Rf Measurements Of Die And Packages

by Scott A Wartenberg

Overview

This text is dedicated to the issues surrounding RFIC (radio-frequency integrated circuit) testing. It explains how to perform high-accuracy RF measurements of die and packages in the RF test lab. It defines the essential elements in an RF system, explains where errors can be found in such a system and shows how to mathematically remove them with calibration.

Product Details

ISBN-13:	9781580532730
Publisher:	Artech House, Incorporated
Publication date:	05/31/2002
Series:	Microwave Library
Pages:	244
Product dimensions:	6.14(w) x 9.21(h) x 0.56(d)

Table of Contents

	Preface	xiii
	Reference	xiv
	Acknowledgments	xv
1	Introduction	1
1.1	Topics Covered in This Book	1
1.1.1	Calibration	1
1.1.2	Coplanar Probes	2
1.1.3	High-Volume Probing	2
1.1.4	Test Fixtures	2
1.1.5	On-Wafer Characterization	4
1.1.6	RF Test Systems	4
1.1.7	Package Characterization	4
1.2	Components of an RF Test System	4
1.2.1	VNA	5
1.2.2	LCR Meter	7
1.2.3	RF Cables	8
1.2.4	Bias Cables	9
1.2.5	Bias Tees	10
1.3	RF Connectors	11
1.3.1	Connector Types	11
1.3.2	Making the Connection	11
1.3.3	Connector Care	12
1.4	RF Connector Adapters	12
1.5	The Probe Station	12
1.6	Summary	13
	References	13
2	Calibration	15
2.1	Test System Errors: Random or Systematic	15
2.2	Concept of a Reference Plane	16
2.3	Error Models	17
2.3.1	Signal Flow Graph	19
2.3.2	Error Adapter	21
2.4	Calibration Standards	23
2.4.1	Calibration Coefficients	24
2.4.2	Short	25
2.4.3	Open	26
2.4.4	Load	28
2.4.5	Thru	29
2.5	Improving the Standards	31
2.5.1	Offset Delay	31
2.5.2	Offset Loss	33
2.6	Calibration Methods	33
2.6.1	SOLT	35
2.6.2	SOLR	37
2.6.3	TRL	38
2.6.4	LRM	41
2.6.5	LRRM	42
2.7	Verification	43
2.7.1	Verification Elements	44
2.7.2	Verifying with a Reference or "Golden" Unit	45
2.8	Isolation	45
2.9	Traceability	47
2.10	Repeatability, Reproducibility, and Accuracy	48
2.11	Calibration Tips and Tricks	48
2.12	Summary	50
	References	51
3	Coplanar Probes	55
3.1	Theory of CPW	55
3.2	Mechanical Construction	57
3.3	Equivalent Circuit	58
3.4	Characterizing a Coplanar Probe	60
3.5	Using Coplanar Probes	62
3.5.1	Planarization	62
3.5.2	Alignment	63
3.5.3	Skating	64
3.5.4	Cleaning	67
3.6	Probe Configurations	67
3.6.1	Balanced	67
3.6.2	Unbalanced	68
3.6.3	Differential	69
3.6.4	Other Probe Configurations	71
3.7	Noncontact Probing	71
3.8	Applications	72
3.8.1	Millimeter-Wave Probing	72
3.8.2	Impedance-Matching, Low-Impedance Probes	73
3.9	Coplanar Probe Calibration Standards	74
3.9.1	Alumina Calibration Substrate	75
3.9.2	On-Wafer Calibration Standards	76
3.9.3	Open: In the Air or on Open Pads	77
3.9.4	More Design Tips	78
3.9.5	Verification	79
3.10	Summary	80
	References	80
4	High-Volume Probing	83
4.1	High-Volume Test	84
4.2	RF Probe Card	84
4.2.1	Load Board	85
4.2.2	Probe Board	86
4.2.3	Contactor	86
4.3	Membrane Probe	88
4.3.1	Construction	88
4.4	Designing Membrane Probes	89
4.4.1	Digital and RF Signals	90
4.4.2	Grounding	90
4.5	Using Membrane Probes	91
4.6	Calibration	93
4.7	Summary	93
	References	93
5	Test Fixtures	95
5.1	The Basic Test Fixture	95
5.1.1	Qualities of a Good Test Fixture	97
5.1.2	Characterizing the Fixture's Parasitic Effects	97
5.1.3	Types of Fixtures: R&D or Manufacturing	98
5.1.4	Fixturing for Passive Components	98
5.1.5	Fixturing for Active Components	99
5.2	RF Transitions	99
5.2.1	Coaxial to Microstrip	100
5.2.2	CPW to Microstrip	102
5.2.3	Rectangular Waveguide to CPW	102
5.2.4	Rectangular Waveguide to Microstrip	104
5.2.5	Rectangular Waveguide to Coaxial	105
5.3	Defining the Reference Planes	105
5.4	Two-Tier Calibration	107
5.5	Test Fixture Calibration	108
5.5.1	Calibration Standards: Coaxial Versus In-Fixture	108
5.5.2	Calibration Methods	109
5.5.3	Calibration Phase Uncertainty	111
5.6	Summary	112
	References	112
6	On-Wafer Characterization	115
6.1	Conductive Versus Insulating Substrates	116
6.2	Probe Pads and Interconnecting Lines	118
6.3	De-embedding the Pads and Interconnects	118
6.3.1	Open	119
6.3.2	Open and Short	122
6.3.3	Open, Short, and Thru	122
6.3.4	Two-Port Network with a Thru	123
6.3.5	Two Shorts, an Open, and a Thru	124
6.3.6	Some Points to Consider When De-embedding	126
6.3.7	Should the Transistor Finger Metal Be De-embedded?	128
6.3.8	Effect of Pad Parasitics on f[subscript T]	129
6.4	De-embedding Pads for Noise	131
6.5	Measuring High-Isolation Devices	134
6.6	Characterizing Vertical Devices	136
6.7	Characterizing Passive Components	138
6.8	Millimeter-Wave Characterization	138
6.9	Summary	140
	References	141
7	RF Test Systems	145
7.1	On-Wafer Noise Testing	145
7.1.1	Basic Concepts in Noise	145
7.1.2	On-Wafer Noise Sources	147
7.1.3	Faraday Shielding	147
7.2	High-Power RF Testing	148
7.3	Characterizing over Temperature	150
7.3.1	Heating the Wafer	152
7.3.2	Cryogenic Cooling	152
7.4	Summary	154
	References	154
8	Package Characterization	157
8.1	Designing a Test Fixture for Package Characterization	158
8.1.1	RF Launchers	158
8.1.2	Coplanar Probes as RF Launchers	159
8.1.3	Test Fixture Body	159
8.2	The Carrier	161
8.2.1	Designing the Carrier	163
8.2.2	Carrier Board Material	164
8.3	Attaching the Package to the Carrier	165
8.3.1	Bond Wires	165
8.3.2	Conductive Adhesives	168
8.4	Calibration	171
8.4.1	Partitioning by Reference Planes	172
8.5	De-embedding the Fixture from the Measurement	174
8.5.1	De-embedding by Using a Thru Line	175
8.5.2	Time-Domain Analysis	176
8.5.3	How to Apply Time-Domain Techniques	180
8.6	Procedure for Characterizing a Package	180
8.6.1	Characterizing with a Thru	182
8.6.2	Characterizing with a Short	183
8.6.3	Characterizing with an Open	183
8.6.4	Characterizing with a Load	183
8.6.5	Characterizing with a PIN Diode	184
8.6.6	What to Do with the Unused Package Pins	186
8.7	Modeling a Package Mounted to a Carrier	186
8.7.1	Ground Inductance	187
8.7.2	Ground Paddle	188
8.8	Designing the Interconnecting Lines on the Carrier	191
8.8.1	CPW or Microstrip	191
8.8.2	CPW or CBCPW	192
8.9	Quantifying the RF Effect of the Package on the Die	193
8.9.1	Effective Relative Dielectric Constant [varepsilon subscript eff]	193
8.9.2	Propagation Constant [gamma] and Characteristic Impedance Z[subscript 0]	193
8.9.3	Loss Tangent tand	195
8.10	Package Styles	196
8.10.1	Plastic Surface Mount Packages	196
8.10.2	Flip-Chip	196
8.10.3	Bumped Chip Carrier	199
8.11	Summary	200
	References	200
9	Future Trends	205
9.1	The Typical Design Cycle	205
9.2	The Separate Worlds of Digital and RF	206
9.3	The Goal: The Marriage of Digital and RF into a Single Wireless Product	207
9.4	New Substrate Materials	208
9.5	The Direction of RF Development	209
9.6	The Future of the RF Test	210
9.7	Summary	211
	References	211
	About the Author	213
	Index	215

Editorial Reviews

This guide to improving RF measurements in a lab setting covers calibration, coplanar probes, high-volume probing, test fixtures, on- water characterization, RF test systems, and package characterization. Current trends and future prospects are also discussed. More basic concepts are presented first, and followed by more advanced concepts, in building-block fashion. Black and white diagrams illustrate the principles, techniques, and equipment described. Wartenberg is an electrical engineer. Annotation c. Book News, Inc., Portland, OR (booknews.com)