shielding RF components from electromagnetic interference

EMI Shielding and SinterInks for 5G RF components

RF com­po­nents are an inte­gral part of the 5G rev­o­lu­tion. The amount of RF front end com­po­nents required has dou­bled dur­ing the tran­si­tion from 4G to 5G. This, obvi­ous­ly, goes in the oppo­site direc­tion of the indus­try’s minia­tur­i­sa­tion trend where every­thing needs to be small­er and denser. 

That’s why RF anten­nae trends require thin­ner and more effi­cient pack­ages. Inte­grat­ed Anten­na in Pack­age 5G com­po­nents are rapid­ly mov­ing from asym­met­ric and stacked anten­nae to ultra thin hybrid and fan out with mul­ti band and high­er fre­quen­cies. This allows, at least, keep­ing devices on a sim­i­lar size as with pre­vi­ous generations.

But high­er fre­quen­cy sig­nal trans­mis­sion, increas­ing com­po­nent count and adding more pro­cess­ing and func­tion­al­i­ty in the same space come at a cost and with ele­vat­ed design and reli­a­bil­i­ty requirements.

That’s where Pack­age lev­el EMI shield­ing comes in.

What is EMI Shielding?

Elec­tro­Mag­net­ic Inter­fer­ence Shield­ing is the reflec­tion or absorp­tion of Elec­tro­mag­net­ic radi­a­tion through the use of a shield­ing mate­r­i­al. It pro­tects sig­nals from being exter­nal­ly dis­rupt­ed while also pre­vent­ing them from inter­fer­ing with sur­round­ing components. 

In the elec­tron­ics indus­try and in sim­ple terms it is the prac­tice of iso­lat­ing the sig­nal of com­po­nents so that they don’t inter­fere with each other.

Board level shielding

Tra­di­tion­al­ly this sep­a­ra­tion is being done on a Board lev­el. You would sol­der a lid or con­duc­tive enclo­sure on the board, cov­er­ing the com­po­nent and sep­a­rat­ing it from what­ev­er you want­ed to be sep­a­rat­ed. As you can imag­ine enclo­sures are heavy and require a lot of board space, lim­it­ing the design flexibility. 

Remem­ber when we said RF com­po­nents dou­bled in 5G appli­ca­tions? Well, with tra­di­tion­al board lev­el shield­ing you would have to dou­ble enclo­sures, weight and space. If this does­n’t sound great it’s because it isn’t.

Package level EMI Shielding

Enter Pack­age lev­el EMI shield­ing. In a stroke of genius engi­neers decid­ed that we don’t need enclo­sures any­more. We can fend those sig­nals with­in the pack­age itself. 

How? We dig walls in the mold­ed pack­age, we fill them with EMI shield­ing pastes and then we final­ly cov­er them with a con­for­mal coat­ing. This way we can have mul­ti­ple con­duc­tive par­ti­tions with­in the pack­age and iso­late mul­ti­ple com­po­nents with­in the same pack­age, lead­ing to high den­si­ty designs and miniaturisation.

Pack­age lev­el EMI shield­ing enables Fara­day cages direct­ly applied at the pack­age lev­el. This reduces the dimen­sions and weight of the over­all design and pro­vides a com­pact and effec­tive shield­ing method.

We, as Caplinq, can aid you with most of these steps. From Die attach mate­ri­als to Encap­su­lants and Mold­ing com­pounds, we have solu­tions for every step of the semi­con­duc­tor pack­ag­ing process. Now we are hap­py to announce that we also pro­vide Henkel’s newest and great­est EMI shield­ing materials.

After cut­ting the wall and in order to jet dis­pense EMI shield­ing there are elec­tri­cal­ly con­duc­tive, void free pastes such as EMI 3620FA that can be used to fill trench­es and gaps and exhib­it no cracks or delam­i­na­tion after reli­a­bil­i­ty testing.

The next step is to coat and cure the pack­age. The con­for­mal shield­ing needs to have a uni­form coat­ing thick­ness with­in 3–10um, be applied by atom­iz­ing spray and shield in a range between 10MHz and 10GHz. These are all prop­er­ties of EMI 8880S, a sprayable, effec­tive mate­r­i­al with extreme­ly low resis­tiv­i­ty and good laser mark­ing vis­i­bil­i­ty. All in all, if you are inter­est­ed in tran­si­tion­ing to pack­age lev­el shield­ing, we got you covered.

Printed Silver interconnects

EMI shield­ing is not the only solu­tion for the minia­tur­i­sa­tion of pack­ages. Print­ed sil­ver inter­con­nects with Sin­terINKS (Sin­ter­ing Inks) are also a great solu­tion to replace wire bond inter­con­nects, print high­ly con­duc­tive cir­cuits and at the same time have improved RF per­for­mance at fre­quen­cies up to 110GHz. 

These mate­ri­als can help dras­ti­cal­ly reduce the pack­age foot­print in height and width and and also oper­ate in high­er fre­quen­cies. But we are slow­ly start­ing to drift away from the scope of this blog. 

EMI Shield­ing and Sin­terinks will be thor­ough­ly dis­cussed and pre­sent­ed by Henkel’s Busi­ness Devel­op­er, Ruud de Wit dur­ing the upcom­ing Microtech 2021.

Smart Elec­tron­ics’ mar­ket trends like 5G are dri­ving advanced semi­con­duc­tor pack­ag­ing inno­va­tions towards high­er func­tion­al­i­ty, enhanced con­nec­tiv­i­ty at high­er fre­quen­cies, small­er form fac­tors (minia­tur­i­sa­tion) and reduced pow­er con­sump­tion. Espe­cial­ly for next gen­er­a­tion RF devices includ­ing anten­nas, pack­age lev­el EMI shield­ing, and short­er inter­con­nects are key to enable next gen­er­a­tion mmWave devel­op­ments run­ning at increas­ing fre­quen­cies above 100 GHz.

Ruud De Wit, Henkel Elec­tron­ic Materials

This is part of Ruud’s abstract for the upcom­ing MicroTech 2021 Online Con­fer­ence on Het­ero­ge­neous Inte­gra­tion. This online event takes place on the 25th of March and is organ­ised by iMAPS UK. MicroTech 2021 is the Annu­al IMAPS-UK Con­fer­ence which focus­es on key emerg­ing mar­kets and their asso­ci­at­ed tech­no­log­i­cal challenges.

Even though we are not IMAPS mem­bers yet, we can con­fi­dent­ly sug­gest attend­ing. We joined mul­ti­ple online webi­na­rs and work­shops over the last year and have thor­ough­ly enjoyed them. They have suc­cess­ful­ly adapt­ed to the cur­rent remote cir­cum­stances and there’s always some­thing new and excit­ing to learn. That’s why we are hap­py to sup­port and pro­mote them for their great work on shar­ing and sup­port­ing indus­try knowl­edge and developments.

Want to learn (even) more about EMI shield­ing and all things semi­con­duc­tor? Fol­low our blog or con­tact us for addi­tion­al information.

About George Kountardas

George is a Jack of all trades with an unappeasable inquiring mind. Obsessed with new products and technologies, he is always pushing forward for better, faster and more efficient applications. Always learning something new.

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