JP4361379B2 - Method for manufacturing electronic device package - Google Patents

Description

The present invention provides an electronic device in which a sealing member for protecting an electronic device from the external environment is fixed to a predetermined fixing surface via an adhesive layer, and a gap is provided between the electronic device and the sealing member. a method for manufacturing a device package.

  Similar to general semiconductor devices, electronic devices are used in a packaged state for the purpose of protection from the external environment.

In packaging of an electronic device, a sealing member such as a cover glass is disposed so as to cover the electronic device, and is fixed to a substrate provided with the electronic device via an adhesive (see, for example, Patent Document 1). ).
Some electronic devices include sensitive parts such as various sensors. Therefore, in order to allow the electronic device to function normally without degrading the sensitivity, the package of the electronic device needs to have a highly airtight structure in order to prevent a functional deterioration due to moisture or the like of the sensitive portion. .

  Moreover, in order to make an electronic device function normally without deteriorating the sensitivity of a sensitive part, a space | gap may be needed between an electronic device and a sealing member. In this case, in order not to deteriorate the sensitivity of the sensitive part, the size of the air gap must be uniform throughout the package, that is, the distance between the electronic device and the sealing member must always be constant.

  However, some adhesives commonly used for sealing semiconductor devices in semiconductor packages and the like have high moisture permeability. When an electronic device package is manufactured using such a highly moisture-permeable adhesive, the function of the electronic device may be deteriorated.

  Moreover, when fixing the board | substrate with which the electronic device was provided, and the sealing member via an adhesive agent, a heat | fever and a load are applied to the area | region where an adhesive agent exists. As a result, the adhesive is deformed and is cured as it is, so that the distance between the electronic device and the sealing member (the size of the gap) cannot be set to a predetermined size.

Furthermore, since the adhesive, the substrate, and the sealing member are different from each other, their thermal expansion coefficients are also different. For this reason, in an environment with a temperature change, the stress generated by the difference in the thermal expansion coefficient may cause cracks in the substrate, the sealing member, the electronic device, and the like, which may make it unusable.
JP-A-7-202152

The present invention has been made in view of the above circumstances, high airtightness, a thickness of the adhesive layer is constant, and, in the adhesive layer, a method of manufacturing an electronic device package capable of alleviating the external stress The purpose is to provide.

In order to solve the above problems, the present invention is arranged to cover a substrate, an electronic device provided on one surface of the substrate, and to cover the electronic device, and is fixed to the substrate via an adhesive layer. and a sealing member, the electronic device and Ri Na voids are provided between the sealing member, the adhesive layer, an adhesive, a large number of particles of substantially uniform particle size A method of manufacturing an electronic device package in which the content of the particles in the adhesive layer is 10% by volume or more and 70% by volume or less, on one surface of the substrate on which the electronic device is provided, After applying the mixture with the adhesive, the sealing member is slid several times or the vibration is applied to the sealing member while the sealing member is placed on the mixture applied to the substrate. Between the sealing member and the substrate By heating the mixture applied to one surface of the substrate, or irradiating the mixture applied to one surface of the substrate with ultraviolet rays, the step of bringing the particles in a line The adhesive is cured to form an adhesive layer in which the particles are aligned in a row between the sealing member and the substrate, and each particle is filled with the adhesive. And a step of adhering and fixing the sealing member to one surface of the substrate .

  In the electronic device package of the present invention, the sealing member is fixed to the substrate on which the electronic device is provided via an adhesive layer composed of an adhesive and a large number of particles having a substantially uniform particle size. The airtightness of the electronic device package is sufficiently ensured, and the function of the electronic device can be prevented from being deteriorated by moisture. Moreover, since the distance between the electronic device and the sealing member is kept constant by the particles contained in the adhesive layer, and a gap is formed between the two, the function of the electronic device is an image sensor or the like. It is fully demonstrated without being damaged. In addition, since the adhesive area between the adhesive, the substrate, and the sealing member is reduced, the adhesive layer can exhibit a stress relaxation function that does not directly transmit external stress from the sealing member to the electronic device side.

  Moreover, if the content of the particles in the adhesive layer is 70% by volume or less, the distance between the electronic device and the sealing member can be kept constant without impairing the airtightness of the electronic device package.

  In addition, by setting the thermal expansion coefficient of the particles in the adhesive layer to an intermediate value between the thermal expansion coefficient of the substrate and the thermal expansion coefficient of the sealing member, or a value close to one of the two, Even in a changing environment, it is possible to prevent the substrate, the electronic device, the sealing member, and the like from being cracked due to the stress caused by the difference in thermal expansion coefficient.

  Hereinafter, an electronic device package embodying the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an electronic device package according to the present invention. FIG. 2 is an enlarged schematic cross-sectional view of a region indicated by a symbol A in FIG.
1 and 2, reference numeral 11 denotes a substrate, 12 denotes an electronic device, 20 denotes an adhesive layer, 21 denotes an adhesive, 22 denotes particles, 30 denotes a sealing member, 40 denotes an electronic device package, and 41 denotes a gap. Yes.

  In this embodiment, the electronic device package 40 is schematically configured from a substrate 11, an electronic device 12 provided on one surface 11 a of the substrate 11, an adhesive layer 20, and a sealing member 30.

  In the electronic device package 40, the sealing member 30 disposed so as to cover the electronic device 12 is fixed to a portion of the one surface 11 a of the substrate 11 where the electronic device 12 is not provided via the adhesive layer 20. Yes. The adhesive layer 20 includes a large number of spherical particles 22 having a substantially uniform particle diameter, and the adhesive layer 20 is formed so that the particles 22 come into contact with the substrate 11 and the sealing member 30. By providing, the distance between the electronic device 12 and the sealing member 30 is kept constant, and a gap 41 is provided between them.

  The substrate 11 is not particularly limited and is selected according to the function and material of the electronic device 12 provided on the substrate 11, and the material is appropriately selected from plastic, metal, ceramics, and the like.

  As the electronic device 12, a MEMS (Micro Electro Mechanical System) device, a general semiconductor device, or the like is applied. Specifically, as the electronic device 12, a solid-state imaging device such as a CCD image sensor or a CMOS image sensor, a semiconductor pressure sensor, a semiconductor device such as an LSI, an IC, a memory, a light emitting device, a light receiving device, or the like is mounted Various electronic devices such as an electronic circuit, an electronic circuit board, various sensors other than a solid-state imaging device and a semiconductor pressure sensor, and a sensor chip including a necessary detection circuit, and various electronic devices having a movable portion can be applied.

  The adhesive layer 20 is composed of an adhesive 21 and a large number of particles 22, and is formed by curing the adhesive 21. The particles 22 are used to keep the distance between the electronic device 12 and the sealing member 30 constant. By blending the particles 22 with the adhesive 21, the adhesive 21, the substrate 11, and the sealing member 30 Therefore, the adhesive layer 20 can exhibit a stress relaxation function that does not directly transmit external stress from the sealing member 30 to the electronic device 12 side.

  The content of the particles 22 in the adhesive layer 20 is preferably 70% by volume or less, and more preferably 10% by volume or more and 70% by volume or less. When the content of the particles 22 in the adhesive layer 20 exceeds 70% by volume, the proportion of the particles 22 in the adhesive layer 20 is excessive, and the contact area between the adhesive 21 and the substrate 11 and the sealing member 30 is increased. Becomes too small. As a result, the airtightness of the electronic device package 40 is impaired. Further, in order to accurately adjust the thickness of the adhesive layer 20 with the particle size of the spherical particles 22, the particles 22 must be present in a single stage without being stacked in multiple stages in the adhesive layer 20. Therefore, when the content of the particles 22 in the adhesive layer 20 exceeds 70% by volume, the particles 22 are likely to be agglomerated, and there is a possibility that the one-stage particles 22 are not arranged between the substrate 11 and the sealing member 30. There is.

  As the adhesive 21, an adhesive having a low water absorption rate is preferable in order to ensure sufficient airtightness of the electronic device package 40 and prevent the function of the electronic device 12 from being deteriorated by moisture, and the water absorption rate is 1%. (Mass ratio) The following adhesives are more preferable. In the present invention, the water absorption rate of the adhesive is measured according to ASTM D570. If an adhesive having a high water absorption rate is used, the airtightness of the electronic device package 40 is impaired, and the function of the electronic device 12 may be deteriorated by moisture that has permeated the adhesive layer 20 and entered the gap 41. is there.

  Examples of the adhesive 21 include various adhesives such as a polyimide resin adhesive, an epoxy resin adhesive, a cyanoacrylate adhesive, and a hot melt adhesive. Among these, the water absorption is very low. A polyimide resin adhesive is preferable from the viewpoints of handling and ease of handling.

  As the particles 22, inorganic particles such as metal particles, ceramics and glass, or synthetic resin beads such as polystyrene beads and polyethylene beads are preferably used. The shape of the particle 22 is not limited to a spherical shape, but it is possible to realize a structure in which the spherical particle 14 and the surface on the electronic device 11 side and the spherical particle 14 and the fixed surface 13 are in contact with each other in a point contact state. preferable.

 The particle size of the particles 22 is such that the distance between the electronic device 12 and the sealing member 30 is kept constant, and a gap 41 is formed between them, and the adhesive layer 20 is separated from the sealing member 30. In order to exhibit a stress relaxation function that does not directly transmit the external stress to the electronic device 12 side, the adhesive layer 20 is set to have a sufficient thickness, and is usually 5 μm or more, preferably about 10 μm to 100 μm. Is done.

The thermal expansion coefficient (10 ⁻⁶ / K) of the particles 22 is an intermediate value between the thermal expansion coefficient of the substrate 11 on which the electronic device 12 is provided and the thermal expansion coefficient of the sealing member 30, or both. It is preferable that it is a value close | similar to either one of these. If the thermal expansion coefficient of the particles 22 is such a value, cracks may occur in the substrate 11, the electronic device 12, the sealing member 30, and the like due to the stress caused by the difference in thermal expansion coefficient even in an environment with temperature changes. It can be prevented from occurring.

 As the sealing member 30, it is desirable to select a member having a coefficient of thermal expansion close to that of the substrate 11 at the bonding temperature with the substrate 11. Specifically, Pyrex (registered trademark) glass or a glass substrate generally used for a liquid crystal substrate is suitable. When the electronic device 12 is required to have optical characteristics such as an image sensor, the sealing member 30 has a sufficiently practical transmittance with respect to the sensitivity wavelength region of the electronic device 12, that is, the effective wavelength region. What consists of material which has is used.

 The size of the void 41 is appropriately set according to the function of the electronic device 12, but the size (thickness) is determined by the size of the particles 22.

Next, an example of a method for manufacturing an electronic device package according to the present invention will be described with reference to FIGS.
First, the board | substrate 11 with which the electronic device 12 was provided in the one surface 11a is prepared.
Next, a material for forming the adhesive layer 20, that is, an adhesive 21 and particles 22 are prepared.

Next, a predetermined amount of particles 22 is mixed with the adhesive 21.
Normally, the adhesive 21 and the particles 22 are mixed immediately before being applied to the substrate 11 or the sealing member 30, but a material in which the adhesive 21 and the particles 22 are mixed in advance may be used. For example, when a reaction (crosslinking reaction) curable adhesive is used as the adhesive 21, it is desirable that the particles 22 are mixed and applied to a predetermined surface when the adhesive 21 has a low viscosity.

 In order to accurately adjust the thickness of the adhesive layer 20 with the particle size of the spherical particles 22, it is preferable that the particles 22 exist in the adhesive layer 20 in a single stage without being stacked in multiple stages. In order to make the particles 22 one stage, for example, after applying a mixture of the particles 22 and the adhesive 21 to the one surface 11 a of the substrate 11, a sealing member 30 to be bonded and fixed is placed on the adhesive layer 20. By moving the sealing member 30 several times or applying vibration to the sealing member 30, the single-stage particles 22 are arranged between the sealing member 30 and the substrate 11 (see FIG. 2). Can do.

 Next, the adhesive 21 is cured by heating or irradiating the adhesive 21 with ultraviolet rays. When the adhesive 21 is cured, as shown in FIG. 2, particles 22 are arranged in a row between the sealing member 30 and the substrate 11, and an adhesive layer 20 in which the spaces between the particles 22 are filled with the adhesive 21 is formed. Then, the sealing member 30 is bonded and fixed to the one surface 11a of the substrate 11 through the adhesive layer 20, and the electronic device package 40 is obtained. As a result, the distance between the sealing member 30 and the substrate 11, that is, the distance between the sealing member 30 and the electronic device 12, is maintained at a predetermined interval by a large number of particles 22 having a substantially uniform particle size. The stop member 30 and the substrate 11 are bonded and fixed in an extremely flat state. Further, by keeping the distance between the sealing member 30 and the substrate 11 constant, a gap 41 having a predetermined size is provided between them.

  In this embodiment, the method for manufacturing a chip electronic device package is shown, but the present invention is not limited to this. In the present invention, after an electronic device package in a wafer state is manufactured, the wafer may be diced along a dicing line to manufacture a chip-formed electronic device package. For dicing, a general dicing apparatus or an etching apparatus can be applied.

It is a schematic sectional drawing which shows one Embodiment of the electronic device package which concerns on this invention. It is the schematic sectional drawing which expanded the area | region shown with the code | symbol A in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Board | substrate, 12 ... Electronic device, 20 ... Adhesive layer, 21 ... Adhesive, 22 ... Particle | grains, 30 ... Sealing member, 40 ... Electronic device package, 41 ... gap.

Claims (1)

A substrate, an electronic device provided on one surface of the substrate, and a sealing member disposed to cover the electronic device and fixed to the substrate via an adhesive layer, A gap is provided between the sealing member, and the adhesive layer is composed of an adhesive and a large number of particles having a substantially uniform particle diameter, and the content of the particles in the adhesive layer Is a manufacturing method of an electronic device package that is 10 vol% or more and 70 vol% or less,
After applying a mixture of particles and an adhesive to one surface of the substrate on which the electronic device is provided, the sealing member is placed on the mixture applied to the substrate. Or by sliding the sealing member several times, or by applying vibration to the sealing member, the step of bringing the particles in a row between the sealing member and the substrate;
Heating the mixture applied to one surface of the substrate, or irradiating the mixture applied to one surface of the substrate with ultraviolet rays to cure the adhesive, and The particles are arranged in a row with the substrate, and an adhesive layer in which the particles are filled with the adhesive is formed, and the sealing is performed on one surface of the substrate via the adhesive layer. And a step of adhering and fixing the member.

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