SG10201407601XA - Mold for measuring flow characteristics, method for measuring flow characteristics, resin composition for encapsulating semiconductor, and method for manufacturing semiconductor apparatus - Google Patents

Mold for measuring flow characteristics, method for measuring flow characteristics, resin composition for encapsulating semiconductor, and method for manufacturing semiconductor apparatus

Info

Publication number
SG10201407601XA
SG10201407601XA SG10201407601XA SG10201407601XA SG10201407601XA SG 10201407601X A SG10201407601X A SG 10201407601XA SG 10201407601X A SG10201407601X A SG 10201407601XA SG 10201407601X A SG10201407601X A SG 10201407601XA SG 10201407601X A SG10201407601X A SG 10201407601XA
Authority
SG
Singapore
Prior art keywords
flow characteristics
resin composition
measuring flow
mold
flow
Prior art date
Application number
SG10201407601XA
Inventor
Atsunori Nishikawa
Original Assignee
Sumitomo Bakelite Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Bakelite Co filed Critical Sumitomo Bakelite Co
Publication of SG10201407601XA publication Critical patent/SG10201407601XA/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/76—Measuring, controlling or regulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14639—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14639—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components
    • B29C45/14655—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components connected to or mounted on a carrier, e.g. lead frame
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/37—Mould cavity walls, i.e. the inner surface forming the mould cavity, e.g. linings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/76—Measuring, controlling or regulating
    • B29C45/7646—Measuring, controlling or regulating viscosity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
    • G01N11/02—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material
    • G01N11/04—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/93—Batch processes
    • H01L24/95—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
    • H01L24/97—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
    • B29K2101/10—Thermosetting resins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/34—Electrical apparatus, e.g. sparking plugs or parts thereof
    • B29L2031/3425—Printed circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H01L2224/48227—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73265—Layer and wire connectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/93—Batch processes
    • H01L2224/95—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
    • H01L2224/97—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1301—Thyristor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/14—Integrated circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/151—Die mounting substrate
    • H01L2924/153—Connection portion
    • H01L2924/1531—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface
    • H01L2924/15311—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface being a ball array, e.g. BGA
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation

Abstract

48 MOLD FOR MEASURING FLOW CHARACTERISTICS, METHOD FOR MEASURING FLOW CHARACTERISTICS, RESIN COMPOSITION FOR ENCAPSULATING SEMICONDUCTOR, AND METHOD FOR MANUFACTURING SEMICONDUCTOR According to the invention, a mold for measuring flow characteristics which is used to measure the flow characteristics of a resin composition, which is a measurement subject, by injecting the resin composition into a flow path provided in the mold, in which^ the minimum distance from the cross-sectional center of gravity to the outline in the cross-sectional shape of the flow path is equal to or more than 0.02 mm and equal to or less than 0.4 mm, and a method for measuring flow characteristics in which a resin composition, which is a measurement subject, is injected into the flow path of the mold for measuring flow characteristics, and made to flow in a single direction, and the flow distance from the start point to the end point of the flow of the resin composition is obtained as the flow length are provided. FIG. 1
SG10201407601XA 2009-11-24 2010-11-17 Mold for measuring flow characteristics, method for measuring flow characteristics, resin composition for encapsulating semiconductor, and method for manufacturing semiconductor apparatus SG10201407601XA (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009265872 2009-11-24

Publications (1)

Publication Number Publication Date
SG10201407601XA true SG10201407601XA (en) 2015-01-29

Family

ID=44066079

Family Applications (1)

Application Number Title Priority Date Filing Date
SG10201407601XA SG10201407601XA (en) 2009-11-24 2010-11-17 Mold for measuring flow characteristics, method for measuring flow characteristics, resin composition for encapsulating semiconductor, and method for manufacturing semiconductor apparatus

Country Status (7)

Country Link
US (1) US20120280425A1 (en)
JP (1) JP5742723B2 (en)
KR (1) KR101748897B1 (en)
CN (1) CN102686996A (en)
SG (1) SG10201407601XA (en)
TW (1) TWI477756B (en)
WO (1) WO2011064964A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5957961B2 (en) * 2012-03-01 2016-07-27 住友ベークライト株式会社 Fixing resin composition, rotor and automobile
JP6217099B2 (en) * 2013-03-22 2017-10-25 住友ベークライト株式会社 Epoxy resin molding material, molded coil manufacturing method, and molded coil
CN104309085B (en) * 2014-10-11 2016-08-24 浙江师范大学 The device and method of composite Form Development in the micro-injection of a kind of on-line monitoring
CN105058686A (en) * 2015-07-21 2015-11-18 深圳市盛元半导体有限公司 Method for fast detecting flowing length of IC packaging material
US9704767B1 (en) 2015-12-23 2017-07-11 Intel Corporation Mold compound with reinforced fibers
US20210124265A1 (en) * 2017-04-21 2021-04-29 Nipppon Kayaku Kabushiki Kaisha Photosensitive Resin Composition And Cured Product Therefrom
KR102455721B1 (en) * 2018-03-06 2022-10-17 쇼와덴코머티리얼즈가부시끼가이샤 A method for evaluating the fluidity of a resin composition, a method for screening a resin composition, and a method for manufacturing a semiconductor device
WO2021048977A1 (en) * 2019-09-12 2021-03-18 昭和電工マテリアルズ株式会社 Sealing material for compression molding and electronic component device
CN116670821A (en) * 2020-12-03 2023-08-29 住友电木株式会社 Sealing resin composition and semiconductor device

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03105234A (en) * 1989-09-20 1991-05-02 Hitachi Ltd Apparatus for measuring fluidity and hardening property of resin
JPH10138254A (en) * 1996-11-11 1998-05-26 Sumitomo Metal Mining Co Ltd Mold for evaluating flow of bonding wire and resin fluidity and evaluation using this mold
JP3123482B2 (en) * 1997-10-08 2001-01-09 日本電気株式会社 Low thermal resistance semiconductor package and method of manufacturing low thermal resistance semiconductor package
JP3255110B2 (en) * 1998-04-09 2002-02-12 日本電気株式会社 Mold for resin property test and resin property test method
JP2000178345A (en) * 1998-12-14 2000-06-27 Sumitomo Bakelite Co Ltd Resin composition for semiconductor sealing and semiconductor device sealed therewith
JP4088430B2 (en) * 2001-07-31 2008-05-21 日立化成工業株式会社 Method for producing epoxy resin composition for semiconductor encapsulation
DE10236122A1 (en) * 2002-08-07 2004-02-19 Bayer Ag Device and method for determining viscosities and liquids by means of capillary force
JP3984921B2 (en) * 2003-03-19 2007-10-03 住友ベークライト株式会社 Model mold and resin flow measuring device
JP4300878B2 (en) * 2003-05-29 2009-07-22 住友ベークライト株式会社 Mold and method for evaluating weld using the same
JP2004361348A (en) * 2003-06-06 2004-12-24 Sumitomo Bakelite Co Ltd Spiral flow test method, spiral flow test die, and spiral flow test device
JP2005097411A (en) * 2003-09-24 2005-04-14 Matsushita Electric Works Ltd Sealing epoxy resin composition, and semiconductor device sealed with the same
JP2008115373A (en) * 2006-10-12 2008-05-22 Hitachi Chem Co Ltd Method for measuring flow rate of resin composition, epoxy resin composition for sealing and electronic component device
JP2009173812A (en) * 2008-01-25 2009-08-06 Panasonic Electric Works Co Ltd Epoxy resin composition for sealing and semiconductor device
KR101524898B1 (en) * 2008-03-25 2015-06-01 스미토모 베이클리트 컴퍼니 리미티드 Epoxy resin composition, resin sheet, prepreg, multilayer printed wiring board, and semiconductor device

Also Published As

Publication number Publication date
TWI477756B (en) 2015-03-21
WO2011064964A1 (en) 2011-06-03
JPWO2011064964A1 (en) 2013-04-11
CN102686996A (en) 2012-09-19
JP5742723B2 (en) 2015-07-01
KR101748897B1 (en) 2017-06-19
KR20120123039A (en) 2012-11-07
TW201128177A (en) 2011-08-16
US20120280425A1 (en) 2012-11-08

Similar Documents

Publication Publication Date Title
SG10201407601XA (en) Mold for measuring flow characteristics, method for measuring flow characteristics, resin composition for encapsulating semiconductor, and method for manufacturing semiconductor apparatus
GB2497709A (en) Measurements of properties of sample of curing compositions under high pressure
MX359164B (en) Molding material mixtures containing an oxidic boron compound and method for the production of molds and cores.
MX356268B (en) Method and apparatus for substantially constant pressure injection molding of thinwall parts.
MY152389A (en) Resin composition for encapsulating semiconductor, method for producing semiconductor device and semiconductor device
IN2014DN07048A (en)
RU2016102830A (en) Devices and methods of injection molding, taking into account changes in the properties of the material during the injection molding process
MX369888B (en) Method for injection molding at low, substantially constant pressure.
RU2016102962A (en) Devices and methods of injection molding, taking into account changes in the properties of the material during the injection molding process
AR100068A1 (en) DEVICE AND METHOD OF MOISTURE MEASUREMENT IN FUNDITION MOLDS IN MATRIX
IN2014CN04397A (en)
MX2015006012A (en) Method for manuf acturing polarizing plastic lens.
MY156992A (en) Die formed lollipop filled with chocholate and method of manufacture thereof
WO2013060568A3 (en) Method of manufacturing a coil support member and coil support member
WO2013093352A3 (en) Method of manufacturing a ceramic core for a blade, ceramic core and blade
WO2014127310A3 (en) Molded dental root canal filling points/cones and process of making same
WO2015007353A3 (en) Method for producing a component from a composite fiber material
MX2017007084A (en) Moulding device for the manufacture of composite components from liquid polymer resin by high-pressure injection.
MX2017009348A (en) System and method for forming an oral care implement.
TW200640005A (en) Lead frame, sensor including lead frame and method of forming sensor including lead frame
EA201201151A1 (en) EFFICIENT BY ENERGY AND WEIGHT INDICATORS OF THE WALL BLOCK, METHOD OF MANUFACTURE AND APPLICATION OF THE WALL BLOCK
MX336066B (en) Method and assembly for continuous manufacturing of preforms.
HUE043254T2 (en) Mould material mixture containing resols and amorpous silicon dioxide, moulds and cores produced therefrom and method for the production thereof
MX347364B (en) Method for obtaining a foundry body from a granular mixture including a modified polycondensed resin and a formaldehyde sensor.
MY160933A (en) Injection molding of part having nonuniform thickness