CLA-2 CO:R:C:M 951151 EJD

TARIFF NO: 3921.90.40

J. F. Fritz
Customs Liaison
Norman Krieger, Inc.
P.O. Box 92599
Los Angeles, California 90009

RE: Prepreg; GRI 2(b); GRI 3(b); HQ 087721; HQ 951321; Heading 7019

Dear Mr. Fritz:

This is in response to your letter of December 31, 1991, to Customs in New York, concerning the tariff classification of a commodity referred to as prepreg under the Harmonized Tariff Schedule of the United States (HTSUS). Your letter was referred to this office for a response.

FACTS:

Prepreg is a composite material that is manufactured by Multi-Layer International Inc. in the Philippines and is composed of "E" grade (electrical) glass fabric, brominated epoxy resin, dioyanex 200 and dimethyl formamide. It is, in essence, a woven electrical grade fiberglass fabric, coated by a white colored plastic which is impregnated with a brominated epoxy resin which is used as a dielectric or insulator in printed circuit boards.

The process by which prepreg is made is a reel to reel technique, wherein woven fiberglass is unwoven from a mill roll and immersed in a bath which thoroughly saturates the glass. It is then passed through a forced air oven where the solvents are devolatilized, and then rewound to rolls of suitable length. The saturating bath consists of a solid epoxy resin and curing agent blended with appropriate solvents. The resultant varnish is homogeneous, medium viscosity solution.

The glass fabrics employed are available in a number of styles, although the chemical composition of the glass does not vary. The difference among the styles has to do with the glass

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filament diameter, the number of filaments which comprise each strand, and the number of strands used in the weaving process.

ISSUE:

What is the proper classification of prepreg under the HTSUS?

LAW AND ANALYSIS:

Merchandise is classifiable under the Harmonized Tariff Schedule of the United States (HTSUS) in accordance with the General Rules of Interpretation (GRIs). GRI 1 states in part that for legal purposes, classification shall be determined according to the terms of the headings and any relative section or chapter notes, and provided the headings or notes do not require otherwise, according to GRIs 2 through 6.

GRI 2(b) provides that a reference to a material in a heading shall be taken to include mixtures or combinations of that material with other materials and that any reference to goods of a given material shall be taken to include goods partly of that material; if goods consist of more than one material, then classification will be according to GRI 3.

GRI 3(a) requires that where two or more headings describe the merchandise, the more specific will prevail; or if two or more headings each refer to part only of the materials in the goods, then classification will be by GRI 3(b). GRI 3(b) states that the material or component which imparts the essential character to the goods will determine their classification.

After reviewing the file on this matter, by memorandum dated May 5, 1992, the Customs Office of Laboratories and Scientific Services has furnished us with the following information.

* * * In the instant prepreg case, (as in the case of the other two) [HQ 087721 and HQ 951321] we are of the opinion that the primary purpose of the fiberglass is to act as a carrier for the resin and as a reinforcement material for the finished product. The fiberglass material's insulative and thermal properties simply make it more suitable for usage in the product than any other reinforcement fabric. Consequently, the major physical characteristics of the prepreg are given by the epoxy resin and not the fiberglass.

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Pursuant to GRI 2(b), the merchandise is described by and prima facie classifiable under heading 3921, HTSUS, as other sheets and film of plastics, and heading 7019, HTSUS, as articles of glass fibers. Therefore, it must be determined whether the glass cloth or brominated epoxy resin gives the merchandise its essential character.

In Headquarters Ruling Letter (HQ) 087721, March 5, 1992, Customs dealt with the classification of polyimide prepreg. In this case the formulation of the prepreg was different than the instant prepreg only in that the impregnating and coating resin is an epoxy rather than a polyimide. In HQ 087721, Customs determined

that polyimide plastics is a very specialized type of plastics with unique insulating and heat resistent properties. As such, while it appears that the glass fiber fabric in the instant merchandise has similar properties, those properties merely make the glass fiber fabric more suitable as a carrier for the polyimide plastics material. On the basis of all the information that we have available, it appears that it is the polyimide plastics which provides the primary insulative attributes to the prepreg. Accordingly, it is the polyimide plastics which imparts the essential character to the imported merchandise[.]

Further, in Headquarters Ruling Letter (HQ) 951321, July 28, 1992, Customs dealt with the classification of epoxy prepreg. In this case the formulation of the prepreg is essentially identical to the prepreg in the instant case. In this ruling, Customs Office of Laboratories and Scientific Services furnished us with the following information.

The prepreg product under consideration is used to manufacture a product which is known as an electrical laminate, a product in which epoxy resins are commonly found. Epoxy resins have gained wide acceptance in electrical applications due to their exceptional combination of properties such as toughness, adhesion, chemical resistance and superior electrical properties. Epoxy resins which are used to produce electrical laminate sheets, such as the prepreg, are present due to its excellent electrical properties as well as its adhesive properties.

Information in the file shows that the prepreg layers are used to separate layers of copper foil and/or printed circuits in the construction of multi- layer printed circuit boards. Therefore, it appears that the prepreg is being used not only for its excellent insulative (electrical) properties but also

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for its adhesive properties and its ability to cure to a rigid infusible machineable (engineering plastic) state. These characteristics are given to the prepreg by the epoxy resin and not the fiberglass component. Therefore, although the prepreg would probably not be excluded from Heading 7019 and directed to Chapter 39 by Exclusionary Note (a) to that Heading, the prepreg sheet in its cured state most definitely would.

We note that fiberglass is an excellent insulative material in its own right. However, in the case at hand, it appears that the fiberglass material is used as a carrier for the epoxy resin in its precured state and acts as a reinforcement material in the finished product. * * * It appears that in the case of the prepreg, fiberglass fabric is used as the carrier and reinforcement agent because it is a highly non- conductive material and it is more resistive to heat than ordinary fabrics of organic composition. Based on our experience with plastics sheeting materials, we are of the opinion that the primary purpose of the fiberglass is to act as a carrier for the prepreg and a reinforcement material for the finished product. The fiberglass material's insulative and thermal properties simply make it more suitable for usage in the product than any other reinforcement fabric.

In view of the above, and other product information, we are of the opinion that the essential character of the subject composite good is derived from the brominated epoxy resin material.

GRI 3(b) requires that the prepreg is properly classified under subheading 3921.90.40, HTSUS, which provides for "[other plates, sheets, film, foil and strip of plastics...[o]ther... [o]ther," with a rate of duty of 4.2 percent ad valorem.

HOLDING:

The subject prepreg is classifiable under the provision for other flexible plates, sheets, film, foil, and strip of plastics, in subheading 3921.90.40, HTSUS.

Sincerely,

John Durant, Director
Commercial Rulings Division