SC-2100, SC-2110 (Conductive Paste, Paste for PCB)

Model Number

SC-2110

How To Use The New Product SC-2110 For PCB Through Hole

Through Hole Process

1. Board preparation

Must be removed the oxidation and contaminations on Cu laminate by the standard cleaning process. For example, it's acceptable of brushing with a 3 ~ 5% H2SO4 aqueous solution. Please refer to the "Appendix #1".

After cleaning, the board also must be properly dried. The moisture trapped in the holes may cause voiding.

2. Print silver paste

To obtain optimum results, please print silver paste at the supplied viscosity as possible. But if you need a lower viscosity, you can dilute the paste with the "IMD STH THINNER" by less 5wt% of the original weight(Refer to the "Appendix #2"). Also before the printing process, all of the process parameters (e.g. squeegee contact angle, screen emulsion thickness, squeegee speed and screen mesh etc.) must be optimized.

3. Dry & Cure silver paste

Drying condition varies for each material, oven configuration, air flow, board thickness, hole diameter and temperature. The printed and dried board is ready for the curing process if the silver paste is dried enough to cure without forming voids or volcanoes. The following page will describe the recommended dry and cure temperature profile of "SC-2110".

4. Cover silver with solder mask

A final coating of solder mask is applied to cover the silver holes to provide protection from oxidation, physical and chemical damages.

Drying & Curing

STEP1 : 60℃ X 90min (STEP2 : 75℃ X 30min) STEP3 : 150℃ X 30min

Characteristics Of SC-2110

Characteristics

• Good electrical conductivity
• Good printability
• Good Reliability
• Low silver migration
• Good adhesion on Cu laminate
• Good hole shape
• High hole openness

Compositions

Physical properties

SC-2110 Reliability

Reliability

Items	Results
Initial Hole Resistance 0.5Φ FR-1	< 30mΩ/hole,Pass
Solder Test 260℃,5sec,5cycles	< 10% variation, pass
Boiling Water Test 100℃,2hrs	< 20% variation, pass
PCT 121℃,95%RH,2atm,8hrs	< 30% variation, pass
Hot Oil Test 260℃,5sec+25℃,10sec, 100cycles	< 30% variation, pass
Silver Migration Test 40℃, 95%RH, 50V, 1000hrs	> 300MΩ,Pass

Hole shape

Before Solder Test	After Solder Test

Application

Screen

• 100~180mesh with 80~100microns of emulsion
• Both polyester and stainless steel screen are applicable
• Solvent resistant emulsions must be used

Laminates

All STH grade laminates can be used, but the less amount of out-gassing of laminates, the higher quality is achieved.

CEM-3 or FR-4 > CEM-1 > FR3 > FR1 > FR2 > XPC

• CEM : composite epoxy material
• FR : fire retardant
• XPC : paper phenolics

Board Density

How to store & Use

Storage

To guarantee optimum quality, we recommend storing the paste in a refrigerator(< 5℃). The shelf life is 2 months under 5℃.

How to use

Upon removal from the refrigerator, we recommend letting the paste reach room temperature before opening the jar. This will prevent the paste from condensing moisture from the air as it warms up. We recommend a warm-up time of 3 hours at room temperature for a 1.0 or 1.5kg jar. And also the paste must be mixed properly for 30minuates before printing. We recommend using a mixer with a impeller.

Troubleshooting

Problems	Solution
Poor fluidity of paste	Optimize the squeegee angle and pressure Adjust paste viscosity Check the conditions of hole drilled
Paste overflowing over the copper land	Control the temperature and humidity Minimize the deviation of hole in the screen pattern
Voids or volcanoes	Increase drying time and temperature Use the STH grade laminate
Poor electrical conductivity	Allow less time between cleaning and printing process Increase drying and curing times and temperatures Check cleaning and rinsing process
Poor adhesion to substrate	Increase cure cycle Check cleaning and rinsing process Allow less time between cleaning and printing process (In general, it’s shorter than 30minuates)