.