X0306 4 2017-03-17 0001029125 Sun BioPharma, Inc. SNBP 0001394821 GILBERTSON RYAN RANDALL 1000 PARKER'S LAKE ROAD WAYZATA MN 55391 1 Convertible Promissory Note 1.01 2017-03-17 4 A 0 200000 200000 A 2017-03-17 2018-12-01 Common Stock 198020 200000 I Northern Capital Partners I, LP Convertible into issuer common stock a price of $1.01 per share upon reporting person's election. Upon a "qualified financing", automatically converts into common stock at the foregoing price per share or (if less) a price representing a 33% discount from either (a) the price per share of common stock (if any) offered in such financing or (b) the closing price of issuer common stock on the date the material terms of such financing are first publicly announced, subject to reporting person's right to elect an alternate conversion into the securities then offered at a 10% discount to the price paid in the financing. Upon a corporate transaction, automatically converts into common stock at a price equal to $30 million divided the number of issuer common stock outstanding (calculated on a fully-diluted basis). Represents original principal amount. Represents shares of issuer common stock into which the outstanding principal amount was convertible upon the date of the transaction. Does not include shares issuable upon conversion of unpaid interest, which accrues at a rate of 5.0% per annum. /s/ Joshua L. Colburn, Attorney-in-fact for Ryan R. Gilbertson 2017-03-21