JP2004354374A - Method and device for evaluating weldability onto material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation method and an evaluation test device capable of conducting easily an evaluation test for the condition where a worked material is welded onto a material for a tool or the like. <P>SOLUTION: The first material is brought into a rotatable or reciprocatable condition, the second material is held by a holding member comprising a material having 60W/m ×K or less of thermal conductivity, the second material is formed into structure contacting with the first material, and the second material is brought into pressurization contact with the first material to measure the welding condition onto the first material, so as to be evaluated. The device of the present invention constituted into structure having the first rotatable or reciprocatable attaching part, and the second attaching part provided with a pressurizing means, to bring the second material mounted on the the second attaching part into pressurization contact with the first material mounted on the first attaching part, and the second attaching part comprises the holding member having 60W/m ×K or less of thermal conductivity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an evaluation method and an evaluation apparatus for performing performance evaluation on welding to a tool material or the like on which a hard film such as diamond is formed.

  The outer lead of an IC / LSI package used as an electronic component incorporated in various electronic devices such as a computer and a control device is bent and formed into a predetermined shape. As the molding tool, for example, a tool described in Patent Document 1 can be mentioned.

JP-A-7-212842

  This tool is a die and a punch that bends the lead. These tools have a flat surface (coplanarity) in which the lead contact surface is worn or the solder on the lead surface is welded and the lead is bent. Further, in order to minimize the deterioration of the bending (skew) of the leads in the parallel direction, at least the contact surface of the leads is coated with a hard film such as diamond.

  In such tools, the formation of a film with low frictional resistance, such as a diamond film, suppresses solder welding to some extent and improves the bending accuracy of the lead, but this is not sufficient, and the surface condition of the film is not sufficient. Affects welding. For this purpose, many improvements have been made to the diamond film itself, and diamond films have been developed according to the respective purposes. Then, in order to evaluate the performance of the diamond film, as described in an example of Patent Document 1, the Fe-Ni alloy was incorporated into a forming apparatus having a bending mechanism of an LSI lead by solder plating. The lead is subjected to a molding test and the like, and one test product is evaluated by processing at least one million shots.

  However, as described above, it takes a long time to process and evaluate the lead on the actual machine because the number of tests is extremely large, and it is not practical for a tool maker to carry out an evaluation test with a molding device. Since it is not appropriate, it is necessary to have the user evaluate on a test line. However, it is difficult to perform an accurate and stable evaluation quickly.

  In particular, when an evaluation test is performed by a user, only an evaluation test specific to the user can be performed, and it is impossible to perform a wide evaluation applicable to other users. Therefore, it has been necessary to evaluate each user.

  From the above, it is an object of the present invention to quickly and accurately evaluate the state of welding of a workpiece to a tool when processing with a tool or the like, enabling a wide range of performance evaluations without performing actual processing. To provide an evaluation method and an evaluation device.

The evaluation method of the present invention is an evaluation method for performing a test of a state where the second material is welded to the first material,
The first material is capable of rotating or reciprocating, and the second material is held by a holding member made of a material having a thermal conductivity of 60 W / m · K or less, and the second material is held in the second material. A structure capable of contacting the first material is provided, and the state of welding to the first material is measured by bringing the second material into pressure contact with the first material.

  In this evaluation method, the first material is rotated or reciprocated, the second material is mounted on the holding member, and then the second material is brought into pressure contact with the surface of the first material. Then, the welding state of the second material deposited on the surface of the first material is measured. By performing such a method, it is possible to perform continuous pressure contact and welding under certain conditions, so that an evaluation test can be performed quickly and accurately. The holding member is made of a material having a thermal conductivity of 60 W / m · K or less. This is to prevent heat generated by friction between the second material and the first material from escaping through the holding member, generate welding, and perform an evaluation test efficiently. The material of the holding member itself is not particularly selected, and the same applies even when a method of providing a heat insulating material made of a material having a thermal conductivity of 60 W / m · K or less between the holding member and the second material is used. The effect is obtained.

  In the evaluation method of the present invention, a test in which a material in which a hard film such as a diamond film is coated on a base material such as a hard metal is selected as the first material is suitable. With such a material, abrasion and welding hardly occur, and a large amount of time is required for conducting a test on an actual machine. Therefore, the test by the evaluation method of the present invention is effective. Also, a test using a material that is easily welded, such as a soft metal or a resin, is suitable as the second material.

Further, the evaluation test device of the present invention is an evaluation test device for performing a test of a state in which the second material is welded to the first material,
A first mounting portion capable of rotating or reciprocating; and a second mounting portion provided with a pressurizing means, wherein the second mounting portion is attached to a first material mounted on the first mounting portion. A second material attached to the part is brought into pressure contact with the second part, and the second mounting part is formed of a holding member having a thermal conductivity of 60 W / m · K or less.

  The evaluation device of the present invention has a first mounting portion that can rotate or reciprocate, and can rotate or reciprocate by attaching a first material to the first mounting portion. In addition, a second mounting portion is provided separately from the second mounting portion, and the second mounting portion has a structure in which pressurizing means is provided. A second material is mounted on the second mounting portion, and the second mounting portion is movable in a direction perpendicular to the movement direction of the first mounting portion by the pressing means. With the device having such a structure, the second material is brought into pressure contact with the first material while rotating or reciprocating, and the second material is welded to the first material, and the welded state is measured. It is possible. The moving speed of the first material, the pressing force of the second material, and the like can be appropriately set, and the evaluation test of the welding state under various conditions can be performed quickly and accurately. The second mounting portion needs to be made of a material having a thermal conductivity of 60 W / m · K or less, and prevents heat generated by friction between the second material and the first material from escaping through the holding member. This is for preventing the occurrence of the welding and efficiently performing the evaluation test.

  ADVANTAGE OF THE INVENTION According to the evaluation method of this invention, it can be accurately performed in a short time, when performing the test of the welding property to tool materials. The test can be performed under various test conditions, and an evaluation test corresponding to different use conditions can be performed for each user. Further, according to the evaluation apparatus of the present invention, an accurate test can be performed with a simple test material, and the test conditions can be easily set, so that an evaluation test corresponding to various use conditions can be easily performed. .

  FIG. 1 shows an example of an evaluation device used in the evaluation method of the present invention. In this evaluation device, an axially rotatable first mounting portion 2 is provided on an upper surface of a device main body 1. A first material 6 formed in the shape of a disc is mounted on the first mounting portion 2 and is also rotatable. In addition, a second mounting portion 3 is provided on the apparatus main body 1 separately from this, and is provided integrally with a column 4 fixed to the apparatus main body 1. The second mounting portion 3 is made of a material having a thermal conductivity of 60 W / m · K or less. For example, materials such as alumina, sapphire, silicon carbide, silicon nitride, zirconia, and cermet can be used. The column 4 can be moved in the horizontal direction, and can be fixed at an appropriate position. The column 4 is provided with a second mounting portion 3, and the second material 7 is mounted on the second mounting portion 3. Pressing means 5 such as a spring is provided between the support 4 and the second mounting portion 3 so that the second material 7 can be brought into pressure contact with the first material 6. The pressurizing means 5 may have a structure in which a weight is applied to pressurize as an example other than a spring, or a structure in which an air cylinder is attached.

  In order to be able to cope with various test conditions, a heater and a Peltier element are incorporated in the first mounting part 2 and the second mounting part 3, and the first material 6 and the second material 7 are individually heated. It is also effective to add a function of cooling or cooling, or to incorporate a device for applying ultrasonic vibration. It is also possible to enclose the entire apparatus in a vacuum chamber so that evaluation in a vacuum atmosphere can be performed.

Examples of the first material 6 include a material in which a hard film 6a is formed on a base material 6b. As hard films 6a, diamond, diamond-like carbon (DLC), TiN, TiC, CrN, SiC, there are _{Si 3 N 4, Al 2 O} 3 and the like film, as the substrate 6b, the cemented carbide, Mo, W , SiN, SiC, single-crystal Si, polycrystalline Si, and the like. When a material in which the hard film 6a is formed on such a base material 6b is used as a tool material, the material to be processed is rarely welded, and it takes a lot of time to perform an evaluation test of a welded state while actually working. In short, according to the evaluation method of the present invention, accurate evaluation can be performed in a short time. The second material 7 includes a soft metal or a resin, and the soft metal includes Sn, Ag, Pb, Pd, Sb, Pt, Au, Al, Cu, In, Ni, Ga, Zn, and Ge. Solder or brazing material consisting of a single or alloy. An evaluation test is possible even with a hard metal such as Ti.

  With the above-described apparatus, the first material 6 is rotated at a predetermined number of revolutions, and the support is moved and fixed so that the second material 7 is at a predetermined position. Then, the second mounting portion 3 and the second material 7 are pressed downward by the pressing means 5 to bring the second material 7 into press contact with the upper surface of the first material 6. In this state, the second material 7 is welded to the upper surface of the first material 6 for a certain period of time, and the welded state is measured.

(Example 1 of the present invention)
A test was performed under the following conditions as a substitute evaluation test for a test in which solder was welded to a punch and a die for bending the outer lead of a semiconductor package. Using a commercially available ball-on-disk friction and wear tester, a holding member made of a material having a thermal conductivity of 60 W / m · K or less was incorporated in the apparatus as the second mounting portion 3. As the first material 6, a surface of a cemented carbide base material is mirror-finished to a surface roughness of 0.005 μm Ra, and a diamond film (surface Two kinds of materials coated with a roughness of 0.025 μm Ra) were mounted on the first mounting portion 2. In addition, a solid material of 100% Sn solder was used as the second material 7 and was attached to the second mounting portion 3. The test conditions were such that the rotation speed of the first material 6 was 500 min ⁻¹ , the pressure of the second material 7 was 1 N, and the first material 6 was rotated dry without using a lubricating liquid or the like. Was. The contact position of the second material 7 was set at a position 1 mm from the rotation center of the first material 6. As a result of performing an evaluation test of the above two types of first materials 6 under the above conditions, a result of different welding states was obtained by rotating the first material 6 for about 2 minutes, and the difference between the welding states became clear.

(Comparative Example 1)
Using a cemented carbide of the same material as in Example 1 of the present invention, two punches and two dies for bending the outer lead of the semiconductor package were manufactured. Each of these punches and dies had a surface roughness of 0.005 μm Ra by mirror-finish the portion in contact with the lead. The remaining one was coated with a diamond film (surface roughness: 0.025 μmRa) similar to that of Example 1 of the present invention in a portion in contact with the lead. These were mounted on an outer lead processing device for a semiconductor package, and the outer leads plated with 100% Sn solder were bent. As a result, welding started on the material not covered with the diamond film at the time of 30,000 times of processing, and 100,000 times of processing was required until the difference between the two welding states became clear. The test took about one month.

(Example 2 of the present invention)
An evaluation test was performed in the same manner as in Example 1. As the first material 6, a surface of a cemented carbide base material is mirror-finished to a surface roughness of 0.008 μmRa, and a diamond film (surface) is formed on a cemented carbide surface of the same material by a vapor phase synthesis method. Two kinds of materials coated with a roughness of 0.025 μm Ra) were mounted on the first mounting portion 2. Further, a solid material of 96.5% Sn-3% Ag-0.5% Cu solder was used as the second material 7, and was attached to the second mounting portion 3. The test conditions were the same as in Example 1. As a result, a result in which the welding state was different by rotating for about 2 minutes was obtained, and the difference in the welding state became clear.

(Comparative Example 2)
Two punches and two dies for bending the outer leads of the semiconductor package were manufactured using a cemented carbide of the same material as that of Example 2 of the present invention. In each of these punches and dies, a portion in contact with the lead was mirror-finished to have a surface roughness of 0.008 μmRa. The remaining one was coated with a diamond film (having a surface roughness of 0.025 μm Ra) similar to that in Example 1 at the portion in contact with the lead. These were attached to an outer lead processing device of a semiconductor package, and the outer lead plated with 96.5% Sn-3% Ag-0.5% Cu solder was bent. As a result, when 50,000 times of processing were performed, welding started on the one not covered with the diamond film, and 200,000 times of processing was required until the difference between the two welding states became clear. The test took about two months.

(Example 3 of the present invention)
A test was performed under the following conditions as a substitute evaluation test for a test in which solder was welded to a punch and a die for cutting an outer lead of a semiconductor package. As the first material 6, a surface of a cemented carbide substrate is mirror-finished to a surface roughness of 0.010 μmRa, and a diamond film (surface The first mounting portion 2 was mounted using two types of materials, one coated with a roughness of 0.020 μm Ra). In addition, a solid material of 100% Pb solder was used as the second material 7 and was attached to the second mounting portion 3. The test conditions were the same as in Example 1. As a result, a result in which the welding state was different by rotating for about 2 minutes was obtained, and the difference in the welding state became clear.

(Comparative Example 3)
Two punches and two dies for cutting the outer leads of the semiconductor package were manufactured using a cemented carbide of the same material as that of Inventive Example 3. Each of these punches and dies has a surface roughness of 0.010 μmRa by mirror-finish the portion in contact with the lead. The remaining one was coated with a diamond film (surface roughness 0.020 μmRa) similar to that in Example 1 at the portion in contact with the lead. These were attached to an outer lead processing device for a semiconductor package, and the outer leads plated with 100% Pb solder were cut. As a result, when 50,000 times of processing were performed, welding started on the one not covered with the diamond film, and 200,000 times of processing was required until the difference between the two welding states became clear. The test took about two months.

FIG. 1 is a conceptual diagram illustrating an example of an evaluation test device according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 1st mounting part 3 2nd mounting part 4 support | pillar 5 pressurizing means 6 1st material 7 2nd material

Claims (4)

An evaluation method for performing a test of a state in which a second material is welded to a first material,
The first material is capable of rotating or reciprocating, and the second material is held by a holding member made of a material having a thermal conductivity of 60 W / m · K or less, and the second material is held in the second material. An evaluation method comprising: a structure capable of contacting the first material; and measuring a state of welding to the first material by bringing the second material into pressure contact with the first material.   The evaluation method according to claim 1, wherein the second material is a soft metal or a resin.   3. The evaluation method according to claim 1, wherein the first material is obtained by coating a hard film on a base material. An evaluation test apparatus for performing a test of a state in which a second material is welded to a first material,
A first mounting portion capable of rotating or reciprocating; and a second mounting portion provided with a pressurizing means, wherein the second mounting portion is attached to a first material mounted on the first mounting portion. An evaluation test apparatus having a structure in which a second material mounted on a part is brought into pressure contact with the second part, wherein the second mounting part is formed of a holding member having a thermal conductivity of 60 W / m · K or less.

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