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Rule 13d-l(b)

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Rule 13d-l(c)

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Rule 13d-l(d)

CUSIP No. 693282 10 5

1.

Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
JOHN KACHIG KIBARIAN

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

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(b)

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3.

SEC Use Only

4.

Citizenship or Place of Organization
United States Citizen

Number of
Shares

5.

Sole Voting Power
2,512,474

6.

Shared Voting Power
0

7.

Sole Dispositive Power
2,512,474

8.

Shared Dispositive Power
0

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
2,512,474

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions).  ☐

11.

Percent of Class Represented by Amount in Row (9)
7.82 % based on a total of  32,111,833 shares of Issuer’s Common Stock issued and outstanding on December 31, 2017

12.

Type of Reporting Person (See Instructions)
Individual

Item 1.

(a)

Name of Issuer:
PDF SOLUTIONS, INC.

(b)

Address of Issuer’s Principal Executive Offices:
333 West San Carlos Avenue, Suite 1000, San Jose, CA  95110

Item 2.

(a)

Name of Person Filing:
John Kachig Kibarian

(b)

Address of Principal Business Office or, if none, Residence:
333 West San Carlos Avenue, Suite 1000, San Jose, CA  95110

(c)

Citizenship:
United States

(d)

Title of Class of Securities
Common Stock

(e)

CUSIP Number:
693282 10 5

Item 3.

If this statement is filed pursuant to §§240.13d-l(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

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Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

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Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

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Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

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Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8);

(e)

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An investment adviser in accordance with §240.13d-l(b)(l)(ii)(E);

(f)

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An employee benefit plan or endowment fund in accordance with §240.13d-l(b)(l)(ii)(F);

(g)

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A parent holding company or control person in accordance with §240.13d-l(b)(l)(ii)(G);

(h)

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A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

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A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

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A non-U.S. institution in accordance with § 240.13d–l(b)(l)(ii)(J).

(k)

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Group, in accordance with § 240.13d–l(b)(l)(ii)(K). If filing as a non-U.S. institution in accordance with

§ 240.13d–l(b)(l)(ii)(J), please specify the type of institution:____________________________.

Item 4.

Ownership.

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a)

Amount beneficially owned:.    

2,512,474 

(b)

Percent of class:    

7.82 % of Issuer’s common stock.

(c)

Number of shares as to which the person has:

(i)

Sole power to vote or to direct the vote    

2,512,474 

(ii)

Shared power to vote or to direct the vote     

0

(iii)

Sole power to dispose or to direct the disposition of

2,512,474 

(iv)

Shared power to dispose or to direct the disposition of    

0

Instruction.  For computations regarding securities which represent a right to acquire an underlying security see §240.13d-3(d)(l).

Item 5.

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   ☐.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

Not applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Not applicable

Item 8.

Identification and Classification of Members of the Group

Not applicable

Item 9.

Notice of Dissolution of Group

Not applicable

Item 10.

Certifications

Not applicable

Date

/s/ John K. Kibarian

Signature

JOHN KACHIG KIBARIAN

Name/Title

ATTENTION:

Intentional misstatements or omissions of fact constitute Federal Criminal Violations (See 18 U.S.C. 1001)