JPH04176153A - Manufacture of lead frame - Google Patents

Abstract

PURPOSE:To enable a part small in dimensions to be accurately etched even if it is small in size as compared with the thickness of a material plate by a method wherein small holes are bored in the part to etch, and then an etching process is executed. CONSTITUTION:When a semiconductor device lead frame is manufactured, an etching process is carried out after small holes 4 are bored in a part of a material plate to etch. For instance, an island 1, suspension pins 2, and inner leads 3 of a material metal 5 excluding a part which is to be etched are coated with resist. The small holes 4 are made in the part of the material metal 5 to etch at the prescribed positions through a wire cut processing method, a discharge processing method, or the like. Then, an etching process is executed. By this setup, etchant enters the holes 4 to accelerate an etching rate in the direction vertical to the direction of the thickness of the metal 5, whereby an etching rate is relatively lessened in the direction of the thickness of the material plate 5, in result an etching pattern excellent in dimensional accuracy can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a lead frame, and particularly to a method for manufacturing a lead frame including an etching process.

[Conventional technology]

Conventionally, when processing this type of lead frame by etching, the etching process was carried out after applying a resist solution to the raw metal, performing drying and baking, and removing the resist I solution from the portion to be etched.

[Problem to be solved by the invention]

In the conventional etching method described above, if the dimension to be etched is small compared to the thickness of the material, narrow dimensions cannot be achieved with high accuracy because the etching is performed not only in the direction perpendicular to the thickness of the material, but also in the direction of the thickness of the material. There were drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lead frame manufacturing method that can ensure a narrow dimension with high accuracy even when the dimension to be etched is small compared to the thickness of the material.

[Means to solve the problem]

The present invention is a method for manufacturing a lead frame for a semiconductor device, which includes a step of drilling a plurality of small holes in a location to be etched and then performing an etching process.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a sectional view of a main part for explaining a manufacturing method according to an embodiment of the present invention.

As shown in FIGS. 1(a) and (b), first, the material metal 5
Island part 1 and hanging pin part 2 excluding the etched part
．． The inner lead portion 3 is coated with a resist.

Next, a small hole 4 is bored at a predetermined position in the portion of the raw metal 5 to be etched by a wire cutting method, an electric discharge machining method, or the like.

Next, etching is performed. At this time, the etching liquid enters the small holes 4 and accelerates the etching speed in the direction perpendicular to the thickness of the raw metal 5, thereby making the etching in the thickness direction relatively slow and creating an etching pattern with high dimensional accuracy. is obtained.

〔Effect of the invention〕

As explained above, the present invention has small holes 4 in the part to be etched.
By providing this, the etching speed in the direction perpendicular to the plate thickness can be accelerated, and the etching progress in the plate thickness direction can be slowed down when processing fine dimensions, resulting in a machining pattern with high dimensional accuracy. be.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1(a) and 1(b) are a plan view and a sectional view of a main part, illustrating a manufacturing method according to an embodiment of the present invention. 1... Island part, 2... Hanging pin part, 3... Inner lead part, 4... Small hole, 5... Material metal.

Claims (1)

[Claims] A method for manufacturing a lead frame for a semiconductor device, the method comprising the step of drilling a plurality of small holes in a location to be etched and then performing an etching process.