{"id":47278,"date":"2022-12-09T01:43:24","date_gmt":"2022-12-09T01:43:24","guid":{"rendered":"https:\/\/silmantech.com\/?p=47278"},"modified":"2024-04-13T02:09:30","modified_gmt":"2024-04-13T02:09:30","slug":"if-the-fpc-curved-radius-is-unreasonable-this-will-cause-breaks","status":"publish","type":"post","link":"https:\/\/silmantech.com\/fr\/if-the-fpc-curved-radius-is-unreasonable-this-will-cause-breaks\/","title":{"rendered":"Pourquoi le rayon de courbure optimal des FPC est-il important dans l'\u00e9lectronique ?"},"content":{"rendered":"
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When the FPC is bent, the types of stress on both sides of the heart line are different. The inner side of the curved surface is pressure and the outer side is tension. The size of the stress is related to the thickness of the FPC and the bending radius. Excessive stress will lead to FPC layers and copper foil breaks. Therefore, the layer pressure structure of the FPC should be arranged reasonably during design to make the layer pressure at both ends of the central line of the curved curved surface as symmetrical. Calculate the curved radius based on different applications.
\nCalculation of bending radius required
\nConditions 1. The curvature of the unilateral flexible line board is shown in the figure below:
\nIts curved radius can be calculated according to the following formulas:
\nR = (c\/2) [(100-eb)\/eb] -D
\nThese:
\nR = bending radius (unit \u03bcM)
\nC = copper skin thickness (unit \u03bcM)
\nD = Cover thickness (unit \u03bcM)
\nEB = copper skin allows deformation (calculated at a percentage rate)
\nThe types of copper and the deformation of copper skin are different.
\nA. The deformation of copper pressing copper plate is \u226416%
\nThe deformation of the copper skin during copper electrolysis is \u226411%.
\nIn addition, the deformation of the same material copper skin on different use occasions is also different. For a bending occasion, the limit of the critical state of the break is used (the value of the delay copper, the value is 16%). In the bending installation design, the deformation values (10%, pair of copper) specified by IPC-MF-150 are used. For dynamic applications, the deformation of copper skin is 0.3%. In magnetic head applications, the deformation of copper skin is 0.1%.
\nAt the same time, the radius of the curved plate is set by setting the deformation allowed by the copper plate.
\nMoving: The scenarios of this type of copper skin can be achieved through deformation. For example, the phosphorus and copper shifts in the IC card seat, that is, the part of contact with the chip after the IC card is inserted. This application scenario is flexible.
\nExample: 50 \u03bcM polytamide, 25 \u03bcm glue, so D = 75 \u03bcm, C = 35 \u03bcM Flexible plate total thickness T = 185 \u03bcm
\nBending at a time, 16%= 16.9\u03bcm, R\/T = 0.09
\nWith 10% R = 80 \u03bcm or R\/T = 0.45 Bend installation
\nDynamic bent, 0.3% R = 5.74 mm, R\/T = 31
\nIn the scene shown above, the connector is needed to be inserted, and the “dynamic bend” is required. The curved radius is controlled to the> 6 mm, and the diameter> 12 mm.
\nGreat algorithm: about 50 times the total thickness.
\n2. Double panel
\nThese:
\nR = bending radius, unit \u03bcM
\nC = copper skin thickness, unit \u03bcM
\nD = coating thickness, unit \u03bcM
\nEB = copper skin deformation, calculate at a percentage rate.
\nThe EB value is the same as the above value.
\nD = The thickness of the medium of each layer \u03bcM
\nfor example:
\nLower substrate thickness: 50 \u03bcM polytamide;
\n2X25 \u03bcM glue;
\n2X35 \u03bcM copper, d = 100 \u03bcm; C = 35\u03bcm
\nCoating thickness: 25 \u03bcM polytamide film; 50 \u03bcm glue layer d = 75\u03bcm
\nTotal thickness: t = 2 d+2+2 c = 320\u03bcm
\nAccording to the equation:
\nBending at one time, EB = 16% R = 0.371\u03bcm, R\/T = 1.16
\nEB = 10% R = 0.690 mm Bend installation,
\nR\/T = 2.15 dynamic bending, EB = 0.3% R = 28.17 mm, R\/T = 88<\/div><\/div><\/div><\/div><\/div><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

Lorsque le FPC est pli\u00e9, les types de contraintes des deux c\u00f4t\u00e9s de la ligne cardiaque sont diff\u00e9rents. Le c\u00f4t\u00e9 int\u00e9rieur de la surface incurv\u00e9e est sous pression et le c\u00f4t\u00e9 ext\u00e9rieur est sous tension. L'ampleur de la contrainte est li\u00e9e \u00e0 l'\u00e9paisseur du FPC et au rayon de courbure. Un stress excessif entra\u00eenera\u2026<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_stopmodifiedupdate":false,"_modified_date":"","footnotes":""},"categories":[87,1],"tags":[],"class_list":["post-47278","post","type-post","status-publish","format-standard","hentry","category-bonding-machine","category-news","category-87","category-1","description-off"],"_links":{"self":[{"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/posts\/47278","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/comments?post=47278"}],"version-history":[{"count":0,"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/posts\/47278\/revisions"}],"wp:attachment":[{"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/media?parent=47278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/categories?post=47278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/silmantech.com\/fr\/wp-json\/wp\/v2\/tags?post=47278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}