Father's debt has no legal basis. But as far as friendship is concerned, Zi can pay his father's debts.
At present, the best way for banks is to apply to the court for property preservation (mainly your personal business property and its income). The part that cannot be repaid depends on whether the original risk control department of the bank is strict and whether there is any fault. And the principle of appropriate sharing.
The personal part often uses the credit part to continue to repay the loan, such as personal salary, husband and wife property, etc. .