JP5334746B2 - Device storage package and mounting structure - Google Patents

Description

  The present invention relates to an element storage package and a mounting structure using the element storage package.

  2. Description of the Related Art Conventionally, an element storage package having an input / output terminal in which a signal line is formed on one main surface of a dielectric layer and a ground layer is formed on the other main surface of the dielectric layer is known. In input / output terminals used at high frequencies such as microwaves and millimeter waves, it is necessary to use a dielectric layer having a low relative dielectric constant and a low dielectric loss in order to efficiently transmit high frequency signals. A technique for reducing the relative dielectric constant of the entire dielectric layer by forming the dielectric layer from a porous material has been proposed (see Patent Document 1 below).

JP-A-8-227949

  By the way, when the dielectric layer is made of a porous material, many bubbles exist at the interface between the signal line and the dielectric layer. Therefore, the adhesive strength between both the signal line and the dielectric layer is not sufficient, and there is a possibility that peeling occurs between them. As a result, the airtightness of the package may be impaired.

  The present invention has been made in view of the above, and an object of the present invention is to provide an element housing package excellent in airtightness and a mounting structure using the element housing package.

In order to solve the above-described problems, an element storage package according to a first aspect of the present invention is provided on a substrate having an element mounting region on an upper surface thereof and on the substrate along the outer periphery of the mounting region. A frame body partially having a through hole, a first dielectric layer provided in the through hole and extending in and out of the frame body, and formed on an upper surface of the first dielectric layer, the frame A signal line that electrically connects the inside and outside of the body, a ground conductor formed on a lower surface of the first dielectric layer, a second dielectric layer provided on the signal line and having a gap formed therein , And a portion of the second dielectric layer is interposed between the gap and the signal line .

  A mounting structure according to a second aspect of the present invention includes the element storage package and an element mounted on the element storage package.

  According to the present invention, it is an object to provide an element storage package having excellent airtightness, and a mounting structure using the element storage package.

It is a perspective view which shows the general view of the element storage package which concerns on this embodiment. It is a perspective view which shows the external appearance of the input / output terminal of the element storage package which concerns on this embodiment. FIG. 3 is a cross-sectional view of an input / output terminal along X-X ′ shown in FIG. 2. FIG. 3 is a cross-sectional view of an input / output terminal along Y-Y ′ illustrated in FIG. 2. FIG. 6 is a cross-sectional view according to a modified example of the input / output terminals along Y-Y ′ shown in FIG. 2. It is a perspective view which shows the external appearance of the input / output terminal which concerns on one modification. FIG. 7 is a cross-sectional view of an input / output terminal along Y-Y ′ illustrated in FIG. 6. It is a perspective view which shows the external appearance of the input / output terminal which concerns on one modification. It is sectional drawing of the input-output terminal along Y-Y 'shown in FIG.

  Embodiments of an element storage package according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention shall not be limited to the following embodiment.

<Schematic structure of element storage package>
FIG. 1 is a schematic perspective view showing an element storage package 1 according to the present embodiment. FIG. 2 is a schematic perspective view of input / output terminals used in the element storage package 1 of FIG. The element storage package 1 is used for home appliances such as a television, and electronic devices such as a mobile phone or a computer device. In particular, it is used for a high-frequency circuit of an electronic device used at a high frequency such as a microwave and a millimeter wave.

  The element storage package 1 includes, for example, an active element such as a semiconductor element, an optical semiconductor element, a transistor, a diode, or a thyristor, or a passive element such as a resistor, a capacitor, a solar cell, a piezoelectric element, a crystal oscillator, or a ceramic oscillator. Used to mount the element 2.

  The element storage package 1 includes a substrate 3 having a mounting region R of the element 2 on the upper surface, a frame 4 provided on the substrate 3 along the outer periphery of the mounting region R, and having a through hole H in a part thereof. The signal line 5 provided in the through hole H and electrically connecting the inside and the outside of the frame body 4 and the input / output terminal having a pair of dielectric layers 6 that sandwich the signal line 5 and in which the air gap A is formed 7. A ground conductor 8 is formed on a part of the outer periphery of the pair of dielectric layers 6 so as to be separated from the signal line 5. Here, the signal line 5 and the ground conductor 8 are paired and function as a high-frequency transmission line.

  The substrate 3 is a member formed in a square shape when viewed in plan. The board | substrate 3 consists of metal materials, such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or the alloy containing these metal materials, for example. The substrate 3 has a function of improving heat conductivity and efficiently dissipating heat generated from elements mounted in the mounting region R to the outside through the substrate 3. The thermal conductivity of the substrate 3 is set to, for example, 15 W / (m · K) or more and 450 W / (m · K) or less.

  Further, the substrate 3 is manufactured in a predetermined shape by using a conventionally known metal processing method such as rolling or punching for an ingot obtained by casting and solidifying a molten metal material into a mold. Note that the length of one side of the substrate 3 is set to 3 mm or more and 50 mm or less, for example. Moreover, the thickness of the board | substrate 3 is set to 0.3 mm or more and 5 mm or less, for example.

  Further, a plating layer such as nickel or gold is formed on the surface of the substrate 3 by using an electroplating method or an electroless plating method in order to prevent oxidative corrosion or to easily braze the element 2 to the mounting region R. Has been. The mounting region R of the substrate 3 is a region that is not connected to the frame body 4 when the frame body 4 is connected to the upper surface of the substrate 3. In the present embodiment, the substrate 3 has a quadrangular shape, but is not limited to a quadrangular shape and may be a polygonal shape or an elliptical shape as long as an element can be mounted.

  The frame body 4 is a member that is connected along the outer periphery of the mounting region R of the substrate 3 and protects elements mounted on the mounting region R from the outside. Further, the frame body 4 is formed with a through hole H provided with an input / output terminal 7 in a part of the side surface. The frame 4 is brazed to the substrate 3 via a brazing material. The brazing material is made of, for example, silver, copper, gold, aluminum, or magnesium, and may contain an additive such as nickel, cadmium, or phosphorus.

  The frame 4 is made of, for example, a metal material such as copper, iron, tungsten, molybdenum, nickel or cobalt, or an alloy containing these metal materials. The frame body 4 has a function of efficiently dissipating heat generated from the element 2 to the outside of the frame body 4 in a state where the element 2 is mounted in the mounting region R. The thermal conductivity of the frame 4 is set to, for example, 15 W / (m · K) or more and 450 W / (m · K) or less.

  Here, the input / output terminal 7 will be described. FIG. 3 is a cross-sectional view of the input / output terminal 7 along X-X ′ shown in FIG. 2. FIG. 4 is a cross-sectional view of the input / output terminal 7 along Y-Y ′ shown in FIG. 2.

  The input / output terminal 7 is provided in the through hole H of the frame body 4. The input / output terminal 7 is formed on the upper surface of the first dielectric layer 6a extending in and out of the frame 4 and the signal line 5 electrically connecting the inside and outside of the frame. And a ground conductor 8 formed on the lower surface of the first dielectric layer 6a, and a second dielectric layer 6b formed on the signal line 5 and having a gap A formed therein.

  The signal line 5 has a function of transmitting a predetermined electric signal. The signal line 5 is used as, for example, a microstrip line or a coplanar line. The signal line 5 is made of a metal material such as copper, silver, gold, aluminum, nickel, or chromium, for example. The line width of the signal line 5 is ¼ or less of the wavelength of the signal transmitted to the signal line 5, and is set to, for example, 0.05 mm or more and 0.5 mm or less.

  A lead terminal 9 is formed on the signal line 5. The lead terminal 9 is a member for electrically connecting an external electronic device or the like to the element 2. The lead terminal 9 is connected to the signal line 5 through a brazing material. The signal line 5 and the lead terminal 9 are electrically connected.

  Further, the input / output terminal 7 has a ground conductor 8 surrounding the first dielectric layer 6a and the second dielectric layer 6b, as shown in FIG. 3 or FIG. The ground conductor 8 has a function of setting a common potential, for example, a ground potential. The ground conductor 8 is made of a metal material such as copper, silver, gold, aluminum, nickel, or chromium, for example. The ground conductor 8 is formed in a region overlapping the signal line 5 in plan view. The frame 4 is made of a metal material, and the ground conductor 8 and the frame 4 are electrically connected.

  The first dielectric layer 6a and the second dielectric layer 6b are insulating substrates, for example, inorganic materials such as aluminum oxide, aluminum nitride, or silicon nitride, or organic materials such as epoxy resin, polyimide resin, or ethylene resin. It is made of a material, a ceramic material such as alumina or mullite, or a glass ceramic material. Or it consists of a composite material which mixed several materials among these materials. The thicknesses of the first dielectric layer 6a and the second dielectric layer 6b are not more than one half of the wavelength of the signal transmitted to the signal line 5, and are set to, for example, 0.1 mm or more and 1.0 mm or less. Yes.

  The first dielectric layer 6a or the second dielectric layer 6b may contain a large number of fillers. When the first dielectric layer 6a or the second dielectric layer 6b is made of an organic material, the first dielectric layer 6a or the second dielectric layer 6b contains a filler so that the first dielectric layer 6a or the second dielectric layer 6b The viscosity before curing of the second dielectric layer 6b can be adjusted, and the thickness dimension of the first dielectric layer 6a or the second dielectric layer 6b can be brought close to a desired value. The filler is spherical, and the diameter of the filler is set to, for example, 0.05 μm or more and 6 μm or less, and the coefficient of thermal expansion is, for example, −5 ppm / ° C. or more and 5 ppm / ° C. or less. The filler is made of, for example, silicon oxide, silicon carbide, aluminum oxide, aluminum nitride, or aluminum hydroxide.

  The relative dielectric constant of the filler contained in the first dielectric layer 6a or the second dielectric layer 6b is smaller than the relative dielectric constant of the material constituting the first dielectric layer 6a or the second dielectric layer 6b. Can be set. Thus, by using a low dielectric constant filler smaller than the dielectric constant of the first dielectric layer 6a or the second dielectric layer 6b, the entire dielectric layer 6 can be further reduced in dielectric constant, The transmission efficiency of the signal transmitted to the signal line 5 can be improved.

  The filler can be an insulating filler. By making the filler insulative, the influence on the characteristic impedance of the signal transmitted to the signal line 5 can be reduced.

  A void A is formed in the second dielectric layer 6b. The signal line 5 is covered with a second dielectric layer 6b. The air gap A is provided on a part of the second dielectric layer 6 b covering the signal line 5. The air gap A is provided inside the second dielectric layer 6b through the signal line 5 and a part of the second dielectric layer 6b.

  The air gap A is formed in a region overlapping the signal line 5 in plan view. The width of the gap A is set larger than the width of the signal line 5 as shown in FIG. The width of the gap A is set to, for example, 0.2 mm to 1.0 mm, and the width of the signal line 5 is set to, for example, 0.05 mm to 0.5 mm.

  The signal transmitted to the signal line 5 changes in transmission characteristics due to the material located immediately above or below the signal line 5, but if the change in the transmission characteristics is large, the signal transmitted to the signal line 5 is reflected. The amount increases. The signal line 5 is formed to extend inside and outside the frame body 4 in order to electrically connect the inside and outside of the frame body 4. Therefore, a change in transmission characteristics of a signal transmitted to the signal line 5 is large in a region where the signal line 5 and the frame 4 overlap in plan view. In the present embodiment, in the region where the signal line 5 and the frame body 4 overlap, a part of the dielectric layer is pasted directly above and below the signal line 5 to reduce the region where the signal line 5 is in contact with the atmosphere. As a result, it is possible to suppress a change in transmission characteristics of the signal transmitted to the signal line 5 and to reduce reflection of high frequency transmitted to the signal line 5.

  The input / output terminal 7 has a ground conductor 8 that surrounds the first dielectric layer 6a and the second dielectric layer 6b. When the ground conductor 8 is connected to the inner wall surface of the through hole H, It can suppress that the signal transmitted to the signal track | line 5 reflects in the area | region where the track | line 5 and the frame 4 overlap.

  The mounting structure 1X can be configured by flip-chip mounting the element 2 on the element storage package 1 via bumps such as solder. When a semiconductor element such as an IC or LSI is mounted, for example, silicon, germanium, gallium arsenide, gallium arsenide phosphorus, gallium nitride, or silicon carbide can be used as the semiconductor element.

  According to this embodiment, in the region where the signal line 5 and the frame 4 overlap, the signal line 5 is covered with the dielectric layer 6 so that the upper surface of the signal line 5 is not exposed. Good adhesion strength with the dielectric layer 6 can be maintained. And it can suppress favorably that peeling generate | occur | produces between the signal track | line 5 and the dielectric material layer 6, and can maintain the airtightness of a package favorable. Moreover, it can suppress that the transmission characteristic of the signal track | line 5 falls, and the element storage package 1 and the mounting structure 1X which were excellent in the electrical property can be provided.

  In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

  For example, although the input / output terminal 7 shown in FIG. 4 has the air gap A inside the second dielectric layer 6b, the inside of the first dielectric layer 6a of the input / output terminal 7 as shown in FIG. An air gap A ′ may be provided in the space. In the region where the signal line 5 and the frame 4 overlap, by providing the air gap A ′ inside the first dielectric layer 6a, the relative dielectric constant of the entire dielectric layer 6 can be reduced. And it can suppress favorably that the dielectric loss of the signal transmitted to the signal track | line 5 becomes large by reducing the dielectric constant of the dielectric material layer 6 whole.

<Manufacturing method of element storage package>
Here, a method for manufacturing the element storage package 1 shown in FIG. 1 will be described.

  First, each of the substrate 3 and the frame 4 is prepared. Each of the substrate 3 and the frame 4 is manufactured in a predetermined shape by using a metal processing method on a solidified ingot obtained by casting a molten metal material into a mold.

  Next, the input / output terminal 7 is prepared. Here, a method for manufacturing the input / output terminal 7 when the material of the dielectric layer 6 is an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or the like will be described.

  Specifically, when the material of the dielectric layer 6 is made of an aluminum oxide sintered body, first, an organic binder, a plasticizer, a solvent, or the like is added to raw powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. Mix to form a mud.

  Then, molds for the first dielectric layer 6a and the second dielectric layer 6b are prepared, and the frame body is filled with a slurry-like aluminum oxide material, and the first dielectric layer 6a before sintering is filled. Then, the second dielectric layer 6b is taken out. The second dielectric layer 6b is decomposed into three layers before the second dielectric layer 6b is sintered. The three layers include a plate-like first layer laminated on the line conductor 5, a frame-like second layer laminated on the first layer, and a plate-like third layer laminated on the second layer. It is formed by laminating these layers.

  Moreover, a high melting point metal powder such as tungsten or molybdenum is prepared, and an organic binder, a plasticizer, a solvent, or the like is added to and mixed with the powder to obtain a metal paste.

  Then, a metal paste is applied to the upper surface of the extracted first dielectric layer 6a of the precursor, for example, using a screen printing method to form the line conductor 5. In addition, when the first dielectric layer 6a and the second dielectric layer 6b are combined, the ground conductor 8 is formed at a location surrounding them by using, for example, a screen printing method.

  Next, the second dielectric layer 6b as a precursor is placed on the first dielectric layer 6a as a precursor and pressed to be brought into close contact with each other. And the laminated body which apply | coated the metal paste by printing is baked at the temperature of about 1600 degreeC, and the input-output terminal 7 which consists of ceramics in which the base member was formed can be produced.

  And the input / output terminal 7 is fitted and connected to the through-hole H of the prepared frame 4 through the brazing material. In this way, the element storage package 1 can be manufactured.

  Next, the mounting structure can be manufactured by mounting the element 2 on the element storage package 1 via solder.

<Modification 1>
In the above embodiment, the gap A formed in the second dielectric layer 6b of the input / output terminal 7 cannot be confirmed from the outside, and is formed in the second dielectric layer 6b. Not limited. For example, as shown in FIG. 6 or FIG. 7, the gap B extends to the end face of the second dielectric layer 6b, and is formed so that the bottom 6bx of the gap B is exposed when viewed from the side. May be.

  It is generated between the signal line 5 and the ground conductor 8 by increasing the size of the air gap B formed in the second dielectric layer 6b until it extends to the end face of the second dielectric layer 6b. Capacitance components can be reduced, and transmission characteristics transmitted to the signal line 5 can be improved.

  The air gap B formed in the second dielectric layer 6b does not penetrate the second dielectric layer 6b, so that the airtightness of the package can be maintained.

<Modification 2>
In the first modification described above, the gap B formed in the second dielectric layer 6b is formed to extend only to one end of the second dielectric layer 6b. However, the present invention is not limited to this. For example, as shown in FIG. 8 or FIG. 9, a plurality of gaps C are provided in the second dielectric layer 6b, and one gap C extends to one end of the second dielectric layer 6b. And another gap C may extend to the other end of the second dielectric layer 6b.

  As shown in FIG. 8 or FIG. 9, the design freedom of the shape of the second dielectric layer 6b, that is, the shape of the input / output terminal 7 can be increased by appropriately selecting the location where the gap C is provided.

DESCRIPTION OF SYMBOLS 1 Element accommodation package 1X Mounting structure 2 Element 3 Board | substrate 4 Frame 5 Signal line 6 Dielectric layer 6a 1st dielectric layer 6b 2nd dielectric layer 7 I / O terminal 8 Grounding conductor 9 Lead terminal H Through-hole A Space | gap

Claims (5)

A substrate having an element mounting region on the upper surface;
A frame body provided on the substrate and along an outer periphery of the mounting region, and having a through hole in a part thereof;
A first dielectric layer provided in the through hole and extending in and out of the frame; a signal line formed on an upper surface of the first dielectric layer and electrically connecting the inside and outside of the frame; An input / output terminal having a ground conductor formed on a lower surface of the first dielectric layer and a second dielectric layer provided on the signal line and having a gap formed therein ,
An element storage package, wherein a part of the second dielectric layer is interposed between the gap and the signal line . The device storage package according to claim 1,
The element housing package, wherein the gap is formed in a region overlapping with the signal line. The element storage package according to claim 1 or 2,
The grounding conductor is formed along the inner wall surface of the through hole, and is connected to the inner wall surface of the through hole. The element storage package according to any one of claims 1 to 3,
The package for storing elements, wherein the gap extends to an end face of the second dielectric layer in which the gap is formed, and the bottom of the gap is exposed when viewed from the side. An element storage package according to any one of claims 1 to 4,
A mounting structure comprising an element to be mounted on the element storage package.

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