get方法params转换并附加到url后乱码，怎么解决

Question

var getSnInfo = function(){
        var url = Api.getInfo,
            sn = $scope.data.id;
            console.log(sn)
        $http({
                method: 'GET',
                url: url,
                params: sn,
                headers: {'Content-Type': 'application/x-www-form-urlencoded'},

            }).then(function(response){