Epoxy Molding Compounds — Pellet Sizes: Diameter, Height & Weight

In a pre­vi­ous arti­cle, we talked about how epoxy mold­ing com­pound pel­lets have spe­cif­ic aspect ratios. In this arti­cle, we will explain in more detail how epoxy mold­ing com­pounds pel­lets have their sizes defined.

As you can imag­ine, each pel­let diam­e­ter requires a new mold tool. The only way to get oth­er diam­e­ter pel­lets is to have a whole new mold made. Epoxy Mold Com­pound man­u­fac­tur­ers have many such molds made, name­ly in sizes rang­ing from 10mm to 70mm in diameter.

The weight of the pel­let on the oth­er hand are deter­mined by pack­ing more or less mate­r­i­al into the diam­e­ter hole. More weight makes the pel­lets “taller” while less weight makes them short­er. “Tall” pel­lets are sus­cep­ti­ble to break­age as the aspect ratio does not lend itself to very tall pel­lets before they start break­ing in deliv­ery. The rea­son the weight is giv­en as opposed to the height of the pel­let is because the inspec­tion machine checks the weight of each pel­let, not the height. Fur­ther­more, each epoxy mold­ing com­pound has its own spe­cif­ic grav­i­ty (den­si­ty), so the height could be dif­fer­ent for dif­fer­ent epoxy mold compounds.

The table below gives a typ­i­cal selec­tion of avail­able pel­let sizes, diam­e­ters and weights.

Var­i­ous Pel­let Sizes, Diam­e­ters and Weights
Pel­let Diameter Pel­let Weight Range (grams)
Mil­lime­ters Inch­es Min­i­mum Max­i­mum
Micro Pel­lets 5 0.197 0.5 1.9
5.7 0.224 0.6 2.2
8.5 0.335 0.9 3.3
Mini Pel­lets 10 0.394 1.1 4.1
11 0.433 1.3 4.5
12 0.472 1.6 5.7
13 0.512 1.7 6.5
14 0.551 2.1 7.8
14.3 0.563 2.2 8.2
16 0.63 2.5 10.2
18 0.709 3.5 12.9
20 0.787 3.7 15.9
25 0.984 4.9 20.3
Con­ven­tion­al Pellets 35 1.375 14 105
38 1.496 16 125
40.6 1.6 20 150
45 1.75 25 175
48 1.9 28 280
55 2.165 36 360
58 2.28 40 400
61 2.4 45 445
70 2.75 55 580
Note 1: Pel­let weight spec­i­fi­ca­tion tol­er­ances and epoxy mold com­pound spe­cif­ic grav­i­ty must be con­sid­ered when deter­min­ing capability.

Accord­ing to the table above, the lim­it to the weight (and thus height) of a 20mm epoxy pel­lets is 15.9 grams. In order to offer larg­er weights, we need to offer dif­fer­ent diam­e­ters that allow for the weights you require. So if there is a diam­e­ter you can work with, the weight can be adjust­ed upward until a cer­tain max­i­mum. There is also a nec­es­sary min­i­mum as the table explains, below which the oppo­site aspect ration has a sim­i­lar neg­a­tive effect of bro­ken pellets.

Please vis­it us at www.caplinq.com to learn more about our whole range of epoxy mold com­pounds includ­ing our semi­con­duc­tor-grade epoxy mold com­pounds, fiber­glass rein­forced epoxy mold com­pounds, opti­cal­ly clear epoxy mold com­pounds. If you have any oth­er ques­tions about epoxy mold­ing com­pound pel­let sizes, please feel free to leave a com­ment below or don’t hes­i­tate to con­tact us.

About Chris Perabo

Chris is an energetic and enthusiastic engineer and entrepreneur. He is always interested in taking highly technical subjects and distilling these to their essence so that even the layman can understand. He loves to get into the technical details of an issue and then understand how it can be useful for specific customers and applications. Chris is currently the Director of Business Development at CAPLINQ.

Leave a Reply

Your email address will not be published. Required fields are marked *