JP2003133452A - Manufacturing method of electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of electronic equipment that has easy manufacturing processes, and at the same time can achieve a desired airtight state. SOLUTION: The manufacturing method comprises the process of forming an electronic device 3 on a substrate 2, the process of installing a frame material 5a that surrounds the electronic device 3 on the substrate 2 and at the same time has a shape for securing a gas passage to outside atmosphere, the process of installing a lid material 7 on the frame material 5a while specific space is being secured at a portion to the electronic device 3 formed on the substrate 2, the process of reducing the pressure of the outside atmosphere of the substrate 2 to remove gas in the specific space via the gas passage, and the process of fusing the frame material 5a to block the gas passage and airtightly sealing the electronic device 3 on the substrate 2 into the specific space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic device having an electronic element hermetically sealed.

[0002]

2. Description of the Related Art In general, glass is used as a lid for hermetically sealing and joining a substrate having electronic elements such as a solid-state image pickup element, a laser emitting element, and a light receiving element. A large gap (cavity) is required. Further, if dew condensation occurs on the element or the lid of the glass, the function of the electronic element is impaired, so that hermetic sealing is required.

In the past, packaging materials such as ceramics and resins were used to secure this cavity.
When these are used, the external dimensions become large, and there is a problem that it is not possible to cope with the miniaturization of the element. Also,
Ceramics and the like are expensive and the material cost is high. Further, since a plurality of ceramic substrates are bonded together to form a cavity, the number of manufacturing steps is increased, resulting in a high cost.

Therefore, in recent years, a method is being introduced in which a solder frame material is installed so as to surround the electronic element on a silicon substrate or the like on which the electronic element is formed, and a lid is directly attached via the solder frame material.

When the package is sealed, moisture, oxygen, organic gas, etc., remaining in the cavity after the sealing will affect the characteristics of the electronic device, and therefore must be excluded as much as possible. Therefore, in the preheating step before sealing, the electronic element is heated and evacuated in a furnace to exclude water, oxygen, organic gas and the like attached / adsorbed to the substrate.

When the atmosphere in the cavity after sealing is kept in a depressurized state in accordance with the function of the electronic device, the temperature is raised to the melting point of the solder in the sealing step while keeping the pressure in the furnace at a reduced pressure. , The solder frame material was melted to complete hermetic sealing.

Further, when it is necessary to fill the atmosphere in the cavity after the sealing with gas according to the function of the electronic element,
After the above preheating step, after filling the furnace with the gas to be filled in with a predetermined heating state and pressure setting that considers the pressure in the cavity after cooling, raise the temperature to the melting point of the solder in the sealing step. Thus, the solder frame material was melted to complete the sealing.

[0008]

However, as described above, since it is necessary to exchange the gas inside and outside the element cavity with each other, in general, the substrate, the solder frame material, and the lid are kept until just before they are joined by solder melting. It is necessary to provide a distance without overlapping and to bring the substrate and the lid into contact with each other via the solder frame material immediately before joining by melting the solder.

As described above, during the heating process such as the preheating process before melting the solder, it is necessary to keep the relative distance between the substrate and the lid away from each other, and the apparatus is also required to have a function for realizing the work. Therefore, there is a problem that the device configuration becomes complicated.

Further, in the sealing step, since it is necessary to bring the substrate and the lid into close contact with each other, there is a problem that dust is generated from the mechanism moving part of the apparatus and the yield is lowered. .

In order to avoid the above-mentioned problems, even if the alternating current of the gas inside and outside the element cavity is sacrificed, from the preheating stage,
The board, solder frame material, and lid may overlap. In this case, the solder frame material, the board, and the lid are attached to the board, etc.
The adsorbed water, oxygen, organic gas, etc. are excluded, and the gas to be sealed is fed into the cavity.

However, in this case, the alternating current of the gas inside and outside the element cavity is sacrificed, and when it is desired to set the inside of the sealed cavity under a predetermined reduced pressure, or when the inside of the sealed cavity has a predetermined humidity. However, there are restrictions when it is desired to keep the atmosphere of the enclosed gas, and it becomes difficult to sufficiently maintain the function of the electronic element.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing an electronic device in which the manufacturing process is easy and a desired hermetic state can be realized.

[0014]

In order to achieve the above object, a method of manufacturing an electronic device of the present invention comprises a step of forming an electronic element on a substrate, surrounding the electronic element of the substrate, and an external atmosphere. A step of installing a frame material having a shape capable of ensuring a gas passage to the substrate, and a predetermined space between the electronic element formed on the substrate and a predetermined space is secured on the frame material. A step of installing a lid material, a step of decompressing an atmosphere outside the substrate to remove gas in the predetermined space through the gas passage, and a step of melting the frame material to close the gas passage, And hermetically sealing the electronic element on the substrate in the predetermined space.

In the step of installing the frame member on the substrate, the frame member having a shape capable of forming a gap serving as the gas passage at a contact portion between the frame member and the substrate is installed on the substrate. . For example, in the step of installing the frame material on the substrate, the frame material having the protrusions is installed on the substrate. Alternatively, in the step of installing the frame member on the substrate, the frame members having a difference in wall thickness are installed on the substrate. Alternatively, in the step of installing the frame member on the substrate, the frame member having a step formed in the plane direction is installed on the substrate.

In the step of depressurizing the external atmosphere of the substrate, the external atmosphere is depressurized in a heated state within a range not exceeding the melting point of the frame material.

After the step of removing the gas in the predetermined space and before the step of hermetically sealing the electronic element in the predetermined space, the atmosphere outside the substrate is changed to a predetermined sealed gas atmosphere, The method further includes the step of introducing a sealed gas into the predetermined space via the gas passage.

Before the step of placing the frame member on the substrate, a step of forming an adhesive layer on the substrate at the contact point with the frame member, which can secure the adhesion between the substrate and the frame member. Further has.

Before the step of installing the lid material on the frame material,
The method further includes the step of forming an adhesive layer capable of ensuring adhesion between the lid member and the frame member on the lid member at a contact point with the frame member.

In the above method of manufacturing an electronic device of the present invention,
On the substrate on which the electronic element is formed, a frame member that surrounds the electronic element and has a shape that can secure a gas passage to the external atmosphere is installed, and after the lid member is installed, a predetermined amount is provided through the gas passage. The gas in the space is removed. Further, if necessary, after filling the predetermined space through the gas passage into the predetermined space, the frame material is melted to close the gas passage, and the electronic element on the substrate is hermetically sealed in the predetermined space. It

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for manufacturing an electronic device of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view of an electronic device manufactured by the method for manufacturing an electronic device according to the present embodiment.
FIG. 1B is a sectional view taken along the line AA ′ of FIG.

The substrate 2 has an element forming surface 2a and is made of, for example, a silicon substrate, a GaAs substrate, a glass substrate or the like. Although the element forming surface 2a is shown as a concave portion in the drawing, it may be flat.

An electronic element 3 having a desired function is formed on the element forming surface 2a of the substrate 2. The electronic element 3 is formed by depositing and patterning various films by a known semiconductor microfabrication technique, and includes, for example, a solid-state image sensor, a laser light emitting element, a light receiving element, and the like. In addition to the above, the electronic element 3 is a MEMS (Mi
It may be manufactured by using a semiconductor microfabrication technique such as a micromachine called cro Electro Mechanical Systems).

An adhesive layer 4, a solder frame material 5, and an adhesive layer 6 are formed on the substrate 2 so as to surround the electronic element 3 described above.

Since it is difficult to directly bond the solder frame material 5 to the board 2, the adhesive layer 4 is provided between the solder frame material 5 and the board 2, and the solder frame material 5 and the board 2 are bonded together. It is made of a material that is easy to bond to both sides.
And a laminated film of Ni and Au.

The solder frame material 5 is formed so as to surround the electronic element 3 on the substrate 2. The solder frame material 5 is formed to have a thickness that can secure a predetermined cavity on the electronic element 3. The material of the solder frame material 5 is not particularly limited, and examples thereof include AuSi and AuSn.

Since it is difficult to directly bond the solder frame member 5 to the lid member 7, the adhesive layer 6 is provided between the solder frame member 5 and the lid member 7. It is composed of a material that can be easily bonded to both
And a laminated film of Ni and Au.

The lid member 7 is bonded to the upper end portion of the solder frame member 5 with an adhesive layer 6 in a state where a predetermined space is secured between the lid member 7 and the element forming surface 2a of the substrate 2. The lid member 7 is made of, for example, a transparent material, and is the same as the seal glass used in the well-known hollow package structure.
Thus, by closing the opening of the solder frame member 5, the electronic element 3 is hermetically sealed in the predetermined space.

On the substrate 2 outside the element forming surface 2a hermetically sealed by the solder frame material 5 and the lid material 7,
A plurality of pads 8 that are electrically connected to the electronic element 3 are formed.

FIG. 2 is a cross-sectional view after mounting the electronic device 1 having the above structure on a mounting board. As shown in FIG. 2, the electronic device 1 includes a mounting substrate 1 made of glass epoxy resin or the like.
0, for example, via a bonding agent 11.

As the bonding agent 11, for example, a material whose main component is a thermosetting resin such as an epoxy resin is used.
When conductivity is required, a desired electrical conductivity is secured by mixing metal powder such as silver (Ag) in a predetermined ratio, and the mixture is used as a conductive paste. On the other hand, when conductivity is not required, a filler such as silica or alumina is mixed in consideration of viscosity, stress relaxation, etc., and used as an insulating paste.

Pads 12 for connecting to a circuit pattern formed in a region (not shown) are formed on the mounting substrate 10. The bonding wire 1 in which the pad 12 of the mounting substrate 10 and the pad 8 formed on the substrate 2 are gold wires or the like
3 is connected to electrically connect the electronic element 3 to a circuit pattern formed in a region (not shown), thereby realizing a desired operation.

Next, a method of manufacturing the electronic device having the above-described structure according to this embodiment will be described with reference to FIG.

First, as shown in FIG. 3A, an element formation surface 2 of the substrate 2 is formed on a substrate 2 made of silicon, GaAs, glass or the like by a known semiconductor fine processing technique.
The electronic element 3 is manufactured in a. Then, a laminated film of Ti, Ni, and Au is formed on the substrate 2 by a sputtering method or a vapor deposition method, and is patterned by etching using a lithography technique so that only the mounting area of the solder frame material 5 on the substrate 2 is formed. The adhesive layer 4 is formed.

Next, a solder frame material 5a having a shape surrounding the element forming surface 2a is sandwiched between the substrate 2 and the lid material 7. Here, in the same manner as in the case of the substrate 2, the lid member 7 is previously attached to the contact portion of the solder frame member 5a with Ti, Ni and A by the same method.
The adhesive layer 6 made of a laminated film of u is patterned.
As a result, the solder frame material 5a is sandwiched between the substrate 2 and the lid material 7 via the adhesive layers 4 and 6. At this time, as shown in FIG. 3B, the solder frame material 5a having a shape in which a gap is formed between the solder frame material 5a and the adhesive layers 4 and 6 is used.

An example of the shape of the solder frame material 5a used in the above embodiment is shown in FIGS. For example, a solder frame material 5a having protrusions formed at four corners as shown in FIG. 4 or a solder frame material 5a having steps as shown in FIG. 5 is used. Alternatively, a solder frame material 5a formed by bending four corners as shown in FIG. 6 or a solder frame material 5a formed by bending two opposite sides as shown in FIG. 7 is used. Alternatively, as shown in FIGS. 8 and 9, the solder frame material 5a having a difference in wall thickness is used. Alternatively,
A solder frame material 5a in which a gap is formed by bending only a predetermined portion as shown in FIG. 10 and a frame as shown in FIG. 11 (a) and FIG. 11 (b) which is a cross-sectional view taken along line BB ′ of FIG. Instead of the prism, the solder frame material 5a whose cross section is raised with a predetermined curvature is used. The shape of the solder frame material 5a is formed at the time of press molding or injection molding of the solder frame material 5a. By using the above-mentioned solder frame material 5a, a gap is formed between the solder frame material 5a and the adhesive layers 4 and 6 by the height of the protrusions or steps of the solder frame material 5a,
The gap serves as a gas passage to the external atmosphere.

Next, in the preheating step, the substrate 2 having the electronic element 3 is heated and evacuated in a furnace to remove moisture, oxygen, and the like, which are attached and adsorbed to the substrate 2 and the like through the above-mentioned gap. Exclude organic gas, etc. The preheating step is performed because moisture, oxygen, organic gas, etc. remaining in the cavity after sealing affects the characteristics of the electronic element 3 and must be excluded as much as possible. In the process, since the gap is formed along with the mounting of the solder frame material 5a, moisture, oxygen, organic gas and the like in the cavity are effectively excluded.

Next, when the atmosphere inside the cavity after sealing is kept in a reduced pressure state according to the function of the electronic element 3, the solder is heated by raising the temperature to the melting point of the solder while keeping the inside of the furnace in a reduced pressure. Melt and seal. In addition, when the gas is sealed in the cavity according to the function of the electronic element 3, after the sealed gas is put in the furnace in a predetermined heating state and pressure setting in consideration of the pressure in the cavity after cooling. The sealing is performed by raising the temperature to the melting point of the solder. Also in this step, gas exchange between the cavity and the external atmosphere is easily performed until the sealing immediately following the melting of the solder, the gap is closed with the melting of the solder, and the substrate 2 and the lid member 7 are closed.
Are joined together via the solder frame material 5 to be hermetically sealed.

In the subsequent steps, the electronic device 1 manufactured as described above is fixedly mounted on the electronic device mounting portion of the mounting board 10 with the bonding agent 11, and the electronic device 1 and the pad 8 are mounted. Mounting is performed by connecting the pads 12 of the mounting substrate 10 with the bonding wires 13.

According to the method of manufacturing an electronic device according to this embodiment described above, the solder frame material 5a is provided between the substrate 2 and the lid material 7.
By providing a gap due to the shape of the above, the gas inside and outside the element cavity can be exchanged until just before sealing by melting the solder, and the lid member 7 and the substrate 2 are superposed immediately before sealing as in the conventional case. There is no need for work such as matching, and the function of the device for realizing that work is unnecessary. Also, from the preheating stage, the substrate 1, the solder frame material 5, and the lid material 7
Even if the layers are stacked, it becomes easy to remove the moisture, oxygen, organic gas, etc. attached / adsorbed to the substrate 2 or to send the gas to be enclosed into the cavity, so that the desired airtight state is secured. Therefore, the quality and yield of the electronic elements 3 can be improved. Further, since the process is facilitated, the cost can be reduced and the price of the electronic device can be reduced.

The method for manufacturing the electronic device of the present invention is not limited to the above description of the embodiment. For example, in the present embodiment, an example in which the substrate 2 and the lid member 7 are joined via the solder frame member 5 is shown, but the present invention is not limited to this, and for example, instead of the solder frame member 5, the thickness may be changed. It is also possible to realize the same function by using a sheet-shaped adhesive material having a difference between the two. In this case, it is necessary that the sheet-shaped adhesive material is sufficiently deformed by heating in the subsequent sealing step, and if the deformation is insufficient, external load is applied to the lid member 7 and the substrate 2 in the sealing step. Will be required.

Further, in the present embodiment, the solder frame member 5a is provided with protrusions and steps.
Although a gap is secured when a is sandwiched between the substrate 2 and the lid member 7, the invention is not limited to this.
By forming a through hole in the solder frame material 5a in press molding or injection molding, the through hole can be used as a gas passage to the outside.

Further, in the present embodiment, the electronic device in which the electronic element 3 integrally formed on the substrate 2 is hermetically sealed has been shown, but the present invention is not limited to this, and as in recent multi-chip modules, In addition to the electronic element 3 formed integrally on the substrate 2, in order to realize other functions, for example, another electronic element in the form of a chip is also mounted, and these electronic elements are hermetically sealed. You may do it. Besides, various modifications can be made without departing from the scope of the present invention.

[0045]

According to the present invention, it is possible to manufacture an electronic device which is easy to manufacture and has a desired airtight state.

[Brief description of drawings]

1A is a plan view of an electronic device manufactured by a method of manufacturing an electronic device according to an embodiment, FIG.
2 is a sectional view taken along the line AA ′ of FIG.

FIG. 2 is a cross-sectional view after mounting the electronic device manufactured by the method of manufacturing an electronic device according to the present embodiment on a mounting substrate.

FIG. 3 is a cross-sectional view showing a manufacturing process in the method for manufacturing the electronic device according to the present embodiment.

FIG. 4 is a perspective view showing an example of the shape of a solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 5 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 6 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 7 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 8 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 9 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

FIG. 10 is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment.

11A is a perspective view showing another example of the shape of the solder frame material used in the method for manufacturing an electronic device according to the present embodiment, and FIG. ) BB '
It is sectional drawing in a line.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic device, 2 ... Substrate, 2a ... Element formation surface, 3 ... Electronic element, 4 ... Adhesive layer, 5,5a ... Solder frame material, 6 ... Adhesive layer, 7 ... Lid material, 8 ... Pad, 10 ... Mounting Substrate, 11 ... Bonding agent, 12 ... Pad, 13 ... Bonding wire.

Claims (9)

[Claims] 1. A step of forming an electronic element on a substrate, and a step of providing a frame member surrounding the electronic element of the substrate and having a shape capable of ensuring a gas passage to an external atmosphere on the substrate, A step of installing a lid material on the frame material in a state where a predetermined space is secured between the electronic element formed on the substrate, and depressurizing an external atmosphere of the substrate to form the gas passage. A step of removing the gas in the predetermined space through the step of melting the frame material to close the gas passage, and hermetically sealing the electronic element on the substrate in the predetermined space. Electronic device manufacturing method. 2. In the step of installing the frame member on the substrate, the frame member having a shape capable of forming a gap serving as the gas passage at a contact portion between the frame member and the substrate is provided on the substrate. The method for manufacturing an electronic device according to claim 1, wherein the electronic device is installed. 3. The method of manufacturing an electronic device according to claim 2, wherein in the step of installing the frame member on the substrate, the frame member having a protrusion is installed on the substrate. 4. The method of manufacturing an electronic device according to claim 2, wherein in the step of installing the frame member on the substrate, a frame member having a difference in wall thickness is installed on the substrate. 5. The method of manufacturing an electronic device according to claim 2, wherein in the step of installing the frame member on the substrate, a frame member having a step formed in a plane direction is installed on the substrate. 6. The method of manufacturing an electronic device according to claim 1, wherein, in the step of reducing the pressure of the outside atmosphere of the substrate, the pressure of the outside atmosphere is reduced in a heating state within a range not exceeding the melting point of the frame material. 7. After the step of removing the gas in the predetermined space and before the step of hermetically sealing the electronic element in the predetermined space, the atmosphere outside the substrate is changed to a predetermined enclosed gas atmosphere. The method of manufacturing an electronic device according to claim 1, further comprising the step of introducing an enclosed gas into the predetermined space via the gas passage. 8. An adhesive layer capable of ensuring adhesion between the substrate and the frame material is formed on the substrate at a contact position with the frame material before the step of installing the frame material on the substrate. The method of manufacturing an electronic device according to claim 1, further comprising: 9. Before the step of installing a lid member on the frame member,
2. The method of manufacturing an electronic device according to claim 1, further comprising: forming an adhesive layer on the cover material at a contact point with the frame material, the adhesive layer ensuring adhesion between the cover material and the frame material.