JP2005302990A - Sealing board with brazing material for package, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a sealing board with a brazing material for a package which facilitates control of conditions for welding work of the brazing material to the sealing board, and which is provided with stabilized quality. <P>SOLUTION: In the sealing board with the brazing material for the package, wherein the brazing material is molten and adhered annularly to the sealing surface of the sealing board, a preventive belt for the flow of brazing material is formed along the inner periphery of the annular adhering section of the brazing material for the package or the preventing belts for the flow of the same are formed along the inner and outer peripheries of the same adhering section of the brazing material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing plate with a brazing material for a package and a method for producing the same.

  An increasing number of electronic components use ceramics in various electronic device packages. Most of them have a structure in which an electronic element is housed in a ceramic package in which a concave portion is formed, and an open portion of the ceramic package is sealed with a metal flat cap (hereinafter referred to as a sealing plate).

  FIG. 7 is a cross-sectional view of the electronic component in which the electronic element is a crystal resonator. Reference numeral 1 denotes a surface-mount type crystal resonator, and reference numeral 4 denotes a ceramic substrate constituting a package of the surface-mount type crystal resonator 1. 3 is a flat lid (sealing plate of the present invention) that covers the ceramic substrate 4 constituting the package of the surface-mounted crystal resonator 1 and is usually made of Kovar (iron, nickel, cobalt alloy). is there. Reference numeral 2 denotes a crystal piece, which is housed in an internal space 11 regulated by the ceramic substrate 4 and the lid 3.

  A wiring layer 6 is formed on the upper surface of the ceramic substrate 4 so as not to be electrically connected to the lid 3. Reference numeral 8 denotes a wiring layer as a terminal electrode formed on the lower surface of the ceramic substrate 4. Reference numeral 5 denotes an internal wiring as an electrically conductive portion for connecting both wiring layers 6 and 8. Reference numeral 7 denotes a conductive paste, and one end of the crystal piece 2 is bonded onto the wiring layer 6 via the conductive paste 7. A metallized layer 9 is formed on the uppermost surface of the ceramic substrate 4 for bonding the lid 3. Reference numeral 10 denotes a bonding layer, which is made of a brazing material formed on the metallized layer 9 or on the lower surface of the lid 3. The ceramic substrate 4 and the lid 3 are fused via the bonding layer 10.

  FIG. 8 is a front view seen from the brazing material side of a lid (hereinafter referred to as a sealing plate) and a cross-sectional view with the brazing material down. A brazing material 10 is fused as a bonding layer to the outer periphery of the sealing plate 3 (hereinafter referred to as a sealing plate with a brazing material for a package). The brazing material 10 is made of gold-tin alloy, lead-tin solder, tin-copper alloy or the like depending on the application.

  As a method of manufacturing a sealing plate with a brazing material for a package, a thin brazing foil is pressed into a ring shape, combined with the sealing plate, heat treated at a temperature equal to or higher than the melting point of the brazing material, and the outer periphery of one side of the sealing plate Discloses a method of fusing a brazing material in a ring shape (for example, the prior art of Patent Document 1).

  A method of forming a brazing material by a plating method or a printing method is also disclosed. (For example, Patent Document 2 and Patent Document 3) The manufacturing method disclosed in Patent Document 1 is the same, but a plurality of sealing plates are formed in an aligned and connected shape via a connecting portion, and the sealing plate is positioned. It is handled in a fixed state.

  FIG. 9 is a top view of a metal substrate formed by aligning and connecting a large number of sealing plates in a matrix to the metal substrate. A positioning hole 24 and a large number of sealing plates 21 are formed in the metal substrate 20 by punching or etching. Each sealing plate 21 is connected to the outer frame 23 by a connecting bar 22. The brazing material 25 is directly formed and fused on the brazing material fusion part of the sealing plate by plating, printing, or the like, or the brazing material foil is punched out and set on the sealing plate 21 and then fused. The method of separating into a sealing plate with a brazing material is employed. When forming the brazing material after creating the sealing plate, the sealing plate and the brazing material are set and fused in a suitable jig.

JP 2002-9186 A JP 2003-163298 A JP 2002-163299 A

  It is good to be able to form a brazing material on the sealing plate in a state where many are aligned and connected, but the brazing material is controlled by temperature and time, so if the temperature is not uniform, the brazing material will flow out. Will occur, or the solder will not melt. If the temperature is raised, the brazing material is completely melted, but the brazing material flows out to the portion other than the brazing material fusion part, and the thickness of the brazing material varies depending on the state of the flowing out. Further, when the fusing temperature is increased for the purpose of keeping the thickness of the brazing material constant and the recrystallization temperature of the sealing plate is exceeded, the thin sealing plate is deformed and warped during recrystallization. An object of the present invention is to facilitate the management of the fusing operation conditions of the brazing material to the sealing plate, and to make it possible to produce a sealing plate with a brazing material for packaging of stable quality.

  A sealing plate with a brazing material for a package that fuses a brazing material in a ring shape to the sealing surface of the sealing plate, the inner periphery of the ring-shaped brazing material fusion portion of the sealing plate with a brazing material for a package, or It is set as the sealing board with the brazing material for packages which formed the brazing material flow prevention band in the inner periphery and the outer periphery. By providing a brazing material flow prevention zone on the inner circumference of the brazing material fusion part, the flow of brazing material can be prevented even if the fusing temperature is raised, and the temperature and time management of the brazing material can be easily controlled. The thickness of the later brazing material can be made constant. In the manufacturing process of the sealing plate with brazing material, when it is necessary to prevent the brazing material flow to the outer peripheral portion of the brazing material fusion portion, it is possible to prevent the flow by providing a brazing material flow prevention band at the outer peripheral portion.

  The flow of brazing material formed on the inner peripheral surface of the brazing material flow prevention band formed on the inner periphery of the ring-shaped brazing material fusion portion of the sealing plate with brazing material for package and / or the inner circumference and outer periphery of the ring-shaped brazing material fusion portion The brazing material sealing surface surrounded by the prevention band is a sealing plate with a brazing material for packaging, which is a smooth surface. By making the sealing surface side of the sealing plate a smooth surface, it is necessary to prevent bubbles remaining in the brazing material layer on the brazing material fusion surface, and to vacuum the inside of the package on surfaces other than the brazing material fusion surface Gas generation in a certain package can be reduced.

  The sealing material with the brazing material for packaging is lower than the recrystallization temperature of the sealing material. Deformation of the sealing plate can be prevented, a stable quality sealing plate with a brazing material for a package can be manufactured, and even when fusing with the package, production defects due to deformation of the sealing plate can be prevented.

  Sealing with a brazing material comprising at least a step of forming a brazing material flow prevention band on the sealing plate, a step of forming or placing the brazing material on the sealing plate, and a step of fusing the brazing material to the sealing plate. It is set as the manufacturing method of a board. According to this manufacturing method, the flow of the brazing material can be prevented even if the fusing temperature is raised, the temperature and time management of the brazing material can be easily controlled, and the thickness of the brazing material after fusing can be made constant. Bubbles remaining in the raw material can be eliminated.

  At least a step of forming a brazing material flow prevention band on the sealing plate on a flat plate forming a plurality of sealing plates, a step of forming or placing a brazing material on the sealing plate, and a brazing material on the sealing plate A method for producing a sealing plate with a brazing material includes a step of fusing and a step of separating a plurality of sealing plates with a brazing material for a package from a flat plate. According to this manufacturing method, since the sealing board with a brazing material for packaging can be manufactured by batch processing or continuous processing, mass production can be facilitated.

  According to the present invention, it is possible to prevent the brazing material from flowing out of the brazing material fusion portion, and if the feeding amount of the brazing material is the same, the brazing material having the same thickness can be fused, and the fusing temperature and time management are easy. Can be. In addition, the produced sealing plate with a packaging brazing material has a stable quality and can be easily sealed with the package.

  A sealing plate with a brazing material for a package that fuses a ring-shaped brazing material to the sealing surface of the sealing plate, the inner circumference or the inside of the ring-shaped brazing material fusion portion of the sealing plate with a brazing material for a package A brazing material flow prevention band is formed on the circumference and the outer circumference to prevent the brazing material from flowing out to the sealing plate surface when the brazing material is fused.

  1A and 1B are views showing an embodiment of a sealing plate according to the present invention, in which FIG. 1A is a top view, FIG. 1B is a cross-sectional view along AA, and FIG. 30c in the outer peripheral part of the sealing plate 30 is a brazing material fusion part, and brazing material flow prevention bands 30b and 30a are formed on the inner circumference and the outer circumference of the brazing material fusion part. The brazing material flow prevention bands 30a and 30b are rough surfaces formed on the surface of the sealing plate 30, and are processed by one of surface treatment methods such as pressing, honing, and etching. After forming the brazing material flow prevention bands 30a and 30b, the brazing material is fused to the sealing plate by placing a brazing material plated, printed or die-molded on the brazing material fusion portion 30c and performing heat treatment. .

  As the sealing plate, a metal flat plate (or a lid having a recess formed by drawing in the center) is used. When the package substrate is ceramic, a Kovar material, 42 alloy, or the like having a close thermal expansion coefficient is selected. When the package substrate is a metal, it can be selected appropriately according to the package. The surface roughness for preventing the flow of the brazing material is appropriately selected depending on the kind of the brazing material and the brazing material fusion temperature. For example, when the melting operation temperature is 280 to 300 ° C. with a gold-tin alloy, The surface roughness may be 35 μm for the uneven average spacing (Sm of JIS standard B0601), and the Sm of the low flow prevention band that becomes the rough surface may be 40 μm or more, preferably Sm = 40 μm to 50 μm. When surface treatment is performed by honing or etching, masking suitable for each processing method is necessary, but this is a well-known technique and may be appropriately employed.

  FIG. 2 is a schematic diagram showing the shape of the brazing material flow prevention band according to the present invention, and (a) shows a groove 30d which is a brazing material flow prevention band on both sides (inner peripheral portion and outer peripheral portion) of the brazing material fusion portion. 30b is formed, (b) is formed with a groove 30d, which is a brazing material flow prevention band, on the inner periphery of the brazing material fusion portion, (c) is brazing material flow prevention on both sides of the brazing material fusion portion. (D) is formed with a rough surface 30b as a brazing material flow prevention band on the inner peripheral portion of the brazing material fusion part, (e) is brazing material. The part and the brazing material flow prevention band are rough surfaces 30f. The brazing material flow prevention effect to the brazing material flow prevention zone can be obtained. Although not shown in the figure, it is also possible to obtain a brazing material flow preventing effect by making the entire surface of the brazing material fusion surface rough.

  When the brazing surface of the brazing material is rough, the bonding strength between the brazing material and the sealing plate is improved, but air bubbles may be trapped between the brazing material and the sealing plate. If the sealed space is evacuated, it should be avoided. There is no particular problem when the sealed space is air or nitrogen gas replacement. Whether or not to use the brazing material fusion surface as the ground surface can be selected according to the application.

Next, the manufacturing method of the sealing board with the brazing material for packages according to the present invention will be described.
3 to 6 are schematic process diagrams for explaining a method of manufacturing a sealing plate with a brazing material for a package according to the present invention. FIG. 3 is a partial top view and a side view of a Kovar strip that is a material for the sealing plate used in the present invention. The thickness of the strip 40 is the same as the required thickness of the sealing plate (for example, 0.1 mm). First, this strip 40 is prepared.

  FIG. 4 is a top view in which a hole for conveying positioning and a brazing material flow prevention groove are formed in the band material, a CC cross-sectional view, and an enlarged view of a portion D. In this embodiment, the brazing material flow prevention band is a V groove. The conveyance positioning hole 41 and the brazing material flow prevention grooves 30d and 30e are formed by continuous pressing.

  FIG. 5 is a top view, a cross-sectional view taken along line E-E, and an enlarged view of the F portion, in which a ring-shaped brazing material is applied by printing to a brazing material fusion portion surrounded by a brazing material flow prevention groove. The ring-shaped brazing material 42 is prepared, for example, by mixing gold-tin alloy powder with a flux, a solvent, a thixotropic agent and the like so as to be easily printed, and is applied to the brazing material fusion portion 30c by screen printing. The amount of brazing material is adjusted by the amount of gold-tin alloy powder and the thickness of the screen. The ring-shaped brazing material 42 may be formed by punching a foil or by a plating method. As shown in this figure, it is effective to form a brazing material flow prevention band on the outer periphery of the brazing material fusion part so that the brazing material does not flow and connect to the outer circumference when the parts that become the sealing plates are adjacent to each other It becomes.

  FIG. 6 is a top view, a GG sectional view, and an enlarged view of the H portion after the above-described printed ring-shaped brazing material is fused. A heat treatment is performed in order to fuse the band material on which the ring-shaped brazing material 42 is printed. By adjusting the time for passing through the continuous furnace and the temperature in the continuous furnace, the ring-shaped brazing material 42 is fused to the strip (sealing plate), but it is important that the temperature be below the temperature at which the strip recrystallizes. Yes, it is necessary to select the brazing material and the furnace temperature appropriately according to the band material. This is because warping occurs when the strip is recrystallized. For example, since the recrystallization temperature of the Kovar material is about 500 ° C., it is necessary to select a brazing material that melts below that temperature. The above gold-tin alloy is suitable as a combination because it can be melted at about 280 ° C.

  In this embodiment, the brazing material flow prevention band is a V-groove, but it is possible to form a rough surface by the same process as described above, and a plating film that is difficult to flow brazing material may be used. . In addition to the sealing plate of the present invention, when supplying brazing material partially on the metal plate and joining with other parts, a brazing material flow prevention band is provided on the outer periphery of the necessary brazing material installation portion. It is also effective to provide it.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the Example of the sealing board by this invention, (a) is a top view, (b) is AA sectional drawing, (c) is the B section enlarged view. The schematic diagram which shows the shape of the brazing material flow prevention band by this invention Partial top view and side view of Kovar strip, which is the material of the sealing plate used in the present invention Top view, CC cross-sectional view, and enlarged view of part D in which a hole for conveying positioning and a brazing material flow prevention groove are formed in the band material Top view, EE cross-sectional view, and F section enlarged view of ring-shaped brazing material applied by printing to brazing material fusion portion surrounded by brazing material flow prevention groove Top view, GG cross-sectional view and H-part enlarged view after fusion of brazing material Sectional drawing of the said electronic component whose electronic element is a crystal oscillator Front view seen from the brazing material side of the lid (hereinafter referred to as sealing plate) and cross-sectional view with the brazing material down Top view of a metal substrate formed by aligning and connecting a large number of sealing plates in a matrix on a metal substrate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface mount-type crystal oscillator 2 Crystal piece 3 Lid (sealing board)
4 Ceramic Substrate 5 Internal Wiring 6 Wiring Layer 7 Conductive Paste 8 Wiring Layer 9 Metallized Layer 10 Bonding Layer (Raw Material)
11 Internal space 20 Metal substrate 21 Sealing plate 22 Connecting bar 23 Outer frame 24 Positioning hole 25 Raw material 30 Sealing plate 30a Raw material flow prevention band 30b Raw material flow prevention band 30c Raw material fusion part 30d Groove 30e Groove 30f Rough surface 40 Strip material 41 Transport positioning hole 42 Ring-shaped brazing material

Claims (5)

  A sealing plate with a brazing material for a package that fuses a brazing material in a ring shape to the sealing surface of the sealing plate, the inner periphery of the ring-shaped brazing material fusion portion of the sealing plate with a brazing material for a package, or A sealing plate with a brazing material for a package, wherein a brazing material flow prevention band is formed on an inner periphery and an outer periphery.   The flow of brazing material formed on the inner peripheral surface of the brazing material flow prevention band formed on the inner periphery of the ring-shaped brazing material fusion portion of the sealing plate with brazing material for package and / or the inner circumference and outer periphery of the ring-shaped brazing material fusion portion The sealing plate with a brazing material for a package according to claim 1, wherein the brazing material fusion surface surrounded by the prevention band is a smooth surface.   The sealing plate with a brazing material for a package according to claim 1, wherein the soldering temperature of the brazing material is lower than the recrystallization temperature of the sealing plate.   It includes at least a step of forming a brazing material flow prevention band on the sealing plate, a step of forming or placing the brazing material on the sealing plate, and a step of fusing the brazing material to the sealing plate. Manufacturing method of sealing plate with brazing material. At least a step of forming a brazing material flow prevention band on the sealing plate on a flat plate forming a plurality of sealing plates, a step of forming or placing a brazing material on the sealing plate, and a brazing material on the sealing plate A method for producing a sealing plate with a brazing material, comprising a step of fusing and a step of separating a plurality of sealing plates with a brazing material for a package from a flat plate.

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