JPH04503480A - composite solder articles - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] composite solder articles The invention applies to solders and in particular to so-called "soft solders", i.e. brazing. Unlike the hard solder used, it usually contains tin and/or lead and has a comparative melting point. The present invention relates to solder having a low temperature, for example, 430°C or less.

Solder has been used for many years to protect strong, high-quality electrical and mechanical connections. It's been coming. In recent years, the required one or more meltable plastics to seal the connections from water ingress. Along with Quinsert, an electrical connection device was manufactured in which solder was placed.

This item is placed on top of the objects to be connected and then heated to melt the solder and connect the objects between the objects. form a connection to the object, restore the article around the object, and provide electrical insulation for the connection. can be provided. These articles are described, for example, in U.S. Patent No. 3.243.21. No. 1, No. 4,282.396 and No. 4.283.596 and British Pat. No. 1,470,049, located in Menlo Park, California. From Raychem Corporation Sold under the product name Solder Sleeve (Solder 5leave) J. There is.

International patent application GB88100335 describes the use of composite solder in devices such as those described above. It has been proposed to use a double insert. This composite solder insert is compared It contains a relatively low melting point solder and a relatively high melting point solder, so it is difficult to compare while installing the device. When the device is heated until the relatively high melting point solder melts, the relatively low melting point solder However, it is ensured that it receives sufficient heat to melt and flow.

In most cases such articles work well, but high In certain cases using devices with solder-receptive substrates, the so-called "Wickin" "G" can occur. Wicking is the strand or plaid conductor to be connected. The body sucks the molten solder out of the connection area by wick-like capillary action and removes the molten solder from the connection area. This is a phenomenon that can deplete solder. This means that the strands adjacent to the connection or or associated with undue stiffness due to the presence of solder in parts of plaid conductors. Often. When the solder is depleted in the connection area, the connection conductor becomes especially stiff. connections may have an unacceptably high resistance or cause mechanical damage to the connections. may occur. The tendency of a conductor to wick typically increases with temperature. However, continuous heating of the device to melt high-temperature solder can exacerbate the problem. It seems so.

According to the invention, (a) a basic solder comprising a non-eutectic alloy of two or more metals, and (b) contains one or more metals and has a solidus temperature higher than the solidus temperature of the non-eutectic alloy; The composition of the temperature control component and the temperature control component include a temperature control component having a melting point. The relative amount of base solder and base solder melted together with the base solder and temperature control components Sometimes the resulting solder alloy has a smaller liquid-solid temperature difference than the basic solder. A composite solder article is provided.

In use, the composite solder is heated as the solder joint is formed, and the temperature increases to a non-eutectic composition. If the temperature rises above the solidus temperature of the product, the basic solder will melt (it will become a paste). The paste-like nature of the basic solder causes the solder to be pulled out along the conductor. That is, the tendency for "wicking" to occur is prevented or delayed.

If you continue to heat the solder, the temperature control component will melt at a temperature well below its melting point. or paste-like base solder, thereby causing substantial wicking. It has been observed that the likelihood of the connection heating up to the extent that this occurs can be reduced. temperature of a non-eutectic alloy, even though its melting point can never be reached before the controlling component disappears. The liquidus temperature decreases as the temperature-controlling component dissolved in it increases, so its extinction The loss can be used as an indication of sufficient melting of the base solder.

Preferably, the melting point of the temperature control component is higher than the liquidus temperature of the base solder, e.g. at least 5° C. above the temperature, especially at least 10° C., but preferably above the liquefaction point. Not higher than 35°C, especially not higher than 25°C.

In many cases, it is desirable for the temperature control component to exhibit a substantially defined constant melting point. in which case a substantially pure elemental metal or eutectic alloy can be selected. . Preferably, the temperature control component includes a metal that is also included in the base solder. For example, the base This solder must have a composition that lies on the opposite side of the eutectic point of the phase diagram of the basic solder components. Can be done.

An example of such a system is a non-eutectic tin-lead alloy containing less than eutectic amount (63% by weight) of tin. Basic solders containing gold and relatively high tin content, e.g. substantially pure tin. or a temperature control component consisting of a eutectic alloy of 96.5% tin and 3.5% silver. That's it. The composition and proportions of the basic solder and temperature control components are as follows: It is desirable that the article have a composition that is substantially at the eutectic point. in this way , it can be ensured that the entire solder melts at the lowest possible temperature.

In general, the amount of base solder is greater than the amount of temperature control component, usually considerably more, e.g. For example, if the ratio is low (both 2:1, preferably 3:1, especially at least 5:1) All percentages, ratios, etc. are by weight. ), and in this case typically non-co-fusion The temperature control ring is formed from pure metal used in gold, while the basic solder is have a composition relatively close to that of the melt composition, for example 30% or less, more preferably 10% Below, in particular, 10% or less is excluded from the eutectic point (for example, in the case of a two-component system).

For a tin/lead solder composition with a eutectic point of 63% tin and 37% lead (melting point 183°C) , the composite solder preferably does not exceed 62%, more preferably exceeds 61%. preferably at least 40%, especially at least 50% tin. strips of basic solder such that the remainder is lead, and bonded to the basic solder. It consists of a thin strip of pure tin.

Basic solders contain a number of metals in addition to or instead of tin and lead, e.g. It can be formed from mass, indium or cadmium. If necessary, further Other metals such as silver may also be present.

The two parts of the composite solder can be joined by any number of means. example For example, by bonding them with e.g. adhesive or solder flux, or , by a third solder material or by either of the two parts of the device. It can be soldered with the same solder used for formation. another way Then, the solder parts can be joined by cold working. This can be used, for example, for tubular In the case of inserts, when the second part is punched from the blank sheet, the tubular flanges a punching operation in which a part, for example as a collar, is joined to the second part of the orange shape; This is achieved by Two parts that can be used to form composite solder inserts Another method is to cold work the high melting point solder and the low melting point solder together. two or more strips of solder material including at least one strip of Place the strips side by side or one on top of the other, and then roll the strips together. This is a cold rolling method to join the trips. Next, the composite strip thus formed The cut material is cut to length and the cut article is wrapped around a suitably shaped mandrel. to form an enclosed solder insert or wrapped around a mandrel. It can be cut to a predetermined length. Another way to form composite solder is , form separate suitably shaped inserts, and then form from different solder materials Including pressing together the inserted inserts.

Any composite solder shape is formed from at least one solder material. The individual separate parts that have been It is preferable that That is, the composite insert is made of two separate pieces of solder material. formed by an operation that does not involve preforming of the solder portion. Such an operation is performed − times No more than one type of individual solder insert is used in the It has the advantage of being simple. An example of such an operation is a solder strip cold rolling, cutting and wrapping the strips, and one piece is made into a blank sheet. This involves performing a punching operation where the parts are simultaneously cut out from the sheet and joined to other parts. nothing.

The insert is preferably shaped into a suitable shape for the soldering device. formed from a solder strip, for example by wrapping it around a mandrel. It will be done. When forming this type of insert, often a composite strip is formed. Connect the two solder strips at least until separate composite inserts are formed. It is necessary to integrate them by specific means. In the case of many (for example, one han) When solder strips are placed in the grooves of other solder strips, separate device shapes When the strips are wrapped around the mandrel to create It is held together by its shape. The insert preferably has a or the presence of any substances other than fluxes or It can be formed so that it is present in at most trace amounts. Solder like this Inserts can be formed by several different methods of soldering The lips are joined together without adhesive to form a composite solder strip, and then the composite Holds the strip together with a removable adhesive applied only to the surface of the strip can do. Place the strip around the mandrel so that glue is no longer needed. After wrapping to form a composite insert, the adhesive is heated, e.g. removed by irradiation or by application of a suitable solvent, and the manufacturing process is carried out in a conventional manner. I can continue. Alternatively, strip two solder strips, be stripped from the composite strip just before wrapping it around the mandrel. Can be held together using an adhesive-coated paper layer.

In another form of device, two solder strips, e.g. Press the electrodes on opposite sides of the composite solder strip and apply current to the composite strip. The strips can be welded by electric welding, which uses Joule heat to weld the strips together. Wear. In yet another type of device, the laser is placed in one spot on the strip. to form a hole through the composite strip and connect the two strips at the same time. The two strips are joined together by a series of matching laser welds. this strike The lip bonding method is very quick and the solder flows when the device is heated. The insert has the advantage of having a large number of small holes formed in the insert.

A further aspect of the device includes an insert formed from a coextruded solder strip. can be incorporated.

Another option that allows composite inserts to be formed without preforming separate solder parts. One method is that the insert is formed from a dense, preferably sintered solder powder. This is a method to That is, for example, if a low melting point or high melting point solder powder is placed in the mold, , sintered under pressure, then add other solder powders to the same mold, temperature up to 150℃ Both powders can be sintered together by sintering it under pressure.

Composite solders can be used in heat-shrinkable articles such as those described above; In some cases, it is preferred, but not required, that the base solder and temperature control components be combined. Yes. That is, in another gist, the present invention provides (a) two or more types of a base solder comprising a non-eutectic alloy of the above metals, and (b) contains one or more metals and has a solidus temperature higher than the solidus temperature of the non-eutectic alloy; The composition of the temperature control component and the temperature control component include a temperature control component having a melting point. The relative amount of base solder and base solder melted together with the base solder and temperature control components Sometimes the resulting solder alloy has a smaller liquid-solid temperature difference than the basic solder. Solder connections between multiple long articles comprising dimensionally heat recoverable sleeves such as Provides a device for forming.

The heat recoverable sleeve is crosslinked and stretched as described in the above patent specification. formed from any polymeric material that can be made dimensionally heat recoverable by can be done. Preferred materials are elastomeric materials such as low, medium or high density polyethylene. Thyrene homo and copolymers, copolymers of ethylene and 03-C6 alpha olefins polymers as well as ethylene/vinyl acetate copolymers. Preferred materials are full Including orocarbon polymers such as polyvinylidene fluoride.

Examples of articles and devices of the invention are described with reference to the accompanying drawings: FIG. 1 is a partial schematic diagram of a composite solder article in an expanded state.

FIG. 2 is a schematic diagram of the solder article of FIG. 1 assembled.

FIG. 3 is a cross-sectional view of a heat-shrinkable connector article of the present invention.

In the accompanying drawings, figures 1 and 2 show inserts from a wound composite strip 1. This figure schematically shows the manufacturing process of a solder device using this method. As shown, Lip 1 consists of a main strip 2 of non-eutectic solder and a small amount of water soluble or cyano It consists of small strips 3 made of pure tin held together by acrylate adhesive 4. good Preferably, instead of this, the two strips 2 and 3 can be soldered with Can be bound by gin flux. Contains 60% tin and 40% lead with a solidus temperature equal to the Sng3Pbst eutectic temperature of 183 °C and a solidus temperature of about 188 °C. Solder strips can be formed from binary alloys that have liquidus temperatures. pure tin The strip has a melting point of 231°C.

After forming the composite strip, wrap it around a mandrel and cut it ( Form the tubular insert for the solder connection device (not necessarily in this order) . Such a connecting device is shown in FIG.

This device can be used with ordinary hot melt adhesives, e.g. polyethylene, ethylene such as vinyl acetate copolymer, polyamide or polyvinylidene fluoride Two uncrosslinked sealing rings 7 and 8 that can be formed from fluoropolymer and partially recovered heat-shrinkable polyvinylidene around composite solder ring 1. It comprises a fluoride sleeve 6.

In use, a pair of objects to be connected, e.g. several strands of wire, or Simply insert the electrical wire and coaxial cable with exposed braid into the device and Heat to restore the sleeve 6 around the object and melt the composite solder strip. The liquid is allowed to flow around the object, melting the sealing ring and creating a seal against moisture intrusion. can provide a stop. When heating the device, the basic solder strip 2 becomes pasty when its temperature rises above its solidus temperature, and its pasty properties change to Limits the extent to which solder flows around objects. As the temperature increases, strip 2 is heated above its liquidus temperature and the tin temperature control strip 3 begins to melt, reaching about 215 At a temperature of ~220°C the tin strip 3 melts and the sleeve fully recovers. .

A basic solder strip 2 with an optionally slightly larger temperature control strip 3 A 50% tin and 50% lead alloy can be used, in which case strip 2 is about 212 Remains pasty until liquidus temperature of °C is achieved, thereby melting the solder composition The tendency for objects to flow around objects is further reduced.

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Claims (15)

[Claims] 1. (a) Basic solders comprising non-eutectic alloys of two or more metals, call (b) contains one or more metals and has a solidus temperature higher than the solidus temperature of the non-eutectic alloy; The composition of the temperature control component and the temperature control component include a temperature control component having a melting point. The relative amount of base solder and base solder melted together with the base solder and temperature control components Sometimes the resulting solder alloy has a smaller liquid-solid temperature difference than the basic solder. A composite solder article characterized by: 2. The article of claim 1, wherein the temperature control component has a melting point higher than the liquidus temperature of the base solder. 3. A claim that the melting point of the temperature control component is at least 10°C higher than the liquidus temperature of the basic solder. Articles described in item 1 or 2. 4. According to any one of claims 1 to 3, the amount of the basic solder is greater than the amount of the temperature control component. goods. 5. Claim 4, wherein the ratio of base solder to temperature control component is at least 5:1. Goods. 6. 6. The method of claim 1, wherein the temperature control component comprises a substantially pure metal or a eutectic alloy. Articles listed in any of the above. 7. Any one of claims 1 to 6, wherein the temperature control component includes a metal present in the base solder. Articles listed in . 8. The base solder and temperature control components are on the opposite side of the eutectic point of the phase diagram of the base solder components. 8. An article according to claim 7, having a composition comprising: 9. The basic solder is selected from the group consisting of tin, lead, indium or bismuth. 9. An article according to any one of claims 1 to 8, comprising one or more of: 10. 10. The article of claim 9, wherein the base solder comprises an alloy of tin and lead. 11. A claim in which the basic solder has a composition of 62% tin, 38% lead to 40% tin, and 60% lead. 10. Article according to item 10. 12. A claim in which the basic solder has a composition of 61% tin, 39% lead to 50% tin, and 50% lead. Article described in 11. 13. Temperature control component is substantially pure tin or eutectic of 96.5% tin and 3.5% silver The article according to any one of claims 1 to 12, comprising gold. 14. 14. Article according to any one of claims 1 to 13 in the form of a strip. 15. A heat-shrinkable polymeric sleeve and claims 1-1 retained within the sleeve. Forming an electrical or mechanical connection comprising a composite solder article according to any of 4. device.