JP2002346741A - Jig and method for brazing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jig for brazing which is suitable for use at a high temperature. SOLUTION: A carbon based spring member 18 containing amorphous carbon and graphite is used, as a jig for fixing a ceramic substrate 14 to a jig body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brazing jig using a carbon spring member for the purpose of positioning and applying a load when brazing lead pins and lead frames in a process of manufacturing electronic components such as a semiconductor ceramic package. And a brazing method.

[0002]

2. Description of the Related Art With the diversification of electronic industrial parts and their reduction in size and weight, the shape of heat-resistant jigs used for manufacturing electronic industrial parts has become complicated and diverse. Specifically, the wiring density of the input / output electric signal lines on the package substrate, which is mainly a multilayer ceramic, is increased, the resistance value of the signal line conductor is reduced, a low-cost material is used for the signal line conductor, the insulating material is used. It is required to lower the dielectric constant. As a technique for attaching connection pins to this multilayer ceramic substrate, conventionally, a multilayer ceramic substrate is made of silver brazing or gold-tin brazing material, and the connecting pins made of a material such as Kovar or 4.2 alloy are mainly made of carbon jigs. It was attached by. Jigs for the purpose of manufacturing electronic components such as this type of semiconductor ceramic package are, by their nature, ceramic substrates, lead pins,
It is necessary to accurately position many components such as a lead frame and an element on the surface of the main body. Also for brazing small lead pins, lead frames, etc.
An auxiliary load is required at the time of bonding, and the load also requires high precision.

[0003]

Conventionally, in a jig for manufacturing an electronic component such as a ceramic package, positioning is performed by a method of fixing with a graphite screw of the same material as that of the jig body, or a metal spring such as stainless steel. The method of fixing by pressing with a key was mainly used. However, when manufacturing ceramic packages, etc., at high temperatures such as when brazing lead pins and lead frames, in the case of the method of fastening with screws, due to the difference in the coefficient of thermal expansion between the jig made of graphite etc. and the product, Often, adverse effects on both, such as cracking of the jig and deformation of the product shape, were a problem. In addition, even if the spring is pressed using a metal spring, the spring "sets" under high temperatures, the spring characteristics cannot be maintained, and the spring does not have any meaning. .

When an auxiliary load is applied at the time of bonding, a method of pressing with a metal spring such as stainless steel or a method of applying a so-called "weight" corresponding to the load has been adopted.
When using a normal metal weight as a jig, it is difficult to handle it because it requires a weight for the actual load, making it difficult to adjust the load evenly and weakly. Problems such as poor energy consumption efficiency occur due to repeated heating and cooling. For this reason, metal or ceramic coil springs, which can save space instead of weights, have been studied as jigs. Stainless steel, Inconel, etc. are used as metal spring materials. However, if the temperature exceeds 600 ° C., it is difficult to maintain the performance as a spring, and the durability is poor. Alumina, silicon nitride or the like is used as a ceramic spring material. However, it is impossible to use ceramics beyond the melting point of the material. When the value exceeds, it is difficult to maintain the performance as a spring, and it is also difficult to produce a coil spring capable of finely adjusting the load.

SUMMARY OF THE INVENTION An object of the present invention is to provide a brazing jig and a brazing method with high precision and high efficiency which solve the above-mentioned conventional drawbacks.

[0006]

Means for Solving the Problems As a result of diligent research, the present inventor has found that a method of manufacturing an electronic component such as a semiconductor ceramic package includes amorphous carbon and graphite when brazing lead pins and lead frames. Since the brazing jig and the brazing method using the carbon-based spring member obtained by firing at a high temperature have a small heat capacity and a small amount of energy consumed for heating, the energy cost can be reduced. In addition, there is no adverse effect on both, such as cracking of the jig and deformation of the product shape, and there is no "slack" of the spring even when repeatedly used at high temperatures, so the accuracy of the product is dramatically improved Thus, the present inventors have completed the present invention.

According to the present invention, there is provided a brazing jig containing amorphous carbon and graphite and having a required shape as a brazing jig used for manufacturing electronic components. According to the present invention, there is also provided a brazing method in which a member including amorphous carbon and graphite is used as a brazing jig in electronic component production. The member can be used as a holder for positioning during brazing. The member may be used for the purpose of applying a load in order to assist the bonding with the brazing material during brazing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A brazing jig and a brazing method for positioning during brazing according to the present invention will be described with reference to FIG. In FIG. 1, a jig body 10 made of carbon is used.
In order to fix the ceramic substrate 14, a seat 12 for receiving the substrate 14 is provided. 14 is fixed on the jig body 10.

As the ceramic substrate 14, an alumina multi-layer ceramic substrate obtained by sintering tungsten or molybdenum as a conductor at 1500 ° C. or higher on an alumina green sheet, or a gold, platinum, Silver, silver-palladium, copper
There is a glass-alumina low-temperature sintering multilayer ceramic substrate sintered below 00 ° C. With reference to FIG. 2, another example of a brazing jig and a brazing method for brazing a connection pin to a ceramic substrate according to the present invention will be described. In FIG. 2, a chromium layer 2 is formed by sputtering on a through-hole portion 24 formed in a ceramic substrate 22 of a glass alumina green sheet.
6. A palladium layer 28 is formed, attached to a carbon jig body 34 assembled with carbon connection bolts 30 and nuts 32, and then a gold-tin brazing material 36 is attached, and a carbon spring 38 is used. A desired load is applied to the connection pins 40 and the ceramic substrate 22 via the load pins 39. Next, in order to melt the brazing material, 300 ° C.-9
The heat treatment is performed in a vacuum of 00 ° C. or in an inert atmosphere. The processing temperature is appropriately set according to the melting point of the brazing material used.

Here, carbon jigs 10, 12, 1
6, 20, 30, 32, and 34 are made of high-purity graphite due to the nature of the product, and the carbon-based spring members 18 and 38 must be subjected to high-purity treatment such as high-temperature treatment under vacuum. It is. The carbon-based spring member used in the present invention is a carbon-based spring member containing amorphous carbon and graphite, which are substantially composed of only non-graphitizable carbon. This carbon-based spring member
It is manufactured by mixing graphite with a resin composition containing one or more resins that become non-graphitizable carbon after firing, shaping the mixture into a desired shape, and firing the shaped object. . The graphite is highly oriented pyrolytic graphite (HOPG) having an average particle diameter of 100 μm or less, quiche graphite, natural graphite, artificial graphite, and vapor-grown carbon having a diameter of 100 nm or less in order to facilitate shapeability and structure control. Desirably selected from fibers. Also, at the manufacturing stage, when molding a mixture obtained by uniformly dispersing and compounding graphite powder in a polymer resin using a molding method used for ordinary resin molding into a desired coil spring shape, a plate shape, the graphite is used. After highly oriented control in one direction using ordinary resin molding method, in an inert atmosphere,
By baking in a non-oxidizing atmosphere or in a vacuum to carbonize the polymer resin, it is possible to use the bonding force, packing, and shrinkage force during resin baking without applying special pressure from the outside. Thus, a coil spring-shaped jig in which graphite and amorphous carbon are integrated without loss and the carbon powder does not peel off when used as a jig can be easily and inexpensively manufactured.

A polymer resin which can be converted into amorphous carbon by firing, preferably non-graphitizable carbon which does not progress graphitization when used at a high temperature, is formed by intermolecular cross-linking during heating prior to carbonization to form tertiary carbon. It has a high carbon residue yield, and has the ability to pack and shrink graphite powder during firing carbonization, and can be one or two types of thermosetting resins and thermoplastic resins. This is the above complex. Here, as the thermosetting resin, phenol resin, furan resin, epoxy resin, xylene resin,
Benzoxazine resin, unsaturated polyester resin, melamine resin, alkyd resin, copna resin, etc. are used,
Preferably, furan resin and phenol resin are used because of little change in thermal structure with time. Further, as the thermoplastic resin, polychlorinated vinyl chloride resin, polyacrylonitrile, polyamide, polyimide and the like are used,
Polychlorinated vinyl chloride resin is preferably used from the viewpoint of easy moldability and easy handling when combined with a furan resin or a phenol resin.

Next, the graphite powder used in the present invention will be described. The graphite powder is highly oriented pyrolytic graphite (HOPG), quiche graphite, natural graphite, artificial graphite, or the like. The type and amount of the graphite powder to be used is appropriately selected depending on the size, strength, etc. of the target spring, and can be used alone or in a mixture of two or more kinds. Particularly, control of the strength of the spring is easy. Therefore, it is preferable to use a scale-like graphite powder in which crystals are well developed. The average particle size of the graphite powder is preferably 100 μm or less in view of moldability and easy control of the orientation of graphite in one direction. In the following, according to the present invention, in a high-temperature inert atmosphere or a high-temperature vacuum, used in the step of bonding the material while heating and pressing, comprising a composite carbon material of amorphous carbon and graphite powder, high-temperature heat resistance and high-temperature lower spring characteristics. A method for manufacturing a coil spring-shaped jig having the same will be described.

First, for the purpose of providing the necessary properties as a coil spring-like jig, a polymer resin and graphite powder which become amorphous carbon after firing are appropriately selected and then sufficiently dispersed using a mixer. . Next, this mixture is formed into a coil spring shape while controlling the orientation of the graphite fine powder in one direction using a molding machine used when performing ordinary plastic molding such as a film forming machine or an extrusion molding machine. I do. The obtained coil spring-shaped body is subjected to carbon precursor treatment and solidification treatment in an air oven, and then carbonized by firing in an inert gas atmosphere such as nitrogen or argon while controlling the temperature rising rate. After the termination, a coil spring-like jig made of a carbon composite in which graphite powder is oriented in one direction in amorphous carbon is obtained. Here, the carbonization is performed by heating and raising the temperature to about 700 to 2800 ° C. in an inert gas atmosphere or under vacuum. However, if the heating rate during the carbonization is high, the shape of the shaped body may be deformed or fine cracks may occur. Defects. Therefore, it is appropriate to perform the process at 50 ° C. or less per hour up to 500 ° C. and at 100 ° C. or less thereafter.

Further, in the present invention, when manufacturing a coil spring made of a composite material of amorphous carbon and graphite powder by using a molding method used for ordinary resin molding, the desired size and strength of the spring are obtained. In order to obtain high-temperature heat resistance, the graphite powder is shaped in one direction by controlling the orientation at a high temperature, and in an inert atmosphere, or at a temperature of 260 ° C or more and 500 ° C or less than the temperature used as a jig in a vacuum. By performing the carbonization treatment at a high temperature, preferably about 300 ° C. higher, a coil spring that meets the required specifications as a jig can be easily manufactured, and a material that can adjust a weak load can be manufactured. This makes it possible to efficiently and inexpensively manufacture a coil spring-like jig that does not generate exfoliated carbon powder during use.

[0015]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Embodiment 1 As shown in FIG. 1, a seat 12 for receiving a substrate for fixing a ceramic substrate 14 is provided on a jig main body 10 made of carbon, and a spring member 18 made of carbon is fixed by a seat 20. When the ceramic substrate 14 is fixed on the jig main body 10 via the substrate holding jig 16 by the spring pressure of 18, and the lead pins and the lead frame are brazed on the ceramic substrate 14, the conventional screws are used to stop them. Compared with the method, there is no cracking of the jig or deformation of the product shape due to a difference in the coefficient of thermal expansion between the jig made of graphite or the like and the product. The yield with the improvement has improved.

Embodiment 2 As shown in FIG. 2, a chromium layer 26 and a palladium layer 28 are formed in a through-hole portion 24 formed in a ceramic substrate 22 of a glass alumina green sheet by sputtering, and a connection bolt 30 and a nut made of carbon are formed. After attaching to the carbon jig body 34 assembled in 32,
A gold-tin brazing material 36 is attached, and a carbon spring 38 applies a desired load via a load-loading pin 39 to a lead pin 40.
And load on the ceramic substrate 22. Next, a heat treatment was performed for 20 minutes in an inert atmosphere at 600 ° C. to melt the brazing material. Since a sufficient load can be applied as compared with the method using the conventional "weight", sufficient adhesive strength was obtained, and at the same time, the energy cost was reduced to about one third. In addition, since a load can be applied to each product, the yield associated with the improvement in product accuracy has been improved.

[0017]

As described above, the brazing jig and the brazing method using the carbon-based spring member of the present invention not only reduce the energy cost, but also reduce the jig cracking and product shape. It has no adverse effect on both sides such as deformation of the spring, and even when used repeatedly at high temperature, there is no "sag" of the spring.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a brazing jig and a brazing method for positioning during brazing according to the present invention.

FIG. 2 is a diagram showing an example of a brazing jig and a brazing method when brazing a connection pin or a lead frame to a ceramic substrate.

[Explanation of symbols]

 10, 34: jig body 12: seat for receiving base material 14: ceramic substrate 16: jig for holding base material 18: carbon-based spring member 20: seat for receiving carbon-based spring member 30: jig connection bolt 32 ... jig Connection nut 22 Ceramic substrate 40 Lead pin 36 Brazing material 28 Palladium layer 26 Chromium layer 24 Metal conductor 39 Load pin 38 Carbon spring member

Claims (4)

[Claims] 1. A brazing jig comprising amorphous carbon and graphite and having a required shape as a brazing jig used for manufacturing electronic components. 2. A brazing method using a member containing amorphous carbon and graphite as a brazing jig in the production of electronic components. 3. The brazing method according to claim 2, wherein the member is used as a holder for positioning during brazing. 4. The brazing method according to claim 2, wherein the member is used for applying a load in order to assist bonding of the brazing material during brazing.