Exhibit 4.18



 Exhibit 4.18 
  
 [English Translation] 
  
 Confidential 
  
 MOSEL VITELIC INC. 
  
 1990 SERIES NO. 1 GUARANTEED CORPORATE BONDS 
  
 SALE AND PURCHASE AGREEMENT 
  
 Parties to this Agreement: 
  
 ChipMOS TECHNOLOGIES INC., a company duly established and validly existing under the law of the Republic of China, with its principal office at No. 1, Research and
Development Road 1, Science-based Industrial Park, Hsinchu (“Party A”), and 
  
 Ron How Investment Corp., a company duly established and validly existing under the law of the Republic of China, with its principal office at 3F., No. 53, Section 3, Chengde Road, Datong District, Taipei (“Party B”). 

 
 Whereas Party B is the holder of the Mosel Vitelic Inc. (“Mosel Vitelic”) 1990
Series No. 1 Guaranteed Corporate Bonds (the “Mosel Vitelic Bonds”). Prior to the date of this Agreement (the “Execution Date”), Party B holds unmatured Mosel Vitelic Bonds with the aggregate principal amount of NT$55,000,000 and
all the related rights (excluding the overdue interest payments in the amount of NT$780,000 for the period starting from February to April, 2003) (the “Corporate Bonds Rights”). 
  
 Whereas Party A intends to buy from Party B the Corporate Bonds Rights held by Party B, and Party B intends to transfer and sell to Party A
the Corporate Bonds Rights. After negotiation in good faith, the parties execute this Agreement and agree upon the following terms and conditions: 
  

	Article 1    Sale	 	and Purchase of Corporate Bonds 

  
 Party B agrees to sell to Party A the Corporate Bonds Rights and all related present and future rights (excluding the overdue interest payments for the period starting
from February to April, 2003) for the purchase price of NT$55,000,000 (the “Purchase Price”) plus the interests payments on installments (see Article 2 for details). Party A also agrees to purchase at the Purchase Price from Party B such
Corporate Bonds Rights in accordance with the terms of this Agreement. 








	Article 2	 	Settlement and Payment 

  
 1. Both parties agree that April 25, 2003 is the closing date for the sale and purchase of Corporate Bonds Rights under this Agreement (the “Closing Date”).

  
 (1) On the Closing Date, Party B shall deliver to Party A the Mosel Vitelic
Bonds of the Corporate Bonds Rights. 
  
 (2) The Purchase Price shall be paid in
12 installments. When Party A receives the Mosel Vitelic Bonds as provided in the preceding paragraph, Party A shall from May 2003 pay an installment on the 25th day of each month on each payment date. When Party A receives the Mosel Vitelic Bonds
of the Corporate Bonds Rights, Party A shall deliver to Party B twelve (12) checks, each issued by Mosel Vitelic Inc. (“Mosel Vitelic”) for the amount of the installment payment stated above, endorsed by Party A and dated the various
payment dates as described above. On each payment date, Party A shall pay the interest payments for any unpaid balance of the Purchase Price, calculated monthly on a simple interest rate of 5.7% per annum. After Party A receives the Mosel Vitelic
Bonds as provided in the preceding paragraph, Party A shall deliver to Party B twelve (12) checks, each dated with the various payment dates as provided above and issued by Party A for the amount of the interests that are due as stated above (after
deducting taxes withheld and paid by Party A on its behalf). (The claims to the Purchase Price and interests mentioned in this paragraph shall be referred to as the “Installment Payments Claims”. See Appendix 1 for details on the list of
various Installment Payments Claims and photocopies of checks.) 
  
 2. Party A and
Party B agree that upon the closing, Party B shall fully transfer to Party A the creditor rights, interest claims that have or have not matured, the collateral rights and other related rights that Party B may have under the memorandum of Mosel
Vitelic 1990 Series No. 1 Guaranteed Corporate Bonds and its appendices and related agreements, including but not limited to the corporate bonds trust indenture (the “Original Trust Indenture”) between Mosel Vitelic and the trustee, China
Trust Commercial Bank. Party B shall not exercise any rights based on the Original Trust Indenture. If it becomes necessary for Party A or Party B to provide relevant documents to the Trustee, China Trust Commercial Bank, or other third parties in
order to prove the transfer and assignment of the Corporate Bonds Rights, Party B shall cooperate and produce the relevant documents required. 
  

	Article 3	 	Entrusted for Custody 

  
 1. Party A agrees that, at the closing, Party A shall deliver shares of ProMOS TECHNOLOGIES INC. duly affixed with the transfer seals (the “ProMOS Shares”) to a
bank (the “Custodian Bank”) jointly designated by both parties. 
  
 2.
The ProMOS Shares that are delivered for custody in accordance with the preceding paragraph shall have, at the time of closing, an aggregate value of 160% of the Purchase Price. The value of the ProMOS Shares shall be calculated based on their
closing price on the day before the Closing Date. After the check for each of the Installment Payments Claims is cashed, Party A may request the Custodian Bank to return 1/12 of the aggregate number of the ProMOS Shares; Party B shall assist as
necessary, including but not limited to providing consent letters. Both parties confirm that the production of consent letters by Party B is not a prerequisite for the Custodian Bank to return the ProMOS Shares. 
  
  

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 3. Unless otherwise provided in this Agreement, on the day on which the Installment Payments Claims are fully paid, Party
A may request the Custodian Bank to return to Party A all the ProMOS Shares that have not been collected by Party A, and Party B shall assist as necessary. 
  
 4. If there are ex-dividends in respect of the shares entrusted for custody, they shall be collected by Mosel Vitelic. 
  

	Article 4	 	Prepayment 

  
 Before the expiration of the various payment dates for the Installment Payments Claims, Party A may pay one, several (the order of prepayments is to be decided by Party A) or all of the installments for the
Installment Payments Claims; Party B may not refuse such prepayments, and Party B shall return to Party A the checks intended by Party A for paying for such Installment Payments Claims, and Party B, jointly with Party A, shall also fill in and
prepare an “Application Letter for Repossession of Shares in Custody” affixed with original seals and deliver to the Custodian Bank, to enable Party A to collect the ProMOS Shares entrusted for custody in proportion to the Installment
Payments Claims that have been paid. 
  

	Article 5	 	Representations and Warranties 

  
 Party B hereby represents, warrants and undertakes that Party B has legally obtained and held the Corporate Bonds Rights, that Party B has the full power to sell,
transfer and dispose of the Corporate Bonds Rights, and that Party B has not created any pledge or other encumbrances in favor of a third party, and that there is no restriction whatsoever against the transfer or disposal of the Corporate Bonds
Rights. 
  

	Article 6	 	Event of Default 

  
 If any one of the checks that are delivered by Party A in accordance with Article 2 is dishonored, and if Party A fails to make the payment after three (3) business days of the due date, all of the unpaid Installment
Payments Claims are deemed to be immediately due and payable, and Party B may use the bounced checks as delivered to Party A in accordance with Article 2 and request the Custodian Bank to deliver all the ProMOS Shares entrusted to its custody, and
Party B may dispose of the ProMOS Shares to settle the unpaid Installment Payments Claims and late interest payments with the surplus to be returned to Party A. 
  


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	Article 7	 	Taxes and Levies 

  
 Any taxes arising out of the trading of corporate bonds pursuant to this Agreement and other related taxes shall be borne individually by the respective parties under applicable law. 
  

	Article 8	 	Confidentiality 

  
 1. Unless agreed to by the other party or otherwise provided by the law, no party may disclose to third parties the contents of this Agreement, any related documents, information or matters. 
  
 2. This Article shall remain effective after the termination of this Agreement; any party,
despite having ceased to be a party to this Agreement, will be under an obligation to observe the provisions of this Article. 
  
 3. Prior to making any public announcement, consent from both parties must be obtained, and the announcement may be made only by a spoke-person designated by Party A. The
parties may not make any public announcement on their own. 
  

	Article 9	 	Notices 

  
 1. Written notices and other communications delivered in accordance with the provisions of this Agreement shall be deemed to have been delivered upon delivery to the various parties via messenger or double registered
mail to the following addresses or other addresses that are notified in writing to the other party: 
  
 To Party A: ChipMOS TECHNOLOGIES INC. 
  
 Recipient: Shih-Jye Cheng, Chief Executive Officer 
  
 Address: No. 1, Research and Development Road 1, Science-based Industrial Park, Hsinchu 
  
 Facsimile: 03 – 5668980 
  
 To Party B: Ron How Investment Corp. 
  
 Recipient: Shih Chieh HUANG 
  
 Address: 3F., No. 53, Sec. 3, Chengde Road, Datong District,
Taipei 
  
 Facsimile: 02 – 25466168 
  

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 2. When a party mails a notification, the notification is deemed to have been duly received by the other party seven (7)
days after the mailing. 
  

	Article 10	 	Assignment 

  
 A party may not assign any rights or obligations under this Agreement to any third parties without the written consent of the other party. 
  

	Article 11	 	Amendment 

  
 Any amendments or modifications to this Agreement must be written and agreed upon by both parties. 
  

	Article 12	 	Governing Law and Courts with Jurisdiction 

  
 The governing law of this Agreement is the law of the Republic of China. The parties agree that in any disputes arising from this Agreement, the Taipei municipal court
shall be the court of first instance with jurisdiction. 
  

	Article 13	 	Whole and Complete Agreement 

  
 This Agreement constitutes the only and complete agreement between the parties, and replaces all written or oral promises, agreements or representations of the parties
before the execution of this Agreement. 
  

	Article 14	 	Number of Deed of Agreement 

  
 This Agreement is executed in two (2) original counterparts, each of which shall be retained by each party. 
  
 Parties to the Agreement: 
  
 Party A: ChipMOS TECHNOLOGIES INC. 
  
 Legal representative: Hung-Chiu Hu 
  
 Address: No. 1, Research and Development Road 1, Science-based Industrial Park, Hsinchu 
  
 Party B: Ron How Investment Corp. 
  
 Legal representative: Shih Chieh HUANG 
  
 Address: 3F., No. 53, Sec. 3, Chengde Road, Datong District, Taipei 
  
 April 25, 2003 
  

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