3.	Goodwill and Purchased Intangible Assets

Changes in the carrying value of our goodwill during the years ended

December 29, 2018,

and

December 30, 2017,

were as follows (

in thousands

	Semiconductor Test & Inspection (1)			PCB Test			Total Goodwill
Balance December 31, 2016	$	58,849		$	-		$	58,849
Additions		2,654			-			2,654
Impact of currency exchange		4,110			-			4,110
Balance December 30, 2017		65,613			-			65,613
Additions		157,661			21,602			179,263
Impact of currency exchange		(2,466	)		(283	)		(2,749	)
Balance December 29, 2018	$	220,808		$	21,319		$	242,127

(

)

After the acquisition of Xcerra on

October 1, 2018

we report in

two

segments, Semiconductor Test & Inspection and PCB Test. Prior year amounts would have been reported in our Semiconductor Test & Inspection segment and have been presented accordingly.

Purchased intangible assets, subject to amortization, are as follows

(in thousands)

	December 29, 2018					December 30, 2017
					Remaining
	Gross Carrying		Accumulated		Useful Life	Gross Carrying		Accumulated
	Amount		Amortization		(years)	Amount		Amortization
Developed technology	$	214,266	$	21,197	7.4	$	20,780	$	12,623
Customer relationships		73,104		7,378	10.1		7,934		4,838
Trade names		22,701		1,807	10.5		6,185		972
Backlog		6,372		4,696	0.5		-		-
Favorable leases		1,100		62	5.3		-		-
Covenant not-to-compete		314		63	8.0		313		31
	$	317,857	$	35,203		$	35,212	$	18,464

The table above excludes

$36.3

million of in-process technology which has an indefinite life and is subject to impairment or future amortization as developed technology when the projects are completed. Changes in the carrying values of purchased intangible assets presented above are a result of the impact of fluctuation in currency exchange rates.

Amortization expense related to purchased intangible assets was approximately

$17.2

million in

2018,

$4.2

million in

2017

and

$6.9

million in

2016.

The increase in amortization expense in the current year is the result of amortization of assets acquired in the Xcerra transaction. The decrease in

2017

is a result of certain intangible assets that became fully amortized in

2016.

As of

December 29, 2018,

we expect amortization expense in future periods to be as follows:

2019

$38.9

million;

2020

$37.1

million;

2021

$33.8

million;

2022

$33.7

million

2023

$33.4

million; and thereafter

$105.8

million.