woocommerce/templates/taxonomy-product_cat.php

<?php
/**
 * The Template for displaying products in a product category. Simple includes the archive template.
 *
 * Override this template by copying it to yourtheme/woocommerce/taxonomy-product_cat.php
 *
 * @package WooCommerce
 */

woocommerce_get_template( 'archive-product.php' );