JP2002261236A - Electronic component device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component device having a lid which is not peeled off from a substrate, when thermal stress such as solder reflow is applied, and both the electronic component device and a mother board can be mounted stably, after the electronic component device has been mounted on the mother board. SOLUTION: In this electronic component device, a substrate 1 has a part 4 where one surface is opened and the section is recessed, an electronic component element 3 is accommodated in the recessed part 4, and the aperture of the recessed part 4 is sealed with a lid member 7 for sealing, which is constituted of the laminated structure of a metal layer 7a on the exposed surface side and a resin layer 7b of a substrate jointing surface side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component device in which an electronic component element, for example, a piezoelectric element such as a SAW element is housed in a recess (cavity) formed in a substrate and hermetically sealed.

[0002]

2. Description of the Related Art In recent years, demands for smaller, thinner, and more sophisticated electronic component devices have been increasing. In order to meet these demands, a plurality of electronic components are mounted on one main surface of a substrate such as ceramic. The device is mounted, and a recess is formed in the other main surface of the substrate, and the electronic component device is accommodated in the recess.
Examples of the electronic component element mounted on one main surface of the substrate include a capacitor, a resistor, a diode, a coil, and a surface-mounted electronic component element such as a semiconductor element such as an IC or a transistor. Examples of the electronic component element housed in the recess include a piezoelectric element and the like, and include a SAW element, a ceramic vibrator,
A device such as a crystal unit that requires hermetic sealing for environmental protection.

In such an electronic component device, a concave portion is formed in the other main surface of the substrate, and the electronic component element is accommodated in the concave portion. The electronic component element housed in the concave portion of the electronic component device is sealed by bonding a lid made of metal or ceramic to the opening of the concave portion in which a piezoelectric element requiring a space is arranged around the electronic component element. I was

[0004] A typical sealing method is solder or Au-Sn.
A solder seal method using an alloy, a seal ring brazed around the opening, and a seam weld method in which a metal lid is sealed to the seal ring by seam welding. A glass sealing method for bonding a lid is known.

[0005] These sealing methods are high in airtightness and excellent in reliability, but have the disadvantage that they are inferior in productivity and expensive.
Considering the heat applied during sealing, the temperature in the concave portion is about 150 ° C. in the seam weld method, 320 to 340 ° C. in the salter seal method, and 380 to 420 ° C. in the glass seal method. . At such a high temperature at the time of sealing, it is conceivable that the characteristics of the electronic component element housed in the concave portion are greatly changed. Particularly, in the case of an element which is weak to heat, such as a quartz oscillator or a surface acoustic wave element, Cannot be adopted because of the deterioration of the characteristics.

In order to solve these problems, a method of bonding a substrate and a lid using a resin-based adhesive as a bonding material has been proposed (for example, Japanese Patent Laid-Open No. 4-85).
857 and JP-A-7-212169). In these sealing structures, as shown in FIG. 3, a metal foil body is used as a cover material, and sealing is performed with a resin-based adhesive such as an epoxy resin. In FIG. 3, 1 is a substrate, 2 is an electronic component element mounted on one main surface side of the substrate, 4 is a concave portion, 3 is an electronic component element housed in the concave portion 4, 70 is a cover made of metal foil, 8 is a resin adhesive, 9 is an external terminal electrode, 10 is a motherboard, 11 is a wiring pattern for an external terminal electrode, 12
Is a wiring pattern, and 13 is solder.

[0007]

The first problem of such an electronic component device is that, in recent years, in response to demands for miniaturization and reduction in height, the lid is made thinner in order to reduce the height of electronic component elements. There is a need. For example, as shown in FIG. 3, when connecting the electronic component element 3 with the bonding wire in the concave portion 4, a short circuit may occur between the metal cover and the bonding wire, and the miniaturization of the electronic component device is achieved. Hard to do. In addition, a large restriction is imposed on the connection method for the electronic component element housed in the recess.

The bonding between the substrate 1 and the metal lid 70 is
This is achieved via the resin-based adhesive 8. That is, since the resin-based adhesive 8 joins the substrate 1 and a member having a completely different thermal expansion coefficient from the metal, the electronic component device can be used even when thermal stress such as solder reflow is applied to the motherboard 10 or the like. May peel off from the substrate.

Further, when the metal cover 70 protrudes from the other surface of the substrate of the electronic component device, the electronic component device cannot be surface-mounted on the motherboard 10.

The present invention has been devised in view of the above-mentioned problems, and has as its object to prevent the lid from peeling off from the substrate even when a thermal stress such as solder reflow is applied, so that the electronic component can be prevented. An object of the present invention is to provide an electronic component device and an electronic component device that can be stably mounted on the motherboard after the device is mounted on the motherboard.

[0011]

According to the present invention, there is provided an electronic component in which an electronic component element is housed in a concave portion on a substrate having a concave portion having an open cross section, and the opening of the concave portion is sealed with a sealing lid. The electronic component device is characterized in that the sealing lid has a laminated structure of a metal layer on the exposed surface side and a resin layer on the substrate bonding surface side.

Also, the sealing lid and the periphery of the opening of the concave portion of the substrate are joined via a resin adhesive. Alternatively, the bonding between the sealing lid and the substrate is performed by a resin layer on the substrate bonding surface side of the sealing lid.

[0013] Further, a dent at least equal to the thickness of the sealing lid is provided around the opening of the recess, and external terminal electrodes are arranged on the substrate surface around the dent. .

Further, electronic component elements are arranged on the other main surface of the substrate by surface mounting.

According to the present invention, the sealing lid has a laminated structure of a resin layer and a metal layer. The metal layer is disposed on the exposed surface side, and the resin layer is disposed on the inner surface side. The resin layer of the sealing lid and the substrate of the electronic component device are bonded via a resin-based adhesive, or are directly bonded to the substrate using a resin layer coated on the inner surface side as a lid as an adhesive layer. Is done. Thereby, the adhesive force between the sealing lid and the substrate of the electronic component device is increased, and the sealing lid does not peel off from the substrate even when thermal stress such as solder reflow is applied.

Further, even if the electronic component element is electrically bonded to the substrate by, for example, a bonding wire, a short circuit of the bonding wire does not occur because the inner surface of the sealing lid is made of an insulating material. .

Since the sealing lid does not protrude from the substrate surface of the electronic component device, the gap between the electronic component device and the motherboard is substantially equal to the gap between the substrate and the motherboard, and the solder reflow. The cleaning liquid easily flows between the electronic component device and the motherboard during cleaning, and the cleaning performance is improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic component device according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of an electronic component element layer device of the present invention, and FIG. 2 is a plan view of a bottom surface side of the electronic component device of the present invention. The same parts as those in the related art will be described with the same reference numerals.

In the figure, 1 is a substrate, 2 is an electronic component element arranged on one main surface of the substrate, 4 is a concave portion, 3 is an electronic component element housed in the concave portion 4, 7
Is a sealing lid for sealing the opening of the concave portion 4, 8 is a resin adhesive, and 9 is an external terminal electrode.

The substrate 1 is made of a resin material such as ceramic, glass ceramic material, or glass epoxy.
A predetermined wiring conductor is formed on one main surface of the substrate 1,
The electronic component element 2 is mounted on the wiring conductor.
The electronic component element 2 can be exemplified by a capacitor, a resistor, a diode, a coil, a surface-mounted electronic component element such as a semiconductor element such as an IC or a transistor, and the like.

Further, on the other main surface of the substrate 1 at a predetermined depth,
A recess 4 having a predetermined planar shape is formed. An electrode pad (not shown) is formed on the bottom surface of the recess 4. And, in this recess 4,
The electronic component element 3 is housed. This electronic component element 3
Are capacitors, resistors, and the like as in the electronic component element 2 described above.
A diode, a coil, a semiconductor element such as an IC or a transistor, or the like may be provided, but a piezoelectric component such as a SAW element, a ceramic resonator, or a crystal resonator is particularly advantageous. As described above, since the electronic component element can be hermetically sealed from the structure in which the electronic component element is housed in the recess 4 and sealed with the sealing lid 7, a space is functionally formed around the electronic component element 2. This is because, for example, it is possible to stably generate vibrations and elastic waves that greatly affect the characteristics of the piezoelectric component.

The wiring conductors and electrode pads of the substrate 1 and the external terminal electrodes 9 are formed by a conventionally known method. For example, when the substrate 1 is a ceramic or a glass ceramic, each conductor film is formed by simultaneous firing when the substrate material is fired, as in the formation of the multilayer circuit board. Also, the conductive film is formed on the fired substrate 1 by baking. Further, even when the substrate 1 is made of a glass epoxy material, the substrate 1 is formed in a predetermined shape by etching a copper foil or the like as in the related art.

Around the opening of the concave portion 4 of the substrate 1, a concave portion 5 which is one step lower than the other main surface of the substrate 1 is provided. The overall shape and depth of the depression 5 are
Are designed in accordance with the shape and thickness of the substrate 1 so that the lid 7 does not project from the other main surface of the substrate 1 even when the lid 7 is disposed in the recess 5 via the resin-based adhesive 8. Has become.
The depth of the recess 5 is, for example, about 100 μm.

The connection between the electronic component element 3 arranged in the concave portion 4 of the substrate 1 and the electrode pad of the concave portion 4 is connected via a bump. In addition, a bonding wire can be used instead of the connection using the bump.

For example, the electronic component element 3 housed in the recess 4
For example, a surface acoustic wave element in which an interdigital electrode is formed on a piezoelectric substrate can be exemplified. In this case, an extraction electrode is formed on the surface on which the interdigital electrode is formed, and a bump made of gold or the like is formed on the extraction electrode. Then, the piezoelectric substrate on which the interdigital electrodes are formed is arranged so that the front side faces the bottom surface of the concave portion 4,
Bump connection is performed using ultrasonic vibration.

The sealing lid 7 for sealing the opening of the concave portion 4 is composed of a flat metal layer 7a and a resin layer 7b covering the inner surface of the metal layer 7a on the substrate side. I have. The metal layer 7a is made of, for example, iron, nickel, copper, gold, silver,
Examples include aluminum, tin, stainless steel, lead, and alloys thereof. Among these, it can be processed to be thin,
A material having a thermal expansion coefficient close to that of the substrate of the main body and less likely to generate thermal stress is preferable. The thickness of the metal layer may be any thickness as long as it can block moisture intrusion, and is preferably in the range of 2 μm to 300 μm. Specifically, stainless steel (SUS430)
Is about 30 μm. The material of the resin layer 7b is not particularly limited, but preferably has excellent heat resistance, insulation properties and adhesiveness. For example, polyimide (PI), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), Ether imide, polysulfone, polyether sulfone, polyhydroxyphenylene ether (PPO), polyether ketone (PEEK), polyketone sulfide (PKS), fluororesin, epoxy resin, silicone resin, phenol resin, maleimide resin, Examples thereof include urethane resins and diallyl fretate resins. The thickness of each resin layer can be appropriately selected in consideration of the insulating property to the metal layer 7a.
A range of 300 μm is preferred. Specifically, a polyimide resin is used, and its thickness is 12.5 μm. The sealing lid 7 having such a laminated structure is formed by directly joining the metal layer 7a and the resin layer 7b by a casting method. When the metal layer 7a has a thickness of several μm, for example, the surface of the resin layer 7b may be covered with a metal layer by plating or vapor deposition.

The adhesive 8 is, for example, an epoxy-based adhesive, and bonds the sealing lid 7 to the bottom surface of the recess 5 around the recess 4 of the substrate 1. The thickness of the adhesive layer made of the adhesive 8 is 10 μm to 60 μm. Specifically, it is desirable to print an adhesive on the inner surface side of the sealing lid 7 and to make it into a B stage. The sealing condition of the adhesive 8 is such that a predetermined pressure is applied and the temperature is 150 ° C. for 2 hours.
r is crimped. Thus, the adhesive 8 in the B-stage state
Is melted, and a strong bond between the substrate 1 and the sealing lid 7 is obtained. The adhesive 8 is applied to the resin layer 7 c on the inner surface side of the lid 7.
(Resin is B-staged) may be used as the adhesive. In this case, a resin layer (a portion that is bonded to the bottom surface of the recessed portion 5) located around the inner surface side of the sealing lid 7 functions as an adhesive member, and the other resin layer 7b serves as an inner surface of the metal layer 7a. It has an insulating coating function. The sealing condition of the adhesive 8 is such that a predetermined pressure is applied and the temperature is 150 ° C. for 2 hours.
r is crimped. Thus, the adhesive layer 8 can be omitted (the resin layer 7b of the sealing lid 7 can be omitted), the thickness of the sealing lid 7 itself can be reduced, and the height of the electronic component device can be reduced. Can contribute to

The material of the resin adhesive 8 is not particularly limited, and examples thereof include an epoxy resin, a phenol resin, a polyimide resin, a silicone resin, and a polyester resin. Epoxy resins having excellent moisture resistance are preferred.

In the other main surface of the substrate 1,
An external terminal electrode 9 is formed around the opening (recess 5). The external terminal electrodes 9 are formed on the other main surface of the substrate 1 by printing and baking a conductive paste. Further, the external terminal electrodes may be formed at the same time when the above-mentioned wiring conductor is formed. Although not shown, each external terminal electrode is electrically connected to various electronic component elements 2 mounted on the surface and electronic component elements 3 accommodated in the recess 4 via via-hole conductors and internal conductors. Have been. When the electronic component device is mounted on the motherboard 10, the external terminal electrodes 9 are connected to the wiring pattern 1 on the motherboard 10.
1 and solder 13 are connected to an external circuit.

According to the electronic component device of the present invention, the sealing member 7 uses a laminated member in which the resin layer 7b is coated on the inner surface side of the flat metal layer 7a. The sealing lid 7 and the substrate 1 are bonded and sealed with a resin adhesive 8. Therefore, the resin-based adhesive 8 can be joined to the resin layer 7b on the lid side, so that the resin-to-resin is joined, the conformability is good, and the interface between the sealing lid 7 and the resin-based adhesive 8 is good. Separation hardly occurs. Then, for example, even if the motherboard 10 is subjected to a solder reflow process, stable bonding can be maintained. Also, even if, for example, a solder reflow process is performed on the motherboard, stable bonding can be maintained.

Further, even if the electronic component elements 3 housed in the recesses 4 are connected by bonding wires, the inner surface of the sealing lid 7 is covered with the resin layer 7c. Can be prevented from being short-circuited.

An electronic component element 2 is provided on one main surface of the substrate 1.
And the electronic component element 3 is disposed on the other main surface side, so that the electronic component device can be downsized and the mounting area can be reduced. In addition, the electronic component element 3 is covered with the shield case 6, and stable operation of the electronic component device can be maintained.

Even if the sealing lid 7 is joined into the recess 5 formed around the recess 4, it does not protrude from the other main surface of the substrate 1. The electronic component device can be surface-mounted stably.

If the external terminal electrodes 9 are arranged around the opening of the recess 4 (around the lid) and the recess 5 to which the sealing lid 7 is joined is set to a sufficient depth, the mother board 10 Even if it is joined via the solder 13, no solder bridge is formed on the sealing lid 7, and the cleaning property for removing the solder flux is also improved.

Even if surface mounting is performed on the motherboard 10 by solder reflow or the like, the metal layer 7a and the resin layer 7b do not peel off from each other due to thermal stress, and high adhesion can be obtained.

Further, since the entire thickness of the sealing lid 7 can be at most about 100 μm or less, a change in the internal pressure in the recess 4 occurs when the motherboard 10 is mounted after sealing. Even if the internal pressure changes, the sealing lid 7 itself elastically deforms and follows the internal pressure, so that the characteristics of the electronic component element 3 do not change.

If the resin layer 7b of the sealing lid 7 is also used as the adhesive 8, the height of the electronic component device can be reduced as described above, and the manufacturing process can be simplified at the same time.

The sealing lid 7 includes a stainless steel metal layer 7a and a resin layer 7b made of a polyimide resin.
It is coated with a thickness of 5 μm. Then, the metal layer 7a and the resin layer 7b are formed by being directly joined by a casting method.

Alternatively, the metal layer 7a may be made of a rolled copper foil, and the resin layer 7b may be made of a polyimide resin. At this time, the thickness of the metal layer 7a may be 18 μm, and the thickness of the resin layer 7b may be 12.5 μm (the thickness of the entire sealing lid 7 is 30.5 μm). Then, 10 μm is used as the resin adhesive 8.
m may be used.

Further, the metal layer 7a of the sealing lid 7 is made of electrolytic copper foil, and the resin layer 7b is made of a polyimide resin. At this time, the thickness of the metal layer 7a was 8 μm, and the thickness of the resin layer 7b was 12.5 μm. The metal layer 7a was formed by plating a polyimide film. A composite material having a thickness of about 20 μm may be used.

Further, the metal layer 7a of the sealing lid member 7 is made of S
In US430, the resin layer 7b is formed by coating a polyimide resin, and the resin layer 7c is formed by coating a modified polymitotic adhesive. At this time, the thickness of the metal layer 7a is 30 μm, and the thickness of the resin layer 7b is 1 μm.
It may be 2.5 μm. At this time, the resin layer 7 b adheres the modified polyimide-based adhesive to the depression 5 of the substrate 1. The sealing conditions at this time were pressure bonding at a predetermined pressure at a temperature of 180 ° C. for 5 minutes.

It was confirmed that the filter characteristics of 22 electronic component devices having the above-mentioned structure were not abnormal in a temperature cycle test (500 cycles of 30 minutes each at -40 to 100 ° C.) and a high temperature test (500 hours of 85 ° C./85% RH). did.

[0043]

According to the electronic component device of the present invention, the adhesion between the sealing lid and the substrate of the electronic component device is increased, the airtightness is high, and the reliability is improved. Further, it can follow the fluctuation of the internal pressure in the concave portion, and can be mounted on the motherboard stably. Further, the electronic component device can be downsized. The method of joining the electronic component elements in the concave portion can be arbitrarily selected such as a bump or a bonding wire.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electronic component device according to the present invention.

FIG. 2 is a plan view of a bottom surface side of the electronic component device according to the present invention.

FIG. 3 is a mounting cross-sectional view of a conventional electronic component device.

[Explanation of symbols]

 1, board 2, 3, electronic component 4, recess 5, recess 7, sealing lid 7a, flat metal layer 7b, resin layer 8, resin adhesive 9, etc. External terminal electrode

Claims (5)

[Claims] 1. A substrate having a concave section having an open section on one side,
In an electronic component device in which an electronic component element is housed in the concave portion and an opening of the concave portion is sealed with a sealing lid, the sealing lid has an exposed surface side metal layer and a substrate bonding surface side. An electronic component device having a laminated structure with a resin layer. 2. The electronic component device according to claim 1, wherein the sealing lid and the periphery of the recess opening of the substrate are joined via a resin adhesive. 3. The electronic component device according to claim 1, wherein the joining of the sealing cover and the substrate is performed by a resin layer on the substrate joining surface side of the sealing cover. 4. A recess around the opening of the recess at least as thick as the sealing lid is provided, and an external terminal electrode is arranged on the surface of the substrate around the recess. 2. The electronic component device according to claim 1, wherein: 5. The electronic component device according to claim 1, wherein an electronic component element is disposed on the other main surface of the substrate by surface mounting.