JPH07283353A - Method for manufacturing lead frame - Google Patents

Abstract

PURPOSE:To continuously manufacture a clean lead frame without requiring degreasing process by refining a metal machining oil used for blanking the lead frame with a high purity and making the oil to be dried rapidly so that it evaporates when the oil is left from several hours to several days at a room temperature. CONSTITUTION:In a manufacturing line, a punching mold 4 and a hot air drying oven 5 are connected by a carrier means, thus enabling drying process to be made continuously after punching process, where the a material 3 for lead frame is supplied continuously to the punching mold 4 and a metal machining oil 2 which can be dried rapidly and has a purity of 70% or higher is applied to the material 3 for lead frame before machining from an oil container 1 at the supply side. A lead frame 7 which is machined by the punching mold 4 to a specific shape is supplied to the hot air drying oven 5 and is subjected to hot air from a hot air drying nozzle 6, thus evaporating a residual oil from the lead frame 7 and hence obtaining the lead frame 7 with a high cleanliness continuously from the carry-out port of the hot air drying oven 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lead frame which uses a quick-drying metal working oil for punching.

[0002]

2. Description of the Related Art Conventionally, a metal working oil used for punching a lead frame into a predetermined shape has a high viscosity of 3 to 4 cSt in order to prevent wear and damage of the die. For example, Japan Machine Oil G series containing 99.8% or more of paraffin hydrocarbons is exclusively used. Therefore, oil remains on the surface of the lead frame even after punching, and a cleaning step using a solvent-based, water-based, or semi-water-based solution is essential to degrease the remaining oil.

[0003]

However, as described above, the conventional techniques have the following problems.

(1) Since the solution is used in the step of cleaning the residual oil, the step of lead frame punching cannot be continued and the productivity is poor.

(2) Since the metalworking oil used for punching the lead frame contains impurities such as additives, if left naturally attached to the leadframe after the punching process, moisture in the atmosphere Discoloration occurs in the lead frame when mixed with.

(3) Since the metalworking oil used for punching has a high viscosity, if the lead frame is in close contact with other members via residual oil, the oil can be easily removed even with an organic solvent. I could not do it, and the workability was poor.

(4) Since the residual oil is washed with a solvent-based, water-based or semi-water-based solution, the treatment of the dirty solution leads to environmental pollution.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a method of manufacturing a lead frame capable of continuously obtaining a clean lead frame after punching without a solution cleaning step. It is in.

[0009]

According to the method of manufacturing a lead frame of the present invention, in a method of manufacturing a lead frame by punching a lead frame material into a predetermined shape with a mold, the metal working oil used for punching has a high purity. It is a quick-drying product that evaporates when left at room temperature for several hours to several days. If it dries faster than a few hours, there is the inconvenience that stain-like discoloration can occur,
This is because if the time required for drying exceeds several days, the difference from the conventional method does not occur and the degreasing step is required. The purity is at least 70%.

The quick-drying metalworking oil is an isoparaffinic hydrocarbon oil (main component C ₁₂ H ₂₆ ), whose characteristics are: viscosity 1.5-2.0 cSt, specific gravity 0.75-0. 7
6, it is preferable that the KB value is 27 to 28. In addition,
Here, the KB value is introduced on the scale showing the dissolving power. In addition, a hydrocarbon oil containing C ₁₀ H ₂₂ as a main component can be used. This is because if the viscosity is less than 1.5, wear and breakage of the mold cannot be effectively prevented, and if it exceeds 2.0, oil cannot be easily removed by natural drying or hot air drying. KB
This is because if the value is smaller than 27, the dissolving power is small, and if it exceeds 28, the dissolving power becomes unnecessarily large.

In order to completely remove the oil, it is preferable to dry the oil adhering to the lead frame after hot stamping the lead frame, and the hot air drying conditions are: air pressure: 500 to 1000 mmAq, 〓 Hot air temperature: 7
The temperature is preferably 0 to 80 ° C. If the air pressure is less than 500 mmAq, liquid shortage will occur, and if it is more than 1000 mmAq, the temperature of the hot air will rise, which is not preferable. This is because if the hot air temperature is lower than 70, the liquid will be insufficiently drained, and if it is higher than 80 ° C, the product will be discolored.

[0012]

[Function] If a high-purity quick-drying oil that evaporates when left at room temperature for several hours to several days is used as the metal working oil used for punching the lead frame, the lead is simply dried after the punching process for the above-mentioned standing period. Since the oil scatters from the frame, the residual oil on the surface is equivalent to the case of degreasing cleaning without degreasing cleaning.

After punching, it may be left at room temperature for several hours to several days to be slowly dried. However, if the oil adhered to the lead frame is forcibly dried by hot air, the oil adhered to the surface of the lead frame can be quickly and completely removed. Can be vaporized.

[0014]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a schematic view of a manufacturing process line for explaining an embodiment of a method for manufacturing a lead frame of the present invention. The punching die 4 and the hot-air drying furnace 5 are connected by a conveying means so that the drying step can be continuously performed after the punching step.

The punching die 4 punches the lead frame material 3 into a predetermined shape. The lead frame material to be punched is a copper-based material (for example, MF20
2. Oxygen-free copper), iron-based materials (eg 42 alloy), etc. are used.

On the supply side of the lead frame material 3 of the punching die 4, an oil container 1 for storing metal working oil used for punching is provided, and the lead frame material 3 before punching is supplied to the die 4. A predetermined amount of metalworking oil is applied on top.

The metalworking oil for punching stored in the oil container 1 is refined to a high purity. Here, the purity is 70
% Or more was used. Also, a liquid containing C ₁₀ H ₂₂ which is a quick-drying isoparaffinic hydrocarbon system that evaporates when left at room temperature for several hours to several days was used.

In the hot air drying oven 5, the hot air introduced into the oven 5 from the duct 9 is blown from the hot air drying nozzle 6 to the lead frame 7 conveyed on the conveying roller 8 to process the metal working adhered to the surface of the lead frame. Evaporate the oil.

The lead frame material 3 is continuously supplied to the punching die 4 in the form of a strip. On its supply side, the oil container 1
Then, the metal working oil 2 having a quick drying property and a high purity is applied onto the unprocessed lead frame material 3. The characteristics of the oil are: viscosity: 1.5-2.0 cSt, specific gravity: 0.75-0.76,
KB value: 27 to 28. The lead frame 7 processed into a predetermined shape by being processed by the punching die 4 is supplied to the hot air drying furnace 5. Hot air pressure 500-100 when passing through here
Under the condition of 0 mmAq and hot air temperature of 70 to 80 ° C., hot air is blown from the hot air drying nozzle 6 onto the lead frame 7, whereby the residual oil remaining in the lead frame 7 is completely evaporated. The lead frame 7 that has passed through the hot-air drying furnace 5 is vaporized with oil to obtain sufficient cleanliness.

According to the present embodiment, instead of degreasing and washing using a solution, this is dried with hot air, so that the lead frame punching process and the step of removing residual oil are continuously performed without interruption. Since it can be performed, productivity is improved.

Since the punching oil is a quick-drying metal working oil of high purity, it easily evaporates even if it is left to stand on the lead frame after the punching process even if it is naturally left. No discoloration occurs in the lead frame when mixed with.

Furthermore, since the metal working oil used has a low viscosity within the range in which the wear and damage of the mold can be prevented,
Even if the lead frame is in close contact with another member via the residual oil, this can be easily removed.

Further, since it is not necessary to use solvent-based, water-based and semi-water-based solutions for degreasing the residual oil, and it is not necessary to treat dirty cleaning liquid, there is no fear of environmental pollution.

[0024]

According to the present invention, since a quick-drying metal working oil is used, the oil is easily vaporized only by natural drying without a solution washing step. Therefore, residual oil is continuously removed after punching. it can. Further, since the oil purified to high purity is used, the lead frame after vaporization can be maintained at the cleanliness level equivalent to that of the conventional one that has undergone the cleaning step.

Further, by forcibly drying with hot air after punching, the metal working oil can be removed from the lead frame quickly and completely.

[Brief description of drawings]

FIG. 1 is a schematic view of a manufacturing process line for explaining an embodiment of a method for manufacturing a lead frame of the present invention.

[Explanation of symbols]

 1 Oil Container 2 Metalworking Oil 3 Lead Frame Material 4 Punching Die 5 Hot Air Drying Furnace 6 Hot Air Drying Nozzle 7 Lead Frame

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area C10N 20:02 30:08 40:24 Z

Claims (4)

[Claims] 1. A method for producing a lead frame by punching a lead frame material into a predetermined shape with a mold, wherein the metal working oil used for punching has a purity of 70% or more, and is left at room temperature for several hours to several days. A method for manufacturing a lead frame, which is quick-drying and evaporates. 2. The metalworking oil is an isoparaffinic hydrocarbon oil (main component C ₁₂ H ₂₆ ), and its characteristics are: viscosity: 1.5 to 2.0 cSt specific gravity: 0.75 to 0. 76 〓 KB value (kauributanol value): 27 to 28, The method for producing a lead frame according to claim 1, wherein 3. The method for manufacturing a lead frame according to claim 1, wherein the oil attached to the lead frame is dried with hot air after the lead frame is punched. 4. The method for producing a lead frame according to claim 3, wherein the hot air drying conditions are: 〓 air pressure: 500 to 1000 mmAq 〓 hot air temperature: 70 to 80 ° C.