JPH08164477A - Ultrasonic soldering joining method - Google Patents

Abstract

PURPOSE: To cope with fine wiring pattern without using flux, free from breaking and melting package wiring board by heating/pressurizing. CONSTITUTION: One side of a joining part 21 at least is made of a solder consisting of either alloy of Sn, Pb or alloy of Sn, Pb, or a pretinning layer consisting of the solder containing essential components of Sn, Pb or alloy of Sn, Pb and the balance of one kind at least as an adding metal among Ag, Sb, Cu, In, Bi, Zn, the other side is made of either the solder composition or Sn, Pb, Au, Ag, Pd, Pt, In, Cu, Al, Ni. In the joining between a first object 23 to be joined and second object 25 to be joined in which the pretinning layer is used for a binder, the preliminary heating temp. is set to the temp. between the liquidus temp. and solidus temp. of the solder composition, by giving ultrasonic vibration vibrating parallel with the first/second objects 23, 25 to be joined at joining time only, joining is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining an article to be joined consisting of electronic parts such as leads for taking out electrodes and IC chips and an article to be joined consisting of a mounting wiring board made of resin, glass or the like. More particularly, the present invention relates to a sonic bonding method, and more specifically, at least one bonding portion is formed of a preliminary solder layer formed by solder immersion or solder plating, and the other bonding portion is formed by preliminary solder layer formation by solder immersion or solder plating, or Sn, Pb, Au, Ag, In, Al, N
The present invention relates to an ultrasonic solder joining method in which joining such as i is performed by using ultrasonic waves and heating in combination.

[0002]

2. Description of the Related Art Conventionally, when an electronic component such as a lead for taking out an electrode or an IC chip as an article to be joined and a mounted wiring board made of a material such as resin or glass as the article to be joined are to be spared. A thermocompression bonding method is used for joining the soldered electrodes.

In this method, a preliminary solder layer is formed by solder immersion or solder plating on the joint portion to be joined, and the solder obtained by melting the preliminary solder layer on this electrode by heating is applied with a force of about 50 kg / cm ^2. The electrodes to be joined are crimped and joined.

[0004]

By the way, in the above-mentioned conventional joining method, since it is necessary to melt the preliminary solder layer, the entire objects to be joined are heated to a temperature higher than the liquidus temperature. As a result, the glass wiring board and the resin wiring board, which are inferior in heat resistance as the objects to be joined, are damaged or melted.

Further, it is necessary to use a flux in order to secure the wettability of the solder, and the residual flux removing cleaning agents such as CFCs and ethane pollute the global environment, and an expensive system for the alternative cleaning is required. There is a problem that becomes.

Further, since the pressure bonding is performed, the preliminary solder layer is excessively crushed, short circuit between wirings is caused, and it is impossible to cope with a fine wiring pattern. Also, 50k to crush the preliminary solder layer
Since a pressure of about g / cm ² is required, there is a problem that the glass wiring board and the resin wiring board, which have poor pressure resistance, are damaged.

An object of the present invention is to provide an ultrasonic soldering method which can cope with a finer wiring pattern without using a flux, without damaging or melting the mounted wiring board by heat and pressure. To do.

[0008]

In order to achieve the above object, the ultrasonic solder bonding method of the invention according to claim 1 is a solder in which at least one of the bonding portions is made of Sn, Pb or an alloy of Sn and Pb, or Sn. , Pb or Sn and P
The main component is the alloy of b, and the balance is Ag, Sb, Cu, In,
A preliminary solder layer made of solder containing at least one of Bi and Zn as an additive metal, and the other is the solder composition or S.
n, Pb, Au, Ag, Pd, Pt, In, Cu, A
The liquidus temperature and solidus temperature of the solder composition to which the preliminary heating temperature is applied when joining the first and second objects to be joined, each of which is composed of 1 and Ni and uses the preliminary solder layer as an adhesive agent. In between, the joining is performed by applying ultrasonic vibration that vibrates parallel to the first and second objects to be joined only during joining.

The ultrasonic solder bonding method of the invention according to claim 2 is characterized in that the cavitation effect obtained by applying the ultrasonic vibration is performed after cleaning the surfaces of the bonding surfaces and removing the oxide film. It is what

The ultrasonic solder joining method of the invention according to claim 3 is characterized in that, when the ultrasonic vibration is performed, the submerged distance which is lowered due to melting of the solder is regulated by a mechanical stopper to perform the joining. It is a thing.

In the ultrasonic solder joining method according to the fourth aspect, the pressure applied to the first and second objects to be joined at the time of joining is 0 kg /
It is characterized in that it is set to cm ^{2 to} 15 kg / cm ² .

[0012]

With the ultrasonic solder joining method of the invention according to claim 1 as described above, ultrasonic vibration is applied to the first and second objects to be joined, so that the preliminary solder portion is formed by the vibration energy of the ultrasonic waves. Since they are melted, the first object and the second object are easily joined without damage.

By using the ultrasonic solder joining method of the invention according to claim 2, the preliminary solder surface is cleaned and the oxide film is removed by the cavitation effect of the ultrasonic vibration, the preliminary solder surface is activated, and the flack is used. Without the solder joining method.

According to the ultrasonic soldering method of the invention of claim 3, if the clearance between the first object and the second object is secured with an appropriate clearance, the first object to be bonded and the second object after the bonding can be secured. The distance between the two objects to be joined, that is, the height of the solder portion is controlled, and it is possible to prevent a short circuit between the wirings due to excess solder crushed by crimping.

According to the ultrasonic soldering method of the invention according to claim 4, for example, a first mounting wiring board is used.
Since pressure is applied to the object to be joined through the preliminary solder layer before the solder is melted, the pressure can be absorbed and reduced, and after the solder is melted, the pressure applied to the first object to be joined is reduced. Since it is regulated by the stopper, the pressure applied to the first object is 0 to 1
It is suppressed to 5 kg / cm ² and damage is prevented.

[0016]

Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIGS. 1 and 2, the ultrasonic solder bonding apparatus 1 is provided with an air cylinder 3 which is erected on the floor surface, for example, and a vibrator sandwiching portion 5 is provided on the air cylinder 3. Has been. The vibrating body sandwiching portion 5 is a lower vibrating body sandwiching portion 5.
D and an upper vibrating body sandwiching portion 5U, and the ultrasonic transducer 7 is clamped by the lower vibrating body sandwiching portion 5D and the upper vibrating body sandwiching portion 5U.

A vibrating body 9 is integrated on the front side (left side in FIG. 1) of the ultrasonic vibrator 7, and a connection cable 11 is provided on the rear side (right side in FIG. 1) of the ultrasonic vibrator 7. The ultrasonic oscillator 13 is connected via the. A heater 15 is built in the nodal point of the vibrating body 9.

A stopper 17 is arranged on the floor behind the air cylinder 3. Further, a receiving jig 19 with a heating unit is provided on the lower floor surface in the front part of the vibrating body 9.

With the above-described structure, as shown in FIGS. 1 and 2, the joint 21 is ultrasonically dipped into the joint 21 on the receiving jig 19 with the heater heated to 190 ° C. by the heating portion. A mounting wiring board 23 made of glass, which is pre-soldered with a solder having a composition of Pb of 6 and Sn of 4, is preliminarily soldered, and the mounting wiring board 23 is preheated.

From this state, as shown in FIG. 3, Pb in the flexible lead 25 as the second object to be bonded is 6, at the bonding portion 21 of the mounting wiring board 23.
The solder-plated joint portion 27 having a composition of Sn of 4 is placed so that the wiring patterns thereof match.

In this state, the vibrator 9 heated to 190 ° C. by the heater provided at the nodal point of the vibrator 9 is lowered by the operation of the air cylinder 3 as shown in FIG. Then, the joint portion 21 and the joint portion 27 are kept in contact with each other and left for, for example, 3 seconds. At this time, the height of the vibrating body 9 is regulated by the preliminary solder of the joint portions 21 and 27, and the pressure applied by the vibrating body 9 is transmitted to the mounting wiring silver 23 through the preliminary solder layer.

After being kept in contact with the ultrasonic wave for 3 seconds, the ultrasonic transducer 7 makes it horizontal (in the horizontal direction in FIG. 5) with the obtained joint portion 29 at a frequency of, for example, 40 kHz as shown by an arrow in FIG. Vibration is applied to the vibrating body 9 to instantly melt the solder of the preliminary solder layer formed on the joint portion 29, and the sinking of the ultrasonic vibrator 7 due to melting of the solder is restricted by using the stopper 17. However, it is possible to prevent the preliminary solder layer from spreading due to the sinking.

After the ultrasonic vibration is oscillated for, for example, 1 second, the temperature of the solder layer is lowered while the joint portion 29 is kept in contact with the vibrating body 9 by using the stopper 17, and the temperature is held for 3 seconds, and then, as shown in FIG. As shown in (3), the vibrating body 9 is raised to complete the joining.

As described above, ultrasonic vibration is generated by applying ultrasonic vibration in a state where the joint 21 on the mounting wiring board 23 of the first joint and the joint of the flexible lead 25 of the second joint are in contact with each other. The pre-solder part is melted by the vibration energy of, and the pre-solder surface is cleaned and the oxide film is removed by the cavitation effect of ultrasonic vibration. It can be carried out.

Further, by securing a clearance commensurate with the amount of the preliminary solder, it becomes possible to control the distance between the mounting wiring board 23 and the flexible lead 25 after joining, that is, the height of the solder portion, and to perform crimping. It is possible to prevent a short circuit between wiring lines due to excess solder crushed. Furthermore, the mounting wiring board 23
Before the solder is melted, the pressure is applied through the preliminary solder layer, whereby the pressure can be absorbed and reduced, and after the solder is melted, the pressure applied to the mounting wiring board 23 is reduced by the stopper 1.
Because it is regulated by 7, it is possible to suppress the pressure applied to the mounting wiring board 23 to achieve a pressure of ^{0kg / cm 2 ~15kg / cm 2} .

The present invention is not limited to the above-mentioned embodiments, but can be implemented in other modes by making appropriate changes. In this embodiment, solder having a composition of Pb of 6 and Sn of 4 is immersed in the joint portion 21 of the mounting wiring board 23 by ultrasonic solder, and solder of a composition 27 of Pb of 6 and Sn is 4 for the joint 27 of the flexible lead 25. However, one of Sn and Pb
Solder made of alloy with Sn, Pb or S
The main component is an alloy of n and Pb, and the balance is Ag, Sb, C
A preliminary solder layer made of solder containing at least one of u, In, Bi, and Zn as an additive metal, and the other has the above-mentioned solder composition or Sn, Pb, Au, Ag, Pd, Pt, In, C
It may be a joint portion made of u, Al and Ni.

[0028]

As will be understood from the above description of the embodiments, according to the invention of claim 1, by applying ultrasonic vibration to the first and second objects to be bonded, the vibration energy of ultrasonic waves is increased. Since the preliminary solder portion is melted by the above, the first and second objects to be joined can be easily joined without damage.

According to the second aspect of the present invention, the preliminary solder surface is cleaned and the oxide film is removed by the cavitation effect of ultrasonic vibration, the preliminary solder surface is activated, and the joining method is performed without using a flack. be able to.

According to the third aspect of the invention, if the clearance between the first object and the second object is secured with an appropriate clearance, the distance between the first object and the second object after bonding, that is, The height of the solder portion is controlled, and it is possible to prevent a short circuit between wiring lines due to excess solder that is crushed by crimping.

According to the fourth aspect of the present invention, for example, since the pressure is applied to the first article to be joined, which is the mounting wiring board, before the solder is melted through the preliminary solder layer, the pressure is absorbed. it can reduce, and after molten solder is applied pressure to the first object to be bonded for pressure is regulated by the stopper to the first object to be bonded is suppressed to 0kg / cm ² ~15kg / cm ² It is possible to prevent damage.

[Brief description of drawings]

FIG. 1 is a side view of an ultrasonic solder bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is an operation explanatory view explaining the operation of the present invention.

FIG. 4 is an operation explanatory view explaining the operation of the present invention.

FIG. 5 is an operation explanatory view explaining the operation of the present invention.

FIG. 6 is an operation explanatory view explaining the operation of the present invention.

[Explanation of symbols]

 1 Ultrasonic Solder Joining Device 3 Air Cylinder 5 Vibrating Body Clamping Section 9 Vibrating Body 15 Heating Heater 17 Stopper 19 Receiving Jig with Heating Section 21 Joining Section 23 Mounting Wiring Board (First Object) 25 Flexible Lead (Second Object) Joined product) 27 Joined part 29 Joined product

Claims (4)

[Claims] 1. A solder in which at least one of the joints is made of Sn, Pb or an alloy of Sn and Pb, or Sn, Pb.
The main component is Pb or an alloy of Sn and Pb, and the balance is A
A preliminary solder layer made of a solder containing at least one of g, Sb, Cu, In, Bi and Zn as an additive metal, and the other is the solder composition or Sn, Pb, Au, Ag, Pd,
A liquidus temperature of a solder composition that is preheated in joining a first object to be joined and a second object to be joined which are made of Pt, In, Cu, Al, and Ni and use a preliminary solder layer as an adhesive agent. And the solidus temperature, and only when joining
An ultrasonic solder joining method, characterized by applying ultrasonic vibration that oscillates in parallel with an object to be joined. 2. Cleaning the surface of the joint surface by the cavitation effect obtained by applying the ultrasonic vibration,
The ultrasonic solder joining method according to claim 1, wherein the joining is performed after the oxide film is removed. 3. The ultrasonic solder joint according to claim 1, wherein when the ultrasonic vibration is performed, a submerged distance which is lowered due to melting of the solder is regulated by a mechanical stopper to perform the joint. Method. 4. A first at the time of bonding, the second ultrasonic solder bonding method according to claim 3, characterized in that a 0kg / cm ² ~15kg / cm ² the pressure applied to the object to be bonded.