This specification covers thermoset plastics based on diglycidyl ethers of bisphenol A and amino functional curing agents or amine catalysts for implantable epoxy electronic encapsulants. Encapsulants shall be classified depending on contact with tissues or physiological fluids. Chemical composition requirements may include additives, phthalate esters, amines, catalysts, and carbonates. The material shall be tested for the following physical properties: peak exotherm temperature, transparency, foreign particles, USP biological test plastic containers, USP pyrogen test, sterilant residues, cure shrinkage, embedment stress, tissue culture test, long-term immersion test, and accelerated immersion test. The material shall also be inspected with infrared spectroscopy, amine number, epoxide equivalent weight, spectrographic analysis, and total nitrogen.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

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 Limitations—This 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies

D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation

D257 Test Methods for DC Resistance or Conductance of Insulating Materials

D570 Test Method for Water Absorption of Plastics

D638 Test Method for Tensile Properties of Plastics

D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

D1042 Test Method for Linear Dimensional Changes of Plastics Under Accelerated Service Conditions

D1239 Test Method for Resistance of Plastic Films to Extraction by Chemicals

D1434 Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting

D2240 Test Method for Rubber Property--Durometer Hardness

D2471 Practice for Gel Time and Peak Exothermic Temperature of Reacting Thermosetting Resins

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

D2566 Test Method for Linear Shrinkage of Cured Thermosetting Casting Resins During Cure

D2734 Test Methods for Void Content of Reinforced Plastics

D3137 Test Method for Rubber Property--Hydrolytic Stability

F74 Practice for Determining Hydrolytic Stability of Plastic Encapsulants for Electronic Devices

F135 Test Method for Embedment Stress Caused by Casting Compounds on Glass-Encased Electronic

F602 Criteria for Implantable Thermoset Epoxy Plastics

F748 Practice for Selecting Generic Biological Test Methods for Materials and Devices

F895 Test Method for Agar Diffusion Cell Culture Screening for Cytotoxicity

F981 Practice for Assessment of Compatibility of Biomaterials for Surgical Implants with Respect to Effect of Materials on Muscle and Bone

AAMI Standard

ISO Standard

Keywords

encapsulants; evaluation of biocompatibility; implantable medical devices; Electronic materials/applications--specifications; Epoxy (EP) plastics--specifications; Implantable surgical materials/applications--specifications; Pacemakers; Pulse generators; RF (radio frequency) receivers; Surgical implants--specifications; Telemetry devices; Electronic encapsulants;

ICS Code

ICS Number Code 11.040.40 (Implants for surgery, prothetics and orthotics)

Citing ASTM Standards

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