JPS62137172A - Soldering jig - Google Patents

Abstract

PURPOSE:To improve the resistance to wetting with solder by forming an alloy material consisting of a specific compsn. contg. C, Si, Mn, Cr, Ni, and Fe and heating the material to a red hot or higher temp. in an oxidizing atmosphere thereby forming an oxide film contg. much Cr2O3 on the surface. CONSTITUTION:The material of the alloy compsn. consisting of <=0.1% C, <=5.0% Si, <=2.0% Mn, 5.0-30% Cr, >=40% Ni, and <=55% Fe is formed. The material is heated to the red hot or higher temp. in the oxidizing atmosphere to form the oxide film contg. much Cr2O3 to produce a soldering jig. The soldering jig is equiv. to the worked metallic article on which a ceramic film essentially consisting of Cr2O3 is formed and therefore, the wettability with solder is said to be substantially zero. The film is secure and is highly resistant to the wettability with the solder without exfoliation even after many times of heat cycles. The soldering jig is, therefore, usable for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Industrial Field of Application 1] The present invention relates to an improvement of a jig used in a soldering device.

[Conventional technology] With the advancement of technology that uses semiconductors, the work of soldering ICs and other electronic components to circuit boards has increased. Most of the work is automated, and the process of soldering ICs and other electronic components onto circuit boards has become more common. The process consists of the steps of gripping the metal with a suitable jig, immersing it in a flux bath if necessary, preheating it, and then immersing it in a molten solder bath and pulling it up.

Naturally, this jig must not be easily wetted by molten solder. Currently, the material used for the jig is 5US304 stainless steel coated with Teflon, but it gradually becomes wet with long-term use, so the jig must be replaced after about 6 months of use. Must be.

Ti is known as a material that is more difficult to wet with solder than stainless steel, but l-i is expensive and has poor workability, so it is not suitable for mounting jigs for soldering. Ceramics have been found to be superior in that they are more difficult to get wet and have good resistance to wetting, that is, they can maintain their properties of being difficult to get wet. Ba,
It's more expensive than li.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned problems, and to use a metal material 1 that is inexpensive and has good workability, and which is difficult to get wet with solder.
Another object of the present invention is to provide a jig for soldering f=J with improved wet resistance.

Structure of the Invention [Means for Solving the Problems] The soldering jig of the present invention basically has a C: 0.1
0% or less, Si: 5.0% or less, Mn: 2° or less, and Cr: 5.0 to 30%, with the balance being Ni.
A material having an alloy composition consisting of 40% or more of Fe and 55% or less of Fe is molded and heated to a temperature of red heat or higher in an oxidizing atmosphere to form an oxide film rich in Cr203 on the surface.

In addition to the above basic alloy composition, the materials include at least one member of the following group (a): Y and lanthanide REM (La).

Ce, Pr, Nd, Pm, Sm,
El, Gd.

One or more types selected from Tb, Dy, Ho, Er, Tm, Yb, Lu): O, OO1-1.0% (b) One or two types selected from Ca and Mq: 0.003 A material containing up to 0.03% has the advantage that the Cr2O3-rich oxide film can be easily formed, and the oxide film is strong and difficult to peel off from the base material, so it is a preferable material.

If you want to improve the mechanical properties, especially the strength, of the soldering jig, use at least one of the following materials (c) Mo: 6.0% or less and/or Co: 5.
0% or less (d) N13. J: When using an alloy containing one or more of Ta and Zr in an amount of 6.0% or less (e) A, I) near, 0% or less.

It goes without saying that the optional additive elements 5 and 5 belonging to two or more groups may coexist.

In addition, the +A advantage of the soldering method of the present invention is that it may not be used even if it contains alloy components other than those listed above, as long as it does not contradict the purpose. Choose from, ease of availability and Idl
From the i-case point to j', there are 7 options. -For example, N
177% or more and Cr 19-21% as main components,
The main components are 57% Ni and 15% to 18% 0r, and the remainder is mainly Fe. NCH with symbol
1 and NCH2>.

The formation of an oxide film rich in Cr2O3 occurs in the atmosphere at 700~
Temperature above aoo'c, preferably 1100-1200
This may be carried out by heating to about 'C for 0.5 to 2 hours.

[Function I: When a Ni-based alloy containing 5.0% or more of Cr is heated to a temperature above red heat in an oxidizing atmosphere to form an oxide film, oxides of Fe and Ni will not be formed. However, a large amount of Cr2O3 oxide is generated in priority. This fact was confirmed by the fact that when the surface of the treated material was examined by X-ray diffraction, M2O3 type compounds were overwhelmingly present, and by analysis by EPMA, a large amount of Cr was present. Furthermore, it was observed by scanning electron micrographs that this oxide film had a dense structure and was firmly attached to the base.

This effect becomes weaker when the Cr content is less than 5.0%. On the other hand, adding more than 30% is not a good idea because it only reduces the processability of the material and increases the price, and the effect is reduced.

C [2], which is necessary to ensure the strength of the jig, should be present. However, if the amount is too large, it will affect the formation of a dense oxide film, so the upper limit is set at 1.0%.

Si: 5.0% or less and Mn: 2.0% or less are both added as deoxidizers, or if the upper limit of each is exceeded, 3i makes the material mechanically brittle and makes processing difficult. In addition, there is a risk of solder iA due to the generation of minute cracks, and Mn reduces the ability of the oxide film to adhere to the paste hole.

The addition of Y and lanthanide REM not only produces a dense oxide film as described above, but also reduces V on the base material.
: Enhances 4-sexuality. This effect can be increased by 1q with the addition of a trace amount of 0°001%. If it is too thick, it tends to reduce hot workability and is disadvantageous in terms of price, so 1.
It is a good idea to limit the addition to 0% or less. The effect of addition of Ca and IVII groups and the reasons for limiting the composition are the same as those of Y and lanthanide-based REMs.

The groups Mo; Nb, Ta, Zr: and J increase the strength of the material as described above, but also serve to increase the adhesion of the oxide film to the base material. This effect can be obtained by adding 0.002% or more in total. The MO and Nb groups are 6.
If the content exceeds the upper limit of 0%, there will be no problem in terms of physical properties, but the price will increase.

When added in excess of 7.0%, 8ρ makes the material brittle.

[Example] By machining an alloy with the composition shown in the table, a width of 14#
A plate with a thickness of 2 mm and a length of 200 mm was manufactured.

Each sample was treated to form an oxide film by heating at 1200''C in the air for 2 hours.

Select the following conditions as typical soldering work conditions: Solder used: 63% 5n-Pb (common solder), melting point is 183°C Bath temperature: 250'C Cycle: (flux immersion and preheating) for about 20 seconds →
Immersed in solder bath for about 10 seconds...approximately 1000 cycles/8 hours To achieve test conditions close to this, grab the above test piece and immerse the lower half in a solder bath kept at 250'C for 10 seconds. We prepared a device to pull it up for seconds.

After 15,000 cycles, the state of solder adhesion was examined.

No solder adhesion was observed in any of the Examples.

On the other hand, a large amount of solder adhesion was observed in the comparative example.

〜α CSi 〜In Cr
N+Example 1 0.05 0.80 0.20 19.
7 78.12 0.04 1.20 0.1
3 19.8 77.93 0.06 11
0 0.2? 20.3 77.84 0
．． 06 1.00 0.14 20.4 77
．． 45 0.04 1.08 0.13 1
7.3 58.36 0.03 1.38 0
．． 15 16.4 58.9 Comparative Example 1 0.05 0.21 0.40 --
-2 0.08 0.2 & 0.80
18.3 - Numbers are % dose.

Comparative Example 1 is a structural carbon steel with a standard Jδ, and Comparative Example 2 is a SUS
c Y, REM Ca , Mg MO
Nb, Choa A, Qr -Y0.0125m0.005 - -
−−− − −
1. OZr0.5 -- --
- - TaO, 30,
4304 stainless steel.

Effects of the Invention Since the soldering jig of the present invention is equivalent to a soldering jig made of gold coated with a solder coating containing Cr2O3 as a main component, it can be said that the soldering jig has virtually no wettability.

Since the coating is strong and does not peel off even after repeated heat cycles, it has excellent wet resistance and the jig can be used for a long period of time. It can be easily regenerated by cleaning the surface of a jig that has deteriorated using a method such as pickling and then applying force.

The materials are existing alloys that are easily available on the market, and since they generally have good workability and are easy to add, it is easy to solder.

The cost of equipment is low.

Claims (3)

[Claims] (1) C: 0.10% or less, Si: 5.0% or less, Mn
Cr: 2.0% or less and Cr: 5.0 to 30%, with the balance consisting of Ni: 40% or more and Fe: 55% or less. A soldering jig formed by heating to a temperature of 100 to form an oxide film rich in Cr_2O_3 on the surface. (2) As a material, at least one of the following groups (a) One or more selected from Y and lanthanide REM: 0.001 to 1.0% (b) 1 selected from Ca and Mg Species or 2 types: 0
．． 003 to 0.03%. (3) As a material, at least one member of the following group (c) Mo: 6.0% or less and/or W: 1.5
% or less (d) One or two selected from Nb, Ta and Zr
The soldering jig according to claim 1 or 2, which contains at least 6.0% (e) of Al: 7.0% or less.