<SEC-DOCUMENT>0000056978-22-000110.txt : 20221012
<SEC-HEADER>0000056978-22-000110.hdr.sgml : 20221012
<ACCEPTANCE-DATETIME>20221012192315
ACCESSION NUMBER:		0000056978-22-000110
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20221010
FILED AS OF DATE:		20221012
DATE AS OF CHANGE:		20221012

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Wong Nelson MunPun
		CENTRAL INDEX KEY:			0001536288

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-00121
		FILM NUMBER:		221307732

	MAIL ADDRESS:	
		STREET 1:		23A, SERANGOON NORTH AVE 5
		STREET 2:		#01-01
		CITY:			SINGAPORE
		STATE:			U0
		ZIP:			554369

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KULICKE & SOFFA INDUSTRIES INC
		CENTRAL INDEX KEY:			0000056978
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				231498399
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1001

	BUSINESS ADDRESS:	
		STREET 1:		23A SERANGOON NORTH AVENUE 5, #01-01
		CITY:			SINGAPORE
		STATE:			U0
		ZIP:			554369
		BUSINESS PHONE:		2157846000

	MAIL ADDRESS:	
		STREET 1:		23A SERANGOON NORTH AVENUE 5, #01-01
		CITY:			SINGAPORE
		STATE:			U0
		ZIP:			554369
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_166561696969117.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-10-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000056978</issuerCik>
        <issuerName>KULICKE &amp; SOFFA INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>KLIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001536288</rptOwnerCik>
            <rptOwnerName>Wong Nelson MunPun</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>23A SERANGOON NORTH AVENUE 5</rptOwnerStreet1>
            <rptOwnerStreet2>#01-01</rptOwnerStreet2>
            <rptOwnerCity>SINGAPORE</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>U0 554369</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-10-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10512</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>176679</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2022-10-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10512</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10512.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Performance Share Units (PSUs) awarded October 10, 2019 and December 11, 2019, achieved a 138% pay-out based on total shareholder return (TSR) relative to a peer group. The peer group consisted of the companies of the GICS 45301020 (Semiconductors) not including companies traded on the Pink Sheets LLC Exchange as of the beginning of the Performance Period with relative TSR measured over a three-year period. The pay-out was certified, and shares issued on October 10, 2022. Each PSU is convertible to one share of common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Zi Yao Lim, Attorney-in-Fact for Wong Nelson MunPun</signatureName>
        <signatureDate>2022-10-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
