JPH05299402A - Method of cleaning electronic conponent - Google Patents

Abstract

PURPOSE:To excellently clean the contaminated surface of various electronic components such as PGA by a method wherein excimer laser beams are emitted to contaminated portions of the electronic components to clean them. CONSTITUTION:In order to emit laser beams to predetermined parts to be cleaned in objective electronic components such as PGA, etc., the laser beams are emitted from an excimer laser oscillator to pass through a predetermined mask, and thereafter the laser beams are guided to a predetermined part through a mirror and a lens. At this time, a strength of the laser beams, an emitting area, an emitting time, atmospheric conditions, and the like are appropriately controlled. For example, in the case of the PGA, the excimer laser beams are emitted under a condition that air is pressurized or it flows. Thus, as a method of non-fluorocarbon cleaning of various electronic components including PGA, cleaning with an excellent quality is possible.

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 electronic parts. More specifically, the present invention is
The present invention relates to a new cleaning method which is useful for cleaning electronic component parts such as PGA gold plating bonding and enables excellent performance cleaning without using a CFC cleaner.

[0002]

2. Description of the Related Art As the performance of electronic devices such as semiconductors and integrated circuits increases, and as the density and packaging of these parts progress, the demand for cleaning of electronic parts is increasing. There is a strong demand for the realization of ultra-clean surfaces.
Conventionally, so-called CFC cleaning agents have been used for such cleaning, but the use of CFC cleaning agents cannot avoid the harmful effects on the global environment including the destruction of the ozone layer. Its use has become internationally regulated. However, since the cleaning effect of this conventional CFC cleaning agent is very excellent, it is the actual situation that no cleaning means capable of substituting for the CFC cleaning agent has been found.

[0003]

However, the realization of a clean state such as an ultra-clean surface is indispensable as the performance of electronic parts is improved. For example, even in the case of the PGA having the gold (Au) plating cavity illustrated in FIG. 2, there is a serious problem that the defective appearance due to the adherence of contaminants cannot be avoided and the reliability during wire bonding is impaired.

Therefore, it has been strongly desired to realize a new means capable of cleaning the contaminated surface of various electronic components such as PGA with excellent quality without using the CFC cleaning agent as described above. The present invention has been made in view of the above circumstances, and is a new non-CFC cleaning method that can replace conventional CFC cleaning and can clean contaminated surfaces and the like with excellent quality. It is intended to provide a way.

[0005]

In order to solve the above problems, the present invention provides a method for cleaning electronic parts, which comprises irradiating a contaminated part of an electronic part with excimer laser light for cleaning. provide.

[0006]

In other words, the present invention is applicable to the case where contamination due to flux, talc (inorganic substance such as resist cutting layer), resist organic substance, etc. as in the case of the above-mentioned PGA becomes a problem, contamination of the lead surface, rust, etc. In the case where the reliability is impaired, excimer laser light is applied to those inconvenient parts to remove contaminants and improve the surface quality.

When irradiating the excimer laser light,
Optimum cleaning can be achieved by controlling the laser power according to the type of the target site, its configuration, and the type and state of contamination. Further, the atmosphere is controlled for the irradiation of the laser light, and it becomes possible to perform cleaning with higher quality and higher quality. Moreover, in the cleaning by the excimer laser light irradiation of the present invention, it becomes possible to remove the contamination which cannot be removed by the conventional CFC cleaner.

Hereinafter, the cleaning method of the present invention will be described in more detail with reference to examples.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a PG as a cleaning method of the present invention.
It is a block diagram which illustrated the cleaning of A. For example, this figure 1
In order to irradiate a required cleaning portion of a target electronic component such as PGA with a laser beam, a laser beam is emitted from an excimer laser oscillating device, and the laser beam is passed through a required mask as shown in FIG. And lead to the required site through the lens.

At this time, the intensity of the laser beam, the irradiation area, the irradiation time, the atmospheric conditions, etc. are controlled appropriately. For example, PG
In the case of A, the excimer laser light is irradiated under pressure or circulation of air. It may be an inert gas or a reduced pressure atmosphere. In order to remove surface contaminants from various electronic parts, the intensity of excimer laser light is generally 0.10 J /
The power may be 0.5 cm ² or more, and a power of about 0.5 to 0.7 J / cm ² can be adopted when improving the surface properties of the metal. Of course, such strength should be appropriately changed according to the target site, the purpose of cleaning, and the conditions.

Example of cleaning process Actually, in the configuration of FIG. 1, the irradiation area is about 3 × 2 mm,
The PGA was cleaned in an atmosphere of ² kg / cm ² of air. The PGA contaminants consisted of: flux 70%, talc 20%, resist organic matter 10%, etc.

The excimer laser light intensity is set to 0.23 J / c.
The inner lead, the cavity and the backup were irradiated with m ² . As a result, contaminants on the surface are effectively removed, and the contaminated sample 1 is visually observed by visual observation.
Approximately 75% of the 00 pieces were improved in high quality. When the laser light intensity was 0.32 J / cm ² , the gold (Au) electrode surface layer was removed, and when the intensity was 0.64 J / cm ² , the gloss of the gold (Au) surface was observed to change to almost 10
A 0% cleaning was achieved.

From these results, it was found that the irradiation of the excimer laser light realizes 1) removal of contaminants, ablation of organic substances, 2) improvement of bondability, formation of diffusion layer, and improvement of surface roughness.

Of course, the method of the present invention is not limited to the above examples. It goes without saying that further various configurations are possible in the aspect of the details.

[0015]

As described above, the present invention enables the cleaning of excellent quality as non-CFC cleaning of various electronic parts such as PGA, and can greatly improve the performance reliability of the electronic parts. ..

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of the present invention.

FIG. 2 is a perspective view showing a PGA as an example of an electronic component.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // H01G 13/00 9174-5E

Claims (1)

[Claims] 1. A method for cleaning an electronic component, which comprises irradiating a contaminated portion of the electronic component with excimer laser light for cleaning.