JPS6150724B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cutting tool that has excellent wear resistance and exhibits excellent cutting performance over a long period of time, particularly when used for drilling holes in electronic integrated circuit laminated substrates. Generally, for the production of electronic integrated circuit laminated boards, very rigid FRP reinforced with glass fibers, for example, is used.
(fiber-reinforced resin) and other materials are used, and when manufacturing this laminated board, it is essential to drill small diameter holes. router is used. Therefore, these cutting tools are required to have high toughness that will not break during drilling and excellent wear resistance that can withstand hard work materials, so the main hard dispersed phase forming component is usually carbonized. WC composed of tungsten (hereinafter referred to as WC) or titanium carbide (hereinafter referred to as TiC), and whose main binder phase forming component is an iron group metal.
Those made of cemented carbide or TiC-based cermet are used. However, although these WC-based cemented carbides and TiC-based cermets have toughness, they do not have sufficient wear resistance, so they are not used particularly as cutting tools for drilling holes in electronic integrated circuit laminated boards. In this case, the service life was relatively short. Therefore, from the above-mentioned viewpoint, the present inventors conducted research to obtain a cutting tool suitable for drilling holes in electronic integrated circuit laminated substrates, and as a result, they found the above-mentioned cutting tool.
If necessary, the periodic table is applied to at least the machined surface of the tip of the cutting tool body made of WC-based cemented carbide or TiC-based cermet, for example, in the case of a miniature drill, at least the lip and/or margin. A single layer of one of the carbides of group 4a, 5a, and 6a metals, and the nitrides and carbonitrides of group 4a and 5a metals (hereinafter collectively referred to as metal carbonitrides). Or, through a surface coating layer consisting of two or more types of multilayers, a hard layer consisting of crystalline diamond with a high hardness of 8000 Kg/mm ² or more in terms of micro-Vickers hardness is formed by vapor phase synthesis with an average thickness of 0.2 to 20 μm. When formed thickly, the hard layer made of the crystalline diamond ensures excellent wear resistance, while the cutting tool body ensures excellent toughness. They found that when used for drilling holes in laminated substrates, it exhibits excellent cutting performance over a long period of time. This invention has been made based on the above findings, and in the cutting tool of this invention, the average layer thickness of the crystalline diamond hard layer is 0.2 to 20 μm.
The reason for this is that if the average layer thickness is less than 0.2 μm, the desired effect of improving wear resistance cannot be obtained.
This is because if the average layer thickness exceeds 0.5 m, peeling due to chipping will easily occur in the crystalline diamond hard layer.
An average layer thickness of 10 μm is preferred. In addition, the crystalline diamond hard layer in the cutting tool of this invention is 0.5 to 0.5 mm thick from the surface of the cutting tool body.
CH ₄ with a filament made of W, Ta, Mo, or graphite placed 3 cm apart.
The capacity ratio between CH4 and _H2 , that is, _CH4 / _H2 , is 0.001~
While flowing the mixed reaction gas adjusted to 0.05 through the filament so as to hit the surface of the cutting tool body, the surface temperature of the cutting tool body: 500~
It can be formed by performing the process at 1200° C. and a filament temperature of 1800 to 2500° C. The crystalline diamond thus formed has a granular or film-like shape. Next, the cutting tool of the present invention will be specifically explained using examples. Example 1 As the cutting tool body, each of the cutting tools shown in Table 1 was used.

[Table] Prepare small diameter miniature drills with a tip diameter of 0.6 mmφ, and some of these miniature drills, that is, the miniature drills shown in Table 1, have a normal Using a chemical vapor deposition device, form a single or multilayer surface coating layer having the composition and average layer thickness also shown in Table 1,
Next, the tips of these various miniature drills were inserted into a quartz tube reaction vessel with a diameter of 120 mmφ, and the atmosphere inside the reaction vessel was a vacuum of 10 torr, the filament used was metal W, and the space between the drill surface and the filament was Distance: 1.5cm, Drill surface heating temperature: 700℃, Filament temperature: 200℃, Mixed reaction gas: CH ₄ /H ₂ = 0.005, Reaction time: 0.5 hours, 0.8 hours, 3 hours, 6 hours, 15 hours and By performing a gas phase reaction for 30 hours under the following conditions, 0.2 μm and 0.2 μm, respectively, were added to the tip of the miniature drill.
0.5μm, 2.0μm, 4.0μm, 10.0μm, and
Forms a hard layer of 6 types of crystalline diamond with an average layer thickness of 20.0 μm and a micro-Vickers hardness of 8800 to 9300 Kg/ ^mm2 , which also improves the bite into the workpiece. Cutting tools 1 to 15 of the present invention were manufactured by performing a grinding process in which corner portions and lip portions were left and point portions and margin portions were removed in order to obtain verticality and circularity. Next, the cutting tools 1 to 1 of the present invention obtained as a result
15, and for the purpose of comparison, miniature drills (hereinafter referred to as comparative cutting tools) 1 to 1 without the formation of the crystalline diamond hard layer as shown in Table 1.
Regarding 3, drill rotation speed:
Holes were drilled under the conditions of 80,000 rpm and a drilling speed of 80 holes/min, and their service life was measured. The service life was determined by the number of holes drilled until roughness appeared on the cut surface due to wear of the edge of the drill tip. These results are shown in Table 1. From the results shown in Table 1, cutting tool 1 of the present invention
- 15 all showed superior wear resistance compared to comparative cutting tools 1 to 3, which did not have a crystalline diamond hard layer, and were particularly excellent when the average layer thickness of the crystalline diamond hard layer was 0.5 to 10 μm. It is clear that the cutting life is long. Example 2 A router having a composition of 85% by weight of WC and 15% by weight of Co and an outer diameter of 4 mm was used as a cutting tool, and the same as in Example 1 was applied to the machined surface of the tip of this router. Average layer thickness under the conditions: 2μm
A cutting tool of the present invention was manufactured by forming a hard layer of crystalline diamond. Next, the cutting tool of the present invention was used for deburring electronic integrated circuit laminated boards at a rotation speed of 50,000 r.p.
m., speed: 900 to 1000 mm/min, and the machining length until the end of its life was measured, and it was found to be 10 m.
showed that. On the other hand, the above-mentioned router without the formation of a diamond hard layer reached its service life with a machining length of 1 m. As described above, the cutting tool of the present invention has excellent wear resistance due to the crystalline diamond hard layer coated on at least the machined surface of the tip, and is made of WC-based cemented carbide or TiC-based cermet. The main body ensures excellent toughness, so when used for drilling holes in electronic integrated circuit laminated substrates that require these characteristics, it exhibits excellent performance over an extremely long period of time.

Claims (1)

[Scope of Claims] 1. Micro-Vickers hardness of 8000 Kg/mm ² or more formed by vapor phase synthesis on at least the machined surface of the tip of a cutting tool body made of tungsten carbide-based cemented carbide or titanium carbide-based cermet. Hard layer consisting of crystalline diamond with high hardness 0.2~20
A cutting tool for drilling holes in electronic integrated circuit laminated substrates coated with an average layer thickness of μm. 2 Carbides of metals from groups 4a, 5a, and 6a of the periodic table, and nitrides of metals from groups 4a and 5a of the periodic table, on at least the machined surface of the tip of the cutting tool body made of tungsten carbide-based cemented carbide or titanium carbide-based cermet. 8000 microvitkers hardness formed by vapor phase synthesis via a surface coating layer consisting of a single layer or a multilayer of two or more of carbonitrides and carbonitrides.
A cutting tool for drilling holes in electronic integrated circuit laminated substrates, which is coated with a hard layer made of crystalline diamond having a high hardness of Kg/mm ² or more with an average layer thickness of 0.2 to 20 μm.