JP2015039142A - Package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package which can be easily downsized and reduced in height while surely preventing, even when a metal layer formed in a peripheral part of a front face of a package body and a pair of electrode pads formed on the front face surrounded by the metal layer become closer to each other, the electrode pads and the metal layer from being short-circuited even via a brazing material.SOLUTION: A package 1a comprises: a package body 2 which is formed of a ceramic (insulation material) (c) and has a front face 3 and a rear face 4 having a rectangular shape in a plan view; a metal layer 6 which is formed along the peripheral part on the front face 3 of the package body 2 and has a rectangular-frame shape in a plan view; a metal frame 8 which is joined on a surface of the metal layer 6 via a brazing material 7 and has a rectangular-frame shape in a plan view; and a pair of electrode pads 9 which is formed on the front face 3 of the package body 2 surrounded by the metal layer 6 for packaging a crystal oscillator. In at least a part of the front face 3 of the package body 2 held between the metal layer 6 and the pair of electrode pads 9, a projecting part 10 that is formed of a ceramic (insulation material) is projectingly provided.

Description

  The present invention relates to a package for surface mounting a crystal unit.

  For example, a metal frame for sealing having a rectangular frame shape in plan view is bonded to a conductive film formed along the peripheral portion of the surface of the container body having a rectangular shape in plan view and the whole shape through a brazing material. Then, a pair of electrode pads for bonding and mounting one end of the crystal resonator is formed on the surface of the container body surrounded by the conductor film, and sandwiched between the pair of electrode pads and the conductor film. There has been proposed a crystal oscillator that can be reduced in size and height by forming a pair of grooves having an L shape in a plan view on the surface of the container body in a plan view (see, for example, Patent Documents). 1).

  However, in a structure in which a groove is formed on the surface of a container body sandwiched between a pair of electrode pads and a conductor film like the crystal oscillator, when the electrode pads and the conductor film are close to each other, the solder When one member flows out to the electrode pad side or the position of the groove is displaced along the horizontal direction on the surface of the container body, a part of the brazing material bridges the groove opening and the opening In some cases, the electrode pad is touched and pulled. As a result, there is a problem in that a crystal resonator mounted on the electrode pad may malfunction due to a short circuit between the pair of electrode pads and the conductor film or the electrode pad and the metal frame inadvertently. there were.

JP 2000-138532 A (pages 1-7, FIGS. 1-5)

  The present invention solves the problems described in the background art, a metal layer formed along the periphery of the surface of the package body, and a pair of electrodes formed on the surface of the package body surrounded by the metal layer It is an object of the present invention to provide a package that can be easily reduced in size and reduced in height without being short-circuited reliably even when the pads are close to each other even if the electrode pad and the metal layer are interposed with a brazing material.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above problems, the present invention provides a metal layer formed on the periphery of the surface of the package body and a pair of electrode pads formed on the surface of the package body surrounded by the metal layer. It was conceived of projecting a protruding strip portion made of an insulating material on the surface.

  That is, the package of the present invention (Claim 1) is made of an insulating material, and has a package body having a rectangular front surface and a back surface in plan view, and a plan view formed along the peripheral portion of the surface of the package body. A frame-shaped metal layer and a planar view joined to the surface of the metal layer via a brazing material are formed on the surface of the package body surrounded by the frame-shaped metal frame and the metal layer, and the crystal A package including a pair of electrode pads for mounting a vibrator, wherein at least a part of the surface of the package body sandwiched between the metal layer and the pair of electrode pads is made of an insulating material. A protruding line portion is provided to protrude.

  According to this, a protruding strip portion made of an insulating material protrudes from at least a part of the surface of the package body sandwiched between the metal layer and the pair of electrode pads. Therefore, for example, a part of the brazing material used to join the metal frame on the surface of the metal layer becomes locally excessive and flows out to the surface side of the package body surrounded by the metal layer. The position of the metal layer is deviated from the surface of the package body, or the joining position of the metal frame is deviated from the metal layer, so that a part of the brazing material flows out to the surface side of the package body. The brazing material that has flowed out is blocked by the ridges. As a result, even if the metal layer and the pair of electrode pads are disposed relatively close to each other on the surface of the package body, the situation where the metal layer and the metal frame and the pair of electrode pads are inadvertently short-circuited is ensured. I can stop. Therefore, the performance of the crystal resonator mounted on the pair of electrode pads can be reliably ensured, and the entire package can be reduced in size and height.

The insulating material constituting the package body is a single ceramic layer or resin layer, or a laminate of a plurality of ceramic layers or a plurality of resin layers. In the latter case (multiple layers), a cavity for mounting an electronic component may be opened on the surface of the upper ceramic layer or resin layer.
In addition, when the package body is made of ceramic, the same material, the same kind, or a different kind of ceramic is used for the insulating material constituting the ridge portion, and when the package body is made of resin, The same, the same kind, or a different kind of resin is used.
Further, when the package body is made of ceramic, the metal layer and the pair of electrodes are made of W, Mo, Cu, Ag or the like that can be fired simultaneously with the ceramic, and the package body is made of resin. In this case, Cu, Ag, or the like that is cured by light or heat after printing a conductive paste is used.
The brazing material is, for example, Ag brazing, brass brazing, or Al brazing.

Further, the metal frame is, for example, 42 alloy (Fe-42% Ni), Kovar (Fe-29% Ni-17% Co), 194 alloy (Cu-2.3% Fe-0.03% P), Or it consists of various stainless steels.
The metal layer and the metal frame have a rectangular shape, an elliptical shape, an oval shape, a regular polygon that is a pentagon or more or a deformed polygon in a plan view.
In addition, the ridge portion is a U shape, a pair of symmetric L shapes, or a singular or plural pieces in a plan view along the surface of the package main body sandwiched between the metal layer and the pair of electrode pads. When the package body is made of ceramic and has an I-shape, the insulating paste containing the ceramic powder or resin as described above is formed by screen printing or printing using masking.

The present invention also includes a package (Claim 2) in which the ridge is projected along the surface of the package body sandwiched between the metal layer and the pair of electrode pads.
According to this, since the ridge portion protrudes along the surface of the package body sandwiched between the metal layer and the pair of electrode pads, a part of the brazing material is the surface of the package body. Even if it flows out to the pair of electrode pads, the brazing material can be surely dammed by the above-mentioned protruding strip portion. Therefore, an inadvertent short circuit between the metal layer and metal frame and the pair of electrode pads can be reliably prevented.

Furthermore, the present invention includes a package (Claim 3) in which the height of the protrusion is higher than at least the surface of the metal layer and the surface of the electrode pad.
According to this, since the height of the protrusion is at least higher than the surface of the metal layer and the surface of the electrode pad, a part of the brazing material is a pair of electrode pads on the surface of the package body. Even if it flows out to the side, the brazing material can be reliably dammed by the above-mentioned protruding strip portion. Therefore, an inadvertent short circuit between the metal layer and metal frame and the pair of electrode pads can be prevented more reliably.
In addition, it is desirable that the height of the ridge is higher than the inner peripheral surface of the brazing material formed on the surface of the metal layer.

In addition, according to the present invention, the ridge portion is a package in which a part of the ridge portion covers the inner peripheral surface of the metal layer or the inner peripheral surface of the brazing material. Item 4) is also included.
According to this, for example, at the time of manufacturing, when the insulating paste is screen-printed on the surface of the package body to form the ridges, it is formed in advance along the peripheral portion on the surface of the package body. The surface of the inner peripheral side of the metal layer and the surface of the inner peripheral side of the brazing material used for joining the metal frame on the surface of the metal layer are covered with a part of the above-mentioned ridges by printing misalignment. In addition, a portion of the brazing material that has flowed out of the brazing material is dammed up by the ridges formed by the insulating paste. Therefore, even if it is the convex strip part of the said form, the inadvertent short-circuit between a pair of said electrode pad, a metal layer, and a metal frame can be prevented.

The top view which shows the package of 1 form in this invention. FIG. 2 is a vertical sectional view taken along line XX in FIG. 1. FIG. 3 is an enlarged view of the vicinity of the ridge portion in FIG. 2. The enlarged view similar to the above which shows the vicinity of the protruding item | line part which consists of a protruding item | line of a different cross-sectional shape. Furthermore, the enlarged view similar to the above which shows the vicinity of the protruding item | line part which consists of a protruding item | line of a different cross-sectional shape. The enlarged view similar to the above which shows the vicinity of a protruding line part including the protruding line of a different arrangement form. FIG. 3 is a vertical sectional view similar to FIG. 2 showing a package of a different form. (A), (B) is a partial top view which shows the convex strip part vicinity of a form from which planar view differs. (A), (B) is a partial top view which shows the convex strip part vicinity of a form from which a planar view differs further.

Hereinafter, modes for carrying out the present invention will be described.
1 is a plan view showing a package 1a according to an embodiment of the present invention, FIG. 2 is a vertical sectional view taken along the line XX in FIG. 1, and FIG. 3 is a ridge portion in FIG. FIG.
As shown in FIGS. 1 to 3, the package 1 a is made of ceramic (insulating material) c, and has a front surface 3 and a rear surface 4 that are rectangular (rectangular) in plan view, and four side surfaces 5 that are positioned therebetween. The package body 2 and a planar view formed along the periphery of the surface 3 of the package body 2 are bonded to the rectangular frame-shaped metal layer 6 via the brazing material 7 on the surface of the metal layer 6. A metal frame 8 having a rectangular frame shape in plan view. On the left side of the surface 3 of the package body 2 surrounded by the metal layer 6, a pair of electrode pads 9 for mounting a crystal resonator (not shown) is formed later.

The ceramic c is, for example, alumina, and the metal layer 6 and the pair of electrode pads 9 are made of, for example, W, Mo, or an alloy based on any of these. The metal frame 8 is made of, for example, Kovar, and the brazing material 7 is made of, for example, Ag solder.
In addition, a metal lid (not shown) for sealing the surface 3 of the package body 2 including the crystal resonator to be mounted is welded to the surface of the metal frame 8.
As shown in FIGS. 1 to 3, the surface 3 of the package body 2 sandwiched between the metal layer 6 and the pair of electrode pads 9 has, for example, the same kind as described above along the almost entire length of the surface 3. A protruding portion 10 made of alumina or photosensitive resin (insulating material) and projecting in a U shape in plan view is projected. The ridges 10 are long in the vertical direction in FIG. 1 adjacent along the short sides of the metal layer 6 and the metal frame 8, and in the horizontal direction in FIG. 1 through curved portions from both ends of the ridges 11. And a pair of short ridges 12 extending in the direction.

As illustrated in FIG. 3, the cross section of the ridge 11 constituting the ridge portion 10 has a semicircular or semi-elliptical shape, and the height of the ridge 11 is at least 10 μm or more, and the metal layer 6, the surface of the pair of electrode pads 9, and the surface of the brazing material 7 (the bottom surface of the metal frame 8).
Further, the cross-sectional shape of the ridge 11 constituting the ridge portion 10 is an inverted trapezoidal ridge 11a as illustrated in FIG. 4, or a corner is rounded as illustrated in FIG. It may be a rectangular (rectangular) ridge 11b.
Further, as illustrated in FIG. 6, a form in which a part of the ridge 11 b covers the inner peripheral surface of the adjacent metal layer 6, like the ridge 11 b constituting the ridge portion 10. Or it is good also as a form which a part of the said protruding item | line 11b has covered the surface of the inner peripheral side of the brazing material 7 which adjoins.
The heights of the ridges 11a and 11b are also higher than the surface of the adjacent metal layer 6 and the surface of the electrode pad 9. The ridges 11, 11 a may also cover the inner peripheral surface of the adjacent metal layer 6 or brazing material 7. Further, external connection terminals (not shown) are formed on the back surface 4 of the package body 2, and via conductors (not shown) that penetrate the terminals and the pair of electrode pads 9 through the package body 2. It is supposed to be conducted through.

The package 1a as described above was manufactured by the following method.
A green sheet containing alumina powder is prepared in advance, and a conductive paste containing, for example, W powder or Mo powder is screen-printed on the surface of the green sheet, so that an unfired metal layer 6 and a pair of electrode pads 9 are obtained. And formed.
Next, on the surface of the green sheet sandwiched between the metal layer 6 and the pair of electrode pads 9, for example, an insulating paste containing alumina powder is screen-printed to form an unfired ridge portion 10. . Next, the green sheet having the unfired metal layer 6, the pair of electrode pads 9, and the protrusions 10 is fired, and the metal layer 6 and the pair of fired simultaneously on the package body 2 and the surface 3 thereof. Electrode pad 9 and ridge portion 10 were obtained. Further, a metal frame 8 was brazed (joined) on the surface of the metal layer 6 via a brazing material 7 made of Ag brazing. Then, the package body 2 is sequentially immersed in an electrolytic Ni plating tank and an electrolytic Au plating tank, and the exposed surfaces of the metal frame 8 and the pair of electrode pads 9 are sequentially covered with the Ni plating film and the Au plating film. Thus, the package 1a was obtained.

The protrusion 10 is formed by screen-printing an insulating paste containing a photosensitive resin (for example, cinnamate) on the surface 3 of the baked package body 2 and then applying ultraviolet rays to the insulating paste. You may form by the method of irradiating and hardening. Or you may form by the method (curing process) which heats and hardens this resin, for example after screen-printing thermosetting resins, such as an epoxy type.
Moreover, you may perform the manufacturing method mentioned above by the form of many pieces.

FIG. 7 is a vertical sectional view similar to FIG. 2 showing a package 1b of a different form.
As shown in FIG. 7, the package 1b is formed by laminating a ceramic layer (insulating material) c1 on the upper layer side and a ceramic layer (insulating material) c2 on the lower layer side. A package body 2a having a side surface 5 and a metal layer 6, a brazing material 7, a metal frame 8, and a pair of electrode pads 9 formed in the same manner as described above on the surface 3 of the package body 2a are provided. Further, on the surface 3 of the package body 2 a sandwiched between the metal layer 6 and the pair of electrode pads 9, the ridge portion 10 including the ridge 11 b similar to the above protrudes along substantially the entire length of the surface 3. It is installed.

As shown in FIG. 7, on the right side of the surface 3 of the package body 2a surrounded by the metal layer 6 excluding the portion where the pair of electrode pads 9 are formed, a cavity 16 having a box shape as a whole is formed. It is open. The cavity 16 includes a bottom surface 17 formed of the surface of the lower ceramic layer c2 and side surfaces 18 of four sides in a through hole having a rectangular shape in a plan view that penetrates the upper ceramic layer c1. A plurality of mounting electrodes 15 are formed for joining with electrodes of electronic components (not shown) such as IC chips to be mounted in the cavity 16 later.
The mounting electrode 15 is also made of W, Mo, or an alloy based on any of these.
Further, a wiring layer (not shown) may be formed between the ceramic layers c1 and c2, and the electrode pad 9 and the external connection terminal on the back surface 4 may be conducted through the wiring layer.
In the package 1b as described above, a crystal resonator can be surface-mounted, and an electronic component such as an IC chip can also be mounted in the cavity 16 together.

The package 1b as described above was manufactured by the following method.
A two-layer green sheet similar to the above was prepared, and among these, the green sheet on the upper layer side was punched to form a through hole having a rectangular shape in plan view. An unfired metal layer 6, a pair of electrode pads 9, and ridges 10 were formed on the surface of the upper green sheet around the through hole in the same manner as described above. On the other hand, the same conductive paste as described above was screen-printed at a predetermined position on the surface of the green sheet on the lower layer side to form a plurality of unfired mounting electrodes 15.
Next, after laminating and pressure-bonding the two layers of green sheets, the package body 2a, the metal layer 6 fired simultaneously on the surface 3, the pair of electrode pads 9, and the ridges are fired. 10, a cavity 16 opened in the surface 3, and a plurality of mounting electrodes 15 fired simultaneously on the bottom surface 17.
Thereafter, the package 1b can be obtained by performing the brazing process and the plating process described above.

According to the packages 1a and 1b as described above, the surface 3 of the package main body 2 and 2a sandwiched between the metal layer 6 and the pair of electrode pads 9 has an alumina along substantially the entire length of the surface 3. A protruding strip portion 10 made of (insulating material) is projected. Therefore, for example, a part of the brazing material 7 used locally and excessively to join the metal frame 8 on the surface of the metal layer 6 is on the surface 3 side of the package body 2, 2 a surrounded by the metal layer 6. The brazing material 7 flows out, the position where the metal layer 6 is to be printed is shifted from the surface 3 of the package body 2, 2 a, or the joining position of the metal frame 8 is shifted from the metal layer 6. Even if a part of the brazing material 7 flows out to the surface 3 side of the package main bodies 2, 2 a, the brazing material 7 is dammed up by the ridges 10.
As a result, even if the metal layer 6 and the pair of electrode pads 9 are arranged relatively close to each other on the surface 3 of the package body 2, 2 a, the metal layer 6 and the metal frame 8 and the pair of electrode pads 9 are between them. It is possible to reliably prevent a situation where an inadvertent short circuit occurs. Therefore, the performance of the crystal resonator mounted on the pair of electrode pads 9 can be surely ensured, and the packages 1a and 1b can be reduced in size and height as a whole.

FIG. 8A is a partial plan view of the package body 2 showing the vicinity of a pair of protruding strips 10a of different forms.
As shown in FIG. 8A, the pair of ridges 10 a is formed on the surface 3 of the package body 2 sandwiched between the metal layer 6 located below the metal frame 8 and the pair of electrode pads 9. Along the surface 3 between the metal layer 6 and each electrode pad 9, along the short side of the metal layer 6, a short vertical projection 11 s shown in the figure, and an outer peripheral end of the projection 11 a In the drawing, it is composed of protruding ridges 12 extending sideways, and each has a L-shape in plan view and protrudes symmetrically with each other.
The same effect as described above can also be achieved by the package 1a including the pair of ridges 10a. Further, the pair of ridges 10a can be applied to the package 1b.

FIG. 8B is a partial plan view of the package body 2 showing the vicinity of the ridge portion 10b of a different form.
As shown in FIG. 8 (B), the protrusion 10b is formed on the surface 3 of the package body 2 sandwiched between the metal layer 6 located below the metal frame 8 and the pair of electrode pads 9, and the metal layer. 6 is composed of only a part of the surface 3 between the short side 6 and the pair of electrode pads 9 and a long vertical ridge 11 in the longitudinal direction in the drawing along the short side of the metal layer 6.
The same effect as described above can also be achieved by the package 1a including the ridge portion 10b. Further, the ridge portion 10b can also be applied to the package 1b.

FIG. 9A is a partial plan view of the package body 2 showing the vicinity of the ridge portion 10 c which is an applied form of the ridge portion 10.
As shown in FIG. 9 (A), the ridge portion 10c includes a pair of electrode pads 9 from an intermediate portion of the ridge 11 in addition to the vertically long ridge 11 and a pair of lateral ridges 12. The surface 3 of the package body 2 sandwiched therebetween is further added with a ridge 13 extending in the horizontal direction in the figure, and the whole has an almost E shape in plan view.
According to the protruding line portion 10c, in addition to the effect of the protruding line portion 10, even if the distance between the pair of electrode pads 9 is narrow, an inadvertent short circuit between the electrode pads 9 can be further prevented. . Further, the ridge portion 10c can be applied to the package 1b.

FIG. 9 (B) is a partial plan view of the package body 2 showing the vicinity of a pair of ridges 10d which is still another form.
As shown in FIG. 9B, the pair of ridges 10 d is formed on the surface 3 of the package body 2 sandwiched between the metal layer 6 located below the metal frame 8 and the pair of electrode pads 9. Along the surface 3 sandwiched between a pair of long sides and a pair of electrode pads 9 opposed to each other in the metal layer 6, a laterally extending ridge 12 in the figure, and the metal layer from the left end of the ridge 12. 6, which are curved and extended along the inner corners of the 6, and each have a J-shape in plan view and project symmetrically with each other.
According to the pair of protrusions 10d, even if the long sides of the metal layer 6 and the pair of electrode pads 9 are disposed relatively close to each other, an inadvertent short circuit due to the outflow of the brazing material 7 is prevented. Can be prevented. Further, the pair of ridges 10d can be applied to the package 1b.

The present invention is not limited to the embodiments described above.
For example, the package body 2 uses a resin plate with a copper foil in which a copper foil is stretched on the surface 3 side of a resin plate made of polyimide or the like, and a photolithography technique is applied to the copper foil to form the metal layer. 6 and a pair of electrode pads 9 are formed, and an insulating paste containing a photosensitive resin or a thermosetting resin is printed on the surface 3 sandwiched between them to form the ridges 10 and the like. You may make it do.
Further, the front surface 3 and the back surface 4 of the package bodies 2 and 2a may be substantially square (rectangular) in plan view.

Further, the package bodies 2 and 2a may be formed by laminating two or more insulating layers.
In addition, the metal layer 6 and the metal frame 8 may have an elliptical frame shape, an oval frame shape, or a regular polygon shape or a polygonal shape that is a pentagon or more in a plan view.
Furthermore, the said protruding item | line part 10,10a, 10c is good also as a form which formed the said protruding item | line 11,11s, 12,13 which comprises these in the shape of the several mutually independent straight line.
In addition, the ridges 10, 10a, 10b, 10d are parallel to each other in a plan view on the surface 3 of the package body 2, 2a sandwiched between the metal layer 6 and the pair of electrode pads 9. It is good also as a form provided through two or more rows.

  According to the present invention, even if the metal layer formed on the periphery of the surface of the package body and the pair of electrode pads formed on the surface of the package body surrounded by the metal layer approach each other, the electrode Even if the pad and the metal layer are placed through the brazing material, it is possible to provide a package that does not short-circuit reliably and can be easily reduced in size and height.

1a, 1b ……………… Package 2,2a ………………… Package body 3 ………………………… Front side 4 ………………………… Back side 6 ……… ………………… Metal layer 7 ………………………… Brazing material 8 ………………………… Metal frame 9 ………………………… Electrode pad 10, 10a to 10d ... ridge c c ................................. Ceramic (insulating material)
c1, c2 ............ Ceramic layer (insulating material)

Claims (4)

A package body made of an insulating material and having a rectangular front surface and a back surface in plan view;
A frame-like metal layer formed in a plan view along the periphery of the surface of the package body,
A metal frame having a frame shape in plan view joined via a brazing material on the surface of the metal layer;
A package comprising a pair of electrode pads formed on the surface of the package body surrounded by the metal layer and for mounting a crystal resonator,
On at least a part of the surface of the package body sandwiched between the metal layer and a pair of electrode pads, a protruding strip portion made of an insulating material protrudes.
Package characterized by that. The ridge is projected along the surface of the package body sandwiched between the metal layer and a pair of electrode pads.
The package according to claim 1. The height of the ridge is higher than at least the surface of the metal layer and the surface of the electrode pad,
The package according to claim 1 or 2, wherein The protruding line part covers a part of the protruding line part on the inner peripheral surface of the metal layer or the inner peripheral surface of the brazing material.
The package according to claim 1, wherein the package is a package.

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