JP2010114132A - Plating method for airtight terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for a crystal oscillator such that surface plating layers of a metal outer ring and through leads of an airtight terminal are formed within desired rate ranges and the plating thickness on the through leads is made larger than the plating thickness on the metal outer ring side within a predetermined rate. <P>SOLUTION: The package 10 for the crystal oscillator includes a cylindrical airtight terminal 20, a cylindrical metal cap 30, and a crystal piece 40 soldered to package inner sides 23a as upper ends of the through leads 23. The plating layers formed on surfaces of the metal outer ring and the pair of through leads 23 of the airtight terminal 20 are formed such that the plating thickness of the metal outer ring is selected within a range of 4 to 15 μm and the thickness of the plating layers of the through leads is 1.6 to 2.5 times as large as the thickness of the plating layer of the metal outer ring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention uses a glass-to-metal sealing structure (hereinafter also referred to as GTMS) hermetic terminal as a stem base, and a cylindrical metal cap lid member is hermetically sealed to accommodate a crystal piece in an airtight space. In particular, the present invention relates to a quartz resonator package in which a small-sized cylindrical airtight terminal and a cylindrical metal cap are press-fitted and sealed, and a method for manufacturing an airtight terminal used in the package.

  Conventionally, there are various types of hermetic terminals depending on the application, and a plating layer having a material and thickness corresponding to the application is formed on the exposed portion of the metal outer ring or the metal member of the lead. For example, a cylindrical airtight terminal used for a quartz crystal unit for a watch has a lead hermetically sealed inside a cylindrical metal outer ring through a glass insulating material, and the metal outer ring and the exposed surface of the lead are protected against rust and solder. A plating layer of Ni, Au, solder or the like with good attachment properties is formed. The manufacturing process of this hermetic terminal includes a metal outer ring, a glass tablet obtained by kneading and granulating glass fine powder together with an organic binder into a predetermined shape, preparatory steps for preparing a glass tablet and a lead having a predetermined length, Assembling process in which raw material is placed at a predetermined position of graphite sealing jig, the whole is heated at 980-1000 ° C. in a neutral or weakly reducing atmosphere to melt the glass tablet, and the outside of the metal is exposed through the glass. A hermetically sealing step for insulating the ring and the lead, and a barrel plating step for forming a plating layer on the exposed portion of the metal outer ring and the lead. The hermetic terminal thus manufactured is then mounted with a crystal resonator, and a metal cap is press-fitted with a plating layer of a metal outer ring as a sealing material and sealed by pressure, thereby forming a crystal resonator package. Patent Document 1 discloses an improved method for this type of electronic component.

  On the other hand, as a crystal unit package in which a crystal piece is mounted in a hermetically sealed package, a cylinder type composed of a cylindrical airtight terminal and a cylindrical metal cap is often used when high airtightness and reliability are required. ing. The cylindrical airtight terminal and the cylindrical metal cap ensure the airtightness of the package with a solder plating sealing material. Patent Document 2 discloses a plating layer on the metal outer ring or lead surface of a cylindrical airtight terminal using solder plating of Sn-Ag alloy or Sn-Bi alloy instead of Sn-Pb eutectic solder which is environmentally harmful. Is used as a sealing material. Further, Patent Document 3 discloses a package of a glass-to-metal sealing structure (GTMS) type airtight terminal and a cylindrical metal cap, which is a highly airtight and reliable cylindrical airtight terminal as a crystal oscillator package.

JP 2001-267190 A JP 2002-160089 A JP 2003-152129 A

  By the way, a package using a cylindrical airtight terminal of a quartz crystal for a wristwatch includes a commercially available product called “φ1.2” having an outer diameter d1 of a metal outer ring of about 0.90 to 0.95 mm. In order to increase the work efficiency of forming the plating layer on the metal outer ring of the airtight terminal and the exposed part of the lead, such a very small variety accommodates a large number of terminal parts in the barrel and performs plating in a lump. Barrel plating is performed. However, in the case of a very small metal outer ring as described above, the outer diameter d2 of the lead is accordingly reduced to about 0.13 to 0.17 mm, and the distance g between the leads is 0.10 to 0. .20mm, approximately the same as the outer diameter d2 of the lead, when using the barrel plating method, one lead fits between the other leads, and a plating layer is formed in that state, and the leads are plated. There is a problem that so-called Abeck defects frequently stick to each other, and it has been proposed to bridge a plurality of leads with a conductive material or a resin material to solve the problem (see Patent Document 1). . Further, as described above, since the lead is thin and the waist is weak, the lead is easily bent and it is difficult to control the thickness of the plating layer.

  On the other hand, the inventors focused on the importance of selecting the thickness of the metal outer ring of the hermetic terminal and the plating layer of the lead in the package for the crystal unit in which the cylindrical metal cap is press-fitted into the cylindrical hermetic terminal and sealed. The appropriate and suitable thickness for each plating layer was investigated. According to experimental findings, the proper plating layer thickness when soldering quartz pieces to the leads is different from the plating layer thickness of the metal outer ring that is suitable for pressure welding, and barrel plating method It was found that the thickness of the plating layer on each surface was different from each other. As a result, in the package in which the cylindrical metal cap is attached to the cylindrical hermetic terminal, it is desirable to select the film thickness ratio of the plating layer applied to each surface of the metal outer ring and the lead of the hermetic terminal within a certain range. It has been found that the lead side should be thicker than the outer ring side. Furthermore, in the formation of the plating layer by the barrel plating method, the thickness of the plating layer can be adjusted by making the length of the lead material longer than the predetermined length in advance. It was found that it can be obtained.

  Therefore, the object of the present invention is to select the respective surface plating layers of the metal outer ring and the through lead of the hermetic terminal within a desired ratio range as described above, and in particular, to use a small-sized cylindrical hermetic terminal and the same. A crystal resonator package is provided. Preferably, regarding the thickness of the plating layer between the metal outer ring and the lead by using the barrel plating method, it is suggested that the plating thickness on the through lead side should be adjusted within a predetermined ratio compared to the plating thickness on the metal outer ring side To do.

  Still another object is to propose a method for manufacturing an airtight terminal using a barrel plating method in which the ratio between the thickness of the plating layer of the metal outer ring and the thickness of the plating layer of the lead is adjusted within a predetermined range. At the same time, when a brazing material layer is formed on the outer ring and lead surfaces of a large number of terminal parts by barrel plating, the lead of another terminal part fits into the lead of one terminal part, causing an Abeck failure. An object of the present invention is to propose a method for manufacturing an airtight terminal, which is characterized in that the thickness of the plating layer is adjusted to a desired thickness without causing the lead to be bent. Further, the present invention provides a crystal resonator package using such an airtight terminal.

  According to the present invention, the through leads are arranged on the glass insulator hermetically sealed to the cylindrical metal outer ring to insulate the through leads and the metal outer ring, and the plating layers are formed with different thicknesses on the respective surfaces. Provide airtight terminals. The airtight terminal, a crystal piece brazed by a lead plating layer on one end side of the penetrating lead, and a cylindrical metal cap sealed by press-fitting the plating layer on the metal outer ring, In the crystal resonator in which the space formed by the metal cap is the accommodation space for the crystal piece, the thickness of the plated layer of the through lead is 1.6 to 2.5 times the thickness of the surface plated layer of the metal outer ring. A crystal resonator package characterized in that the thickness is increased within the range described above. Here, the plated layer is a brazing material layer with good soldering. In particular, the outer diameter of the metal outer ring is 0.90 ± 0.05 mm (commonly known as φ1.2), and the plating thickness of the metal outer ring Is set within a range of 4 to 15 μm.

  According to another aspect of the present invention, the cylindrical outer metal ring is provided with leads of a predetermined length that are separated from each other through a glass insulating material and hermetically sealed and penetrated, and each surface of the outer metal ring and the lead is provided. In a method for manufacturing an airtight terminal for forming a plating layer on a metal outer ring, a step of incorporating a metal outer ring of a predetermined size, a glass tablet and a lead material longer than the predetermined length into a sealing jig, melting the glass tablet into the metal outer ring A process for hermetically sealing the terminal component in which the lead material is disposed through the glass insulating material, a large number of terminal components are accommodated in the barrel, and a plating layer is collectively formed on the surface of the metal outer ring and the lead material. A barrel plating step, and a step of cutting the lead material of the terminal component on which the plating layer is formed into a predetermined length, and plating depending on the length of the lead material during the barrel plating The ratio (t1 / t2) of the plating thickness (t2) of the metal outer ring to the plating thickness (t1) of the lead is adjusted within the range of 1.6 to 2.5. A method for manufacturing a characteristic hermetic terminal is proposed. Furthermore, a method of manufacturing an airtight terminal is provided, characterized by adding a step of bridging the lower end portions of the lead materials of the terminal parts with a fixing material and a step of removing the fixing material before and after the barrel plating step. Is done. Preferably, the metal outer ring is made of low carbon steel having an outer diameter of 0.90 ± 0.05 mm, Fe—Ni alloy or Fe—Ni—Co alloy, and the lead has an outer diameter of 0.15 ± 0. .02 mm Fe—Ni alloy or Fe—Ni—Co alloy.

  The crystal resonator package according to the present invention uses a cylindrical airtight terminal with a glass-to-metal sealing structure, so that in addition to enhancing mechanical strength, airtightness and reliability are ensured, and the metal outer ring and lead plating layer are barrels. Since it is plating, the advantage is acquired. That is, the mount part and the seal part each contribute to quality improvement and performance improvement by providing a plating layer having a film thickness having a predetermined ratio. By using a Pb-free plating material for the barrel plating layer, there are no environmental problems and practical effects such as ensuring airtightness and safety can be exhibited. In addition to ensuring the soldering with the crystal piece by providing a relatively thick Sn alloy plating layer with good solderability on the lead side, the plating thickness on the metal outer ring side can be regulated thinly. It is possible to prevent the plating material from protruding when thickly inserted. In addition, barrel plating can process a large amount of processed products in a relatively small amount of liquid, and it saves labor and facilitates mechanization and automation of plating processing. From pretreatment to plating, posttreatment, cleaning and drying. Integrated processing is easy. In addition, a wide range of plating can be performed regardless of the shape and size of the processed product and the type of plating, and it is possible to process objects that are difficult to plate with small objects. In particular, it is suitable for mass production, and can be expected to reduce processing costs, particularly labor costs, and has the advantage that the processed products can be plated with a relatively uniform thickness. Furthermore, the plating solution is constantly stirred, the conditions of the plating solution can be kept uniform, and a plating film that is closely stacked and rich in corrosion resistance even when thin is obtained. Therefore, it is possible to reduce the occurrence of troubles and defects in work, contributing to mass production and cost reduction.

  In the embodiment according to the present invention, a pair of leads penetrating glass is arranged in a cylindrical outer ring, and an airtight terminal in which the through lead and the metal outer ring are insulated, and soldered at one end side of the through lead. A crystal resonator package comprising a crystal piece and a cylindrical metal cap that is hermetically sealed by press-fitting to a metal outer ring of an airtight terminal so as to form a space for accommodating the crystal piece. In this package, the airtight terminal is immersed in the electrolytic solution on the entire surface of the metal outer ring and the metal member of the lead in the same manner as in the prior art to form an electrolytic Cu or electrolytic Ni plating layer. Next, an Sn alloy plating layer is formed on the lead plating layer by a dipping method as a solder material plating layer. Alternatively, the Sn alloy plating layer may be formed directly on the lead metal member. Thereafter, a crystal piece is soldered to the plating layer of the solder material. On the other hand, an electric Ni plating layer is formed on the entire surface of the metal cap. The material used for each plating layer is selected according to its function. Here, the Ni cap layer is formed on the inner peripheral surface of the metal cap, and an effective sealing property is obtained with the Sn-based plating layer formed on the surface of the metal outer ring of the airtight terminal.

  Next, a 4 to 15 μm plating layer can be formed as the Sn alloy plating layer applied to the outer surface of the Kovar material of the metal outer ring of the hermetic terminal. In addition, a Sn alloy plating layer is used as a brazing material as a lead plating layer, and in order to ensure solderability, it is formed relatively thick in the range of 14 to 24 μm to ensure solderability. The lower limit of these plating layers is to ensure the function as a pressure sealing material or a solder material, and the upper limit is a limitation from workability. Thus, using a cylindrical airtight terminal, the metal cap ensures adhesion, improved sealing performance, improved heat resistance against the reflow process, and resistance to chemical changes such as oxidation resistance by using plated layers that exhibit their respective functions. A flexible metal package can be provided.

  1A and 1B show a quartz resonator package according to an embodiment of the present invention, in which FIG. 1A is an exploded perspective view and FIG. 1B is a partially cutaway perspective view. The crystal resonator package 10 is formed of a cylindrical body having a diameter of approximately 1.2 mm, and has a φ1.2 cylindrical airtight terminal 20, a cylindrical metal cap 30, and the inside of the package that is the upper end of the through lead 23 on the airtight terminal 20. A crystal piece 40 soldered to the side 23a. The hermetic terminal 20 and the metal cap 30 are hermetically sealed by the interposition of the pressure sealing material. The plating layer of the hermetic terminal 20 is an example in the case of using a high-temperature solder of Sn—Pb alloy with a low material cost, and the plating layer for solder is formed with a thick plating layer on the through lead of the hermetic terminal, On the metal cap, the Ni plating layer 31 is relatively thinly formed at least on the inner surface seal portion. As shown in the enlarged partial cross-sectional view, the hermetic terminal 20 is configured to insulate the metal outer ring 21, the pair of through leads 23 disposed through the inner side of the metal outer ring 21, and the through leads 23 from the metal outer ring 21. This is a glass-to-metal sealing structure made of insulating glass 22 to be sealed.

  The hermetic terminal 20 is hermetically sealed by softening and melting the glass material in a known manner by previously incorporating the glass material of the glass tablet together with the outer ring and the through lead into the heating assembly jig and passing through the heating furnace. . For the metal outer ring 21 and the pair of through leads 23, materials having thermal expansion coefficients similar to those of the insulating glass 22 are selected and used. Plating layers 24, 25, and 31 are provided on the metal outer ring 21, the through lead 23, and the metal surface portion of the metal cap 30 of the hermetic terminal 20, respectively. The metal surface portions of the metal outer ring 21 and the pair of through leads 23 are formed by immersing an electrolytic Cu plating layer and solder plating layers 24 and 25 as an underlying plating layer in an electrolytic solution. On the other hand, a Ni plating layer is formed on the metal cap 30 by electroplating. In the metal cap 30, after the crystal piece 40 is soldered to the inner terminal portion of the penetration lead 23 of the airtight terminal 20 with the solder plating layer 25, the metal cap 30 is press-fitted onto the Ni plating layer 24 of the metal outer ring 21, and is pressure sealed. It is hermetically sealed in pressure contact with the plating layer. As will be described later, each plating layer is selected so that the metal material for plating and the film thickness of the plating layer are specified and the desired effects are satisfied. That is, a high-temperature solder plating layer 25 that is convenient for joining the crystal piece 40 to the through lead 23 of the hermetic terminal 20 shown in the drawing in a soldering process at 350 ° C. to 400 ° C. is provided. The hermetic terminal 20 becomes a metal base of the package 10, and the crystal piece 40 of the package 10 is attached thereto by soldering. The airtight terminal 20 to which the crystal piece 40 is attached is covered with a metal cap 30 and hermetically sealed by pressure bonding with the plating layer 24 of the metal outer ring 21 and the Ni plating layer 31 on the inner surface side of the metal cap 30. . The metal cap 30 is made of a white material, and an electric Ni plating layer is formed on the inner peripheral surface thereof. The metal cap 30 exhibits an effective sealing property with the plating layer 24 of the metal outer ring 21 and facilitates the workability of the press-fit connection. There are practical effects such as.

  Next, the structure of the hermetic terminal used in the package according to the present invention will be described in detail with reference to the drawings. As the cylindrical airtight terminal used for the quartz crystal unit for wristwatches, a variety called a diameter of about 1.2 mm and a so-called φ1.2 is frequently used. In FIG. 2, two through leads 23 are hermetically sealed inside a metal outer ring 21 through a glass 22. The metal outer ring 21 is made of, for example, low carbon steel, Fe—Ni alloy or Fe—Ni—Co alloy, and has an outer diameter dimension d1 of 0.90 to 0.95 mm and a height dimension of 0.75 to 0.85 mm. It is. The glass 22 is made of soda lime glass, soda barium glass, borosilicate glass, or the like. The through leads 23 are made of Fe—Ni alloy, Fe—Ni—Co alloy or the like, and have two outer diameters d3 of 0.13 to 0.17 mm and length l of 7.0 to 8.0 mm. The distance g between the through leads 3 is 0.10 to 0.20 mm. Plating layers 24 and 25 are formed on the exposed portions of the metal outer ring 21 and the through leads 23. For example, Sn-90 wt% Pb layers are formed as brazing material plating layers 24 and 25 on the exposed portions of the metal outer ring 21 and the through leads 23. On the other hand, the brazing material plating layer 24 at the exposed portion of the metal outer ring 21 serves as a sealant between the metal outer ring 21 and the metal cap and is useful for hermetic sealing when the metal cap is press-fitted and sealed as will be described later. Further, with respect to the penetration lead 23, the brazing material plating layer 25 in the upper part of the lead is useful for brazing the electronic component element of the crystal piece, and the brazing material plating layer 25 in the lower part of the penetration lead 23 is used as the printed board. Helps to ensure brazeability when brazing to etc. Here, the brazing material plating layer 25 in the lower part of the through lead 23 is formed only on the peripheral surface portion of the through lead 23 and is not formed on the lower end surface 23b for the reason described later. Further, even if the plating layer 25 is not provided on the lower end surface 23b of the through lead 23 as described above, the lower end portion of the through lead 23 of the airtight terminal 20 is generally cut after being inserted into a through hole such as a printed board and brazed. Since it is removed, there is no problem.

  Hereinafter, a method for manufacturing the above-described hermetic terminal 20 of the present invention will be described with reference to the drawings. FIG. 3 shows a manufacturing process block diagram of the first embodiment of the manufacturing method of the present invention. First, a metal outer ring 21 is manufactured by extruding a metal plate of iron / nickel alloy or the like having a predetermined thickness after extrusion. In addition, glass fine powder such as borosilicate glass and an organic binder are kneaded and granulated to a predetermined particle size, then press-formed into a predetermined shape, calcined to bind the glass particles together, and the organic binder is baked. Fly to make glass tablet 22a. Furthermore, a metal wire such as an Fe—Ni—Co alloy having a predetermined outer diameter is cut into an appropriate length dimension lc (= l + Δl) longer than the length l of the lead material 23 of the terminal component A, thereby leading to the lead material. 23c is manufactured (step a). Then, the outer metal ring 1, the glass tablet 22a and the lead 23c are assembled at predetermined positions using a graphite sealing jig (not shown) (step b), in a neutral or weakly reducing atmosphere. The glass tablet 22a is melted by heating at about 980 to 1000 ° C., and the lead material 23c is hermetically sealed with glass (step c). 3A to 3C, the terminal component A that is the original form of the hermetic terminal 20 is manufactured.

  When barrel plating is performed, preferably, as shown in FIG. 4, the outer end of the lead member 23c of the terminal component A is bridged with the fixing member 50 while maintaining the lead interval dimension g (step d). The step of bridging the lower end portion of the lead material 23c of the terminal component A with a fixing material is not always necessary and can be omitted. However, in the barrel plating process, a bridge with a fixing material is preferable to prevent the lead from being entangled. Next, a large number of terminal parts A, to which the lower end portion of the lead material 23c is fixed, are accommodated in a barrel (not shown), and this barrel is immersed in a plating bath and rotated, so-called barrel plating. Then, plating layers 24 and 25 of the brazing material are formed on the exposed portions of the lead material 23c (step e). Next, the lower part of the lead 23c of the terminal component A on which the plated layers 24 and 25 are formed is cut at a predetermined position 60 on the upper end side to remove the fixing material 50 (step f). As a result, the hermetic terminal 20 having the lead 23 having a predetermined length l as shown in FIG. Plating layers 24 and 25 are formed on the exposed surface of the metal outer ring 21 and the lead 23 of the airtight terminal 20 obtained in this way, but as described above, on the lower end surface 23b of the through lead 23. Has no plating layer 25.

  In this type of hermetic terminal 20 for a crystal resonator, a crystal vibrating piece (not shown) is fixed to the upper end portion of the penetrating lead 23. At this time, the brazing material plating layer 25 in the upper part of the penetrating lead 23 is formed of the crystal piece. Helps to braze reliably by increasing the brazeability. Further, as shown in FIG. 1, after fixing the crystal piece 40, the metal cap 30 is sealed by press fitting to form a crystal resonator package. At this time, the brazing material plating layer 24 of the metal outer ring 21 is The metal outer ring 21 and the metal cap 30 are filled in a crimped state, which helps to ensure a hermetic seal. Further, the crystal resonator package 10 using the hermetic terminal 20 is assembled by inserting a lead extending downward in the through hole of the printed board and brazing with a jet plating apparatus. At this time, the brazing material plating layer on the peripheral surface portion of the lead helps to secure the brazing property by the brazing material. Although there is no plating layer on the lower end surface of the lead 23 of the hermetic terminal 20, in most cases there is no problem. That is, after the connection lead 23 of the crystal resonator package 10 is brazed to the printed circuit board, it is cut from the brazed portion as an extra lead portion. Therefore, even if there is no brazing material plating layer on the lower end surface of the lead, there is no practical problem. However, if a brazing filler metal layer is also required on the lower end surface of the lead, a plating step on the lower end surface of the lead may be added after cutting the lead (step f).

  Next, as described above, a large number of terminal parts A in which the lead material 23c is bridged by the fixing material 50 are accommodated in a barrel (not shown), and this barrel is immersed in a plating bath and rotated. By the plating method, the brazing material plating layers 24 and 25 are formed on the exposed portions of the metal outer ring 21 and the lead material 23c. At this time, as described above, if the outer diameter dimension of the fixing material 50 is larger than the lead interval dimension g, the entanglement of the leads can be prevented during the plating process. Therefore, the so-called Abeck failure in which the leads are adhered to each other by the plating layer is less likely to occur. Further, when the lead 23c is fixed by the fixing material 50, the strength of the lead is apparently increased and the bending of the lead is less likely to occur as compared with the case of each lead alone. Note that a low melting point metal material or a synthetic resin material is used as the fixing material, and an ultraviolet curable resin or a heat effect resin is used depending on the processing method.

  Here, the characteristic matters of the present invention will be described in detail with respect to a specific example of an airtight terminal named as the product type φ1.2. In this case, first, the component material of the terminal component A shown in FIG. The metal outer ring 1 is made of material: Fe—Ni alloy, dimensions: outer diameter 0.92 mm × height 0.8 mm × thickness 0.1 mm, and the glass 22 is made of material: borosilicate glass. Is a material: Fe—Ni—Co alloy, dimensions: outer diameter 0.15 mm × length 7.20 + α mm (a length longer than a predetermined length of 7.20 mm), and lead interval: 0.15 mm. For example, a ball-shaped fixing material of diameter: 0.5 mm and material: Sn-60 wt% Pb alloy was bridged to the lower end portion of the lead material of the terminal component A. Next, a large number of terminal parts A are accommodated in a barrel and plated by a barrel plating method in which they are immersed in a plating bath, and the brazing material plating layers 24 and 25 are made of a material: Sn-90 wt% Pb alloy. A plating layer having a thickness of 18 μm was formed. At the same time, a 9 μm plating layer 24 was formed on the surface of the metal outer ring. As a result, in the process of forming the brazing material plating layer 24 by the barrel plating method, the ratio of the plating thickness of the lead to the metal outer ring (eyelet) was 2.0. At the end of the manufacturing process of the airtight terminal, the lead was cut to a predetermined length, and at the same time, the bridging fixing material was removed. A crystal piece was soldered to the upper end side of the lead of the manufactured hermetic terminal, and a metal cap was press-fitted into the metal outer ring of the hermetic terminal to be pressed and sealed, thereby completing a crystal resonator package. Here, the thickness of the brazing material plating layer between the outer metal ring and the lead should be practical in the range of 1.6 to 2.5 in consideration of the assembly workability. It was confirmed. In this case, it was found that the appropriate plating thickness of the metal outer ring was 4 to 15 μm, and the appropriate plating thickness of the lead was 14 to 25 μm. The appropriate thickness of the plating layer is based on a hermetic terminal having a common name of φ1.2. However, confirmation experiments have been conducted on other types such as φ3, φ2, and φ1.5, and as a result, the thickness ratio of the plating layer is obtained. The lead-to-metal outer ring is applicable in the range of 1.6 to 2.5.

Comparative example

  On the other hand, it has been found that the following defects occur when the film thickness ratio of the plating layer is other than the predetermined ratio. For example, when the plating thickness of the metal outer ring exceeds the upper limit of the appropriate plating thickness, the solder protrudes during press fitting. Further, when the lead plating thickness exceeds the upper limit of the appropriate plating thickness, the solder flows too much, and there is a risk of short-circuiting due to excess solder brazing material. On the other hand, it was found that when the plating thickness is less than the lower limit of the range of the appropriate value, the lack of bonding results in defects in airtightness and connectivity, resulting in poor airtightness and poor contact, and lacks practicality.

  From the results of the examples and comparative examples of the present invention, the manufacturing method of the hermetic terminal according to the present invention is particularly a crystal vibration using a small cylindrical hermetic terminal as a base and press-fitting and sealing a metal cap on the base. When configuring the package for the child, the ratio of lead to eyelet film thickness was found to regulate the relationship between the film thickness and the thickness of the airtight terminal eyelet and lead as appropriate. is there. In addition, a new and improved preparation method using a barrel plating method for selecting within the specified ratio range is proposed as a method for manufacturing an airtight terminal. According to the method for manufacturing a hermetic terminal of the present invention, first, when barrel plating is performed on the exposed surface of the lead of the terminal component A and the metal outer ring (so-called eyelet), the length of the lead material is set to a predetermined value for the airtight terminal after completion. A method is proposed in which the thickness of the plating layer is adjusted so as to be longer than the length of the through-lead, and the plating layer has a different ratio depending on the part in the plating process peculiar to barrel plating. At the same time, the lead ends are bridged by the fixing material, thereby preventing entanglement between the leads and avoiding defective plating. That is, the airtightness and solderability of the package are improved. Secondly, prevention of Abeck failure between the leads of the airtight terminal and increase of the apparent strength as compared with the case where the lead is single, making it difficult for the lead bending failure to occur, and third, insulation by the glass. The effect of improving the workability of the package assembly can be obtained by adjusting the plating conditions of the through leads.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a crystal resonator package of an embodiment according to the present invention, FIG. 1A is an exploded perspective view, and FIG. It is an expanded sectional view which shows the principal part sectional drawing of the airtight terminal used for the package of FIG. It is a block diagram explaining the manufacturing method of the airtight terminal of FIG. 2 similarly. FIG. 4 is an enlarged cross-sectional view of a main part in a terminal component state in the manufacturing process of the hermetic terminal of FIG.

Explanation of symbols

10 ... Package for crystal unit, 20 ... Airtight terminal, 21 ... Metal outer ring,
22 ... insulating glass, 22a ... glass tablet (insulating glass before melting),
23 ... through lead, 23a ... lead (inside package),
23b ... Lead (lower end surface), 23c ... Lead (before cutting),
24 ... Electrolytic Cu plating layer and solder plating layer (outer ring portion),
25 ... Electrolytic Cu plating layer and solder plating layer (lead part), 30 ... Metal cap,
31 ... Electrolytic Ni plating layer (metal cap part), 40 ... crystal piece, 50 ... fixing material,
60: Lead cutting position,

Claims (8)

  An airtight terminal in which a through lead is insulated and sealed with a glass insulator on a cylindrical metal outer ring, and a plating layer made of a soldering layer with good soldering is provided on each surface of the through lead and the outer metal ring. A hermetic terminal, wherein the thickness of the plated layer of the through lead is 1.6 to 2.5 times the thickness of the plated layer of the metal outer ring.   2. The hermetic terminal according to claim 1, wherein a plating thickness of the metal outer ring is set in a range of 4 to 15 μm.   The hermetic terminal according to claim 2, wherein an outer diameter of the metal outer ring is 0.90 ± 0.05 mm.   A pair of through-leads having a predetermined length spaced apart from each other through a glass insulating material are hermetically sealed to a cylindrical metal outer ring, and brazing material with good soldering to the exposed surfaces of the metal outer ring and the through-leads In a method for manufacturing an airtight terminal provided with a plating layer, a glass tablet and a lead material longer than a predetermined length are incorporated in a sealing jig in a metal outer ring of a predetermined size, and the glass tablet is heated and melted to glass on the metal outer ring. A hermetic sealing process for forming a terminal component through which a lead material is passed through an insulating material, and a barrel plating process for accommodating a large number of the terminal components in a barrel and forming a plating layer on the surface of the metal outer ring and the lead material. And a step of cutting the lead material of the terminal component into through leads having a predetermined length, the plating thickness (t1) of the through lead and the plating thickness (t of the metal outer ring) ) To select the ratio of (t1 / t2) in the range of 1.6 to 2.5 with, manufacturing method of the hermetic terminal, characterized in that to prepare the length of the lead material.   The said barrel plating process is equipped with the adhesion joining process before the plating process which bridges the lower end parts of the lead material of a terminal component, and the adhesion cancellation | release process after the plating process which separates a bridge | bridging. The manufacturing method of the airtight terminal of description.   The metal outer ring is made of any material of low carbon steel, Fe—Ni alloy or Fe—Ni—Co alloy molded to an outer diameter of 0.90 ± 0.05 mm, and the lead has an outer diameter. 6. The method of manufacturing an airtight terminal according to claim 5, wherein the material is made of either an Fe—Ni alloy or an Fe—Ni—Co alloy having a thickness of 0.15 ± 0.02 mm.   A through-hole lead is insulated and hermetically sealed by interposing a glass insulator on a cylindrical metal outer ring, an airtight terminal provided with a predetermined plating layer on the surface of the lead and the metal outer ring, and one end side of the through-lead. A crystal piece to be brazed by the interposition of a lead plating layer and a cylindrical metal cap that is press-fitted and sealed by the interposition of a plating layer of the metal outer ring, and in the formation space of the metal cap in which the crystal piece is sealed The crystal resonator package according to claim 1, wherein the plated layer on the surface of the through lead has a thicker plated layer than the plated layer on the surface of the metal outer ring. The plating thickness of the metal outer ring is selected within a range of 4 to 15 μm, and the thickness of the plating layer of the through lead is 1.6 to 2.5 times the thickness of the plating layer of the metal outer ring. The crystal resonator package according to claim 7, wherein the crystal resonator package is selected according to the thickness of the crystal resonator.

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