Solder Spheres

SnPb, In, BiSn and Lead-Free Solder Spheres

AVAILABLE DIRECTLY AT CAPLINQ.COM

Bonding wires Solder Spheres Tape and Reel

Solder Sphere Selector Guide
Alloy Type	Tin-Lead/ Pb-free	% Metal Loading						Melting Temperature			Remarks
		Tin (Sn) %	Lead (Pb) %	Bismuth (Bi) %	Silver (Ag) %	Copper (Cu) %	Indium (In) %	Eutectic (°C)	Solidus (°C)	Liquidus (°C)
		Sn63Pb37	Tin-Lead	63	37	-	-	-	-	183		-	-	Eutectic Tin-Lead
SAC105	Pb-free	98.5	-	-	1.0	0.5	-	-	220	225		Lowest Silver Content
SAC125N	Pb-free	98.3	-	-	1.2	0.5	-	-	217	219	0.05% Nickel (Also called SAC125Ni)
SAC305	Pb-free	96.5	-	-	3.0	0.5	-	-	217	221	Industry Standard Pb-free
SAC387	Pb-free	95.5	-	-	3.8	0.7	-	-	217	219	Special Application Pb-free
SAC396	Pb-free	95.5	-	-	3.9	0.6	-	-	217	221	Industry Standard Pb-free
SAC405	Pb-free	95.5	-	-	4.0	0.5	-	-	217	225	Highest Silver Content
Sn96.5Ag3.5	Pb-free	96.5	-	-	3.5	-	-	221	-	-	Eutectic Leadfree High Silver
Sn100	Pb-free	99.9928% min	-	-	-	-	-	232	-	-	4N Pure Tin (>99.9928% Sn)
Bi58Sn42	Pb-free	42	-	58	-	-	-	138	-	-	Eutectic Low-Temp Bismuth-Tin
Bi57Sn42Ag1	Pb-free	42	-	57	1.0	-	-	-	139	140	Near-Eutectic Low-Temp Bismuth-Tin
Sn5Pb95	Tin-Lead	5	95	-	-	-	-	-	312	322	High melting point Solder Spheres
In100	Pb-free	-	-	-	-	-	100	156.6	-	-	Pure Indium Solder Spheres In100

Low volume flexibility, high volume pricing

CAPLINQ maintains an inventory of many sphere alloys and sizes, and we specialize in the fulfillment of small orders. CAPLINQ also offers volume breaks and discounts for our higher volume customers. A complete list of sphere diameters, packaging quantities, volume breaks and discounts can be seen by clicking on the product Alloy Type below

Frequently Asked Questions about Solder Spheres

What's the difference between solder spheres and solder balls?

There is no difference between solder balls or solder spheres. Because solder balls do not sound very high tech and balls do not technically have a tolerance, the industry moved to the naming convention of solder spheres. Solder spheres are now more common and solder sphere diameter and spheroid tolerances can now be measured and defined.

Why are the jumps in price breaks so high?

Solder spheres ultimately end up being made-to-order products with a limited shelf-life once produced. Furthermore, there is a lot of "start-up material" that is wasted at the beginning of each production, whether it is for 1 jar or 1000 jars. These wastes are calculated into the lower volume pricing and is the reason the price jumps are as high as they are.

What is the tolerance of your solder spheres?

The tolerance of the solder sphere depends on the size of the sphere. It can generally be summarized as 1.5% of the solder diameter. A more complete answer on the solder sphere tolerance can be found here.

What size solder sphere defines whether it is for BGA, CSP or FlipChip?

There are no hard and fast rules for this, though generally, as solder spheres get smaller, they are used from BGAs to CSPs to Flipchip devices. Typically, it can be said that BGA solder balls are greater than 0.250mm in diameter and bigger, CSP are between 0.100mm and 0.250mm in diameter and flip chips use solder balls that are 0.100mm and under in diameter.

What is the shelf-life of solder spheres in tape and reel packaging?

The guaranteed shelf-life of solder spheres in tape and reel packaging is 1 year from the date of manufacture. There are simply too many variables to be able to account for all the possible scenarios of long term storage of the solder spheres in the tape and reel. In the jars, the solder spheres are preserved in an inert gas (nitrogen). In the tape & reel, the spheres are no longer in the inert gas, but are vacuum sealed, removing air from the individual package

The reason for the shelf-life is to limit the liability during the period in which we have a 100% confidence that the solder spheres have not oxidized. This confidence decreases as the time increases and the storage conditions are unknown.

To the best of our knowledge, the risk of oxidation when the reels are kept in cool, dry conditions are minimum, even for several months (or maybe even years) after the published shelf-life. We cannot officially increase the shelf-life without having scientific data to support this, but we do not believe there is any negative consequence to using the solder spheres beyond the published shelf-life date.

The evolution from lead-containing Sn63Pb37 wire to Pb-free micron-sized solder spheres

The evolution of Printed Circuit Boards and Semiconductors have also forced solder technology to evolve from through-hole and solder baths to surface mounted with solder paste, and now finally solder spheres for BGAs, and flip chips.

Semiconductors and printed circuit board technology are relentlessly evolving industries. Their constant development has forced solder technolgy to change and evolve too. Solder technology, as a whole, has moved from lead-based solder wire and separately applied solder flux to solder spheres. The latest industry break-through being a move away from wire bonding to micron size solder spheres for flipchips. To understand how this happened let's start by breaking down the product name Sn63Pb37 into its parts:

Sn = Tin

63 = 63%

Pn = Lead

37 = 37%

Alloys melt at different temperatures based on their composition or ratio of metals. Sn63Pb37 solder liquifies at exactly 183°C. Because the liquidus phase is so perfectly defined, Sn63Pb37 is known as a eutectic solder. This is very useful for two reasons. The first is that there is no "slurry phase" as some of the metals melt and others have not yet melted. The second is that the 183°C temperature is incredibly useful for circuit boards because it was high enough to melt the solder but low enough not to damage plastic components or the circuit board itself.

Solder wire needs flux. Flux removes oxidation.

Without flux the layer of oxidation acts as a barrier between the solder and the two conductive contact points thus preventing a clean and solid solder joint.

Pre-coating parts in flux was, therefore, an essential extra step that cost more time and labor. So the next step in solder development was hollow solder wire filled with an internal flux. Further developments included multi-core wire with multiple hollows for better distribution of flux.

The industrial mass-produced Printed Circuit Board (PCB), as we know it, started out with through-hole technology. Semiconductor devices and chips had pins which were pushed through holes in the printed circuit board. The bottom side of the entire circuit board would then have flux applied in one go and then be dipped into a solder bath. This automated the soldering process and eliminated unnecessary extra steps. Which, in terms of mass production, saved millions of dollars in energy and material.

Solder Needs Flux. The technology of how flux and solder is applied has evolved and continues to develop. — Solder Needs Flux. The technology of how flux and solder is applied has evolved and continues to develop

As semiconductor technology evolved over time so did soldering technology.

Evolving ICs – Pushing soldering technology to evolve

After through-hole technology PCBs evolved towards surface mounted technology: where solder paste was used. Solder paste is a suspension of powdered flux and powdered solder together. This allowed solder to be printed on circuit boards by a solder paste printer and then melted in one go in a solder reflow process: thereby allowing for much more complex and densely packed installations of semiconductors on the PCB.

Integrated circuits have been getting smaller and smaller and with larger and larger numbers of tiny transistors. This can be best seen in the evolution of Small Outline Integrated Circuits or SOIC: evolving at first by doubling the number of inputs and outputs or pinouts: from SO8, on to SO16, SO32. Eventually for the sake efficiency, instead of two rows of pinouts, all four sides would be used in the Quad Flat Pack (QFP). This also meant that the legs got thinner and thinner and got packed closer and closer together.

Array packaging moved semiconductor packages from wire bonding to solder balls

When you are using all four sides and even stacking wafers what can you do to further increase the number of inputs and outputs? The answer turned out to be: use the bottom of the chip as well. So, instead of many small thin legs, solder spheres would be placed directly on the bottom of the chip and would act as the connection between the Ball Grid Array (BGA) and the circuit board. This meant full encapsulation in an epoxy molding compound was no longer necessary and you could simply use an underfill.

250,000 solder spheres: sounds like a lot, but at micron sizes, that’s just enough for a heaped tablespoon full. Eventually, solder spheres got smaller and smaller so that they could pack even tighter grids of connection on the bottom of silica die. In these flip chips setups, tiny solder spheres are used instead of even 25-micron thick gold wire. Solder spheres are made in an amazing process with incredible accuracy and tight quality control.

Solder spheres or solder balls come microns wide and are used extensively in the semiconductor industry — Solder spheres or solder balls in a varietry of sizes from 0.060mm to 0.760mm and larger are used extensively in the semiconductor industry

A parallel evolution in material: from Lead (Pb) to Lead-free!

Early in the 2000’s in Japan, Sony and other concerned companies started to push for lead-free solder. This was in response to a situation in which electronic devices were ending up in landfills, and these landfills were in turn exposed to rainwater which allowed the lead in the solder to contaminate the groundwater. In 2006 the EU Restriction of Hazard Substances Directive (RoHS) came into effect restricting the use of lead consumer electronics.

This led to SAC305 Lead-free solder replacing eutectic SnPb63/37 solder as the industrial standard: with 75% of companies using it. Here is what the name means:

S = Tin

A = Silver

C = Copper

3 = 3% Silver

05 = 0.5% Copper

As a near eutectic solder it has adequate thermal fatigue properties, strength, and wettability. Another advantage of SAC solder is that it’s more resistant to gold-embrittlement and has substantially higher joint strength than PB solders.

Going Pb-free however means using silver instead of lead which means increases costs. For some applications SAC solders with less silver are suitable. These include SAC105, Bi57Sn42Ag1, as well as silver-free and lead-free solder , Bi58Sn42.

Using silver means that SAC solders have a 34°C higher melting point than Sn63Pb37 solder at between 217-220°C. This requires a higher solder reflow temperature of 235-245°C in order to achieve wetting and wicking. Some printed circuit components are susceptible to SAC assembly temperatures: including capacitors, optoelectronics etc.

Companies have since started offering 260°C compatible components to meet the high temperature required for SAC solder reflow. 260°C compatibility is fast becoming the new standard for semiconductor and component manufacturers.

High Tech Tin

CAPLINQ is not only able to supply the alloys and purify the solder material, but it has an innovative diameter and spheroid selecting system of solder balls and an advanced anti-oxidation technology that actually dopes an anti-oxidation element into the alloy in addition to its OSP surface coating process.

Not only are our solder spheres High-Tech, but they are made from a unique uniform droplet spraying technology that far outperforms competitors in terms of productivity. This combination of high technology and high productivity allow CAPLINQ to offer its customers the best value for the best product.

Correlation between solder ball size and BGApitch
Solder ball diameter (mm)	Variation	Pitch size
0.75	0.90 - 0.65	1.50, 1.27
0.60	0.70 -0.50	1.0
0.50	0.55 - 0.40	1.00, 0.80
0.45	0.50 - 0.40	1.00, 0.80, 0.75
0.40	0.45 - 0.35	0.80, 0.75, 0.65
0.30	0.35 - 0.25	0.80, 0.75, 0.65, 0.50
0.25	0.28 - 0.22	0.40
0.20	0.22 - 0.18	0.30
0.15	0.17 - 0.13	0.25