JPS6355863B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of manufacturing a resin-sealed semiconductor device in which a semiconductor element is sealed with a resin using a mold or the like.

[Technical background of the invention]

Today, resin encapsulation is widely used as a packaging technology for semiconductor devices. The procedure for forming this resin-sealed semiconductor device is as follows, for example: A semiconductor element is mounted on an element base of a lead frame, and a predetermined part of the semiconductor element and a predetermined part of the lead frame are wire bonded. After that, the above lead frame is placed on the mold die, and a liquid molding resin such as epoxy is injected into the cavity of the mold die, filled and cured, and the lead part of the lead frame is sealed with the resin. The shape should be drawn out from the part.

By the way, in the resin sealing process as described above, the lead frame is placed so as to be sandwiched between the upper mold and the lower mold, and the mold resin is injected into the cavity. There is a slight gap between the upper and lower molds, so when molding resin is injected under high pressure, the molding resin protrudes from this gap and seals the resin as shown in Figure 1. Lead part 1 pulled out from part 11
A resin burr 13 is attached on the surface of the resin burr 2 .

Such resin burrs not only have an unfavorable appearance, but also cause problems such as plating defects during the plating process such as soldering to the lead parts after resin sealing, and burrs falling off when the device is mounted. wake up For this reason, a deburring process is performed after the resin sealing process.

As a method for removing the burr, a method of grinding the lead portion with a grindstone or a method of honing in which water containing particles of alumina, silicon carbide, etc. as an abrasive is sprayed at high pressure is adopted.

[Problems with background technology]

However, since both of these methods use mechanical force to remove burrs fixed to the lead portion, the lead portion may be deformed or the lead portion or the resin sealing portion may be damaged. In addition, during the deburring process, abrasive particles and grinding stone particles are often embedded in the reed part and cause problems with the exterior of the reed part afterwards, so chemical treatments such as honing and grinding are performed to remove foreign particles. need to be removed. If this chemical treatment is performed in order to sufficiently remove foreign matter, problems such as roughening of the lead portion arise, so in practice it cannot be carried out satisfactorily, and the manufacturing cost is high.

[Purpose of the invention]

This invention was made in view of the above points, and it is possible to easily remove the resin without causing damage to the resin sealing part, deformation or damage to the lead part, and inconveniences such as abrasive particles being embedded in the lead part. The present invention provides a method for manufacturing a resin-sealed semiconductor device in which burrs can be removed, thereby reducing manufacturing costs and manufacturing time, and improving the reliability of the device.

[Summary of the invention]

That is, in the method for manufacturing a resin-sealed semiconductor device according to the present invention, after a semiconductor element is resin-sealed together with a lead frame to form a semiconductor device in which the lead portion is drawn out from the resin-sealed portion, the semiconductor device is is placed in a plasma etching chamber and subjected to oxygen plasma etching to decompose (ash) the resin burrs attached to the lead parts, and remove the residual resin burrs remaining on the lead parts with, for example, a brush or jet water stream. It is designed to be removed by a light mechanical removal process using, etc.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

First, a resin sealing process similar to the conventional one is performed to form a resin sealing part 11 in which a semiconductor element is sealed, as shown in FIG. 1, and a lead electrically connected to a predetermined part of the semiconductor element. A semiconductor device having a portion 12 is formed. As described above, during the resin sealing process of semiconductor elements, resin burrs 13 are fixed on the lead portions 12, particularly in the portions close to the resin sealing portions 12.

Subsequently, such an apparatus is installed in a plasma etching chamber 21 as shown in FIG. Inside this etching chamber 21 , an anode plate 22 and a cathode plate 23 are provided vertically facing each other. After a plurality of semiconductor devices 20 are installed on the cathode plate 23, the inside of the chamber 21 is removed using a vacuum pump. Degree of vacuum
Oxygen gas is introduced through the introduction hole 24 while exhausting to about 0.24 Torr. After the gas condition in the chamber becomes stable, approximately
Apply a DC voltage of 600V and maintain DC discharge for about 1 minute. During this time, components such as carbon, nitrogen, and hydrogen of the resin burr on the lead portion react with the oxygen plasma, and residues (burnt residue) of the resin burr remain on the lead portion.

After the discharge is finished, the inside of the chamber 21 is returned to atmospheric pressure, and after the semiconductor device is taken out, the residue adhering to the leads is removed by a light mechanical treatment such as a brush or jet water jet (not including abrasives). Drop it.

Thereafter, a process such as soldering the lead portions is performed as appropriate to complete the desired product.

The conditions for the above oxygen plasma etching step may be set as appropriate depending on the degree of resin burr.
If the resin burr is thick and requires sufficient oxygen plasma etching, if the above etching is performed with a metal piece placed on the resin sealing part of the semiconductor device, the surface of the resin sealing part may be roughened by etching. There is no.

〔Effect of the invention〕

In the method for manufacturing a resin-sealed semiconductor device according to the present invention as described above, the resin burr fixed on the lead portion is exposed to oxygen plasma, decomposed into a brittle residue, and then lightly brushed or jetted with water. except. Therefore, unlike in the conventional case, a large impact is not applied to the resin sealing part or the lead part, so there is no risk of damage to the resin sealing part or damage or deformation of the lead part, contributing to the reliability of the device.

In addition, since particles of abrasives and grindstones are not embedded in the lead part, there is no problem with exterior work such as plating, and chemical treatment after the conventional deburring process is no longer required, reducing manufacturing costs. can be lowered. Similarly, the deburring process can be simplified without using large-scale equipment or abrasive materials.
It becomes possible to reduce processing costs and processing time.

[Brief explanation of drawings]

Figure 1 is a diagram showing a resin-sealed semiconductor device, Figure 2 is a diagram showing a resin-sealed semiconductor device;
The figure shows an etching chamber used in a method of manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention. 11... Resin sealing part, 12... External lead, 1
3...Resin burr, 20...Semiconductor device, 21 ...
Plasma etching chamber, 22... Anode, 2
3...Cathode, 24...Introduction hole.

Claims (1)

[Claims] 1 A resin sealing step in which a semiconductor element is resin-sealed together with a predetermined lead frame to form a semiconductor device in which the lead portion of the lead frame is drawn out from the resin sealing portion, and the semiconductor device is exposed to oxygen plasma and the resin sealing process is performed. A resin characterized by comprising an oxygen plasma etching step for decomposing resin burrs adhering to the lead portion in the finishing step, and a step for mechanically removing residue remaining on the lead portion due to the oxygen plasma etching step. A method for manufacturing a sealed semiconductor device.