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<\/p>\n1.0 Scope This test method is to determine the dielectric constant and dissipation factor of raw printed wiring board material at 1 MHz.<\/p>\n
2.0 Applicable Documents None <\/p>\n
3.0 Test Specimens Each specimen shall be 50.8 \u00b1 0.076 mm [2.0 \u00b1 0.003 in] in diameter by thickness of laminate or substrate material. Remove copper of metal-clad specimens by etching using standard commercial practices. At least three specimens are required. <\/p>\n
4.0 Equipment\/Apparatus <\/p>\n
4.1 Meter A 1 MHz Digital LCR Meter, Hewlett Packard Mdl 4271A or equivalent. <\/p>\n
4.2 Test Fixture Hewlett Packard Mdl 16022A test fixture or equivalent. <\/p>\n
4.3 Specimen Holder A special specimen holder made as shown in Figure 1. This holder is designed to be compatible with the H\/P test fixture, Mdl 16022A. <\/p>\n
4.0 Procedure <\/p>\n
5.1 Preparation <\/p>\n
5.1.1 Prepare the specimens as specified in paragraph 3.0. <\/p>\n
5.1.2 Calculate the effect thickness (inches) = Mass = Measured weight in grams Density = Grams per cubic cm (as per ASTM-D-792, Method 1A) <\/p>\n
<\/p>\n
5.1.3 Coat both sides of specimens with one uniform coating of silver conductive paint. <\/p>\n
5.1.4 Air-dry the specimens until dry to touch, then oven-dry at 50\u00b0 \u00b1 2\u00b0C for 1\/2 hour and cool in a desiccator. <\/p>\n
5.1.5 Punch or machine a 25.4 mm [1.0 in] diameter disc from the 50.8 mm [2.0 in] specimens. (Assure that there is no carry over of the paint from one side to the other.)<\/p>\n
5.1.6 Condition the 25.4 mm [1.0 in] specimens for a minimum of 40 hours at 23\u00b0 \u00b1 5\u00b0C at a relative humidity of 50%. <\/p>\n
5.2 Testing <\/p>\n
5.2.1 Turn meter on and allow to warm up for 60 minutes minimum. <\/p>\n
5.2.1.1 Set the controls on the meter as follows: Function \u2013 C-D Range \u2013 Manual Trigger \u2013 Internal Rate \u2013 FCW Test Signal Level \u2013 Low <\/p>\n
5.2.1.2 Connect the cables for the test fixture to the appropriate connectors. 5.2.2 Plug the special specimen holder into the test fixture. <\/p>\n
5.2.3 The digital display on the meter will show the capacitance value and the dissipation factor of the unknown dielectric specimen. <\/p>\n
5.3 Calculation <\/p>\n
5.3.1 Dielectric Constant The dielectric constant shall be determined by using the following formula: <\/p>\n
K = Ct 0.225 A
\nK = Dielectric constant
\nC = Capacitance reading from Mdl 4271A Meter
\nA = Area of a 1-inch disc (square inches)
\nt = Effective thickness (inches)<\/p>\n
![\"post12\"](\"https:\/\/fr4material.com\/wp-content\/uploads\/2021\/08\/post12.png\")
<\/p>\n
5.3.2 Dissipation Factor The dissipation factor value is read directly from the digital display. <\/p>\n
5.4 Report The report shall contain the following: <\/p>\n
1. Measurement of effective thickness of specimens tested.
\n2. Capacitance values of the specimens tested.
\n3. Calculated dielectric constants and averaged measurement.
\n4. Dissipation factor values and averaged measurement. <\/p>\n
6.0 Notes <\/p>\n
6.1 The dielectric constant is defined as the ratio of the capacitance with the test material between the two plates to the capacitance of air between two plates. <\/p>\n
6.2 The dissipation factor of a dielectric material is the relationship between the permittivity (capacitance of material) and conductivity (ability to conduct or the reciprocal of the electrical resistivity) measured at a given frequency.<\/p>\n","protected":false},"excerpt":{"rendered":"
1.0 Scope This test method is to determine the dielectric constant and dissipation factor of raw printed wiring board material at 1 MHz. 2.0 Applicable Documents None 3.0 Test Specimens Each specimen shall be 50.8 \u00b1 0.076 mm [2.0 \u00b1 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1779","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"yoast_head":"\n