JP2741484B2 - Sealed hermetic package and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed package in which electronic components such as a solid-state image pickup device, a quartz oscillator, and a laser pickup are housed and hermetically sealed, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a resin-sealed hermetic package containing electronic components such as a solid-state imaging device and a quartz oscillator, the electronic components are housed in a ceramic package having a concave shape. After that, a method of joining and sealing the lid material via an adhesive is used. In the method for sealing a package as described above, moisture existing in the package in advance is sealed while slightly remaining in the package, or after sealing, moisture is mainly absorbed in the adhesive or from the outside. In some cases, it entered the package through the adhesive interface. As a result, there has been a problem that the reliability of the electronic component element is reduced due to residual or intruded moisture, such as deterioration of the semiconductor element is promoted or the frequency characteristic of the crystal unit is affected. In addition, conventionally, attempts have been made to suppress the ingress of moisture from the outside by improving the adhesive used for sealing, and research has been particularly made on organic adhesives, but in the case of organic adhesives,
The rate of entry of moisture was slightly reduced, and sufficient results were not obtained. At that time, no consideration was given to moisture remaining inside the package immediately after sealing. On the other hand, regarding the moisture immediately after sealing, conventionally, for example, a method of completely replacing the atmosphere for sealing with nitrogen, performing preliminary drying to remove moisture adsorbed on the package surface, and then performing sealing. It has been known. However,
This method is not very effective because it has disadvantages, such as high cost and no effect on entry of moisture after sealing.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a sealed hermetic package containing an electronic component element with a reduced amount of water in the package. And a method for producing the same.

[0004]

As a result of the study, the present inventors have found that when a ceramic package is hermetically sealed using a lid material, a specific resin composition is potted inside the package to thereby form the package. In addition to reducing the moisture that was present immediately after sealing inside, it can also reduce the moisture that has entered from the outside after sealing, thereby improving the reliability of the electronic component elements housed inside. And found that the present invention was completed.

That is, the present invention relates to a sealed hermetic package containing an electronic component element in which the amount of water in the package is reduced, comprising a compound mainly composed of an epoxy resin and having at least one acid anhydride group. A thermosetting resin composition as a curing agent is potted inside the package. Further, the method for producing a sealed hermetic package in which the amount of water in the package is reduced according to the present invention comprises disposing an electronic component element inside the package, using an epoxy resin as a main component, and a compound having at least one acid anhydride group. After the thermosetting resin composition serving as a curing agent is potted inside the package, the package is sealed with a lid material via a thermosetting adhesive.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a sectional structure of a perspective view of a package used in the present invention. In the figure, an electronic resin element, for example, a semiconductor chip 3 is housed in a package 2, and after electrical wiring is completed, an epoxy resin is used as a base material in a place that does not hinder the function of the electronic component element in the package 2, for example, at four corners Then, the thermosetting resin composition 1 using a compound having at least one acid anhydride group as a curing agent is potted. Thereafter, the package is covered with a cover material (not shown) to which an adhesive has been applied in advance, and the package is sealed by heating. The heat applied at this time causes the thermosetting resin composition potted inside the package to react, and at the same time absorbs the moisture present inside. In addition, moisture that enters after sealing is also absorbed by the potted thermosetting resin composition, and a sealed airtight package with a reduced amount of moisture in the package is obtained.

In the present invention, the thermosetting resin composition used for potting contains an epoxy resin and a compound having at least one acid anhydride group as a curing agent as essential components. In the present invention, the epoxy resin used is not particularly limited, and examples thereof include a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an alicyclic epoxy resin. Of these resins, those that are liquid at room temperature are preferred because they can be easily potted. However, even with a solid epoxy resin, for example,
It can be used by mixing with a liquid epoxy resin or by adding a reactive diluent,
For example, a generally solid epoxy resin such as a phenol novolak type epoxy resin and a cresol novolak type epoxy resin can be used. In addition, by raising the temperature at the time of potting, if the viscosity of the resin used is lowered and used, a solid epoxy resin can be used at room temperature, and the solid epoxy resin can be used in a liquid curing agent or a reactive diluent. An epoxy resin can be dispersed and used.

As the curing agent for the epoxy resin used in the present invention, a compound having at least one acid anhydride group is used. Specifically, aliphatic acid anhydride, alicyclic acid anhydride,
Acid anhydrides such as aromatic acid anhydrides and halogen-substituted acid anhydrides are exemplified. Further specific compounds include trimellitic anhydride, glycerol tris-anhydrotrimellitate, ethylene glycol bisanhydrotrimellitate, dodecenyl succinic anhydride, tetrahydrophthalic anhydride, maleic anhydride, dichlorophthalic anhydride and the like. can give. These compounds may be used alone or as a mixture.

In the present invention, in addition to the epoxy resin and the compound having an acid anhydride group, if necessary,
A reactive diluent, a reaction accelerator, a filler, a coupling agent and the like can be blended. As the reactive diluent, it is possible to adjust the viscosity of the thermosetting resin composition, as long as it does not affect the characteristics of the electronic component elements housed by gasification when the package is sealed. Anything can be used. Specifically, a compound having a glycidyl group, for example, BR-250 manufactured by Nippon Kayaku Co., Ltd. can be mentioned. Any reaction accelerator can be used as long as it controls the reaction between the epoxy resin and the compound having an acid anhydride group. Specific examples include imidazoles such as 2-ethyl-4-methylimidazole and 2-undecylimidazole, amines such as m-phenylenediamine, diaminodiphenyl ether, boron trifluoride and monoethylamine, and triphenylphosphine. be able to. Examples of the filler include silica, quartz powder, alumina, calcium carbonate, magnesium oxide and the like.

[0010] The thermoplastic resin composition used in the present invention can be produced by mixing the epoxy resin, the compound containing an acid anhydride group, and other components blended if necessary. The mixing ratio of the acid anhydride with respect to the main agent of the epoxy resin is in the range of the equivalent ratio 0.2 to 500, and preferably set in a range of 0.5 to 10. Generally, acid anhydride is required to completely cure epoxy resin.
Although it is known to be blended at an equivalent ratio of about 0.9 to the epoxy group, the thermosetting resin composition in the present invention is:
Since it is used for the purpose of reducing the moisture inside the package, it is not always necessary to completely cure it, and there is no problem as long as the curing reaction has proceeded to such an extent that it does not affect the stored electronic component elements. Accordingly, the amount of formulation to anhydride equivalents
Even when the amount is considerably smaller than the amount, there is no problem that the potting resin is cross-linked to have a high viscosity, so that the dripping or oozing, or the vaporized components contaminate the stored electronic component elements and wiring and adversely affect the reliability. . Conversely, even when the amount of the acid anhydride is more than the equivalent , there is no problem that the stored electronic component elements and wirings are contaminated and the reliability is adversely affected for the same reason as described above.

[0011] Usually, in order to completely react the epoxy resin with the acid anhydride, heating for a relatively long time is necessary. In the present invention, particularly, only the thermosetting resin composition is reacted. No heating step is required. This is because the potted thermosetting resin composition reacts to some extent even by heating when the lid material and the package are sealed with an adhesive, and even if unreacted components remain, the epoxy resin is crosslinked. This is because the thermosetting resin composition becomes highly viscous and does not drip or bleed out or contaminate the housed electronic component elements and wirings with vaporized components, thereby adversely affecting the reliability.

In the present invention, the form of the thermosetting resin composition used for potting is preferably a one-pack type compounded in advance, but is preferably used in order to improve the storage stability of the epoxy resin.
It may be of a liquid type and blended before potting, or may be of a two-liquid state which is potted in a package and mixed in the package.

When the thermosetting resin composition is potted in a package, the method of dropping the liquid resin composition is that dispensing from a syringe previously filled with the thermosetting resin composition is suitable for automation. For this reason, it is preferable, but potting may be performed in the package by another method. Further, the viscosity of the thermosetting resin composition in the present invention is preferably a liquid at room temperature, and particularly preferably 25
A range of 1 to 1,000,000 centipoise at ° C is preferred. However, any material that becomes liquid upon heating even if it is solid at room temperature can be used in the present invention.

[0014]

According to the present invention, a thermosetting resin composition containing an epoxy resin and a compound having at least one acid anhydride group as a curing agent is potted in a package, and then the package and the cover material are removed. The resin is heated and hermetically sealed through a thermosetting adhesive, whereby the epoxy resin of the thermosetting resin composition and the curing agent undergo a crosslinking reaction, and the curing agent reacts with moisture. Therefore, the moisture remaining in the package and the moisture that has entered from the outside after sealing are absorbed by the thermosetting resin composition, and the moisture content in the package is reduced, and the electronic component element housed in the package is reduced. Reliability is improved.

[0015]

【Example】

Examples 1 to 3 A package made of alumina ceramic having an inner volume of 0.12 mm ³ was used as a package. In addition, a borosilicate glass of 10 × 10 × 0.7 t (mm) is used as a cover material, and a thermosetting adhesive for sealing is applied in a width of 1 mm to a peripheral portion of the cover material, and heated to a half. A cured state was prepared. The thermosetting adhesive used for sealing was "Elephan CS manufactured by Tomagawa Paper Mill". A crystal oscillation circuit element using a crystal oscillator was mounted on the ceramic package as an electronic component element, and a terminal portion of the crystal oscillation circuit element and a pad portion of the package were electrically connected by soldering with a copper wire. Next, a thermosetting resin composition having the components shown in Table 1 was potted at the four corners of the stage portion of the ceramic package so that the total amount was 10 mg. In Table 1 described below, the acid anhydride is used in an amount equivalent to the epoxy group of the epoxy resin in an equivalent amount, and the addition amount when a catalyst is used is described as parts by weight based on 100 parts by weight of the epoxy resin. Then, the above-prepared lid material with adhesive is placed so as to cover the opening of the package, and is heated at 150 ° C./2 hours after heating at 110 ° C./1 hour while applying a load of 1 kg. Was cured and hermetically sealed.

At this time, the sealed package was subjected to a gross leak test to confirm that there was no defective sealing, and then an acceleration test was performed by a pressure cooker test. In addition,
Pressure cooker test: 105 ° C, 100% R
H. The test time was as shown in Table 2. The moisture content was evaluated by quantifying gas components inside the package by GC-MS and measuring the moisture present in the package at the initial stage of sealing and the moisture after the accelerated test. The presence or absence of dew condensation was determined for the package after 90 hours of the pressure cooker test. That is, the package was cooled, and the presence or absence of dew condensation generated on the lid material at that time was confirmed. In the evaluation, those with dew condensation were marked with x, and those without condensation were marked with o. The above results are shown in Table 2 below.

Comparative Examples 1 to 3 As in the example, a ceramic package was prepared by applying the same sealing adhesive using a borosilicate glass lid material and heating to a semi-cured state. did. In the case of Comparative Example 1, unlike the above example, the thermosetting resin composition was not potted in the package. In the case of Comparative Examples 2 and 3, the thermosetting resin compositions having the compositions shown in Table 1 were used.
Potting was performed on the four corners of the stage portion of the ceramic package so that the total amount was 10 mg. Thereafter, a lid material with an adhesive prepared in advance as in the example was placed so as to cover the package opening, and heating was performed at 110 ° C./1 hour under a load of 1 kg, followed by heating at 150 ° C.
For 2 hours, the adhesive was cured by heating and sealed. Further, thereafter, a gross leak test, a pressure cooker test, and the like were performed under exactly the same conditions as in the above-described example, and a moisture measurement method inside the package and an evaluation method based on the presence or absence of dew condensation were also performed in the same manner as in the example. . Table 2 shows the results.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

As described above, the sealed airtight package containing the electronic component element of the present invention has a thermosetting resin composition containing an epoxy resin as a main component and a compound having at least one acid anhydride group as a curing agent. It is made by potting the product inside the package and sealing the package via a thermosetting adhesive with a lid material, so the acid anhydride in the package is present from the beginning when the package is sealed It is possible to absorb moisture and moisture that later enters via the sealing adhesive layer. Therefore, the amount of water in the package after sealing can be extremely reduced, and the reliability of the electronic component element whose function is reduced by the amount of water around the solid-state imaging device, the quartz oscillator, the laser pickup, etc. is increased. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a perspective view of a package used in the present invention.

[Explanation of Signs] 1. Thermosetting resin composition, 2. Package, 3. Semiconductor chip (cross section)

 ──────────────────────────────────────────────────の Continuing the front page (72) Inventor Jun Tochihira 3-1 Yomoba-cho, Shizuoka-shi, Shizuoka Pref. 208860 (JP, A) JP-A-3-285981 (JP, A) JP-A-2-126646 (JP, A)

Claims (2)

(57) [Claims] In a sealed airtight package containing an electronic component element, a thermosetting resin composition containing an epoxy resin as a main component and a compound having at least one acid anhydride group as a curing agent is potted inside the package. A sealed hermetic package in which the amount of moisture in the package is reduced. 2. An electronic component element is placed inside a package, and a thermosetting resin composition containing an epoxy resin as a main component and a compound having at least one acid anhydride group as a curing agent is potted inside the package. A method for manufacturing a sealed hermetic package in which the amount of moisture in a package is reduced, wherein the package is sealed with a lid material via a thermosetting adhesive.