ASTM F641-09 - 1.8.2009
 
1. Scope

1.1 This specification covers thermoset plastics based on diglycidyl ethers of bisphenol A and amino functional curing agents or amine catalysts.

1.2 The epoxy encapsulants covered by this specification are intended to provide a tissue-compatible protective covering for implantable medical devices such as pulse generators, telemetry devices and RF receivers. The biocompatibility of epoxy plastics has not been established. Epoxy plastic is a generic term relating to the class of polymers formed from epoxy resins, certain curing agents or catalysts and various additives. Since many compositions and formulations fall under this category, it is essential that the fabricator assure safety of implantability of the specific composition or formulation for the intended use by current state-of-the-art test methods. This specification can be used as a basis for standardized evaluation of biocompatibility for such implantable encapsulants.

1.3 The encapsulants covered by this specification are for use in devices intended as long-term implants.

1.4 LimitationsThis specification covers only the initial qualification of epoxy encapsulants for implantable electronic circuitry. Some of the requirements are not applicable to routine lot-to-lot quality control.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

D149-20

Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies

ISO 10993

Biological Evaluation of Medical Devices Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.

D257-14(2021)e1

Standard Test Methods for DC Resistance or Conductance of Insulating Materials (Includes all amendments and changes 5/6/2021).

D570-22

Standard Test Method for Water Absorption of Plastics

D638-22

Standard Test Method for Tensile Properties of Plastics

D790-17

Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

D1042-22

Standard Test Method for Linear Dimensional Changes of Plastics Caused by Exposure to Heat and Moisture

D1239-22a

Standard Test Method for Resistance of Plastic Films to Extraction by Chemicals (Includes all amendments and changes 9/12/2022).

D1434-23

Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting

D2240-15(2021)

Standard Test Method for Rubber Property—Durometer Hardness

D2471-99

Standard Test Method for Gel Time and Peak Exothermic Temperature of Reacting Thermosetting Resins (Withdrawn 2008)

D2562-94(2015):2015/ADJD2562

Adjunct to D2562 Practice for Classifying Visual Defects in Parts Molded from Reinforced Thermosetting Plastics

D2566-86

Test Method for Linear Shrinkage of Cured Thermosetting Casting Resins During Cure

D2734-23

Standard Test Methods for Void Content of Reinforced Plastics

D3137-81(2018)

Standard Test Method for Rubber Property´Hydrolytic Stability

F74-73(1989)

Practice for Determining Hydrolytic Stability of Plastic Encapsulants for Electronic Devices (Withdrawn 1994)

F135-76(1991)

Test Method for Embedment Stress Caused by Casting Compounds on Glass-Encased Electronic Components (Withdrawn 1997)

F602-09(2015)

Standard Criteria for Implantable Thermoset Epoxy Plastics

F748-16

Standard Practice for Selecting Generic Biological Test Methods for Materials and Devices

F895-11(2016)

Standard Test Method for Agar Diffusion Cell Culture Screening for Cytotoxicity

F981-23

Standard Practice for Assessment of Muscle and Bone Tissue Responses to Long-Term Implantable Materials Used in Medical Devices

EOS-D

E-O Sterilization Standard Available from Association for Advancement of Medical Instrumentation, 1500 Wilson Blvd., Suite 417, Arlington, VA 22209.

D150-22

Standard Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation