1、 STD-EIA JESD51-4-ENGL 1997 W 3234600 0585350 U17 D Electronic Industries Association September 30,1997 ERRATA TO: Recipients of New Standards and Engineering Publications RE: Changing EINJEP129 to EWJESD51-4 The JC-15.1 Committee has determined that the intent was to publish “Thermal Test Chip Guid
2、eline (wie Bond Type Chip)“ as a part of the JESD51 Series, thus JESD51-4. The cover page and headers are changed from EIA/EP129 to EWJESD51-4. (EWJESDS1-4 replaces EWEP129). We are sorry for any inconvenience this may have caused. Manager, Publications Engineering Department 2500 Wilson Boulevard A
3、rhgton, Virginia 22201-3834 (703) 907-7500 FAX (703) 907-7501 f STDaEIA JESD51-LI-ENGL 1997 3234600 0585351 T55 EINJEDEC STANDARD Thermal Test Chip Guideline (Wire Bond Type Chip) EIA/JESDS 1-4 FEBRUARY 1997 ELECTRONIC INDUSTRIES ASSOCIATION ENGINEERING DEPARTMENT NOTICE EINJEDEC Standards and Publi
4、cations contain material that has been prepared, progressively reviewed, and approved through the JEDEC Council level and subsequently reviewed and approved by the EIA General Counsel. EINJEDEC Standards and Publications are designed to serve the public interest through eliminating misunderstandings
5、 between manufacturers and purchases, facilitating interchangeability and improvement of products, and assisting the purchaser is selecting and obtaining with minimum delay the proper product for his particular need. Existence of such standards shall not in any respect preclude any member or nonmemb
6、er of JEDEC from manufacturing or selling products not conforming to such standards, nor shall the existence of such standards preclude their voluntary use by those other than EIA members, whether the standard is to be used either domestically or internationally. EWJEDEC Standards and Publications a
7、re adopted without regard to whether their adoption may involve patents or articles, materials, or processes. By such action, EINJEDEC does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the EINJEDEC Standards or Publications. The informa
8、tion included in EINJEDEC Standards and Publications represents a sound approach to product specification and application, principally from the solid state device manufacturer viewpoint. Within the EINJEDEC organization there are procedures whereby an EINJEDEC Standard or Publication may be further
9、processed and ultimately becomes an ANSVEIA Standard. Inquiries, comments, and suggestions relative to the content of this EINJEDEC Standard or Publication should he addressed to the JEDEC Executive Secretary at EIA Headquarters, 2500 Wilson Boulevard, Arlington, VA 22201. Published by ELECTRONIC IN
10、DUSTRIES ASSOCIATION 1997 Engineering Department 2500 Wilson Boulevard Arlington, VA 22201 “Copyright“ does not apply to JEDEC member companies as they are free to duplicate this dowment in accordance with the latest revision of the JEDEC Publication 21 “Manual of Organization and Procedu re“. PRICE
11、: Please refer to the current Catalog of EIA, JEDEC, and TIA STANDARDS and ENGINEERING PUBLICATIONS or call Global Engineering Documents, USA and Canada (1800-854-7179) International (303-397-7956) Printed in U.S.A. All rights reserved STDmEIA JESDSL-4-ENGL 1997 m 3234b00 0585353 28 THERMAL TEST CHI
12、P GUIDELINE (WIRE BOND TYPE CHIP) CONTENTS 1 Introduction 1.1 Purpose 1.2 Scope 1.3 Rationale 1.4 References 2 Test Chip Design 2.1 Heating Source 2.2 Temperature Sensor 2.3 Bonding Pads 2.4 Physical Layout 2.4.1 Chip Dimensions 2.4.2 Heating Source Area Coverage 2.4.3 Temperature Sensor Placement 2
13、.4.4 Wire Bonding Considerations 2.5 Surface Properties 3 Data Presentation Page 1 3 3 3 4 4 4 5 5 6 6 6 -1- STD-EIA JESDSL-4-ENGL 1997 m 323Lib00 0585354 7b4 m EINJESDS 1-4 Page 1 THERMAL TEST CHIP GUIDELINE (WIRE BOND TYPE CHIP) 1 Introduction (From JEDEC Council Ballot JCB-96-25 formulated undere
14、 the cognizance of JC- 15.1 Committee on Thermal Characterization). 1.1 1.2 1.3 1.4 Purpose The purpose of this document is to provide a design guideline for thermal test chips used for integrated circuit (IC) package thermal characterization. The intent of this guideline is to minimize the differen
15、ces in data gathered due to nonstandard test chips. Scope The thermal test chips described in this document will apply to single and multiple chip devices. These are designs using standard semiconductor wafer fabrication processes and can be used with a wide variety of industry standard packages. Th
16、ese test chips can operate in a static mode in which constant power is continuously supplied to the device while monitoring the temperature through the measurement of a Temperature Sensitive Parameter (TSP). They can also operate in a transient mode in which the power supply and the TSP are monitore
17、d as a function of time (t). This guideline covers test chips meant to be wire bonded to the package external leads. Rationale The thermal resistance for a specific device varies with many factors. The chip size, location and size of the power dissipation device(s), and location of the temperature s
18、ensor(s) will directly affect the thermal test results. It is essential to standardize thermal test chip design guideline in order to provide meaningfl measurement results. This allows semiconductor suppliers to compare different packages over a wide variety of conditions, such as power levels and a
19、ir flows. It will also help the users to estimate their active device junction temperature under actual operating conditions by allowing them to extrapolate the results of a defined standard condition. References This document contains the guideline for thermal test chip design as a subset of JEDEC
20、methodology for component package thermal measurement. The associated details of test method, environment and test board are given in JEDEC documents 11 - 4. It is also recommended to read the SEMI test standards (E51 - 9) and the related documents lo - 123. i JESD 51 Methodology for the Thermal Mea
21、surement of Component Packages (Single Semiconductor Device) 2 JESD 51-1 Integrated Circuit Thermal Measurement Method - Electrical Test Method (Refer to Annex A for a list of terminology and symbols applicable to this document). , EWJESD51-4 Page 2 3 JESD 51-2 Integrated Circuit Thermal Test Method
22、, Environmental Conditions - Natural Convection 4 JC- 15-95-63 Low Thermal Conductivity Test Board for Leaded Surface Mount Packages. 5 SEMI Test Method #G43-87 Test Method, Junction-To-Case Thermal Resistance Measurements of Molded Plastic Packages. 6 SEMI Test Method #G38-87 Still and Forced Air-t
23、o-Ambient Thermal Resistance Measurements of Integrated Circuit Packages. 7 SEMI Test Method #G42-88 Specification, Thermal Test Board Standardization for Measuring Junction-to-Ambient Thermal Resistance of Semiconductor Packages. SI SEMI Test Method #G30-88 Junction-to-Case Thermal Resistance Measu
24、rements of Ceramic Packages. 9 SEMI Test Method #G32-86 SEMI Guideline for Unencapsulated Thermal Test Chip. 1 O EIA JEDEC EB-20 Accepted Practices for Making Microelectronics Device Thermal Characteristics Test. 1 i Mil Std 883C Method 1012.1 Thermal Characteristics of Microelectronics Devices. 123
25、 NIST Special Publication 400-86 Semiconductor Measurement Technology: Thermal Resistance Measurements. 2 Test Chip Design The thermal test chip should be designed to provide uniform heating across the chip surface, and chip temperature sensing. The general design and construction of the thermal tes
26、t chip includes these basic features: heating source, temperature sensor, and bonding pads. The components of a test chip are discussed below. EINJESDS 1-4 Page 3 2.1 Heating Source Resistor elements or transistors should be used as heating sources. The heating power is calculated as follows: where
27、VH = voltage across the heating source (V) 1s current for the heating source (A) When resistor heating is utilized, the resistance temperature dependence has to be considered in order to set the power supply. Hence, the predefined heating power is achieved by adjusting either VHor IH and monitoring
28、the other because they are dependent on each other. When a transistor is used, both VH and IH can be adjusted separately. Therefore, the heater power dissipation is easy to control. For this reason a transistor is preferred in transient applications and when tight control of power levels is required
29、. However, it is difcult to obtain uniform power distribution with a large transistor. Hence, for a large single unit test chip, the resistor option is preferred. 2.2 Temperature Sensor The temperature sensing elements should function at the operating temperature range of the device. The most common
30、ly used TSP is the voltage drop across a forward biased PN diode. This diode is specifically designed into the thermal test chip. It exhibits a linear forward voltage characteristic with temperature when a fixed measurement current (IM) is forced through the diode. The temperature rise of most diode
31、s is approximately 0.5 OC for 1 millivolt drop in forward voltage, that is -0.5 OC/mV. This parameter is called the K-Factor. It is process-dependent and must be determined by measuring the voltage of the diode at various temperatures. A typical diode characteristic curve is shown in figure 1. The c
32、hip temperature change can be obtained from the voltage drop with respect to a reference (usually zero power) state 2. Another type of TSP is a Resistance Temperature Detector (RTD), which is a single metal trace. The advantage of resistance type sensors is that they are much more linear than diodes
33、 over a much wider temperature range. For a proper local measurement, the RTD may be built as a small spiral or zig-zag patch in the locations on the chip where temperature measurements are to be made. A 4-wire (Kelvin) type electrical connection must be used with RTD sensors. 2.3 Bonding Pads The i
34、nterconnect between the test chip and the package external leads is through wire bonding. The bonding pads are obtained through the standard wafer fabrication process. 2.4 Physical Layout The basic chip unit containing the heating source(s) and temperature sensor(s) can be utilized as a single unit
35、chips. The chip units can also be arrayed to form larger multiple unit chip. The single unit chip will generate heat uniformly. The multiple unit option gives the flexibility to generate heat uniformly if the basic units are electrically interconnected, or non-uniformly if the units are not intercon
36、nected. Interconnection between the basic units can be achieved by wire bonding or by adding metal traces during the fabrication process. If metal traces are added between units, care must be taken to ensure an adequate coverage of oxide in the scribe line to avoid shorting the interconnection trace
37、s to the substrate. Example layouts for single and multiple unit chips are shown in figures 2 and 3, respectively. Recommendations EIMJESDS 1-4 Page 4 for chip size, heating source area coverage, and temperature sensor placement are given in the following sections. 2.4.1 Chip Dimensions Both test ch
38、ip size and thickness affect the measurement data. Square and rectangular chips can be obtained using either single or multiple units configuration. The preferred sizes for newly designed test chips are listed in table 1. The use of other chip sizes is acceptable. The chip thickness used should be c
39、onsistent for the same package. For each set of measurements, the thickness is determined based on the package being tested. The preferred values are 0.28,0.375 and 0.62 mm. The use of other chip thicknesses is acceptable. These preferred dimensions will provide sufficient choice to fit in most pack
40、ages and simulate the active devices. The objective is to minimize the measurement data discrepancy due to using arbitrary test chip dimensions. When applicable, chip dimensions should be selected such that they most closely match the active device. Table 1. Preferred chip dimensions. Square Chip (m
41、m) I Rectangular chip (mm”) 2x2 2x4 I(,. 3x3 - 4x4 4x6 6x6 6x12 9x9 9x1 8 12x12 12x18 12x24 15x1 5 18x18 24x24 18x24 2.4.2 Heating Source Area Coverage The outline of the heating source should cover at least 85% of the chip area inside the bonding pads. If a multiple unit chip is utilized, each indi
42、vidual unit should meet this area coverage requirement. The heating elements shall be designed to dissipate power at the proper levels and provide uniform heat dissipation per unit area. Sufficient heater bonding pads shall be provided to handle anticipated current levels STD-EIA JESDSL-4-ENGL 1797
43、m 3234b00 0585358 3T EINJESD5 1-4 Page 5 2.4.3 Temperature Sensor Placement The temperature sensors should be optimally placed to accurately measure the maximum chip temperature. When uniform heating is applied, the maximum chip temperature is at the center of the chip active surface. Therefore, in
44、the case of single unit chip, one temperature sensor must be located at the center of the chip surface. Additional sensors may be placed in a corner and in the middle of an edge for other purposes. When a multiple unit chip is utilized, one temperature sensor should be placed at each unit center. It
45、 is also recommended that a temperature sensor be placed in a corner to provide a centrally located sensor if an even array of basic units is used. When possible each temperature sensor should be connected to four pads for forcing and sensing circuit measurement technique. 2.4.4 Wire Bonding Conside
46、ration The recommended bonding pad sizes shall be no smaller than O. 10 mm (4 miis). The wiring for the temperature sensor and heaters shali not be connected to common bonding pads. In the case of multiple unit cells without metal interconnect traces, wire bonding to the outer cells is possible; how
47、ever, bonding to the inner cells becomes increasingly more difficult as the array of cells increases in size. Therefore, it is recommended to duplicate the bonding pads and place them on two opposite sides (see figure 2). This will make wire bonding easier for a multiple unit chip because there will
48、 be at least one row of pads along the chip edge. It is also recommended that additional bonding pads be used to fully populate the perimeter of the chip. These bonding pads can then be connected to the chip package to simulate a typical application. , 2.5 Surface Properties The top surface passivat
49、ion and bottom surface finish and metalization should approximate those present in package assembly process. These surfaces should have a level of adhesion between the die and adjoining materials similar to that of the application die. Failure to do so could result in different levels of delamination at the die interfaces, potentially leading to significantly different thermal performance for test and application dice. 3 Data Presentation The test data presentation should include both thermal parameter data and test conditions. The necessaxy
