Krayden Logo

Semiconductor Epoxy Mold Compounds

Semiconductor grade epoxy molding compounds with high electrical stability

AVAILABLE DIRECTLY AT CAPLINQ.COM

Semiconductor Epoxy Mold Compounds

Semiconductor molding compounds are fine filled, electrically stable compounds, ideal for the miniaturised semiconductor packaging requirements. They have small filler sizes, great spiral flow and can be electrically stable at high temperatures.

Epoxy molding compounds that are graded for semiconductor use are CTE matched to common die substrates and are made with nano packages in mind. They cover and protect the die and the wirebonding while also passing the most stringent moisture and temperature tests.

Excellent electrical stability is desired for epoxy molding compounds used in the encapsulation of high power, discrete semiconductors applications that also operate a high temperatures.These molding compounds tend to have the lowest ionic content, the highest dielectric strength, the most stable dielectrics and the lowest ionic conductivity over the widest possible temperature range.

91 products

Product selector guide

▶ EMC for Laminated Integrated Circuits
▶ EMC for Passive Components
▶ EMC for Optocouplers
Semiconductor Epoxy Molding Compound
Product Name Key Properties
Color Filler Content (%) Specific Gravity Glass Transition Temperature (Tg), °C CTE Alpha 1 (ppm/°C) CTE Alpha 2 (ppm/°C) Gel Time (s) Ionic Content Na+/Cl- (ppm) Spiral Flow (cm) Thermal Conductivity (W/m·K) Packages
EMC-1533 Black 80 1.90 170 15 60 20 8/10 68 - TO
EMC-5013 Black - 2.17 178 20 55 32 6/9 60 2.3 TO
EMC-6043 Black 85 1.97 140 11 42 34 7/9 140 - SOT
EMC-7142 Black 89 2.00 122 8 34 30 15/15 90 - SOP, QFP
EMC-7535 Black 75 1.96 176 13 37 24 15/15 86 - TO
EMC-7535MF Black - 1.96 215 9 35 29 <15/<10 85 - TO, SiC MOSFET, IGBT, Modules
EMC-7560 Black 85 1.95 205 10 52 30 10/10 82 0.9 SiC MOSFET
EMC-9070 Black 89 2.01 126 8 30 35 6.7/4.1 127 - QFN, DFN
EMC-9012 Black 89 2.01 133 8 35 45 7/6 165 - QFN, DFN, BGA
EMC-9012H Black 87 1.99 158 10 40 40 4/7 165 - QFN, DFN, BGA
EMC-9023 Black 85 1.96 162 13 47 60 6/7 190 2.3 FCBGA, SIP
EMC-9131 Black 89 2.01 130 8 30 30 3/13.5 55 0.8 SOT
EMC-G194 Black 74 1.82 175 16 62 22 8/6 74 0.7 SMX, TO, DIP
EMC-G135 Black 76.5 2.0 160 25 75 25 4/9 88 1.7 Rectifier Bridges
EMC-G208 Black 84 1.94 185 11 45 27 10/15 152 0.8 Micro SD cards and other thin, high-density packages
EMC-G274 Black - 2.0 140 13 45 30 7/6 95 - Photocouplers & Octocouplers
EMC-G375 Black 85 2.7 175 13 40 40 5/5 110 3.3 TO
EMC-G833 Black 87 1.97 112 11 36 57 6/7 165 - QFN, DFN, QFP
EMC-G833R Black 88 2.0 118 10 36 52 5/5 150 - QFN, DFN, QFP
GR15F-MOD2C Black 81.5 1.93 236 15 42 31 5/5 109 0.78 SiC MOSFET
GR 2220 Black 75 1.82 161 18.5 63.3 18 3.6/10.4 81.28 - MnO2 Caps
GR 2310 Gold 72 1.82 175 20 73 12 9/13 72 0.64 MnO2 Caps
GR 2310V Gold 72 1.85 180 18 70 28 9/19 114 0.7 MnO2 Caps
GR 2320 Black 71 1.8 170 20 75 14 4/10 76.2 0.7 MnO2 Caps
GR 2330 Orange 74 1.83 175 19 67 14 3/8 81 0.65 MnO2 Caps
GR 2710 Gold 81.7 1.93 161 13 51 15 5/8 105 - AO Caps
GR 2710FF Gold 84 1.96 160 11 47 13 6/7 116 0.8 AO Caps
GR 2720 Black 79 1.87 160 18 58 19 2/5 96.5 0.7 AO Caps
GR 2811 Gold 85 1.96 162 13 45 15 1/7 86.3 2.7 POSCAP
GR 2812 Gold 90 2 105 7 29 20 2.7/7.7 73 - POSCAP
GR 2820 Black 83 1.9 183 12 45 20 6.6/7 66 - POSCAP
GR2821 Black 85 1.96 116 13 45 31 1/7 101 2.7 POSCAP
GR 2822 Black 88 1.98 105 7 36 - 2.9/8 99 - POSCAP
GR 30 Black 81 1.9 183 13 57 17 - 62 0.95 T0220/247
GR 300 Black 80 1.94 185 12 51 19 4.5/9.3 34 0.95 T0220/93/252
GR 30HT Black 72 2.1 186 21 56 21 20/20 88 1.9 T0/93
GR 350HT Black 79 2.13 182 20 62 28 15/8 61 1.6 T0/220F
GR 360A-ST Black 77 1.84 168 15 59 23 - 98 - Diodes, TO, DIP
GR 510 Black 88 1.99 113 8 27 36 5/10 111 - QFP, SOT
GR 510-HP Black 88 1.99 116 7.5 30.5 31 4/6.1 101.6 - Resistors
GR 600-P1 Black 88 2 119 7.1 31 27 4.9/5.9 34 - DPAK/D2PAK
GR 600 SL2 Black 87 2.03 165 7 42 27 - 83 - TO252
GR 640HV Black 74 1.83 160 16 60 26 5/10 75 0.85 SOT, SOD, SMX
GR 640HV-L1 Black 75 1.85 165 16 58 28 6/21 71 - TO, SMX, SOT
GR 700 Black 87 1.97 118 8 35 27 4/9 132 0.9 SOP, DPAK, QFP, QFN, SOT
GR 700 C3D Black 87 1.97 118 8 27 27 3/9 107 0.9 TO, SOIC, PQFN
GR 700 C4C Black 89 2 120 7 36 30 3/7 114 0.9 SOP, DPAK, QFP
GR 700-P2 Black - - 115 7 29 24 >15 89 - TO247, TO252
GR 710F Black 88 1.98 115 9 37 31 9/4 93 0.86 T0, SOIC16, TSOP, SSOP
GR 750 Black - - 235 10 40 26 >15 106 - SiC MOSFETs
GR 750 X1 Black - - 207 8 42 24 >15 92 - SiC MOSFETs
GR 750 X2 Black 84 1.94 182 9 32 27 5/15 114 0.8 ZIP, TDA2002
GR 825-73B Black 80 1.9 135 12 45 22 - 100 0.8 SOIC, SSOP
GR 900 Q1G2 Black 89 - 112 6 33 25 3/13 137 - QFN, DFN
GR 900 Q1L4 Black 89 2.02 124 7 24 36 3/8 124 0.9 QFN, DFN
GR 900C Q1L4E Black 86.5 1.98 120 11 37 38 3/8 132 - QFN, DFN
GR 910-K Black 89 2.01 152 9 32 49 -/10 172 - BGA, LGA
GR 910-C4 Black 88 2 130 8 28 44 - 170 1 QFN, BGA, LGA
GR 920 Black 88.5 2 120 9 35 40 - 102 0.9 BGA, Sensors
GR 9810-1P Black 85 1.95 170 11 50 32 - 150 0.9 Sensors
GR 9810-1PF Black 86 1.95 170 11 40 40 - 170 0.9 POP, SCSP
KL G200S Black 77 1.95 175 20 78 20 3/8 80 1.4 DO214
KL 1000-3A Black 75 2 165 25 77 23 3/7 80 1.3 ZIP, SIL, DIP
MG 15F-0140 Black - 1.81 195 21 70 17 3/5 50.8 0.66 Rectifiers
MG 15F-35A Black - 1.82 190 21 70 20 20/20 64 0.7 Rectifiers
MG 21F-02 Black 71 1.81 179 21 62 22 4/6 65 0.7 Diodes
MG 27F-0521LF Gold - 1.91 167 21 67 25 4/3 63 0.65 MLCC Caps
MG 33F-0520 Gold - 1.87 170 20 70 14 - 64 - Ta Caps
MG 33F-0659 Black 76 1.83 175 18 60 14 - 66 - Ta Caps
MG 33F-0660 Gold 76 1.83 175 18 60 14 - 66 - Ta Caps
MG 33F-0661 Gold 72 1.81 164 18 60 22 - 69 0.8 Ta Caps
MG 36F-25A Black - 1.82 170 19 65 30 - 76 - Discrete, DIP
MG 40FS Black - 1.84 160 20 75 25 5/5 89 0.95 PDIP, SOIC
MG 40FS-AM Black - 1.84 160 20 75 25 5/5 71 0.95 PDIP, SOIC
MG 52F Black 79 1.84 155 14 60 24 2/2 76 0.95 TSSOP, SOIC
MG 52F-99BNXP Black 79 1.88 155 14 56 21 2/2 78 0.95 TSSOP
MG 57F-0660 Gold - 1.82 168 21 70 14 20/20 - - MnO2 Ta Caps

Notes: Values are compiled from available datasheets and may be typical unless otherwise stated.

Epoxy Molding Compounds Used in Special Applications
Product Key Feature Package / Application
GR30 Excellent fillability to fine gap; Good anti-ATF oil performance; Suitable for rotor transfer process Permanent Magnet Synchronous Motor (PMSM)
GR50HT Excellent workability; Suitable for end-pin protect coating Permanent Magnet Synchronous Motor (PMSM)
GR710 Ultrathin insulation coating; Stronger adhesion; Suitable for wholly packing stator Permanent Magnet Synchronous Motor (PMSM)
GR510-HP Higher mechanical strength; CTI level 0 Electromagnetic Valve
GR710 Excellent workability; Suitable for wholly packing application Small Motor
GR50HT Fast curing; Higher thermal conductivity; CTI level 0 Doorhandle Sensor
Highly Thermally Conductive Epoxy Molding Compounds
Product Thermal Conductivity Package focus Notes
Hysol GR30HT 1.9 W/mK TO92, TO3P, TO220, TO247 power devices High-thermal-conductivity GR30 variant. Distributor sources indicate it has been superseded by GR350HT.
Hysol GR350HT 1.6 W/mK TO92, TO3P, TO220, TO247 power devices Current GR30-derived high-thermal-conductivity grade for TO power packages; positioned to support high-temperature and bias reliability.
Hysol GR60PT 1.7 W/mK IPM, full-pack type IPM, substrate-type IPM Positioned as a more cost-efficient option for power module encapsulation.
Hysol GR60HT 2.2 W/mK IPM, full-pack type IPM, substrate-type IPM Enhanced moisture resistance and broader adhesion compatibility with Cu, Au, and Ni finishes compared to standard GR60 grades.
Hysol GR600 / GR600‑P1 1.41 W/mK TO251 (IPAK), TO252 (DPAK), TO263 (D2PAK), TO220 Power-discrete EMC focused on DPAK and D2PAK-class packages, with formulations designed to support MSL1 qualification and improved thermal cycling performance.
Hysol GR730HT 3.2 W/mK PSIP, TO applications, TO252 High-thermal-conductivity, halogen-free grade for Power Supply in Package (PSIP) and TO-type power packages.
LINQSOL EMC‑G135 1.7 W/mK Rectifier bridges, SMX Low-cost thermally conductive EMC for bridge packages such as GBU, KBJ, and GBS.
LINQSOL EMC‑5013 2.3 W/mK TO220F, TO3PF, full-pack power packages Thermally conductive EMC for TO and full-pack power devices, with published thermal conductivity exceeding 2 W/mK.
LINQSOL EMC‑G375 Up to 3.3 W/mK TO‑3P, TO‑220, TO‑126, bridge rectifier, high‑power semiconductor packages High-thermal-conductivity grade aimed at full-pack TO power packages, bridge rectifiers, and other high-power semiconductor applications.
Disclosure: Thermal conductivity values are typical, supplier-reported data measured under specified test conditionsi n thier datasheets. Actual in-package performance may vary depending on package design, molding conditions, and application environment.
Legacy Semiconductor Epoxy Molding Compounds
Product Name Key Properties
Color Specific Gravity Glass Transition Temperature (Tg), °C CTE, Alpha 1 ppm/°C CTE, Alpha 2 ppm/°C Moisture Absorption Ionic Content Na+/K+/Cl- ppm Spiral Flow Thermal Conductivity (W/mK) Dielectric Constant
MG15F-35A Black 1.82 191 21 63 0.64% 4/1/7 28" 0.7 3.5
MG21F-02 Black 1.81 179 21 62 0.61% 4/1/6 26" 0.7 3.6
MG33F-0520 Gold 1.87 170 20 70 - 1.5/-/2 25" - 4.3
MG33F-0661 Gold 1.81 164 18 60 0.42% - 27" 0.8 4.1
MG57-0660 Gold 1.82 168 21 70 0.42% - 30" - 4.2
MG33F-0602 Black 1.80 162 22 65 - 2/-/7 43" - 3.9

Frequently asked questions

What exactly is an HTRB test?

A "High Temperature Reverse Bias" test is a common reliability test that exposes the power devices (and hence the EMC) to the "worst case scenario" under which it must perform and not fail. During the HTRB test, the power semiconductor devices are stressed at the maximum rated reverse breakdown voltage at a temperature close to their maximum rated junction temperature (Tj max) over a defined period of time. As such, a HTRB cannot be completely understood until the variables of voltage, temperature and time are defined.

What is the ionic content in epoxy mold compound that causes semiconductor device failure?

There are four main elements that should be minimized in epoxy molding compounds. There are Chlorine (Cl-), Sodium (Na+), Fluorine (F-) and Potassium (K+), where chlorine and sodium are the most important. All the ionic content shoudl be kept under 20ppm for each individual element and less than 5ppm is desired for Chlorine and Sodium.

What is Reverse Bias?

Basically, semiconductors allow current to flow in one direction: from the p-type (positive) to the n-type (negative). Reverse bias is applying direct current (DC) voltage to prevent current flow in a diode, transistor or similar. Wikipedia has a good desription in Reverse Bias

What is the relationship between Permittivity and Dielectric Constant?

The dielectric constant is unitless because it is actually the ratio of two permittivity values: the permittivity of the substance to the permittivity of the free space. Since the lowest possible permittivity is obtained in a vacuum, the permittivity of the substance is always higher and therefore the dielectric constant is always higher than 1.

What is Ionic Mobility?

Otherwise known as Electrical Mobility, it is the ability of charged electrons or protons to move through a substance (in this case epoxy mold compound) in response to an electric field that pulls them.

How can I decap ICs?

We could suggest the obvious mechanical methods but if you came here you probably want to preserve the integrity of the bond wires and the die. That's why, typically, customers use a Nitric or Sulfuric acid to etch away the epoxy. Though you should definitely take the necessary precautions with a hume hood, no inhalation, customers have used this successfully without damaging the wires. Here are almost 8 million words (30 fps, we did the math)

What is the maximum staging time of molded products between molding and PMC?

For EMC molded packages, one-shift maximum, often 8 hours from demold or ejection to the PMC heating start timestamp, is a typical production practice, applicable only under monitored humidity control and validated for the package/EMC. 

Why immediate PMC is ideal?

Immediate PMC is ideal because WIP strips enter the oven in a tighter, more consistent condition, improving lot-to-lot consistency. Shorter waiting reduces moisture exposure and reduces cure drift before oven heating, which usually improves warpage consistency, reduces SAM delamination risk, and lowers reflow crack risk.

Does EMC formulation influence staging tolerance?

Yes, EMC formulation influences staging tolerance because EMC systems differ in cure kinetics and moisture resistance. Some EMCs continue curing faster during room-temperature holds, narrowing the staging window, while other EMCs slow moisture uptake at a given RH and time. Practical rule: staging limits should be verified per EMC and package family.

What to do when staging exceeds the limit?

When staging exceeds the limit or RH control is violated, a simple principle helps: contain, recover, verify. Containment means moving WIP strips within the defined response time into defined dry storage such as a dry cabinet at or below the site dry storage RH specification, sealed moisture barrier bag with desiccant, or an equivalent approved method. Recovery means running dry bake at 125°C for 2 to 4 hours followed by PMC at the earliest opportunity. The dry bake will remove the moisture absorbed in the package prior to PMC. Verification means applying the site excursion disposition, often focused on SAM delamination checks and warpage checks for affected lots.

Learn more

Epoxy Molding Compounds

Epoxy Molding Compounds (EMC) by their nature have very good electrical insulation properties. Epoxy Mold Compounds are often called "functional epoxies" or "high solid epoxies" because they are heavily loaded with fillers. These fillers, (typically silica, though other fillers are used for other properties such as thermal conductivity) are loaded more than 50% by weight be default. Highly filled systems have weight % filler loadings higher than 70% with "very highly filled loadings" as high as 92% filled by weight.

These highly-filled systems provide epoxy molding compounds with very good dielectric strength and a very high breakdown voltage, which themselves are good electrical insulation properties. These two values however are poor indicators of what is meant by "Good electrical stability" for EMCs

Low permittivity means high electrical stability for epoxy mold compounds

Figure 1. Low Permittivity means high electrical stability
Graph of ionic conductivity at different frequencies to show electrical stability of epoxy mold compound

Figure 2. Ionic conductivity at different frequencies

What do we mean by good electrical stability?

Good electrical stability means that there is very little ionic movement within the epoxy mold compounds when semiconductor devices are under reverse bias at elevated temperatures. The High Temperature Reverse Bias (HTRB) reliability test is an excellent industry-developed and accepted test that tests the electrical stability of EMCs

Epoxy mold compound that are considered to have excellent electrically stability are thus those that:

  • Have low ionic conductivity
  • Have a low and stable permittivity at temperatures up to 200°C
  • Have a high dielectric strength
  • Have a stable dielectric constant over a frequency range from 1 kHz up to 1.8 GHz

What causes poor electrical stability in mold compounds?

There are two main causes of poor electrical stability in EMCs:

  1. The ingredients used have high ionic content
  2. The epoxy resin and hardner combination has high ionic conductivity

EMC subcomponents have high ionic content

Epoxy molding compounds are made up of many components including epoxy resins, curing agents, catalysts, fillers, pigments and additives. Each of these ingredients can contain ions in the form of chlorine (Cl-), Sodium (Na+), Fluorine (F-) and Potassium (K+). There are elements other than these that have ions, but these are the ions most frequently present and in the highest quantities - therefore are of the greatest interest. As you can see next to the elements listed, Chlorine and Fluorine both have negative (-) ions and Sodium and Potassium both have postitive (+) ions.

Of these four elements, the biggest culprits are Chlorine (Cl-) and Sodium (Na+). If the total ionic content is too high, or the ionic content of each of the Chlorine or Sodium is too high, then the risk of gate current leakage and device malfunction increases. In all semiconductor applications, it is prudent to have the total extractable ionic content to be less than 80ppm and the extractable content of each element to be below 20ppm. In high power semiconductor applications which operate at higher voltages and higher temperatures, it is better to have the total ionics to be below 20ppm, and of each element to be below 5ppm. As application temperature and power increase, the lower the ionic content the better.

Epoxy resin/hardner combination has high ionic conductivity

When exposed to the electric field caused by the DC voltage applied, these ions have a tendency to move. If they move too much, a gate current leakage occurs and gradually increases which ultimately leads to the device malfunction.

Different combinations of epoxy resin and hardener, will provide different ionic conductivities of the base epoxy. Specifically, as illustrated in Figure 1 below, a standard epoxy cresol novolac resin with a standard phenolic resin might have a low permittivity at lower temperatures, but quickly elevate at higher temperatures leading to gate current leakage failures for power semiconductor devices.

Formulating electrically stable Molding Compounds

Epoxy mold compound formulators can develop materials that will pass the HTRB test by developing EMCs that:

  • Have low ionic content, low ionic content and low ionic mobility
  • Use ion trappers
  • Have low permittivity
  • Use epoxy resin & hardener combinations that have the lowest ionic content and mobility

Selecting Semiconductor Mold Compounds

When looking for epoxy molding compounds that are very electrically stable, look for the following characteristics:

  • Look for epoxies with a low permittivity over a wide temperature range as in Figure 1.
  • Look for epoxies with a low ionic conductivity over a wide frequency range and at elevated temperatures as in Figure 2
  • Look for epoxies with a stable dielectric constant up to 1.8 GHz as in Figure 3.

Choosing between granular and powder molding compound

Compression molding performance is often limited by solids handling and melt timing, not only resin chemistry. Powder EMC can dust, bridge, and contaminate equipment if fines are not controlled, while oversize particles can delay melt and create surface or appearance anomalies. Granule-shape powder EMC exists to tighten particle size distribution for stable feeding and thickness control in compression molding.

Decision factor Granule-shape powder EMC Powder EMC
Feeding stability (bridging, rat-holing, dosing repeatability) Typically stronger due to low fines and tighter PSD Typically more sensitive to fines, moisture pickup, and dust loading
Cleanliness (dust, equipment contamination, maintenance load) Typically lower dust by design Higher dust risk if fines are not tightly limited
Thickness control and uniformity Often easier to maintain due to engineered PSD Achievable, but relies more on deposition method and powder control
Melt timing and appearance risk Lower risk when oversize is tightly limited (top cut enforced) Higher risk if a long oversize tail exists (delayed melt, appearance anomalies)
Intrinsic thermal stability (Tg retention, aging resistance) No inherent advantage from form alone No inherent disadvantage from form alone
True cost of ownership May reduce hidden costs from contamination and yield drift May reduce material cost per kg but can raise cleaning and yield-drift costs depending on controls

Powder versus granule-shape powder EMC is best treated as a solids-handling and melt-behavior decision, not a claim about inherent “better” material properties. Granule-shape powder is engineered to reduce the two main compression-molding pain points: fines-driven dust or blocking and oversize-driven delayed melt. Fine powder increases dust and can cause blocking, while large particles can delay melt and trigger abnormal appearance, which is why granule-shape powders with tighter particle size distributions are commonly used to stabilize compression molding operations.

Use powder EMC when your deposition method, environment, and housekeeping controls can keep dust, moisture pickup, and feeder variation tightly managed, especially in thin-mold applications where uniform melt timing matters. Use granule-shape powder EMC when you want the most robust day-to-day operation across long runs, particularly with dust-sensitive feed and distribution hardware. In either case, write specifications that clearly separate compound form PSD (fines and oversize limits for powder versus granules) from filler PSD (filler D50 and filler top cut), since filler size distribution optimization is a separate lever used to manage long-flow behavior and issues such as resin bleed.

EMC Adhesion on Different Substrates

In semiconductor packaging, delamination rarely starts because the base metal is “wrong”. It starts because the epoxy molding compound (EMC) is bonding to the real surface state: an oxide, a plating top layer, a passivation film, or residues from handling, flux, anti-tarnish, or mold release. That is why a single universal adhesion ranking (Cu vs Ni vs Al vs Ag vs Au) is not reliable unless you also define the finish stack, surface preparation, storage history, and the time between activation and molding.

“Good adhesion” is not just high initial pull strength. For molded packages, good adhesion means:

  • Strong interfacial integrity immediately after mold and post-cure
  • Low voiding and minimal interfacial defects (especially at corners and die edges)
  • Adhesion retention after moisture soak and reflow (MSL preconditioning)
  • Resistance to delamination growth during thermal cycling and humidity aging
Types of delamination in molded packages

Figure 3. Common delamination locations and patterns in molded packages

Practical takeaway: Treat adhesion as an interface engineering problem (surface state + interphase + stress), not a simple “metal name” problem.

Interface creation and validation flow

How EMC Adhesion Is Built and Verified

 

Adhesion is created during surface preparation, activation, and the short window between flow and gel. It is proven only after stress, especially moisture plus reflow, where weak interfaces turn into delamination.

Incoming finish state
→
Clean and dry
→
Activate (plasma or micro-etch)
→
Control time-to-mold
→
Mold fill and pressure
→
Gel and cure
→
Post-cure
→
CSAM baseline
→
MSL soak and reflow
→
CSAM delta

Practical adhesion order

The most reliable way to discuss “adhesion order” is to rank surface families (finish + surface state), not just elements. Use the table below as a screening guide, then validate on your exact finish stack and process window.

Surface family Typical adhesion potential Most common adhesion killers Highest leverage fixes
Cu and Cu alloys (micro-etched, oxide-controlled) High (when controlled) Over-oxidation, organic contamination, inconsistent roughness Controlled micro-etch/texture, plasma clean, tight time-to-mold
Ni and Ni-based finishes (including Ni stacks) Medium to high (process dependent) Noble top layer exposure, residues in plating stack, aging after activation Plasma activation, define true top layer contact, shorten activation-to-mold time
Al and Al oxide surfaces Medium to high (process dependent) Contamination, moisture sensitivity at weak interphase Plasma activation, bake and storage control, ionic cleanliness discipline
Organic passivation (polyimide, PBO, solder mask, ABF-like organics) Medium to high (when activated) Silicone contamination, under-cure or residual solvent, long delay after plasma Plasma activation, time-to-mold limits, contamination audits (especially silicones)
Solder and solderable surfaces (including die attach-adjacent regions) Variable Oxides, flux residues, poor cleaning and drying, voiding at interface Cleaning validation, dry-bake, optional plasma, control residues and moisture
Ag finishes (Ag spot, anti-tarnish present) Often low unless controlled Anti-tarnish films, tarnish state variability, handling contamination Plasma cleaning, strict storage and handling control, finish strategy review
Au top surfaces (noble top layer) Often low unless controlled Low chemical affinity, rapid surface aging after activation Plasma activation, minimize air exposure before molding, confirm true contact layer

One-line screening order: Cu > Ni > Al > Organic passivation > Die attach (PbSnAg) > Ag > Au

Disclaimer: This is a practical baseline only. Actual adhesion can invert depending on the real surface state (oxide condition, plating stack top layer, anti-tarnish or residues), surface preparation, time-to-mold after activation, and the specific EMC formulation and stress profile.

How to improve EMC adhesion and prevent delamination

Most adhesion escapes fall into three buckets. Fix them in this order:

  1. Surface and contamination: remove organics and silicones, control anti-tarnish and flux residues, prevent mold release transfer, and define storage limits for finishes before molding.
  2. Contact and cure during molding: ensure the compound fully wets and contacts the surface before gel, maintain pressure for intimate contact, and avoid voiding or knit-line driven interfacial defects.
  3. Stress and environment: manage cure shrinkage and modulus-driven peel stress, enforce moisture control (pellets and substrates), and validate adhesion retention after moisture soak and reflow.

Read more: Improving Epoxy Molding Compound Adhesion to Substrates

Related Blogs

High Solder-Reflow, Crack Resistant Molding compounds

High Solder-Reflow, Crack Resistant Molding compounds

Rose Anne Acedera, June 2024

This blog discusses CAPLINQ’s development of solder­ reflow crack resistance (popcorn crack resistance) molding compounds,

Improving Epoxy Molding Compound Adhesion to Substrates

Improving EMC Adhesion

Rose Anne Acedera, February 2024

This blog explores the strategies to improve the adhesion strength of epoxy molding compounds on substrates 

Advances in Epoxy Molding Compounds – Dexter Technical Paper (1992)

Dexter Technical Paper on EMCs (1992)

Rose Anne Acedera, July 2023

This blog simplifies and discusses the technical paper written by  Dr. H. W. Rauhut of the Dexter Electronic Materials Division regarding recent advancements in epoxy molding compounds for semiconductor devices.

Presentations

Introduction to Epoxy Molding Compounds

James Daniel Baduria, March 2024

This presentation introduces epoxy molding compounds (EMCs) used in semiconductor packaging, explaining their functions, material formulations, and key performance requirements. It provides a foundation for understanding how EMCs protect integrated circuits from mechanical stress, moisture, and environmental exposure while ensuring long-term package reliability.

Properties and Characterization Method for EMCs

James Daniel Baduria, May 2024

This presentation examines the key physical, mechanical, thermal, and electrical properties of epoxy molding compounds and the methods used to characterize them. It explains why these properties are critical for semiconductor package reliability and how standardized testing supports material selection and process optimization.

Mold Defect Troubleshooting Guidelines

James Daniel Baduria, April 2024

This presentation provides practical guidance for identifying, analyzing, and resolving common molding defects encountered during semiconductor encapsulation. It reviews typical defect types, their root causes, and recommended corrective actions to improve manufacturing yield, product quality, and overall process reliability.

 

Leading Brands Trust in Our Products and Services

Jabil logo Linxens logo Magna logo Medtronic logo NXP logo Philips logo Semikron logo Teledyne logo Thales logo Vishay logo ZF logo AMS logo Apple logo Audi logo Broadcom logo Borgwarner logo Bosch logo Eaton logo Henkel logo Honeywell logo Hysol logo Intel logo
Products that Perform | Knowledge that Serves | Service that Delivers