JPH07109495A - Cleaning of element sealed with epoxy resin - Google Patents

Abstract

PURPOSE:To clean an element sealed with an epoxy resin at good efficiency without impairing the surface of the element and to provide an element sealed with an epoxy resin and having such high reliability as to be used as an electronic component. CONSTITUTION:An element sealed with an epoxy resin is immersed in a cleaning fluid comprising 70-90wt.% N-methyl-2-pyrrolidone and 10-30wt.% aliphatic amine at 50-100 deg.C, and the immersed element is washed with water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning an epoxy resin-sealed element mainly used in the field of electronic materials.

[0002]

2. Description of the Related Art A sealing element is manufactured by molding a conductor base made of, for example, copper or silver, which is sealed with a sealant such as epoxy resin, phenol resin or silicon resin. When manufacturing such a sealing element, burr derived from resin remains on the surface of the sealing element, so that a fluorocarbon-based or chlorine-based cleaning solvent has been mainly used.

[0003]

However, these solvents pose major problems in terms of safety and environmental impact, and their use is being regulated. Therefore, there is an urgent need to develop these substitute cleaning agents or cleaning methods using them. Currently, there is no universal cleaning agent as a substitute, and there is a situation in which a cleaning agent or a cleaning method must be considered each time depending on the type of resin of the sealing element.

For example, US Pat. No. 3,551,204 proposes a cleaning composition for dissolving polyurethane and epoxy resin systems. The cleaning composition comprises 0.1 to 3 parts by weight water, 3 to 7 parts by weight metal hydroxide, and 90 to 96.9 parts by weight ethylene glycol monoalkyl ether. It may be possible to apply this to an epoxy resin encapsulation element, but there is a possibility that reliability as a product may be significantly impaired, for example, metal ions may remain on the surface of the encapsulation element.

[0005]

Means for Solving the Problems The inventors of the present invention have earnestly studied a method for cleaning an epoxy resin-sealed element mainly used in the field of electronic materials, which requires more rigorous cleaning, and as a result, Was completed. That is, the present invention provides an epoxy resin-sealed element with N-methyl-2-pyrrolidone 70-90.
The present invention relates to a method for cleaning an epoxy resin-sealed element, which comprises immersing in a cleaning liquid containing 10% by weight of an aliphatic amine and 50% by weight of an aliphatic amine at 50 to 100 ° C., and then washing with water.

The present invention will be described in more detail below. The sealing element to be cleaned in the present invention is made of epoxy resin. The most representative epoxy resin is a condensate of bisphenol A and epichlorohydrin, and a resin obtained by adding an aliphatic amine, phthalic anhydride, a phenol resin or the like as a curing agent to this resin is usually used. It is illustrated. In particular, a type in which both side hydroxyl groups of bisphenol A are glycidyl ether is often used as a sealant. In addition, there are fatty acid epoxy resin, alicyclic epoxy resin, glycidyl ester resin and the like.

Examples of the aliphatic amine used in the cleaning solution of the present invention include alkylamines such as methylamine, ethylamine, isopropylamine, diethylamine, triethylamine, ethylenediamine, tetramethylethylenediamine and cyclohexylamine, as well as ethanolamine, diethanolamine and triamine. Ethanolamine, N-
Alkanolamines such as methyldiethanolamine and 2-methylaminoethanol are exemplified, and usually 1 to 10,
Preferably, it has about 2 to 6 carbon atoms and N-methyl-2
Must be compatible with pyrrolidone and water. These aliphatic amines may be used in combination of a plurality of types.

The composition of the cleaning liquid is N-methyl-2-
70-90% by weight of pyrrolidone, preferably 75-85
% By weight, and 10 to 30% by weight, preferably 15 to 25% by weight, of an aliphatic amine.
When the content of the aliphatic amine is less than 10% by weight, the surface of the epoxy resin is significantly softened and the sealing element may be deformed, which is not preferable. On the other hand, when the content of the aliphatic amine exceeds 30% by weight, the deburring and cleaning effect is significantly reduced, which is not preferable.

Further, in the above-mentioned cleaning liquid, other solvents can be contained within the range where they do not adversely affect. Other solvents include alcohols, ethers, esters, aromatic hydrocarbons and alicyclic hydrocarbons. It is possible to enhance the effect of deburring and cleaning itself by adding a small amount of an alkali metal or alkaline earth metal compound to the cleaning liquid, but metal ions are likely to remain on the surface of the sealing element, and the product is They should not normally be added to the wash liquor as they can significantly impair reliability.

The cleaning method of the present invention is achieved by immersing the epoxy resin-sealed element in the cleaning liquid. It is preferable that the entire epoxy resin-sealed element is washed by immersion, and further, in order to enhance the washing effect, stirring of the washing liquid, gas bubbling, application of ultrasonic waves, or the like may be performed. The washing temperature is 50 to 100 ° C, preferably 60 to 90 ° C. If the temperature exceeds 100 ° C, the sealing element may be deformed, which is not preferable.
If the temperature is lower than 0 ° C, the deburring and cleaning effect is significantly reduced, which is not preferable. The washing time may be appropriately set in relation to the washing temperature, but is usually 1 to 60 minutes, preferably 5 to 30 minutes.

Next, after the above washing, the washing liquid is washed off with water and then dried to obtain a product.

[0012]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1 to 4 and Comparative Examples 1 to 3 A cleaning liquid having the composition shown in Table 1 was heated to 80 ° C., and a sealing element manufactured using an epoxy resin was immersed in the cleaning liquid, and 20
Immersion treatment was performed for a minute. After washing, it was washed with water and dried.
The degree of removal of the sealing element burr before and after the cleaning process and the presence or absence of surface deformation were observed using an optical microscope. The above results are shown in Table-1.

In Table 1, NMP is N-methyl-2.
Represents pyrrolidone, and the observation result of the surface of the IC sealing element after washing is shown by the following symbols. ○: Burrs are completely removed. Δ: A slight amount of burr remained. X: Most of the burr remains.

[0014]

[Table 1]

[0015]

According to the cleaning method of the present invention, the epoxy resin-sealed element can be efficiently cleaned without damaging the surface of the epoxy resin-sealed element, and thus the highly reliable epoxy resin-sealed element used as an electronic component or the like. It becomes possible to supply products.

Claims (1)

[Claims] 1. An epoxy resin-sealed element is formed of N-methyl-
2-pyrrolidone 70-90% by weight and aliphatic amine 10-
A method for cleaning an epoxy resin-sealed element, comprising immersing in a cleaning liquid containing 30% by weight at 50 to 100 ° C., and then rinsing with water.