Tag: solder ball jet nozzle

With the development of the electronics industry, traditional integrated heating soldering modes such as wave soldering and hot air reflow soldering cannot meet the needs of engineering in the face of photoelectric interconnection module, three-dimensional assembly, and 5 G optical communication modules as well as heat-sensitive components.

At this time, the laser jet solder ball bonding process has more and more applications in the engineering field due to its high energy density and local heating. Because the temperature field of the entire laser jet solder ball bonding is a highly transient process, which is different from the traditional soldering temperature field, and the temperature of the soldering is very important to the quality of the solder joint.

Therefore, it is important to see that the temperature change of the solder balls when it is heated in the solder ball jet nozzle to ensure the formation of a good solder joint. To solve this problem, the finite element simulation and the experimental method are used to study the heating temperature field of the solder ball in the solder ball jet nozzle. In the simulation, the transient thermal method was used to analyze the transient temperature distribution of the solder ball in the solder ball jet nozzle.

In this experiment, the temperature change of the solder ball in the solder ball jet nozzle was recorded by an infrared thermometer. The simulation results show that when the solder ball is heated by the laser in the solder ball jet nozzle, the effective power of the laser has a significant impact on the temperature field of the solder ball, and the solder ball jet nozzle has an important impact on the melting of the solder ball.

The experimental results show that the temperature change of the heated solder ball in the solder ball jet nozzle is similar to the simulation results, which verify the validity of the model and the reliability of the simulation results. It is of significance to guide the temperature field control in the actual soldering process.

A solder ball jet nozzle bonding tool includes a nozzle having an inner bore having a plurality of columnar surfaces and interposed retention structures that are positioned within the nozzle to retain a solder ball jet nozzle therein.

A projection or projected shape formed by intersecting the retention structures may be generally circular, having a diameter less than the diameter of the solder ball jet nozzle for which the retention structures are positioned to retain.

The solder ball jet nozzle may comprise a cemented carbide having less than or equal to a cumulative 4.5% of cobalt and gold serving as a binder.

The selective soldering process is playing an increasingly critical role in much of electronic assembly manufacturing operations around the world. Complex printed circuit board assemblies place greater demand on the overall accuracy and repeatability of the selective soldering process. This requires the entire selective soldering process to be more precise with increased levels of process control.

The use of advanced closed-loop process control including automatic selective solder ball jet nozzles tinning assures that complex printed circuit board assemblies can be produced at the highest possible quality levels with consistent results ensuring maximum levels of reproducibility.

Selective Soldering Nozzles

Most selective soldering machines use either wetted or non-wetted solder ball jet nozzles, each type having advantages and disadvantages in their application and each type requiring different maintenance criteria. Wetted nozzles, also referred to as bullet nozzles, general purpose nozzles or universal nozzles, have the advantage of being able to approach a solder site from any direction and can solder extremely close to adjacent SMT components since they are omnidirectional making them ideally suited for highly flexible soldering applications.

Most round wetted solder ball jet nozzles produce a minimal height of molten solder which limits the length of the component leads that can be soldered or can reduce flexibility when accessing tighter solder locations. Bullet solder ball jet nozzles are specially designed to establish backpressure raising the height of the molten solder an as much as an additional 50%, while tapering the solder tip to a finer point. This allows soldering to take place with longer length component leads without having the nozzle contact the component pins, as well as allowing opportunity for additional precision in other locations.

Non-wetted solder ball jet nozzles, also referred to as mini-wave or jet-wave nozzles, have directional flow of the molten solder since they are unidirectional making them ideal for soldering of connectors or multi-row through-hole components. Since non-wetted nozzles are unidirectional they typically solder at a 7-degree angle like a traditional laminar wave soldering nozzle to promote the breakaway of excess molten solder to prevent solder bridging. One disadvantage of non-wetted solder ball jet nozzles is that they can only solder in a single direction because of the directional solder flow which means they generally require more keep-out area between the side of the nozzle and adjacent SMT components.

Solder Ball Jet Nozzles Maintenance

A critical area for any selective soldering machine is the preventative maintenance methods, procedures and practices used for the various types of solder ball jet nozzles. Pre-tinning of wetted solder ball jet nozzles extends their working life and improves the flow characteristics of the molten solder as does periodic cleaning and re-tinning. Ideally manual re-tinning should be carried out after first cleaning the solder ball jet nozzles with a highly active solder ball jet nozzles tinning flux followed by tinning the nozzle in a static solder pot filled with the same solder alloy used in production.

During selective soldering a wetted solder ball jet nozzles can become un-tinned which compromises the proper flow of molten solder and increases the surface tension of the solder. Whenever a solder ball jet nozzles does not have the correct flow properties its ability to create defect free solder joints is greatly diminished. This is typically corrected by a manual operation of an operator applying flux to the solder ball jet nozzles using a brush.

Regular and proper tinning of the tip and side surfaces of a solder ball jet nozzles ensures that the solder will flow evenly and consistently out of the nozzle. When not regularly tinned, there is an increased likelihood that the solder will begin to flow unevenly, leading to inconsistent and ineffective soldering of a printed circuit board assembly.

In some cases, operators have been known to use the same alcohol-based, non-aggressive no-clean flux to manually re-tin the solder ball jet nozzles that is being used for soldering of the printed circuit board assembly. This unfortunately is not a good practice since these non-aggressive fluxes do not clean the nozzle properly and will result in more attention from an operator, applying flux more frequently. This can quickly become counterproductive as with each additional attempt to apply flux by hand, more residues will accumulate on the nozzle surface ultimately building to the point when the nozzle must be removed from the machine and manually scrubbed and re-tinned.

This article comes from globalsmt edit released

A solder ball bonding tool includes a solder ball jet nozzle having an inner bore having a plurality of columnar surfaces and interposed retention structures that are positioned within the solder ball jet nozzle to retain a solder ball therein. A projection or projected shape formed by intersecting the retention structures may be generally circular, having a diameter less than the diameter of the solder balls for which the retention structures are positioned to retain. The solder ball jet nozzle may comprise a cemented carbide having less than or equal to a cumulative 4.5% of cobalt and gold serving as a binder.

1. A solder ball bonding tool solder ball jet nozzle, comprising: an inner bore comprising a plurality of equivalent columnar surfaces equally spaced around the perimeter of said inner bore; anda plurality of retention structures each formed by an intersection of two said adjacent columnar surfaces such that only one pointes structure per retention structure extends into said inner bore in a position to retain a solder ball within said solder ball jet nozzle; wherein said nozzle is composed of a cemented carbide having up to a 4.5% cumulative percentage of cobalt and gold serving as a binder.
2. The solder ball jet nozzle wherein a projected shape formed by intersecting said retention structures is substantially circular and has a diameter that is less than the diameter of a solder ball for which said retention structures are positioned to retain.
3. The solder ball jet nozzle wherein said columnar surfaces of said inner bore are concave surfaces.
4. The solder ball jet nozzle wherein said columnar surfaces of said inner bore are substantially circular concave surfaces having a diameter that is less than the diameter of a solder ball for which said retention structures are positioned to retain.
5. The solder ball jet nozzle further comprising a nozzle tip comprising a continuous outer side wall, and wherein said columnar surfaces of said inner bore do not intersect an outermost interface of said outer sidewall of said nozzle tip.
6. The solder ball jet nozzle wherein said plurality of columnar surfaces comprises three or more columnar surfaces and wherein said plurality of retention structures comprises three or more retention structures.
7. The solder ball jet nozzle wherein said plurality of columnar surfaces comprises at least four columnar surfaces and wherein said plurality of retention structures comprises at least four retention structures.