async函數(shù)返回值使用then解析后undefined

service的代碼如下：

exports.findSignupInfo = async function(queryObj) {
    try {
        // 模糊查詢條件開始
        let reg = new RegExp(queryObj.coreName);
        let query = {
            name: reg
        };
        // 模糊查詢條件結(jié)束
        let connection = await DB.connect('coreEnterprises'); // 連接數(shù)據(jù)庫(kù)
        let result = await DB.find(connection, query);
        result.toArray(function(err, result) { // 模糊查詢
            response.data.datalist = [];
            for (let i = 0; i < result.length; i++) {
                let item = {};
                item.name = result[i].name;
                item.hmA = result[i].hmA;
                response.data.datalist.push(item);
            }
            response.data.pagecond = {
                page: 1,
                count: 1,
                pageSize: 5,
                totalPages: 1
            };
            return response;
        });
    } catch (err) {
        console.log(err);
    }
};

在controller的代碼里調(diào)用service中的findSignupInfo方法，代碼如下：

router.get('/v1/ccb/signup/order/find', function(req, res) {
    service.findSignupInfo(req.query).then(response => {
        res.send(response);
    });
});

可是這里的response總是undefined
請(qǐng)問(wèn)這里應(yīng)該怎么改？